Salutogena

Professional Health Care Services

Vaccination & Immunization

 Vaccines

Vaccines produce their protective effect by inducing cell-mediated immunity and serum antibodies, which can be demonstrated by their detection in the serum. Immunity can either be passive or active. Active immunity can be induced by receiving a vaccine, while passive immunity can be receipt of immunoglobulin. Passive immunity is short lived.

Generally speaking, the priority groups for vacccines are the most vulnerable populations; they are recommended for the youngest age group at risk for developing the disease. Hence the need to protect infants before they are exposed to the disease. Infants born prematurely regardlesss of birth weight should be vaccinated at the same chronological age and according to the same schedule and precautions as full-term infants and children.

courtesy (EPI), Ministry of Health; Immunization Maual for Health Professionals, 3rd edition

Vaccination (Principles of)

CHRONOLOGICAL HISTORY OF VACCINATION

  • 1100s: Variolation for smallpox first reported in China
  • 1721: Variolation introduced into Great Britain
  • 1796: Edward Jenner inoculates James Phipps with cowpox, and calls the procedure vaccination ("vacca" is latin for cow)
  • 1870: Louis Pasteur creates the first live attenuated bacterial vaccine (chicken cholera)
  • 1884: Pasteur creates the first live attenuated viral vaccine (rabies)
  • 1885: Pasteur first uses rabies vaccine in a human
  • 1901: First Nobel Prize in Medicine to von Behring for diphtheria antitoxin
  • 1909: Smith discovers a method for inactivating diphtheria toxin
  • 1909: Calmet and Guerin create BCG, the first live attenuated bacterial vaccine for humans
  • 1933: Goodpasture describes a technique for viral culture in hen's eggs
  • 1949: Enders and colleagues isolate Lansing Type II poliovirus in human cell line
  • 1954: Enders isolates measles virus
  • 1955: Inactivated polio vaccine licensed
  • 1961: Human diploid cell line developed
  • 1963: Measles vaccine licensed; Trivalent oral polio vaccine licensed
  • 1966: World Health Assembly calls for global smallpox eradication
  • 1977: Last indigenous case of smallpox (Somalia)
  • 1979: Last wild-virus polio transmission in the USA
  • 1986: First recombinant vaccine licensed (hepatitis B)
  • 1989: Two-dose measles vaccine recommendation
  • 1990: First polysaccharide conjugate vaccine licensed (Hemophilus influenzae type b)
  • 1991: Last wild-virus polio case in the Western Hemisphere; Universal infant hepatitis B vaccination recommended
  • 1994: Polio elimination certified in the Americas
  • 1995: Varicella vaccine licensed
  • 1996: Acellular pertussis vaccine licensed for infants
  • 1997: Sequential polio vaccination recommended
  • 1999: Exclusive use of inactivated polio vaccine recommended
  • 2000: Conjugate pneumococcal vaccine licensed for infants

Vaccination Sechedule of the Americas, 2000

IMMUNIZATION SCHEDULE-AMERICAS, 2000

Note: It is important to keep in mind that since 2000, many countries, islands and territories have changed and since upgraded their immunization schedule to include more vaccine-preventable illnesses such as: HPV (Human Papilloma Virus), Rotavirus, Y/F (Yellow Fever) and HepB (Hepatitis B) vaccines in accordance with most recent EPI (Expanded Programme on Immunization) guidelines. For more detailed and most recent updates, it is advisable to contact the Ministry of Health/Public Health Department of country, island or territory of interest for current guidelines on immunization, THANK You.

The different Types of Vaccines available

1. Bacillus Calmette Guerin (BCG) vaccine

2. Trivalent Oral Polio Virus (TOPV) vaccine

3. Inactivated Polio Virus (IPV) vaccine

4. Diphtheria, Pertussis, Tetanus (DPT) vaccine

5. Diphtheria, Tetanus (pediatrics DT) vaccine

6. Hemophilus Influenzae Type B (HIB) vaccine

7. Hepatitis B (HEPB) vaccine

8. Measles, Mumps, Rubella (MMR) vaccine

9. DT Adults vaccine

10. Rubella vaccine

11. Yellow Fever (Y/F) vaccine

12. RotaVirus vaccine

13. Human Papilloma Virus (HPV) vaccine

14. Pneumococcal vaccine

15. Varicella Zoster (Shingles/Chickenpox) vaccine

16. Rabies vaccine

17. Meningococcal vaccine

18. Hepatitis A (HEPA) vaccine

19. Influenza vaccine

TRAVEL IMMUNIZATION

Most international travelers need a combination of routine immunization and specially recommended vaccination for the country of travel; immunization is EXTREMELY important to prevent the importation of vaccine-preventable diseases from one country to another.

20. Cholera vaccine

21. Typhoid vaccine

      courtesy (EPI), Ministry of Health; Immunization Manual for Health Professionals, 3rd edition        

Click here for more in depth & precise information on vaccinations and vaccinations' schedules

                                                                                                              TOP                           

Vaccine-Preventable Diseases

TUBERCULOSIS

CAUSE:

Tuberculosis (TB) is caused by a bacterium, Mycobacterium tuberculosis,that is carried by more than two billion persons worldwide. The disease usually attacks the lungs but other parts of the body, for example, bones, jonts, and brain may also become infected. There is a difference between tuberculosis infection and disease. Individuals with the infection usually do not feel sick and often has no symptoms. The infection may last for years to decades, lifetime and the infected person may never develop the disease. Persons with the infection but not the disease cannot spread the infection to others. TB does not discriminate with regards to age; all age groups can contract tuberculosis. It spreads rapidly, especially in crowded living conditions, and places where health access is poor and individuals malnourished.

SPREAD:

TB is spread through the air. When a diseased individual coughs or sneezes, the germs enter the air. A person who inhales the contaminated air that contains TB germs may become infected. It is possible to become infected from cattle with the disease by drinking unpasteurized milk. Incubation period for TB is 1-12 weeks, however, the infection may persist for months or years before the disease develops. A diseased individual can infect others for several weeks after he/she starts treatment. The risk of developing TB is highest in children aged under three (3) years and in the very old population. Persons with a weakened immune system, for example HIV/AIDS persons, are more than likely to develop the disease than those with normal immune systems. Concerns about TB have been heightened recently because some strains of the causative organism have developed resistance to a number drugs.

