南非爆發的李斯特菌感染與加工肉類有關
作者：
小柯機器人發布時間：2020/2/18 9:56:55
南非爆發的李斯特菌感染與加工肉類有關，這一成果由南非國家衛生實驗局Juno Thomas研究組取得。2020年2月13日出版的《新英格蘭醫學雜誌》發表了這項成果。
2017年在南非爆發了一場來源不明的李斯特菌感染。
研究組進行了流行病學、回溯和環境調查，並採用全基因組測序對單核細胞增生李斯特菌分離株進行了分型。2017年6月11日至2018年4月7日，實驗室確認1例單核細胞增生李斯特菌感染。
共發現937例感染，其中465例（50%）妊娠相關，406例（87%）為感染孕婦生的新生兒。229例（24%）年齡在15歲至49歲之間（不包括孕婦）。在已知人類免疫缺陷病毒（HIV）感染的患者中，38%妊娠相關者和46%其餘患者均為HIV陽性。
728名患者中有193名（27%）死亡。對609例患者的臨床分離株進行了測序，567例（93%）被鑑定為6型序列（ST6）。在病例對照分析中，與非ST6感染者相比，ST6感染者中有很多人食用了香腸，優勢比為8.55。
香腸和環境樣本也分離出了ST6菌株，這些菌株與患者的菌株屬於同一核心基因組多位點序列分型簇，差異不超過4個等位基因；這些發現表明，在單獨機構生產的香腸是疫情源頭。從該工廠召回香腸後，單核細胞增生李斯特菌ST6感染率迅速下降。
總之，在一個愛滋病感染率很高的中等收入國家，單核細胞增生李斯特菌在年輕孕婦、 婦女和愛滋病感染者中的感染率很高。全基因組測序有助於發現疫情，指導回溯調查，從而鎖定源頭。
附：英文原文
Title: Outbreak of Listeriosis in South Africa Associated with Processed Meat
Author: Juno Thomas, M.D.,, Nevashan Govender, M.Sc., M.P.H.,, Kerrigan M. McCarthy, M.D.,, Linda K. Erasmus, M.D.,, Timothy J. Doyle, Ph.D.,, Mushal Allam, Ph.D.,, Arshad Ismail, Ph.D.,, Ntsieni Ramalwa, M.P.H.,, Phuti Sekwadi, M.P.H.,, Genevie Ntshoe, M.P.H.,, Andronica Shonhiwa, M.P.H.,, Vivien Essel, M.D.,, Nomsa Tau, M.S.,, Shannon Smouse, M.S.,, Hlengiwe M. Ngomane, M.T.,, Bolele Disenyeng, M.T.,, Nicola A. Page, Ph.D.,, Nelesh P. Govender, M.D.,, Adriano G. Duse, M.D.,, Rob Stewart, M.T.,, Teena Thomas, M.D.,, Deon Mahoney, M.S.,, Mathieu Tourdjman, M.D.,, Olivier Disson, Ph.D.,, Pierre Thouvenot, B.S.,, Mylène M. Maury, Ph.D.,, Alexandre Leclercq, M.S.,, Marc Lecuit, M.D., Ph.D.,, Anthony M. Smith, Ph.D.,, and Lucille H. Blumberg, M.D.
Issue&Volume: 2020-02-12
Abstract:
Background
An outbreak of listeriosis was identified in South Africa in 2017. The source was unknown.
Methods
We conducted epidemiologic, trace-back, and environmental investigations and used whole-genome sequencing to type Listeria monocytogenes isolates. A case was defined as laboratory-confirmed L. monocytogenes infection during the period from June 11, 2017, to April 7, 2018.
Results
A total of 937 cases were identified, of which 465 (50%) were associated with pregnancy; 406 of the pregnancy-associated cases (87%) occurred in neonates. Of the 937 cases, 229 (24%) occurred in patients 15 to 49 years of age (excluding those who were pregnant). Among the patients in whom human immunodeficiency virus (HIV) status was known, 38% of those with pregnancy-associated cases (77 of 204) and 46% of the remaining patients (97 of 211) were infected with HIV. Among 728 patients with a known outcome, 193 (27%) died. Clinical isolates from 609 patients were sequenced, and 567 (93%) were identified as sequence type 6 (ST6). In a case–control analysis, patients with ST6 infections were more likely to have eaten polony (a ready-to-eat processed meat) than those with non-ST6 infections (odds ratio, 8.55; 95% confidence interval, 1.66 to 43.35). Polony and environmental samples also yielded ST6 isolates, which, together with the isolates from the patients, belonged to the same core-genome multilocus sequence typing cluster with no more than 4 allelic differences; these findings showed that polony produced at a single facility was the outbreak source. A recall of ready-to-eat processed meat products from this facility was associated with a rapid decline in the incidence of L. monocytogenes ST6 infections.
Conclusions
This investigation showed that in a middle-income country with a high prevalence of HIV infection, L. monocytogenes caused disproportionate illness among pregnant girls and women and HIV-infected persons. Whole-genome sequencing facilitated the detection of the outbreak and guided the trace-back investigations that led to the identification of the source.
DOI: 10.1056/NEJMoa1907462
Source: https://www.nejm.org/doi/full/10.1056/NEJMoa1907462