Leptospirosis in Kazakhstan
After completing this exercise, the student should be able to:
- List the components of descriptive epidemiology, and
- Given data from a surveillance system or field investigation, use tables and graphs to summarize the descriptive epidemiology.
An outbreak of suspected leptospirosis occurred in the Minbulak area of Kazakhstan in August 2004. Leptospirosis is a bacterial disease that affects animals and humans. Clinical presentation in humans varies from no symptoms at all to high fever, severe headache, chills, muscle aches, and vomiting, and may include jaundice (yellow skin and eyes), red eyes, abdominal pain, diarrhea, or a rash. Because these symptoms can occur with other diseases, the diagnosis should be confirmed with laboratory testing of blood or urine. Leptospira organisms have been found in cattle, pigs, horses, dogs, rodents, and wild animals, which may be ill or asymptomatic. Humans become infected through contact with water, food, or soil containing urine from these infected animals. This may happen by swallowing contaminated food or water or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin. Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals. The incubation period between a person's exposure to a contaminated source and becoming sick is 2 days to 4 weeks (average 10 days). The disease is not known to be spread from person to person. Investigators collected clinical and descriptive data from the 24 suspected cases.