SIGNS & SYMPTOMS:

Symptoms of TB may include general weakness, weight loss, fever and night sweats. In pulmonary TB (TB of the lungs), the symptoms include persistent cough, hemoptysis (coughing up blood) and pleuritic pain (chest pain). In young children, however, the only sig of lung TB may be stunted growth or failure to thrive (FTT).

COMPLICATIONS:

 TB generally weakens the body, resulting in increase risk that the affected individual will contract other diseases or that existing diseases will become more severe.

TREATMENT:

Proper and correct treatment for TB is a complete course of chemotherapy, which normally involvestaking two or more anti-tuberculosis drugs for at least six months.

PREVENTION:

The best protection at the present moment for children against TB infection is the IMMUNIZATION with BCG vaccine. In persons who have been vaccinated , it is impossible to determine whether a positive tuberculin skin test reaction is due to immunization or infection with the TB bacterium. Because of the strict control and prevention measures taken, mortality and morbidity from TB have declined to very low rates.

POLIOMYELITIS

CAUSE:

Poliovirus (Enterovirus) types 1, 2, 3 can cause paralytic poliomyelitis. Type most common, type 2 least common. Most cases of vaccine-associated are due to types 2 & 3. Humans are usually the reservoirs. Long-term carriers have not been found.

SPREAD:

The disease is primarily spread through person-to-person contact, principally through the fecal-oral route. The virus is more easily detected in the feces than in throat secretions. Water and sewage  are rarely implicated in the transmission/spread of the virus. The virus enters the body through the mouth when people eat or drink food or water that is contaminated by feces with the virus; hence the reason why the virus tend to spread in poor sanitation conditions. Spread can also occur via the air-borne route: sneezing and coughing. The virus spreads through the body via the bloodstream can invades certain types of nerve cells (motor neurons) resulting in loss of myelin sheath, reduced conduction rates and paralysis.

SIGNS & SYMPTOMS:

Incubation period is commonly 7-14 days for paralytic cases, may range from 3-35 days. Some people with the virus may not feel ill. Some may complain of influenza-like symptoms such as fever, loose stools, sore throat, stomach upset headache; occasionally there may be pain and/or stiffness in the neck, back and legs. THE most serious form of the disease is the paralytic polio! Paralysis usually develops during the first week of illness. The use of one or both legs or arms may be lost and breathing may be impossible without the help of a respirator. Recovery level varies from person to person.

SUSCEPTIBILITY AND RESISTANCE:

Susceptibility to infection is common, paralysis rarely occurs.

COMPLICATION:

A small percentage of infected children may progress to paralysis; dealth may occur IF the respiratory muscles are paralysed and no respirator is available.

Treatment:

No treatment is known; symptoms can be reduced.

PREVENTION: Polio prevention involves vaccination with oral polio vaccine (OPV) or Inactivated polio vaccine (IPV). Antibodies from the mother provide protection to the infant for two to three months after birth. Infected people who recover can develop natural immunity that protects them against future infection.                TOP

DIPHTHERIA

CAUSE:

Diphtheria is caused by the bacteria Corynebacterium diphtheriae of gravis, mitis or intermedius biotype. Toxin synthesis occurs when the bacteria are infected by corynebacteriophage containing the diphtheria toxin gene tox. The toxin produced can harm or destroy the human body tissue and organs. One type of the disease affects the pharynx and other parts of the throat. Tends to be a disease of the colder months and of temperate climate zones.; Diphtheria affects people of all ages, but mostly non-immunized children less than 15 years of age.

TRANSMISSION:

Man is the known reservoir. The type of diphtheria that affects the pharynx and other parts of the throat are spread in droplets and scretions from the nose, throat and eyes when there is close contact between infected and uninfected persons. The other type is spread when contact with skin ulcers has taken place; the disease is often spread here clothing and other dress wear have been contaminated with fluids from the skin ulcers. The disease is more easily sprread when there is overcrowding and poor living conditions.

INCUBATION & COMMUNICABILITY:

Incubation period is usually 2-5 days. Infected individuals usually become ill within 2-4 days and symptoms may appear after six days. Persons who are infected can usually spread the disease to others for up to 4 weeks. Effective antibiotic therapy quickly terminates the shedding.

SUSCEPTIBILITY & RESISTANCE:

In fants born to immune mothers are relatively immune; protection is passive and usually lost before the sixth month. Recovery from a clinical attack is not always followed by lasting immunity.

SIGNS & SYMPTOMS:

When Diphtheria affects the throat and tonsils, the early symptoms are sore throat, loss of appetite and slight fever. Within two to three days a blisish-white or grey membrane forms on the throat and tonsils. Bleeding may occur. The membrane sticks to the soft palate Patients with severe disease may develop swelling in the neck and obstruction of the airway.

COMPLICATIONS:

Abnormal heart beats  may occur during the early phase of the illness or weeks later and heart failure may occur. Death may result in 5-10% of cases.

TREATMENT:

Diphtheria antitoxin and antibiotics (ie erythromycin; penicillin) should be administered. Throat cultures should be obtained to ensure correct diagnosis. Patients  become non-infectious about two days after the commencement of antibiotic management.

PREVENTION:

The most effective manner of preventing diphtheria is to maintain a high level of immunization in the community; a mother can pass protective antibodies to her baby but this protection lasts about six months. A combination of tetanus and diphtheria vaccine may be recommended as a booster to maintain protection every ten years.

 PERTUSSIS (Whooping Cough)

Cause:

Pertussis is an ailment of the pulmonary tract (Lungs) caused by the bacteria (germ) Bordetella pertussis which lives in the mouth, nose and throat. Children with the disease have coughing bouts/spells that may last for many weeks, four to eight. The condition is common in non-immunized children all over the world. The disease is most dangerous in children less than one (1) year old. Whooping Cough is a serious communicable disease; the greatest incidence of complications and highest mortality occur in infancy. Complications can include pneumonia, encephalitis, severe nutritional disturbances and death. Pertussis or Pertussis-like illnesses are still being found in the West Indies.

SPREAD:

The ONLY host is considered to be HUMANS! Pertussis spreads quite easily from person to person in droplets produced by coughing or sneezing. The majority of individuals exposed to the germ become infected. The disease is most readily transmitted from seven days after a person has been exposed to the germs until three weeks after the start of coughing. Incubation period varies between six to 21 days.

