Kenya Medical Research Institute-Centre for Geographic Medicine Research, Coast, Kilifi, Kenya.
Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
PLoS Negl Trop Dis. 2023 Oct 26;17(10):e0011716. doi: 10.1371/journal.pntd.0011716. eCollection 2023 Oct.
Despite the importance of non-Typhoidal Salmonella (NTS) disease in Africa, epidemiologic data on carriage and transmission are few. These data are important to understand the transmission of NTS in Africa and to design control strategies.
To estimate the prevalence of stool carriage of NTS in Kenya, we conducted a cross-sectional study in Kilifi, Nairobi, and Siaya, sites with a low, moderate and high incidence of invasive NTS disease, respectively. At each site, we randomly selected 100 participants in each age-group of 0-11 months, 12-59 months, 5-14 years, 15-54 years and ≥55 years. We collected stool, venous blood (for hemoglobin and malaria rapid tests), anthropometric measurements, and administered a questionnaire on Water Access Sanitation and Hygiene (WASH) practices. Stool samples were cultured on selective agar for Salmonella; suspect isolates underwent serotyping and antimicrobial susceptibility testing.
Overall, 53 (3.5%) isolates of NTS were cultured from 1497 samples. Age-adjusted prevalence was 13.1% (95%CI 8.8-17.4) in Kilifi, 0.4% (95%CI 0-1.3) in Nairobi, and 0.9% (95%CI 0-2.0) in Siaya. Prevalence was highest among those aged 15-54 years (6.2%). Of 53 isolates; 5 were S. Enteritidis, 1 was S. Typhimurium. No S. Typhi was isolated. None of the risk factors were associated with carriage of NTS. All isolates were susceptible to all antibiotics tested, including ampicillin, chloramphenicol, ciprofloxacin and co-trimoxazole.
Prevalence of fecal carriage was high in Kilifi, an area of low incidence of invasive NTS disease and was low in areas of higher incidence in Nairobi and Siaya. The age-prevalence, risk factors, geographical and serotype distribution of NTS in carriage differs from invasive disease.
尽管非伤寒沙门氏菌（NTS）疾病在非洲很重要，但有关其携带和传播的流行病学数据却很少。这些数据对于了解 NTS 在非洲的传播以及制定控制策略非常重要。
为了估计肯尼亚 NTS 粪便携带率，我们在基利菲、内罗毕和锡亚亚进行了一项横断面研究，这三个地点的侵袭性 NTS 疾病发病率分别较低、中等和较高。在每个地点，我们随机选择每个年龄组（0-11 个月、12-59 个月、5-14 岁、15-54 岁和≥55 岁）的 100 名参与者。我们收集粪便、静脉血（用于血红蛋白和疟疾快速检测）、人体测量学数据，并进行有关水接入、卫生和个人卫生（WASH）做法的问卷调查。粪便样本在选择性琼脂上培养沙门氏菌；疑似分离株进行血清分型和抗菌药物敏感性试验。
总体而言，从 1497 份样本中培养出 53 株（3.5%）NTS 分离株。基利菲的年龄调整后携带率为 13.1%（95%CI 8.8-17.4），内罗毕为 0.4%（95%CI 0-1.3），锡亚亚为 0.9%（95%CI 0-2.0）。15-54 岁年龄组的携带率最高（6.2%）。53 株分离株中，5 株为肠炎沙门氏菌，1 株为鼠伤寒沙门氏菌。未分离到伤寒沙门氏菌。没有任何危险因素与 NTS 携带有关。所有分离株均对所有测试的抗生素敏感，包括氨苄西林、氯霉素、环丙沙星和复方磺胺甲噁唑。
在侵袭性 NTS 疾病发病率较低的基利菲地区，粪便携带率很高，而在内罗毕和锡亚亚发病率较高的地区则很低。NTS 粪便携带的年龄流行率、危险因素、地理和血清型分布与侵袭性疾病不同。
