Related Experiment Videos
St. Louis encephalitis in Arkansas
D M Bleed1, A A Marfin, N Karabatsos
1Division of Field Epidemiology, Centers for Disease Control, Little Rock, Arkansas.
The Journal of the Arkansas Medical Society
|August 1, 1992
Summary
The 1991 St. Louis encephalitis (SLE) outbreak in Arkansas primarily affected older adults, with many cases being asymptomatic. This suggests prior SLE virus exposure in the region and potential for future outbreaks.
Area of Science:
- Epidemiology
- Virology
- Public Health
Background:
- The first recorded St. Louis encephalitis (SLE) outbreak in Arkansas occurred in Pine Bluff, Jefferson County, during July-August 1991.
- SLE is a mosquito-borne viral illness with potential for significant public health impact.
Purpose of the Study:
- To investigate the epidemiology and clinical characteristics of the 1991 St. Louis encephalitis outbreak in Arkansas.
- To assess the extent of SLE virus infection in the Pine Bluff population.
Main Methods:
- Case identification through physician reporting and diagnostic testing.
- Review of hospital charts and cerebrospinal fluid specimens.
- Conducting a serosurvey in Pine Bluff to determine past SLE virus exposure.
Main Results:
- Twenty-eight Arkansas residents were diagnosed with SLE, resulting in five deaths.
- Over half of the affected patients were over 60 years old, and nearly half had hypertension.
- The serosurvey indicated pre-existing SLE virus infection in the Pine Bluff population, with most 1991 infections being asymptomatic.
Conclusions:
- The 1991 outbreak highlighted the susceptibility of older individuals and those with hypertension to severe SLE.
- Evidence suggests endemic SLE virus circulation in Pine Bluff, with a high proportion of asymptomatic infections.
- Arkansas physicians should remain vigilant for potential future SLE cases.