SIGNS & SYMPTOMS

Normally there are three levels of the illness. At the start, the child appears to have a common cold, runny nose (Rhinoritis), watery eyes, sneezing, fever and slight cough. Cough progressively worsens and the second level involves numerous burst of rapid coughing. At the end of these bursts of coughing, the child takes in air with a high pitched whoop. The child may turn blue due to lack of oxygen during a long burst of coughing. Vomiting and exhaustion often follow the coughing spell(s), more common at night. The attacks become milder with time. The third level is marked with recovery taking place, coughing slowly becomes less intense and stops in several weeks.

COMPLICATIONS:

Complications are more common in (young) infants.The most common cause of death is bacterial pneumonia. Convulsions and seizures may occur, these complications may arise of the reduced oxygen supply to the brain during the couging bouts; less common complications: loss of appetite, otitis media and dehydration.

TREATMENT:

Usually erythromycin may make the illness less severe. The use of antibiotics also reduces the ability of the patient to infect others because the treatment kills the germ in the nose and throat.

PREVENTION:

Prevention includes immunization with pertussis vaccine, usually given in combination with dipheria and tetanus vaccines. Newborns and infants are not protected against pertussis by maternal antibodies. A person infected with pertussis usually acquires lifelong immunity.

TETANUS

CAUSE:

Tetanus is an cute and frequently deadly disease caused by Clostridium tetani an organism which produces a very potent neurotoxin. The toxin produced poisons the neurons (nerves) that control the muslces which result in stiffness. The diseaes is qiute common and servere in newborns; referred to as neonatal tetanus. Tetanus germ is found throughout the environment. Bacteria form spores that can survive in the environment for many years. Wounds with devitalised tissue or deep ouncture wounds are at greatest risk of becoming infected with the germ.

SPREAD:

Tetanus is not transmitted from person to person. An individual may become infected if soil or manure contaminates a wound/cut.

SIGNS & SYMPTOMS:

Incubation period is usually between three and ten days, but may be as long as as three weeks. The shorter the incubation period, the higher the risk of death. Lock-Jaw (muscular stiffness) is an early sign. This is followed by by neck stiffness, difficulty swallowing, muscle spasm, sweating and fever.

COPLICATIONS:

Fractures of the spine and other bones may occur as a result of muscle spasm and seizures. Death is especially high/common in the very young and very old.

TREATMENT:

Wounds/Cuts must be thoroughly washed and cleaned and dead/devitalized tissue excised (removed). Tetanus toxoid and antibiotics may also be used. Persons who recover from tetanus DO NOT have natural immunity.

PREVENTION:

The prevention of neonatal tetanus requires women of childbearing age to receive vaccine containing tetanus toxoid. This results in the mother being protected and tetanus antibodies being transferred from mother to fetus. Being vaccined on during toddler and kindergarden years ensures a certain degree of protection/immunity.                                                                                                    TOP

MEASLES (Rubeola)

CAUSE:

Measles kills more children than any of the other EPI diseases. The virus that causes measles belong to the genus Morbillivirus of the family Paramyxoviridae. Humans are the reservoir. It is very infectious and is quickly spread. It persists in some populations often is the cause of epidemics. Epidemics tend to occur in conditions of crowding and poverty where large numbers of non-immunized people are in close contact. The disease is more severe in infants and adults than in children. It is a highly communicable illness and is and a leading cuase of death in children in developing states. The measles virus is present throughout the world. It is important to ensure high immunization coverage as the Americas focus on elimination and eradication of the disease.

SPREAD:

Measles is spread by contact with nasal and pharyngeal secretions of infected people and in droplets released when an infected person sneezes or coughs. An infected person can infect other persons several days before and several days after an individual develops symptoms. A herd immunity of 95% or greater may be needed to  disrupt community transmission because of its high communicable infectious state. The time frame of infectious state is from slightly before the beginning of the prodromal period to four (4) days after appearance of the rash and is minimal after the second day of the rash being present.

SYMPTOMS & SIGNS:

  The period of incubation ranges from 7 to 18 days. The 1st sign of infection is a high fever lasting one to seven days. This period may be characterized by rhinorrhea (runny nose), watery eyes, cough and Koplik's spots (small white spots inside the cheeks). After several days, a slighty raised rash develops, spreading from the face and upper neck to the body and to the hands and feet over a short 3 day period. The rash fades over a one week period.

COMPLICATIONS:

Complications may occur particularly in children less than five years old an din grown-ups over twenty years old. In infants, severe diarrhea resulting in dehydration may occur, children may have inflammation of the middle ear (otitis media), respiratory tract infection and croup. Pneumonia is the commonest cause of death associted with measles most likely the measles virus weakens the immune system. Encephalitis may be another serious problem as a result of measles.

TREATMENT:

Vitamin A administration can help avoid the complications of eye damage and blindness. Maintenance of proper nutritional support and proper management of dehydration state with oral rehydration solution is key in the correct treatment of measles.

PREVENTION:

The prevention of measles involves vaccination; children should receive their 1st dose of MMR at 12 months of age. Children admitted to hospital with measles should be isolated for at least four days after the skin rash appears. Malnourished kids with measles should be isolated for the duration of the sickness. ALL individuals who have not had the disease or who have not been succesfully immunized are susceptible. Measles immunity is acquired after illness and is permanent. Infants born to mothers who have had the disease are immune for a period of first 6-9 months depending on the amount of residual maternal antibody at the time of pregnancy and the rate of antibody degradation. Immunization at 12-15 months produces immunity in 95-98%  range; re-immunization may increase immunity levels to as high as 99%! Chilren born to mothers with vaccine-induced immunity receive less passive antibody and thus may become susceptible to measles and require measles vaccination at an earlier age.

MUMPS (Parotitis)

CAUSE:

An acute viral disease caused by the paramyxo-virus. Affects the salivary glands and is characterized by parotitis (inflamed parotid glands) and may cause testicular inflammation. It is highly contagious and is spread usually by droplets infection from person to person. The virus enters the body via the mouth.

SPREAD:

Mumps is spread from individual to individual via respiratory droplets; the virus replicates in the naso-pharynx and the regional lymph nodes. In 12 to 25 days viremia occurs which lasts from 3-5 days. During the viremia stage, the virus spreads to multiple tissues: meninges, glands like the salivary, pancreas, testes and ovaries.

