Influenza Prevention and Treatment- PSM.pptx

PSM Topic

1. Influenza Guided By- Dr. Sudarshan Kale Associate Professor Dept. of Swasthavritta D.M.M. Ayurved College, Yavatmal

2. Introduction- Influenza is an acute respiaratory tract infection caused by influenza virus of which there are three types- A -Pandemic + Epidemic ( 2-3yrs) B - Epidemic (4-7 yrs.) C Family - Orthomyxoviridae

3. Influenza is truly an international disease, it occurs in all countries and affects millions of people every year. Its behaviour is unpredictable It may occure in pandemics every 10-15 yrs due to major antegenic changes – 1918 – Spanish influenza 1957 – Asian influenza 1968 – hongkong influenza There may be outbreaks of influenza practically every year and sometimes twice a year. The peaks of epidemic is reached in 3 – 4 weeks before tending to decline.

4. Why influenza spreads rapidly ? Short incubation period large number of subclinical cases high proportion of susceptible population Short duration of immunity absence of cross immunity

5. Influenza A & B Influenza Virus Two surface antigens: Haemagglutinin (HA) Initiates infection following attachment of virus to susceptible cells Neuraminidase (NA) Release of virus from infected cell 16 'H' antigens (1-16) 9 'N' antigens (1-9) Different combinations of H and N antigens

6. Influenza Virus - 3 Types Type A Type B Type C Causes significant disease: epidemics; pandemics Causes significant disease: milder epidemics Does not cause significant disease Infects both humans and other species Limited to humans Limited to humans Frequent antigenic variations Infrequent antigenic variations! Antigenically stable

7. Antigenic variation Influenza A – is unique among these viruses because it is frequently subject to antigenic variation both major and minor. Shift- when there is sudden complete or major change it is called as shift. Drift – when antigenic change is gradual over a period of time it is called as drift. Antigenic shift appears to result from genetic recombination of human with animal or avian viruses , providing a major antigenic change. This can cause a major epidemic or pandemic

8. Reservoir of Infection Influenza A – The major reservoir of influenza virus is animal and birds such as, Swine Horse Dogs cats Domestic poultry wild birds Influenza B & C- these viruses are found only in man

9. Influenza A(H1N1) T ransmission Through Species

10.   Age & Sex: All ages, both sexes Attack rates lower among adults High Case Fatality Ratio (CFR) during epidemic in high risk cases: (old people; children; persons with diabetes, heart disease, renal & resp. diseases)   Human Immunity Antibodies to 'H': neutralises the virus Antibodies to 'N': modifies the infection Antibodies appear in 7 days after an attack; reach maximum level in 2 weeks; drops to pre-infection level in 8-12 months Host Factors

11. Children under 18 months Old people above 18 months DM, CHD, Kidney disease Respiaratory disease. Who is at greatest risk?

12. Seasonality: Temperate zones : epidemics occur in winter Tropics : epidemics occur in rainy season Sporadic cases : any month   Overcrowding: Enhances transmission Higher attack rates in closed population groups (schools, institutions, ships etc.) Environmental Factors

13. U sually case The secretions of respiaratory tract are infective. Source of Infection

14. Virus is present in the nasopharynx from 1 to 2days before and 1 to 2 days after onset of symptoms. Period of Infectivity

15. Droplet Infection & Droplet Nuclei Mode of Transmission

16. The virus can be spread when a person touches something that is contaminated with the virus and then touches his or her eyes, nose, or mouth. Droplets from a cough or sneeze of an infected person move through the air. The virus can then be spread when a person touches respiratory droplets from another person on a surface like a desk, doorknob, child’s toy or phone handset and then touches their own eyes, mouth or nose before washing their hands. Fomite borne transmission is also possible

17. Respiaratory tract Portal of Entry

18. Incubation period: 18 to 72 hours Incubation period

19. Pathogenesis .

20. Fever with chills (fever last for1-5 days, average 3 days) cough Body ache Generalised weakness Diarrhoea Vomiting Nausea Throat pain (sore throat ) Clinical features

21. Pneumonia Respiratory failure Sinusitis Otitis media Purulent bronchitis Complication

22. What is swine flu? Swine Influenza (swine flu) is a respiratory disease of pigs caused by Type A influenza viruses that causes regular outbreaks in pigs. Swine flu viruses have been reported to spread from person-to-person.. This type of outbreaks are mainly found in colder season.

23. Present Swine flu Strains At this time , there are four main influenza type. A virus sub types that have been isolated in pigs: H1N1 , H1N2 , H3N2 , & H3N1 . However, most of the recently isolated influenza viruses from pigs have been H1N1 viruses.

24. Fast breathing Bluish skin colour Not drinking enough fluids Not waking up Not interacting So irritable Flu symptoms subside but fever and cough increases. Children’s emergency signs

25. Difficulty breathing or shortness of breath, Dyspnoea, Hypoxia Pain or pressure in the chest or abdomen Sudden dizziness Confusion ( CNS involvement ) Severe or persistent vomiting severe dehydration shock Renal failure Adult’s emergency sign

26. Virus isolation nasopharyngeal secretions are best specimen. Real time PCR (RT-PCR) indirect fluorescent antibody technique viral culture Lab diagnosis

27. Swine to Human contact- by using mask, gloves, in swine farm. Preventive measures of Influenza

28. Human to Human contact- 1) Good ventilation of public building avoidance of crowded places 2) Encouraging people to cover their faces with handkerchief when coughing and sneezing. .

29. 3) Stay at home when first sign of flue seen. .

30. . 4) Avoid touching to eyes, nose, mouth and faces.

31. 5) Wash hands frequently with warm water and soap. Or Alcohol based hand sanitizers.

32. 7). Disinfect household surfaces by chlorine bleach solution. 8). Using N95 mask. .

33. Vaccine is not recommended in general population. In view of the changing antigenic characteristics of the virus (i.e. antigenic shift and drift ) new vaccines are constantly required, they should contain H and N component of the prevalent strain to keep the vaccine up to date. WHO makes recommendation every year as to what strain should be included in the vaccine. WHO recommends to all countries to immunise all health care worker as a first priority. Immunization

34. PANENZA- It is inactivated monovalent vaccine. this vaccine contains antigen equivalent to A/ california /7/2009(H1N1)V like strain dose 0.5ml IM (arm) It is stored at 2 to 8 deg.c This vaccine is effective after 14 days of vaccination. Vaccines

35. These vaccines are given via nasal sprays. Live attenuated vaccine

36. Drugs which are effective in Swine Flu There are four different antiviral drugs that are licensed for use for the treatment of influenza: Amantidine, rimantadine, oseltamivir and zanamivir . While most swine influenza viruses have been susceptible to all four drugs Drugs proved resistant at Present Most recent swine influenza viruses isolated from humans are resistant to Amantidine and Rimantadine Treatment

37. 1) Oseltamivir (M.N. Tamiflu) Wt < 15kg – 30mg 15- 23kg -45mg 24- 40kg – 60mg >40kg – 75mg B.D. for 5 days cap-75mg syp-12mg/ml 2) Fluid management 3) Symptomatic T/t. Treatment

38. .