Salmonella infections pose a particularly serious risk if they become blood-borne in the host (septicaemia), carrying a high fatality rate. In your role as a health officer, you have been asked to assist in an investigation of salmonella septicaemia in Kenyan children. You will be working with a team of physicians who have been caring for some of the children with this disease at the Kenyatta National Hospital (KNH).

The term salmonellosis refers to infection caused by bacteria of the genus Salmonella, of which there are 3 primary species: 1) Salmonella typhi - the cause of enteric "typhoid fever", 2) Salmonella. cholerasuis and 3) Salmonella enteridis - which includes Salmonella. typhimurium -a subtype of increasing prevalence and antibiotic resistance in Kenya.

Salmonella septicaemia results when pathogenic species enter and multiply in the bloodstream. This may or may not be accompanied by the typical findings of gastroenteritis (abdominal pain, vomiting, diarrhea), but is of particular concern because infections may spread and mortality and morbidity (e.g. need for amputation) are high.

Infections result from ingestion of food or water contaminated from human or animal sources. Animal sources include poultry, rodents, cattle, pigs, snakes, etc.. Salmonellae are easily killed during cooking.

The main goal of the study is to learn more about salmonella septicaemia in Kenya, particularly to understand which children are at greatest risk for getting sick, so that environmental interventions to reduce the risk can be undertaken.

Study Case Definition:

Any child admitted to the paediatric wards in Kenyatta National Hospital (KNH) and the Infectious Disease Hospital between the ages of 0 and 12 years, who has a positive blood culture for any salmonella bacteria between July 1 and November 30, 1986

Cases will be identified and enrolled prospectively into the study over the 5-month period. You plan to obtain information from the parent or guardian about environmental exposures and past medical history of each case.

The most severe disease occurred in the 53 children with non-typhoidal septicaemia, with an 18% fatality rate (no patients with typhoid died); 19% (10/53) had coexisting malaria parasitemia (compared to none with typhoid). Antibiotic resistance was high, especially for S. typhimurium, and had increased significantly between 1980 and 1986. Four of the cases had sickle cell disease; 42% of children with non-typhoidal bacteria had severe protein-energy malnutrition (PEM).

You confirm that malarial infections (81% of cases come from malaria endemic areas), malnutrition and sickle cell disease are all associated with increased host susceptibility to infections like salmonellosis. But the underlying problem of contamination of food and water sources must be addressed.