SYMPTOMS & SIGNS:

Incubation period is usually 14-18 days, may range from 12-24 days. Prodromal symptoms are non-specific and may include myalgia (musle pain), anorexia, malaise, headache, low grade fever. The pain becomes worse on taking liquids that contain acid: vinegar, fruit juice. Parotitis lasts between one to ten days; parotitis occurs in 30-40% of infected individuals and may be unilateral (one side) or bilateral (both sides) and any combination of single or multiple salivary glands may be affected.

COMPLICATIONS:

Central Nervous System (CNS) may become involved in the form of aseptic meningitis; Meningitis or encephalitis may be associated with headache, vomiting, stiff neck, backache, lethargy and a hot fever lasting for approx. five days. Adults are at higher risk for complications than children; males usually more affected than females.

TREATMENT:

No direct treatment is known; treatment is as needed (PRN).

PREVENTION:

The risk of serious infection from mumps is small in infants, that is why mumps vaccine should be given to children 12 months and older.                                     TOP

RUBELLA (German Measles)

CAUSE:

A mild, viral infection with a transient rash which mimics measles. Is a communicable illness of limited duration. Ailment lasts a several days with malaise, low-grade fever, headache, anorexia, conjunctivitis with palpable occipital and post auricular lymph nodes.

SPREAD:

The virus is transmitted predominantly via nasopharyngeal secretions of infected persons. Infection is by droplet spread or by direct contact with patients or by indirect contact with articles freshly soiled with discharges from nose and throat, blood, urine and feces. Viremia occurs 5-7 days after exposure, with spread of virus throughout the body. In (CRS) Congenital Rubella Syndrome, transplacental infection of the fecus occurs during viremia.

SYMPTOMS & SIGNS:

Incubation period varies from twelve (12) to 23 days; symptoms are often mild less than half of the cases may be subclinical or unapparent. In children,  a rash is usually the 1st manifestation; it may be faint, discrete or maculopapular; may 1st appear on the face then spread quickly to the neck, trunk and extremities. Rash disappears by the third day, seldom pruritic. In older children and adults, a 1-5 day prodrome with low-grade fever, malaise, swollen glands and (upper) pulmonary infection preceding the rash. Lymphadenopathy. The disease is so mild that persons affected hardly ever seek medical attention. Arthralgia and arthritis occur frequently in adults, may be considered a part of the illness as opposed to a complication.

COMPLICATIONS:

Complications are rare but tend to occur more so in adults than in children. The main complications: Arthralgia/Arthritis; Encephalitis; Hemorrhage

TREATMENT:

No treatment for the acute condition is known; supportive therapy geared towards relief of symptoms.

SPREAD:

Prevention of Rubella disease emcompasses vaccintion with rubella vaccine. Emphasis should be placed on women of child-bearing age who are NOT pregnant.

CONGENITAL RUBELLA SYNDROME (CRS):

Rubella immunization policy is focussed on the prevention of CRS. Rubella can have serious consequences in early gestation, leading to fetal demise, premature delivery and many congenital defects. Spontaneous abortion and stillbirths are common. The CLINICAL manifestations of CRS are : CNS - microcephaly, mental retardation, meningo-encephalitis; EYES - cataracts, glacoma or retinitis; EAR defects - deafness that may be bilateral or unilateral; HEART conditions - pulmonary artery stenosis, patent ductus arteriosus; HEPATIC and SPLEEN problems (hepatosplenomegaly, hepatitis); Gestation period - INTRA-UTERINE GROWTH RESTRICTION and post-natal - FTT; Blood conditions - PURPURA and THROMBOCYTOPENIA; Pancreas - DM. CRS is diagnosed by laboratory testing.

VIRAL HEPATITIS B

CAUSE:

Disease is caused by the hepatitis b virus, and affects the liver. Individuals usually recover but some continue to carry the virus for may years and can spread the infection to others throughout the time they are chronic carriers. Hepatitis B Virus (HBV) is one of several viruses that causes hepatitis. HbsAg has been found in virtually all body secretions and excretions; only blood and serum-derived fluids, saliva, semen and vaginal fluids have shown to be infectious. The presence of e antigen or viral DNA indicates high virus titer and higher infection rate of these fluids. Infection is commonly associated with exposure to body fluids blood and blood products. The is found the world over and affects all age groups. Most chronic carriers may be found China, South-East Asia and Africa.

SPREAD:

Incubation period averages six weeks but may be as long as six months; the variation is relatedin part to the amount of virus in the inoculum, the mode of transmission and host factors Transmssion occurs by percutaneous (IV, IM, SC or intradermal) and permucosal exposure to infective body fluids. Because HBV is stable on environmental surfaces for >7 days, indirect inoculation of HBV can also occur via inanimate objects. Fecal-oral or vector borne transmission has not been demonstrated. ALL persons who are HbsAg positive are potentially infectious.

SIGNS & SYMPTOMS:

There is general susceptibility. Often, the illness is milder and and often anticteric in children and in infants it is usually asymptomatic. Protective immunity follows infection if antibody to HbsAg (anti-HBs) develops and HbsAg is negative. Persons with Down Syndrome, HIV infection and on hemodialysis appear to be more likely to develop chronic infection. The younger a person is when infected the more likely it is that he/she will show no signs or symptoms. A person with no symptoms may remain infected for many years and can spread the infection to other persons. Infected persons may feel weak and experience flu-like symptoms. They may also have very dark urine and/or very pale stools. Jaundice may appear (Icteric). Symptoms may last several weeks; general weakness and fatigue may last for months. A laboratory blood test is required to determine with certainty a person has hepatitis B virus or disease. Most acute infections in adults are followed by complete recovery and affected individuals rarely become chronic carriers. Children, on the other hand, though not acutely sick, as a rule, do become chronic carriers and often develop severe complications.

COMPLICATIONS:

The result of acute infection can be quite serious. Death occurs in a small percentage of adults. Most serious complications include chronic hepatitis, cirrhosis, liver failure and liver cancer in long standing liver disease.

TREATMENT:

No treatment for acute condition. In chronic infection the illness can occasionally be stopped with certain medications.

PREVENTION:

It is advocated that chilren receive three doses of HepB vaccine during the first year of life. Persons with Hepatitis B virus should not donate blood and should not allow others to come into contact with their blood or other body fluids. The should use barrier methods when engaging in sexual intercourse and should not share eating utensils, toothbrushes, needles nor razors with other individuals. Health care professionals should be vaccinated against the illness and use ALL necessary precautions with all patients because patients who are carriers of the virus can spread the infection to them quite easily through blood contact.

