NATURAL DISASTERS- A MICROBE S PARADISE - Andrea J. Linscott. (Clinical Microbiology News Letter 29(8) April 2007)

Transcription

1 NATURAL DISASTERS- A MICROBE S PARADISE - Andrea J. Linscott (Clinical Microbiology News Letter 29(8) April 2007)

2 Earthquakes Drought Tornados Natural Disaster Tsunami Hurricanes Flooding Transmission of infectious agents

3 Impact phase (0-4 days) Extrication, Immediate soft tissue infection Post impact phase (4 d 4 w) Air- borne Disease Food -borne disease Water -borne disease Vector- borne disease Recovery phase (After 4 weeks) Those with long incubation (Leptospirosis, Leishmaniasis)

4 Most common causes of death in a disaster Diarrhea Acute respiratory infection Measles Malaria Malnutrition - WHO

5 actors that facilitate the spread of Microorganisms uring a natural disaster Disruption of public water & sewage system Crowded living conditions Air borne transmission Lack of immunization Injury related infection due to exposure to some ebris

6 Communicable diseases with epidemic potential in natural disasters aterborne Transmission Incubation period holera Fecal/oral, 2h-5d epto-spirosis contaminated water 2-28d epatitis or food 15-50d acillary dysentery 12-96h yphoid fever 3-14d

7 Acute respiratory Pneumonia Person to person by 1-3d airborne respiratory Direct contact droplets Measles Person to person by 10-12d airborne respiratory droplets Bacterial Meningitis 2-10d

8 Vector-borne Malaria Mosquito 7-30d Dengue fever Mosquito 4-7d Japanese encephalitis Mosquito 5-15d Yellow fever Mosquito 3-6d

9 iagnosis Direct microscopic observation of V cholerae in stool Leptospira-specific IgM serologic assay Serologic assay detecting anti-hav of anti-hev IgM antibodies Suspect if bloody diarrhea; confirmation requires isolation of rganism from stool Culture from blood, bone marrow,bowel fluids; rapid antibody ests- Salmonella typhi Clinical presentation; culture respiratory secretions-streptococcus neumoniae, Haemophilus influenzae, Generally made by clinical observation-measles Examination of CSF - Meningitis

10 Vector-borne Parasites on blood smear,rapid diagnostic methods Serum antibody testing with ELISA or rapid dot-blot technique-dengue Serologic assay for JE virus IgM specific antibodies in CSF or blood Serological assay for yellow fever virus antibodies

11 Northridge Earthquake An unusual outbreak of coccidiomycosis occurred The infectious fungal spores of Coccidioides immitis ere dispersed via large dust clouds generated by andslides triggered by the earthquake. C.immitis peaked 2 weeks after the earthquake

12 looding ccounts for 40% of all natural disasters ommunicable disease transmitted during the flooding Water borne diseases Vector borne diseases Typhoid fever Malaria Cholera Yellow fever Leptospirosis Water Nile fever Hepatitis A Dengue

13 Diarrheal diseases after flooding and related displacement. Outbreak of diarrheal diseases after flooding in Bangladesh in 004 involved > 17,000 cases of V.Cholerae and E.Col infections. In a large study in Indonesia in S. enterica paratyphi (paratyphoid fever) predominant Risk of diarrheal diseases outbreaks following natural disaster s higher in developing countries than in industrialised countries.

14 Dominican republic-hurricanes David nd Fredrick, August 31 and Sep 5,1979 arked increase in yphoid,gastroenteritis,measles,viral-hepatitiseasured 6 months after the Hurricane Over 75,000 cases of Plasmodium falciparum malaria ssociated with hurricane Flora (haiti) 1966 Following hurricane Katrina (2005) several types of nfections were seen V.Cholerae were confirmed among Katrina evacuees. No disease causing E.coli (CDC report)

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17 sunamis Infections associated with tidal wave include raumatic wound infections Aspiration pneumonia due to inhalation of soil ontaminated salt water Wound infections among survivors were olymicrobic-641 organisms were identified Most prominent-aeromonas species, E.coli, lebsiella pneumoniae & Psudomonas aeruginosa Some of these organisms were resistant to all icensed antibiotics

18 Bacteriological Analysis of water samples from Tsunami hit coastal areas of Kanyakumari District, Tamil Nadu 151 drinking water sources collected from tsunamiaffected villages and relief shelters 37 % of the water samples were contaminated. No reports of acute diarrheal diseases or typhoid during the post-tsunami period A report by the Department of Microbiology,University of Madras P.Rajenndran et al,indian Journal of Medical Microbiology(2006) 24 (2):114

19 Relationship between natural disasters and ommunicable diseases frequently misconstrued Fear derived from an association between large no of ead bodies and epidemics

20 Primary risk factors Population displacement. Availability of safe water and sanitation facilities. Degree of crowding. Health status of population. Availability of health care services.

21 Deaths from communicable diseases after natural disaster are less common. Outbreaks after flooding are better documented than those after earthquakes,volcanic eruptions and tsunamis Natural disasters that do not result in population displacement are rarely associated with outbreaks A pathogen can be transmitted only if it is present in the environment where the natural disaster occurred

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23 Communicable Disease Transmission Risk assessment An accurate communicable disease risk assessment is required Identify Epidemic & endemic disease that are common in the affected area. Living conditions of the affected population. Availability of safe water and adequate sanitation facilities. Nutritional status and immunization coverage. Degree of access to healthcare.

24 revention /Control Hand washing,proper handling of water/food and sewage isposal, Oral rehydration therapy Improved Oral Rehydration salts for ORT) Avoid entering contaminated water Hepatitis vaccine Isolation, proper nutrition-if cause is Streptococcusolyvalent vaccine (pneumonia) Rapid mass vaccination within 72h of initial case eport,vitamin A in children 6 mo to 5 yrs to prevent omplications and reduce mortality (Measles)

25 Rapid mass vaccination-meningitis Mosquito control, insecticide-treated nets,bedding,clothing -malaria Mosquito control,isolation of cases,mass vaccination- Dengue, Japanese encephalitis,yellow fever

26 Rapid detection of the infectious agent is essential Development of novel diagnostic kits for rapid detection of Shigella and E.coli species -Department of Biochemistry,University of Madras Antibiotic treatment and vaccination for Shigella species and other enteropathogens are not always successful because they are increasingly resistant to antibiotics and possess high antigenic variations. We have designed a rapid diagnostic kit and alternative therapeutic strategies

27 Preventive Health Measures against the transmission of infectious agents related to natural disasters ey points listed by WHO Keep hands and vessels clean Avoid preparing food directly in areas surrounded by flood water. Separate raw and cooked food.cook food thoroughly Keep food at safe temperatures Use safe water Appropriate protective clothing to be worn during rescue and clean-up operations Immunization

28 THANK YOU