Assignment_Communicable_Diseases_DR_TANVIR.pptx

Most vaccine-preventable diseases are spread from person to person, which means that if one person in a community gets an infectious disease, they can spread it to others. The best way to help stop the spread of certain diseases is through vaccination. If enough people are vaccinated there are fewer chances for a vaccine-preventable disease to spread, keeping everyone healthier. Measles is a highly contagious disease caused by a virus. It spreads easily when an infected person breathes, coughs or sneezes. It can cause severe disease, complications, and even death.

Measles can affect anyone but is most common in children.

Measles infects the respiratory tract and then spreads throughout the body. Symptoms include a high fever, cough, runny nose and a rash all over the body.

Being vaccinated is the best way to prevent getting sick with measles or spreading it to other people. The vaccine is safe and helps your body fight off the virus.

Before the introduction of measles vaccine in 1963 and widespread vaccination, major epidemics occurred approximately every two to three years and caused an estimated 2.6 million deaths each year.

An estimated 136 000 people died from measles in 2022 – mostly children under the age of five years, despite the availability of a safe and cost-effective vaccine.

Accelerated immunization activities by countries, WHO, the Measles & Rubella Partnership (formerly the Measles & Rubella Initiative), and other international partners successfully prevented an estimated 57 million deaths between 2000–2022. Vaccination decreased an estimated measles deaths from 761 000 in 2000 to 136 000 in 2022. The bacteria that cause whooping cough spread easily from person to person through the air. When a person with whooping cough sneezes or coughs, they release small particles with the bacteria in them. Other people can then breathe in the bacteria.

These bacteria can spread when people spend a lot of time together or share breathing space. The best way to prevent whooping cough is to get vaccinated. Preventive antibiotics are also known as postexposure antimicrobial prophylaxis (PEP). These are medicines given to someone who has been exposed to harmful bacteria to help prevent them from getting sick. Healthcare providers can diagnose whooping cough by doing a -
1. History of typical signs and symptoms
2. Physical exam
3. Laboratory test of a mucus sample from the back of the throat
4. Blood test
Chickenpox is an illness caused by the varicella-zoster virus. It brings on an itchy rash with small, fluid-filled blisters. Chickenpox spreads very easily to people who haven't had the disease or haven't gotten the chickenpox vaccine. Chickenpox used to be a widespread problem, but today the vaccine protects children from it.

The chickenpox vaccine is a safe way to prevent this illness and the other health problems that can happen during it. The rash caused by chickenpox appears 10 to 21 days after you're exposed to varicella-zoster virus.

1. MEASLES, PERTUSSIS, CHICKEN POX DR. TANVIR AHMED LECTURER COMMUNITY MEDICINE & PUBLIC HEALTH CHITTAGONG MEDICAL COLLEGE , CHATTOGRAM [email protected] Communicable diseases: measles, pertussis & chicken pox 1

2. MEASLES Measles is a highly contagious disease caused by a virus (Rubeola). It spreads easily when an infected person breathes, coughs or sneezes. It can cause severe disease, complications, and even death. Measles can affect anyone but is most common in children. Measles infects the respiratory tract and then spreads throughout the body. Symptoms include a high fever, cough, runny nose and a rash all over the body Being vaccinated is the best way to prevent getting sick with measles or spreading it to other people. The vaccine is safe and helps the body to fight off the virus. Communicable diseases: measles, pertussis & chicken pox 2

3. Measles Epidemiology Reservoir Human Transmission Person-to-person via large respiratory droplets Airborne in closed areas for up to 2 hours Temporal pattern Primarily late winter and spring Communicability 4 days before through 4 days after rash onset Communicable diseases: measles, pertussis & chicken pox 3

4. Bangladesh, an overpopulated and poor economic Asian country, has experienced measles outbreaks in different areas between 2000 and 2019. The World Health Organization (WHO) estimated about 14,877 measles cases in 2005, 5,329 cases in 2011, and 1,793 cases in 2012 in Bangladesh According to the estimation of WHO, in 2019, there were 4,181 measles cases in Bangladesh, with most of them were from the Rohingya refugee camp in Cox’s Bazaar . A total of 1,724 measles cases were reported in 2017 and approximately 1,319 cases in 2018. Communicable diseases: measles, pertussis & chicken pox 4