VIRAL HEPATITIS A

CAUSE:

HAV,a picornavirus, a positive-stranded RNA virus has been classified as Hepatovirus, related to the family Picornaviridae. Occurs globally, sporadically and in epidemics. In developing countries, adults usually immune and epidemics of HA are uncommon. Improved sanitation in many countries around the world as left many grown-ups susceptible, outbreaks are increasing. Where environmental sanitation is poor, infection is common and occurs at an early age.

SPREAD:

Reservoir of HA is mainly humans and rarely captive chimpanzees. An enzootic focus has been noted in Malaysia, but there is no suggestion of transmission to humans. Disease is most common among school-aged children and young adults. In approx. 25% of outbreaks, the source of infection is unknown. The method of individual to individual transmission is by the fecal-oral route. The infectious agent is found in feces and reaches peak levels the week or two before onset of symptoms. Common-source outbreaks have been related to contaminated water, food, sandwiches and salads that are not cooked or infected handlers. Incubation period is fifteen to50 days depending on dose.

SYMPTOMS & SIGNS:

Onset is normally sudden with fever, malaise, anorexia, nausea and abdominal discomfort, with jaundice a few days later. The disease varies in clinical severity.Homologous immunity after infrction probably lasts for life.

COMPLICATION:

Normally, severity increases with age, complete recovery without sequelae or recurrences is the rule. Many infections are asymptomatic; many are mild, without jaundice, esp. in children.

TREATMENT:

There is no specific treatment for acute illness. Supportive therapy is geared to alleviate signs and symptoms. Diagnosis is established by detection of IgM antibodies against HepA virus in the serum of acutely or recently ill patients.

PREVENTION:

  1. Educate public about good sanitation and personal hygiene; special emphasis on hand-washing, proper sanitary disposal of feces.
  2. Provide proper water treatment and distribution systems
  3. Management of daycare centres should stress measures to minimize possibility of fecal-oral transmission
  4. ALL travellers to intermediate or highly endemic areas: Africa, Middle East, Asia and Central and South America, may be given prophylactically doses of IG or HepA vaccine.
  5. Oysters, clams and other shellfish from contaminated regions should be heated to a temp. of 85 - 90 oC (185 - 194 oF) for four minutes or steamed for 90 seconds before eating.
  6. An inactivated Hep A vaccine available; vaccine shown to  be safe, immuogenic and efficacious.                                                                           TOP

HAEMOPHILUS INFLUENZAE TYPE B

CAUSE:

A gram-negative coccobacillus, generally aerobic, but can grow as a facultative anaerobe. Six capsular types of the microbe is known; however, type B organisms account for all strains that cause invasive disease. Risk factors to Hib illness include host factors that increase the chances of exposure to Hib. Exposure factors include household crowding, large household size, daycare attendance, low socio-economic status, low parental education levels and school-aged siblings. Protective factors (effect limited to < 6 months of age) may include breast-feeding and passively acquired maternal antibodies.

SPREAD:

The germ (microbe) enters the body via the nasopharynx, colonize it and may remain transiently or for several months in the absence of symptoms. The manner in which the organism invades the blood stream in not quite known. Primary spread is presumably by respiratory droplets. Humans are the only reservoir. Contact with discharges from conjunctivae or upper respiratory tracts of infected individuals from contaminated fingers, clothing and other articles may spread the germ.

SIGNS & SYMPTOMS:

Incubation period may be as short as 25 - 75 hours. Children under the age of 5 years are most often affected and the incidence decreases with age. Clinical conditions caused by Hib may include: meningitis, epiglottitis, septic arthritis, cellulitis, pneumonia. Classic signs of neck stiffness, poor feeding and fever may be present; others may include: respiratory obstruction, stridor and drooling.

COMPLICATIONS:

Complications of the specific invasive disease it may cause. Hib was the leading cause of meningitis (bacterial) in children under 5 years of age before the development and usage of Hib vaccine.

TREATMENT:

Treatment is with antimicrobial therapy: chloramphenicol or an effective third generation cephalosporin.

PREVENTION:

Mode of prevention is by vaccination/immunization of children. This reduces the risk that unvaccinated children will be exposed.

 YELLOW FEVER

CAUSE:

 An acute illness of short duration, caused by a flavivirus and is endemic in tropical regions of Central and South America and Africa. Affects persons of all age groups. Immunity after immunization lasts for many years (10). Revaccination every ten years is required for international travel and is strongly recommended for those persons at risk like laboratory workers, hunters and forest personnel. YELLOW FEVER IS ONE OF THE INTERNATIONAL NOTIFIABLE DISEASES.

SPREAD:

Reservoir for yellow fever in urban areas are humans and the Aedes aegypti mosquito. In forested areas, vertebrates other than humans, mainly monkeys, marsupials and mosquitoes are the reservoirs. The disaese is highly communicable where many susceptible individuals and abundant vector mosquitoes coexist.

SIGNS & SYMPTOMS:

Incubation period is three to six days. The illness may be so mild that it is not noticed or diagnosed. In can be confused with malaria and hepatitis. Sx and Si may include: fever, chills, headache, backache, general muscle pain and vomiting.With disease progression, individuals become slow and weak, may experience bleeding gums and hematuria (blood in the urine), jaundice and hematemesis (vomiting of blood).

COMPLICATIONS:

Illness usually lasts two weeks, thereafter the person reovers or dies. Death may follow seizures and coma. Disease is diagnosed by conducting a laboratory blood test. Individuals who recover from the illness have life-long immunity.

TREATMENT:

No known specific treatment. Patients may need fluids for rehydration.

PREVENTION:

The disease is prevented by vaccination with YF vaccine. The vaccine is very safe and effective, producing antibodies against YF virus which may last for 30 years or more. Prevention should also involve the elimination of the accumulation of stagnant water in which vector mosquitoes breed. Second attacks are unknown; life-long immunity.

PNEUMOCOCCAL DISEASE

CAUSE:

This disease is caused by the germ Streptococcus pneumoniae, a gram-positive diploccocus and is more prevalent in the winter time and early spring. Predisposing factors like season, crowding and pulmonary infection have significant impact on disease occurrence.

