Investigation of a community outbreak of

typhoid 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 an

outbreak of typhoid fever occured in the Nek Muhahammad

village, situated 25km far from metropolitan city of Karachi.

In Oct. 2004, an outbreak of diarrhea and vomitting with

high grade fever hits this area. Onset of symptoms was

rapid, infected more than 300 people within a week!

Local people contacted EDHI Foundation, that immediately

set up a medical camp. They provide treatment and sent

severe patients to local hospitals. BUT...

Only in 5 days three people were DEAD...!!!

So, the team of microbiologists of Karachi Univesity

visited 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 biochemical

reactions 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 .

Samples No. Of samples (n) Average total

viable count*

(CFU/ml or g)

Total coliform

Count*^

Sample positive

for Salmonella

typhi

(%)

Samples

positive for

Fecal idicators

(%)

Clinical

Samples (feces)

100 - - 22 -

Well water

samples

10 3 106 - 1 107 ≥1800 100 100

Household

water samples

90 5 104 - 4 107 ≥1800 72 65

Cooked food

samples

50 2 103 - 1 104 0 2 0

Quality of Clinical & Eniornmental Samples

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 well

water with the outbreak of typhoid fever in a remote

village which claimed three human lives and left more

than 300 people suffered within one week. In order to

avoid such incidences in future, they contacted the

local health authorities and urged them to

immediately make arrangements for safe drinking

water supply because...

for all livingbeings, specially humans..!!!