An association between decreasing incidence of invasive non-typhoidal salmonellosis and increased use of antiretroviral therapy, Gauteng Province, South Africa, 2003–2013

BackgroundHIV-infected persons are at increased risk of opportunistic infections, including invasive nontyphoidal Salmonella (iNTS) infections; antiretroviral therapy (ART) reduces this risk. We explored changing iNTS incidence associated with increasing ART availability in South Africa.MethodsLaboratory-based surveillance for iNTS was conducted in Gauteng Province, South Africa, with verification using the National Health Laboratory Service’s Central Data Warehouse (CDW), between 2003 and 2013. Isolates were serotyped at the Centre for Enteric Diseases. CDW data on patient numbers obtaining HIV viral load measurements provided estimates of numbers of HIV-infected patients receiving ART. A Poisson regression model was used to measure the changing incidence of iNTS infection from 2003 to 2013. The correlation between the incidence of iNTS and ART use from 2004 to 2013 was determined using Pearson’s correlation coefficient.ResultsFrom 2003–2013, the incidence of iNTS per 100,000 population per year decreased from 5.0 to 2.2 (p Salmonella enterica serovar Typhimurium (Salmonella Typhimurium), and Salmonella Enteritidis: 2,469 (55.4%) and 1,156 (25.9%) of 4,459 isolates serotyped, respectively. A strong negative correlation was observed between decreasing iNTS incidence and increasing ART use from 2004 to 2013 (r = -0.94, p Salmonella Typhimurium infection correlated with increasing ART use (r = -0.93, p Salmonella Enteritidis infection increased, however (r = 0.95, p ConclusionsThe incidence of iNTS infections including Salmonella Typhimurium decreased significantly in Gauteng Province in association with increased ART utilization. Adult men accessed ART programs less than women, translating into increasing iNTS incidence in this group. Monitoring iNTS incidence may assist in monitoring the ART program. Increasing incidence of invasive Salmonella Enteritidis infections needs further elucidation.

背景：人类免疫缺陷病毒（HIV，Human Immunodeficiency Virus）感染者发生机会性感染的风险显著升高，其中包括侵入性非伤寒沙门菌（invasive nontyphoidal Salmonella, iNTS）感染；抗逆转录病毒治疗（antiretroviral therapy, ART）可降低此类感染风险。本研究旨在探讨南非境内随着抗逆转录病毒治疗可及性提升，侵入性非伤寒沙门菌感染发病率的变化情况。

方法：2003年至2013年间，本研究在南非豪登省开展了基于实验室的侵入性非伤寒沙门菌感染监测工作，监测数据通过南非国家卫生实验室服务中心的中央数据仓库（Central Data Warehouse, CDW）进行验证。分离菌株于肠道疾病中心完成血清分型。依托中央数据仓库中接受HIV病毒载量检测的患者数据，本研究估算了接受抗逆转录病毒治疗的HIV感染者人数。本研究采用泊松回归模型，分析2003年至2013年间侵入性非伤寒沙门菌感染发病率的变化趋势；并通过皮尔逊相关系数，计算2004年至2013年间侵入性非伤寒沙门菌感染发病率与抗逆转录病毒治疗使用率之间的相关性。

结果：2003年至2013年，每10万人口年侵入性非伤寒沙门菌感染发病率从5.0降至2.2（p 鼠伤寒沙门菌（Salmonella enterica serovar Typhimurium, Salmonella Typhimurium）与肠炎沙门菌（Salmonella Enteritidis）：在完成血清分型的4459株菌株中分别占2469株（55.4%）与1156株（25.9%）。2004年至2013年间，侵入性非伤寒沙门菌感染发病率与抗逆转录病毒治疗使用率呈显著负相关（r = -0.94, p 鼠伤寒沙门菌感染发病率与抗逆转录病毒治疗使用率同样呈显著负相关（r = -0.93, p 肠炎沙门菌感染发病率则呈上升趋势（r = 0.95, p

结论：豪登省侵入性非伤寒沙门菌（包括鼠伤寒沙门菌）感染发病率随抗逆转录病毒治疗使用率提升而显著下降。成年男性参与抗逆转录病毒治疗项目的比例低于女性，导致该群体的侵入性非伤寒沙门菌感染发病率升高。监测侵入性非伤寒沙门菌感染发病率，可辅助评估抗逆转录病毒治疗项目的实施效果。而肠炎沙门菌感染发病率的上升趋势，有待进一步研究阐明。