SPREAD:

Transmission of Streptococcus pneumoniae occurs as a consequence of direct individual to individual contact via droplets and by auto-inculation. S. pneumoniae is the most common cause of pneumonia acquired in nursing homes.Penicillin-resistant S. pneumoniae is an increasing concern in the US and around the globe.

SIGNS & SYMPTOMS:

The important clinical syndrome of invasive pneumococcal illness include: meningitis, pneumonia and bacteremia. The disease most often occurs when a predisposing condition exists. Incubation period of pneumococcal pneumonia is short, approx. 1 to 3 days; Sx tend to include abrupt onset of fever and shaking chills or rigors. Other Sx include pleuritic chest pain, productive cough of mucopurulent, rusty sputum, dyspnea (SOB), tachypnea (rapid breathing), hypoxia (poor oxygenation), tachycardia (rapid heart rate), malaise and weakness. Pneumococci is responsible for up to 36% of adult community-acquired pneumonia and 50% of hospital acquired pneumonia.Fatality rate is 5 - 7% and may be higher in the elderly.

COMPLICATIONS:

Empyema (infection of the pleural space), pericarditis, endobronchial obstruction with atectasis and lung abscess. Bacteremia is present in approx. 25 - 39% of patients.

TREATMENT:
Pencillin is the medication of choice; patients who are allergic to penicillin can be given cephalosporins or erythromycin for oneumonia and chloramphenicol for meningitis.
 IM or IV immunoglobin administration may be useful for preventing pneumococcal infection in children with congenital or acquired immunodeficiency diseases. There are no specific recommendations concerning isolation of patients with pneumococcal disease.

PREVENTION:

  • Penicillin prophylactcally is one mode of preventing pneumococcal infection
  • Oral penicillin G or V is recommended for prevention of pneumococcal illness in children with functional or anatomic asplenia, regardless of whether or not they have been immunized.
  • Oral penicillin V when administered to infants and young children with sickle cell disease has reduced the incidence of severe bacterial infections.     TOP

 VARICELLA/SHINGLES (Chickenpox)

CAUSE:

An acute, contagious disease caused by the varicella zoster virus; it is a member of the Herpes Virus The primary varicella infection is known as chickenpox. The recurrent infection is known as shingles. The VZ virus persists in the sensroy nerve ganglia and herpes zoster is the result of recurrent infection.

SPREAD:

VZ virus enters the body via the respiratory system and conjunctiva and is believed to replicate at the site of entry in the nasopharynx and in the regional lymph nodes. The infection (virus) is spread of vesicle fluid or secretions of the respiratory tract. Spread can also occur indirectly through articles freshly soiled by discharges from vesicles and mucus membranes of infected individuals. IN CONTRAST TO VACCINIA AND VARIOLA, SCABS FROM VARICELLA LESIONS ARE NOT INFECTIVE. Chickenpox is one of the most readily/easily communicable diseases, especially in the realy stages of the eruption. Herpes Zoster has a much lower rate of transmission. Period of communicability may be as long as 5 days, but is usually 1 - 2 days before onset of rash. Contagiousness may be prolonged in patients with altered immunity. Patients with zoster infection may be a source of infection for a week after the appearance of their vesico-pustular lesions. Susceptible persons should be considered to be infectious 10 - 20 days following exposure.

SIGNS & SYMPTOMS:

Susceptibility to chickenpox is universal among those not previously infected and ordinarily a more severe disease occurs in adults than children. Incubation time is from 2 - 3 weeks; infection may be prolonged after passive immunization against varicella and in immunocompromised persons. A mild prodrome may procede the onset of the rash. THE RASH IS GENERALIZED, PRURITIC AND RAPIDLY PROGRESSES FROM MACULES TO PAPULES TO VESICLES BEFORE CRUSTING. The rash usually appears on the scalp, trunk and then extremities. Clinical course in normal children is generally mild with malaise, pruritic and fever for 2 - 3 days. Pulmonary and gastrointestinal symptoms are usually absent. Infection confers long immunity, second attacks are rare.

COMPLICATIONS:

The commonest complications that can result from the infection that requires hospitalization are bacterial infections of skin lesions, pneumonia, dehydration, encephalitis and hepatitis.

TREATMENT: There is no specific treatment but antiviral agents may alter or dimish the course or severity of the illness. Other supportive therapy may be needed.

PREVENTION:

The illness is prevented by immunization with varicella vaccine. The vaccine is very safe and effective, producing antibodies that appearto be long-lasting.

ROTAVIRUS ENTERITIS

CAUSE:

Rota virus is adouble stranded RNA virus. There are at least 10 serotypes. The microbes are very stable and may remain viable in the environment for weeks or months in not disinfected, Reservoir is most likely humans. The animal viruses do not produce illness in humans. Rotavirus infection is nearly universal and the incidence is similar in developed and developing countries.

SPREAD:

The virus enters the body through the mouth and virus replication occurs in the small intestine; infection may result in decrease intestinal absorption of sodium, glucose and water and decreased levels of intestinal lactase, alkaline phosphatase, sucrase activity and lead to isotonic diarrhea. The spread is porbably fecal-oral route. There is some evidence that rotavirus may be present in contaminated water. Period of communicability is mainly during the acute stage of the disease. Rotavirus is not usually detectable after about the eight day of infection.

SIGNS & SYMPTOMS:

Incubation period for rotavirus diarrhea is approx. 24 - 72 hours and the clinical features may vary dependent on whether it is the first infection or re-infection. Susceptibility is greatest between 6 and 24 months of age; by age 3 years, most persons would have acquired rotavirus antibodies. Illness may be asymptomatic, may cause self-limited watery diarrhea or result in severe dehydrating diarrhea with fever and vomiting. Clinical features are non-specific and confirmation of a diarrheal illnessas due to rotavirus requires laboratory testing.

COMPLICATIONS:

Infection in infants and young children can result in severe diarrhea or dehydration, electrolyte imbalance, metabolic acidosis.

TREATMENT: No specific treatment is available other than supportive therapy. Parental education as to prevention and management of diarrhea and dehydration is critical.

PREVENTION:

Prevention can be accomplished by immunization with the rotavirus vaccine. Recovery from rotavirus infection does not confir or result in permanent immunity.