5. Pathogenesis Primary site of infection is alveolar macrophages or dendritic cells Primary viremia 2 to 3 days after replication Secondary viremia 5 to 7 days after exposure Communicable diseases: measles, pertussis & chicken pox 5

6. Measles Clinical Features Incubation period 11 to 12 days Exposure to rash onset averages 14 days (range, 7 to 21 days) Prodrome lasts 2 to 4 days (range, 1 to 7 days) Stepwise increase in fever to 103°F–105°F Cough, coryza, and conjunctivitis Koplik spots (on mucous membranes) Rash Persists 5 to 6 days Begins at hairline, then involves face and upper neck Proceeds downward and outward to hands and feet Severe areas peel off in scales Fades in order of appearance e Communicable diseases: measles, pertussis & chicken pox 6

7. Measles Complications Diarrhea, otitis media, pneumonia, encephalitis, subacute sclerosing panencephalitis, death Most common among children age younger than 5 years and adults Communicable diseases: measles, pertussis & chicken pox 7

8. Measles Vaccine Characteristics Live, attenuated vaccine Available as lyophilized powder and reconstituted with sterile, preservative-free water Administered by subcutaneous injection Contains gelatin Contains neomycin Communicable diseases: measles, pertussis & chicken pox 8

9. Measles Vaccination Schedule 2 dose series at age 12 through 15 months and at age 4 through 6 years Minimum age for dose 1 is 12 months Minimum interval from dose 1 to 2 is 4 weeks for MMR and 3 months for MMRV (although a 4-week interval is valid) Communicable diseases: measles, pertussis & chicken pox 9

10. MMR Vaccination of Adults Certain persons without acceptable presumptive immunity: At least 1 dose MMR for unvaccinated adults 2 doses MMR for students entering colleges, universities, technical and vocational schools, and other post-high-school educational institutions 2 doses MMR for measles and mumps and 1 dose MMR for rubella for healthcare personnel Healthcare personnel during an outbreak 2 doses MMR for measles or mumps outbreak and 1 dose MMR for rubella outbreak Communicable diseases: measles, pertussis & chicken pox 10

11. Measles Vaccine Efficacy Antibodies develop in approximately 95% of children vaccinated at age 12 months and over 99% of children who receive 2 doses Immunity long-term and probably lifelong in most persons Communicable diseases: measles, pertussis & chicken pox 11

12. Treatment There is no specific treatment for measles. Caregiving should focus on relieving symptoms, making the person comfortable and preventing complications. Drinking enough water and treatments for dehydration can replace fluids lost to diarrhea or vomiting. May use antibiotics to treat pneumonia and ear and eye infections. All children or adults with measles should receive two doses of vitamin A supplements, given 24 hours apart. This restores low vitamin A levels that occur even in well-nourished children. It can help prevent eye damage and blindness. Vitamin A supplements may also reduce the number of measles deaths. Communicable diseases: measles, pertussis & chicken pox 12

13. PERTUSSIS Acute infectious disease caused by  Bordetella pertussis Outbreaks first described in 16th century Bordetella pertussis  isolated in 1906 More than 200,000 cases annually in the United States in prevaccine era Communicable diseases: measles, pertussis & chicken pox 13

14. Pertussis Epidemiology Reservoir Humans Transmission Person-to-person through respiratory droplets or contact with airborne droplets Exposure to fomites Temporal pattern No distinct seasonal pattern, but may increase in the summer and fall Communicability Highly communicable Infectious from catarrhal stage through third week of paroxysms Communicable diseases: measles, pertussis & chicken pox 14

15. Pertussis Pathogenesis Primarily a toxin-mediated disease Bacteria attach to cilia of respiratory epithelial cells Toxins cause inflammation which interferes with clearance of pulmonary secretions Pertussis antigens allow evasion of host defenses Communicable diseases: measles, pertussis & chicken pox 15

