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A
Preliminary Report of an investigation of a Fever Cases in Murshidabad District, West Bengal
(11-15 June
2003)
Cases of fever with respiratory symptoms were
reported in the district during the month of May and June 2003. The
Rapid Response Team of the district, a team from National Institute of
Enteric Diseases, Kolkatta National Institute of
Virology, Pune along with the National Institute of
Communicable Diseases investigated the episode. A total of 719 cases
and 45 deaths were reported during the period 15th May to 14th
June. 80% of the deaths were reported in children under
10 years of age. The laboratory investigation carried out confirmed the
cases to be due to influenza A (and possibly Influenza B) virus infection.
Summary
 In
response to a news item, a team from National Institute of Communicable
Diseases investigated the fever cases in Murshidabad
district of West Bengal during 11- 15 June 2003.
A
total of 719 cases and 45 deaths have been reported during the period from
15th May to 14th June.
Maximum
numbers of (82.2%) deaths were reported in children below 5 yrs. of
age. No death was reported in 10 years and above age group.
An
overall fever rate of 14.2% was observed in the community during the
one-month period affecting all age groups and both genders. Maximum attack
rate (31.7%) was in children below 5 years of age.
The
cases presented mainly with fever, running nose, cough and diarrhea.
Respiratory distress and convulsions were also present in a few cases,
especially in those reporting to hospital. The duration of illness in
majority of the cases varied from 2-5 days.
The
team collected nine sera and clots. Four throat swabs and four stool samples
were also collected. In addition, the team brought 12 sera samples collected
on 8 June 2003.
At
NICD laboratories, the samples tested negative for antibodies against measles
and herpes. In addition, four blood clots were cultured for bacteria and
found sterile. High antibody titres were observed
against Influenza A & B in most of the patients.
However a second sample is required for confirmation. One patient showed the
presence of Influenza B antigen in a throat swab. In this sample high
antibody titre (1:80) against Influenza B suggest that that the case had
infection due to Influenza B virus. At National Institute of Virology, Pune majority of the samples tested positive for
Influenza A virus.
The clinico-epidemiological findings show that the present
episode of fever consists of respiratory tract infections and affecting all
age groups with predominance in younger age. The laboratory investigations
indicate that the present episode of fever could be due to Influenza B virus.
Further tests are in progress to isolate the specific etiological agents.
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