Clinical definition for invasive Salmonella infection in African children

Abstract

Invasive salmonellosis is common among children in tropical Africa, typically presenting as a nonspecific febrile illness that is difficult to distinguish clinically from malaria. This study examines the performance of a clinical definition devised to aid its recognition among children ages 1 to 15 years presenting to a mission hospital in rural Zaire. Invasive salmonellosis was defined by: (1) illness requiring admission to hospital in the opinion of an experience pediatrician; (2) history of fever for 5 or more days; (3) no focus of infection on clinical examination; and (4) negative or only scanty positive thick film for malarial parasites. Children fulfilling all these criteria were treated with ciprofloxacin after culture of blood and feces. The primary outcome measure was blood culture-confirmed salmonellosis. Secondary measures were final clinical diagnosis and serologic evidence of recent salmonellosis. Of 120 children fulfilling the definition, 55 (46%) were bacteremia; in 46 (38%) Salmonella species were isolated. In the majority of the nonbacteremic children no definite cause for the fever could be found. Salmonella serology supported invasive salmonellosis as the diagnosis in 62% of the nonbacteremic children. Salmonella serology suggested that invasive salmonellosis without detectable bacteremia was common. The addition of blood culture-proved and serologically diagnosed cases indicates that the definition has a specificity of at least 60%.