RABIES

CAUSE:

Rabies is an almost invariably fatal disease. The virus is an RNA Rhabdovirus contained in the saliva and certain body materials such as brain tissue and cerebrospinal fluid (CSF) of rabid animals and human beings. It is a disease mainly of animals. Urban (canine) rabies is transmitted by dogs whereas sylvatic rabies is a disease of wild carnivores and bats, with sporadic spillover to dogs, cats and livestock.

SPREAD:

Many wild and domestic animals are reservoirs: dogs, foxes, coyotes, wolves, jackals, skunks, raccoons, mongooses and other biting mammals. Virus-containing saliva of a rabid animal is introduced into humans by a bite or scratch. Transmission from individual to individual is theoretically possible since saliva of the infected person may contain virus, this, however, has never been proven nor documented.

SIGNS & SYMPTOMS:

Incubation period is usually 3 - 8 weeks; It depends, however, on the severity of the wound, site of the wound in relation to the quantity of nerve fibres present and its distance from the brain, the amont and strain of virus inoculated, victims defense system and protection provided by clothing. Onset of illness is heralded by a feeling of apprehension, headache, fever, makaise and sensory changes esp. at wound site. The disease progresses to paresis and paralysis; spasm of esophageal musculature causes difficulty in swallowing and hydrophobia (fear of water). Delirium and convulsions usually folllow. Without medical intervention, death is rapid (2 - 6 days) and usually by respiratory paralysis. Diagnosis is confirmed by specific FA staining of brain tissue or by virus isolation.

COMPLICATIONS:

About 20% of patients develop an ascending symmetric paralysis with flaccid and decreased tendon reflexes dominating the acute phase. If the person does not die of cardio-pulmonary failure, he/she goes into an irreversible coma. MOST SIGNIFICANT COMPLICATIONS ARE MYOCARDITIS AND PITUITARY DYSFUNCTION EXPRESSED AS EITHER DIABETES INSIPITUS OR INAPPROPRIATE SECRETION (RELEASE) OF ANTIDIURETIC HORMONE (IADH).

TREATMENT:

The chief requirement for local treatment is that it is prompt and thorough. Prevention of rabies after animal bites should consist of the following:

  1. Treatment of bite wounds: immediate and thorough cleaning with soap and/or detergent and flushing with water. Wounds should not be sutured; large wounds should have loose sutures inserted and not interfere with free bleeding and drainage.
  2. Specific immunologic protection immunologic prevention of rabies in humans is provided by administration of human rabies immune globulin (HRIG) as soon as possible after exposure to neutralize the virus at the bite wound site and then by giving vaccine at a different site to elicit active immunty.
  3. Preventive Measures: a) Register, license and immunize all dogs in enzootic countries. Immunize all cats; b) Maintain acyive surveillance for rabies in animals. Lab. capacity should be developed to perform FA testing on all wild animals involved in human or domestic animal exposures. Educate physicians, veterinarians and animal-control officials to obtain/euthanize/test animals involved in human and domestic animals exposure; c) Detain and clinically observe for approx. 10 days any healthy-appearing dogs or cats that were involved in biting of persons, dogs and cats showing suspicious signs of rabies should be sacrificed and tested for rabies; d) Individuals at high risk (vets, wildlife conserationists, etc, etc) should receive pre-exposure immunization.                                                                                                    TOP

MENINGOCOCCAL DISEASE

CAUSE:

Meningococcal Meningitis and septicemia are systemic infections caused by Neisseria meningitidis, a gram negative diplocloccus with multiple serogroups: A, B, C, X, Y, Z, W-135 and L; Serotype D is rare. There is an association between the onset of seasonal Influenza activity and meningococcal disease. The illness is highest in infants.

SPREAD:

The disease is a world wide illness, but is commonest in poor overcrowded areas. Meningococci are transmitted by droplet spread or direct contact from carriers or from persons in the early stage of illness. The most likely route of invasion is via the nasopharynx. The reservoir is humans. The individual is infectious as long as the meningococci are present in secretions/discharges from nostrils and mouth. Most carriers do not develop the illness but they may transmit the disease for approx. six months.

SIGNS & SYMPTOMS:

Incubation period varies from 2 - 10 days, normally is 2 - 3 days. The onset of illness varies from fulminant to insidious with mild prodromal symptoms. Early Sx and Si may include malaise, pyrexia and vomiting; headache, photophobia, drowsinss or confusion, joint pains, atypical hemorrhagic rash of meningococcal septicemia may develop.  The rash may be purpuric and non-blanching. Patients may also present in a coma. The diagnosis should be suspected in the presence of voming, pyrexia, irritability, if still patent, raised (bulging) anterior fontanelle tension.

COMPLICATION:

Susceptibility to the clinical disease is low and decreases with age. Individuals who are deficient in certain complement components are especially prone to recurrent disease. Splenectomized patients are susceptible to bacteremic illness.

TREATMENT:

Antibiotics of choice for immediate therapy include Benzylpenicillin; Penicillin will temporarily suppress the organisms, it does not normally eradicate them from the oro-nasopharynx.

PREVENTION:

Vaccines against serogroups A, C, Y and W-135 are available; there are no vaccines against serogroup B. Close contacts of persons with meningococcal meningitis have  increase risk of becoming ill even with the use of appropriate chemoprophylaxis; the recommended prophylaxis is rifampicin. Alternative agents are ciprofloxacin and ceftriaxone for pregnant contacts. Vaccination appears to be effective in controlling epidemics and reducing infection rates but not carriage rates.

INFLUENZA

CAUSE:

An acute viral illness of the respiratory tract affecting all ages. There are three types of influenza virus recognized: A, B, and C that are determined by the antigenic properties of the two relatively stable structural proteins: the nucleoprotein and the matrix protein. Emergence of completely new subtypes (antigenic shift) occurs at irregular intervals and only with type A viruses; they are responsible for pandemics and result from the unpredictable recombination of human and swine or avian antigens. Because of these minor antigenic changes (antigenic drift), there are frequent epidemics and outbreaks, making it necessary to, almost, yearly reformulate influenza vaccines. In temperate zones, epidemics tend to occur in winter; in tropics, they tend to occur in the rainy season, but outbreaks or sporadic cases may occur in any month.

SPEAD:

Humans are the primary reservoir for human infections, however, mammalian reservoirs such as swine and avian reservoirs likes ducks are the likely sources of new human sub-types thought to emerge via genetic re-assortment. Airborne spread predominates among crowdedpopulations in enclosed spaces . Transmission may occur by direct contact. The period of communicability is approx. 3 - 5 days from clinical onset in adults and up to 7 days in young children.

