Investigation of a community outbreak of typhoid fever
Investigation of a community outbreak oftyphoid fever assosiated with drinking water Research Journal: BMC Public Health (Published in december 2009) www.biomedcentral.com/1471-2458/9/476 Researchers: Amber Farooqui*, Adnan Khan and Shahana Urooj Kazmi. Presented By: XIA MUJAHID
Introduction Salmonella is the most commonly involved bacteria in gastrointestinal tract infections, its significant involvement in human mortality and morbidity, morbidity is a major health concern. The most important pathogen of this genus is Salmonella typhi. Which causes typhoid fever in humans. All members of this genus are gram negative short bacilli that occurs singly. Motile by peritrichous flagella, they are noncapsulated and nonsporing
Background This report is based on the investigation of anoutbreak of typhoid fever occured in the Nek Muhahammadvillage, situated 25km far from metropolitan city of Karachi.In Oct. 2004, an outbreak of diarrhea and vomitting withhigh grade fever hits this area. Onset of symptoms wasrapid, infected more than 300 people within a week!Local people contacted EDHI Foundation, that immediatelyset up a medical camp. They provide treatment and sentsevere patients to local hospitals. BUT...Only in 5 days three people were DEAD...!!!So, the team of microbiologists of Karachi Univesityvisited the vicinity.
They found the village is so poor and have very limited facilities of water, food, electricity and health care. They also discovered a Well, which was polluted with dead and decaying bodies of birds & amphibians. This Well was cleaned 2 days before the onset of symptoms. They interviewed the villagers, collected the enviornmental & clinical samples.
Methods Sample Collection: 100 Stool samples from patients (>38 C temp.) 10 water samples from well 90 water samples from houses which was collected from contaminated well.
Laboratory diagnosis of Collected Samples Enviornmental samples: The quality of collected water samples were checked by standard methods: SPC MPN MFT
Clinical samples: For the Clinical specimens diarrheal stool samples were collected and analyzed by following methods: Microscopic (for ova & parasites) Bateriology (for Salmonella, Shigella, E.coli (O157:H7), Yersinia & Vibrio cholerae. The following media were used for culture: MacConkey’s agar SS agar TCBS agar Sorbitol MacConkey’s agar (Oxoid)
For bacteriological identification following biochemicalreactions were performed: Oxidase TSI Sulfide Citrate Urease API20E strips (analytical profile index) Antisera (Specifically for Salmonella)
Results: The typhoid fever hit the remort area of Nek village in Oct . 2004 typically after cleaning of “well” 2 days before the onset . In the cleaning no chemical method was followed. In the tatal 500 villagers 300 people showed the symptoms.Enviornmental samples: Microbiological analysis showed the presence of Salmonella enterica serovar Typhi in all well water samples. Gram positive and Gram negative bacteria were also detected as normal flora. E.coli H157:O7 and other enteric pathogens were also observed.
Clinical Samples: Salmonella typhi was isolated as sole pathogen from ALL clinical samples. 22 patients were positive by MDR Salmonella typhi. No other significant pathogen was isolated from any patient stool sample. No evidence of protozoal and parasitic involvement was observed by microscopy .
Quality of Clinical & Eniornmental SamplesSamples No. Of samples (n) Average total Total coliform Sample positive Samples viable count* Count*^ for Salmonella positive for (CFU/ml or g) typhi Fecal idicators (%) (%)Clinical 100 - - 22 -Samples (feces)Well water 10 3 106 - 1 107 ≥1800 100 100samplesHousehold 90 5 104 - 4 107 ≥1800 72 65water samplesCooked food 50 2 103 - 1 104 0 2 0samples
Percent of typhoid patients showing symptoms during the outbreak. (n = 300)
Discussion: Drinking safe and healthy water is the right of every human being. Unsafe drinking water and inadequate sanitary conditions increase the risk of various public health hazards such as typhoid fever. In Pakistan, 13.6% of total deaths are due to water sanitation and hygiene. It is important to keep continuous vigilance in remote areas where people still live under inhumane conditions and provide them basic necessities of life.
Conclusion:This study presented the link of contaminated wellwater with the outbreak of typhoid fever in a remotevillage which claimed three human lives and left morethan 300 people suffered within one week. In order toavoid such incidences in future, they contacted thelocal health authorities and urged them toimmediately make arrangements for safe drinkingwater supply because... for all livingbeings, specially humans..!!!