Invasive Salmonellosis in Kilifi, Kenya

Abstract

Background: Invasive salmonelloses are a major cause of morbidity and mortality in Africa but the incidence and case-fatality of each disease varies markedly by region. Objectives: To describe the incidence, clinical characteristics and antimicrobial susceptibility patterns of invasive salmonelloses among children and adults in Kilifi, Kenya Methods: We analyzed integrated clinical and laboratory records for patients presenting to the Kilifi County Hospital between 1998 and 2014. We calculated incidence, summarised clinical features and multidrug resistance (MDR). Results: Non-typhoidal Salmonella (NTS) accounted for 10.8% and 5.8% of bacteremia cases, in children and adults respectively while Salmonella Typhi accounted for 0.5% and 2.1% of bacteremia cases, respectively. Among 351 NTS isolates serotyped, 160 (45.5%) were Salmonella Enteritidis and 152 (43.3%) were Salmonella Typhimurium. The incidence of NTS in children aged <5 years was 36.6/100,000 person-years being highest in infants aged <7 days (174/100,000 person-years). The overall incidence of NTS in children varied markedly by location and declined significantly during the study period; the pattern of dominance of the NTS serotypes also shifted from Salmonella Enteritidis to Salmonella Typhimurium. Risk factors for invasive NTS disease were HIV infection, malaria, and malnutrition; the case fatality ratio was 22.1% (71/321) in children under 5 years and 36.7% (11/30) in adults. MDR was present in 23.9% (84/351) of NTS isolates and 46.2% (12/26) of Salmonella Typhi isolates. Conclusions: In Kilifi, the incidence of invasive NTS was high, especially among newborn infants but typhoid fever was uncommon. NTS remains an important cause of bacteremia in children under 5 years