16. Pertussis Clinical Features Incubation period 7 through 10 days (range, 4 through 21 days) Catarrhal stage: Insidious onset, similar to the common cold 1-2 weeks Paroxysmal stage: More severe cough and may experience paroxysms of numerous, rapid coughs 1-6 weeks Convalescence stage: Gradual recovery Weeks to months Communicable diseases: measles, pertussis & chicken pox 16

17. Pertussis Complications Most common complication and cause of death is secondary bacterial pneumonia Young infants at highest risk Neurologic complications—seizures, encephalopathy Less serious complications—otitis media, anorexia, dehydration Communicable diseases: measles, pertussis & chicken pox 17

18. Risk Factors Non vaccination in children. Contact with an infected person. Epidemic exposure. Pregnancy. Communicable diseases: measles, pertussis & chicken pox 18

19. Vaccination The best way to prevent pertussis is through immunization. The three-dose primary series diphtheria-tetanus-pertussis (DTP3) (- containing) vaccines decrease the risk of severe pertussis in infancy. In 2018, 86% of the global target population had received the recommended three doses of DTP-containing vaccine during infancy. WHO recommends the first dose be administered as early as 6 weeks of age; with subsequent doses given 4-8 weeks apart, at age 10-14 weeks and 14-18 weeks. A booster dose is recommended, preferably during the second year of life. Communicable diseases: measles, pertussis & chicken pox 19

20. CHICKEN POX (VARICELLA) Acute infectious disease caused by varicella-zoster virus (VZV) Distinguished from smallpox at the end of the 19th century Live, attenuated varicella vaccine developed in 1970s Herpesvirus (DNA) Primary infection results in varicella (chickenpox) Reactivation of latent infection results in herpes zoster (shingles) Short survival in environment Communicable diseases: measles, pertussis & chicken pox 20

21. Epidemiology Reservoir Human Transmission Person-to-person Direct contact with vesicular fluid or inhalation of aerosols Temporal pattern Peak in winter and early spring Communicability 1 to 2 days before onset of rash until all lesions have formed crusts Communicable diseases: measles, pertussis & chicken pox 21

22. Pathogenesis Enters through respiratory tract and conjunctiva Replication in nasopharynx and regional lymph nodes Primary viremia 4 to 6 days after infection Multiple organs infected during viremia Secondary viremia with viral skin infection after replication Communicable diseases: measles, pertussis & chicken pox 22

23. Clinical Features Incubation period 14 to 16 days (range, 10 to 21 days) Prolonged incubation period if received postexposure prophylaxis with varicella specific immune globulin Communicable diseases: measles, pertussis & chicken pox 23

24. Primary Infection (Varicella) Rash often first sign of disease in children; adults may have 1 to 2 days of fever and malaise before rash In unvaccinated individuals, generalized and pruritic rash progresses rapidly Clinical course in healthy children is mild; adults may have more severe disease Recovery usually results in lifetime immunity Communicable diseases: measles, pertussis & chicken pox 24

25. Varicella Complications Bacterial infection of skin lesions Pneumonia Central nervous system manifestations Reye syndrome (rare) Congenital VZV Infection: Results from maternal infection in the first 20 weeks of gestation Associated with newborn limb hypoplasia, skin scarring, localized muscular atrophy, encephalitis, cortical atrophy, chorioretinitis, microcephaly, and low birth weight Communicable diseases: measles, pertussis & chicken pox 25

26. Risk Factors for developing complications Newborns and infants whose mothers never had chickenpox or the vaccine. Pregnant women who haven't had chickenpox. People who smoke. People with cancer or HIV who are taking medication that has an effect on the immune system Communicable diseases: measles, pertussis & chicken pox 26

27. Varicella Vaccination Schedule 2-dose series at age 12 through 15 months and age 4 through 6 years Minimum age for dose 1 is 12 months Minimum interval for dose 1 to 2 is: 3 months for children aged 12 months–12 years (although a 4-week interval is valid) 4 weeks for persons aged 13 years and older Communicable diseases: measles, pertussis & chicken pox 27

28. THANK YOU Communicable diseases: measles, pertussis & chicken pox 28