High Endemic Diseases/Outbreaks
Report
On a Diarrheal Disease Outbreak
A social media
post made by a General Practitioner (GP) in March 2025 triggered the outbreak
investigation. He used the post to educate the public on drinking boiled and
cooled water due to an observed increase in diarrheal cases. The relevant MOHs
of the adjacent areas were immediately informed, and an investigation was
initiated. Further communication with other GPs revealed that by that date, a
total of 70 patients had sought medical treatment for diarrheal illness.
Vigilant
surveillance and field investigations were launched under the guidance of the
district consultants and public health team with the assistance of medical
officers of all health institutions in the area including GPs. They were
requested to notify any new diarrheal cases to the MOH office or Regional Epidemiologist.
Data collection
followed standard formats from GPs, OPDs, and MOHs. Most patients presented
with vomiting, diarrhoea, abdominal pain, and fever. According to this a case
definition was established as follows:
“Two or more instances of vomiting, along with one or
more of the following symptoms:
·
Loose stools
·
Abdominal pain
·
With or without fever”
Surveillance at
the main hospital in the area indicated a significant increase in the number of
diarrheal patients admitted since mid-March, compared to previous disease
trends. All cases were limited to some localities in two MOH areas. Almost all
the affected individuals reported consuming water from the National Water
Supply and Drainage Board (NWSDB). Field visits by MOH and PHI teams were
conducted in high-incidence areas, with affected individuals line-listed and
mapped.
A comparison of
the case distribution map with the water supply map revealed a geographical
overlap. The area engineer was notified, and water samples were collected for
bacteriological testing and residual chlorine (Cl) level assessment. Recent
maintenance activities on water lines were identified as a possible risk
factor, leading to prioritization of routine water quality monitoring. Given
the ongoing festive season and school vacations, increased public movement
further heightens the risk of disease spread.
Residual
chlorine levels in the affected areas were found to be below the standard range
(0.2–0.5 ppm). Water samples from the National Water Supply, community water
supply schemes, and private wells were sent for analysis. Stool, vomitus, and
throat swab samples from affected patients were also sent to MRI for
virological and bacteriological analysis. The water samples tested were
bacteriologically unsatisfactory.
Daily meetings
were held involving the Epidemiology Unit, PDHS Office, RDHS Office, Staff from
the relevant MOHs and Staff from the National Water Supply Division of the
area. Several measures were taken to control the spread of the disease:
·
Field investigations were
promptly conducted with the involvement of PHIs and PHMs.
·
Surveillance activities were
enhanced by increasing awareness among general practitioners and hospital
staff.
·
Public awareness programs were
conducted through public announcement systems, religious institutions, home
visits, and social media. These programs focused on:
o
Using boiled and cooled water
for consumption
o
Proper sanitary disposal of
waste
o
Hand washing with soap and
water
o
Good personal hygiene practices
o
Seeking immediate medical
attention upon experiencing symptoms
·
Super-chlorination of water
supply schemes was carried out, and regular water testing for residual chlorine
was conducted to monitor improvements.
·
Behavioural changes in the
community were monitored, especially in schools, preschools, and religious
places.
As a result of
these interventions, the case load began to decline after one week. Active
surveillance continued to monitor the situation till end of April, covering the
two incubation periods to detect any potential reemergence of cases.