SIGNS & SYMPTOMS:

Incubation period is short, 1- 3 days. Fever, headache, myalgia, coryza, sore throat and cough characterize influenza. Cough is often severe and protracted while otther manifestations are often self-limited with recovery in 2 - 7 days. Recognition is usually by epidemiological characteristic and sporadic cases identified by laboratory procedures. Influenza virus may cause the clinical picture of the common cold, croup, bronchiolitis, viral pneumonia and undifferentiated acute respiratory illness.

COMPLICATIONS:

The importance of influenza is derived from the repidity with which epidemics evolve, the widespread morbidity and seriousness of complications, for example viral and bacterial pneumonia. During major epidemics, severe illness and death occur, principally among the elderly and those debilitated by chronic cardiac, pulmonary, renal or metabolic diseases or immuno-suppression. During the febrile stage of illness, lab. confirmation is made by isolation of influenza viruses from pharyngeal or nasal secretions.

TREATMENT:

Specific treatment - Amantadine or rimandine started within 48 hours of onset of influenza A illness and given approx. 3 - 5 days reduces symptoms and virus titres in respiratory secretions. Doses should be reduced for those > 65 years of age or those with decreased hepatic and renal function. Both pharmaceutical agents are associated withg CNS side effects. The use of these drugs should be considered in non-immunized persons or groups at high risk of complications such as institutions, nursing homes for the elderly. Medication should be continued throughout the epidemics; it will not interfere with the response to influenza vaccine.

PREVENTION:

When a new subtype appears, all children and adults are equally at risk, except those who have lived through realier epidemics caused by the same subtype. Infection produces immunity to the specific infecting virus. Vaccines produce serologic responses specific for the included viruses and elicit booster responses to related strains with which the individual has had prior experience. Preventive measures: a) Educate the public and healthcare staff in basic personal hygiene, esp. the danger of unprotected coughs and sneezes and hand-to-mucous membrane transmission; b) Immunization with available killed-virus vaccines may provide 70 - 80% protection against infection in healthy young adults when the vaccine antigen closely matches the circulating strains of virus. In the elderly, however, immunization may be less effective in preventing illness but may reduce the severity of the disease and the incidence of complications by 50 - 60% and death by approx.80%; c) A single dose suffices for those with prior exposure to influenza A and B viruses. Routine vaccination programmes should be directed primarily at those at greatest risk of serious complications or death and those who might spread infection to them (healthcare workers, household contacts of high-risk persons); d) Immunization should also be considered for those engaged in essential community services and is recommended for military staff. Yearly recommendations for vaccine components are based on the viral strains currently circulating, as determined by international surveillance.

Click Here: Additional information on vaccine-preventable diseases; more... & detailed data.                                                                                                             TOP

 

CONTRAINDICATIONS TO IMMUNIZATION

There are few contraindications for immunization. Some health care providers have misconceptions about specific contraindications to vaccination. ALL vaccines should be given on schedule, even when a child has a low-grade fever, amild cold, diarrhea or other mild illness.

There are few ABSOLUTE contraindications to the Expanded Programme on Immunization (EPI) vaccines. The risk of delaying a vaccination because of mild illnesses is that the child may not return again and the opportunity for immunization is wasted. Infants born prematurely regardless of birth weight should be vaccinated at the same chronological age and according to the same schedule and precautions as full-term infants and children. Birth weight and size are generally NOT factors in deciding whether to postpone routine vaccination of a clinically stable, premature infant. The full recommended dose of each vaccine should be used. Divided or reduced doses are not recommended!

Neither killed nor live vaccines affect the safety of breast-feeding for mothers or infants. Breast-feeding does not adversely affect immunization and is NOT a contraindication for any vaccine. Breast-fed infants should be vaccinated according to routine recommended schedules.

Health Care personnel should use every opportunity to vaccinate eligible children at ALL times.

  1. Generally, live vaccines should NOT be given to individuals with immune deficiency diseases or to persons who are immuno-suppresswed due to malignant disease, treatment with immuno-suppressive agents or irradiation. Both measles and oral poliomyelitis vaccines, however, can be given to individuals with HIV/AIDS.
  2. Children with symptomatic HIV infection should NOT be vaccinated with BCG nor Yellow Fever vaccines.
  3. A severe adverse event following a dose of vaccine (anaphylaxis, encephalitis/encephalopathy or non-pyretic (febrile) convulsions) is a TRUE contraindication to immunization.
  4. Vaccines containing the whole-cell pertussis component should NOT be given to children with an evolving neurological disease: uncontrolled epilepsy or progressive encephalopathy.
  5. Persons with a history of anaphylactic reaction(s): generalized urticaria, dyspnea (SOB), angioedema (swelling of mouth/lips and throat, hypotension, shork following egg ingestion, should NOT receive vaccine prepared on (hen's) egg tissue. Vaccines propagated in chicken fibroblast cells can usually be given safely to those persons. 

Conditions which are NOT contraindications to immunization:

  1. Minor ailments such as upper respiratory tract infections or diarrhea, with fever less than 38.5 oC
  2. Allergy, asthma, or other atopic manifestations, hay fever or snuffles
  3. Prematurity, small-for-date infants
  4. Malnutrition
  5. Child being breast-fed
  6. Family history of convulsions
  7. Treatment with antibitics, lose dose corticosteroids, or locally acting example, topical or inhaled steroids
  8. Dermatoses, eczema, localized skin infection
  9. Chronic diseases of the heart, lung kidney or liver
  10. Stable neurological conditions such as cerebral palsy and Down Syndrome
  11. History of jaundice after birth

Conditions that are (ABSOLUTE) Contraindications to immunization:

  1. Immunization should be postponed in persons suffering from severe infections with or without fever
  2. Anaphylactic reaction to a previous dose contraindicates further immunization with that vaccine
  3. Anaphylactic reaction to a vaccine constituent contraindicates the use of vaccines containing that substance
  4. Meningococcal vaccine should not be used in pregnancy, unless there is a substantial risk of meningococcal infection; safety of the vaccine in pregnancy has not yet been established

Serious reactions should be reported promptly to your local Health Authorities via the Officer  in charge of the EPI programme!

       courtesy (EPI) Ministry of Health; Immunization Manual for Health Professionals, 3rd edition                                                                                                         TOP