Mugabe Vánio André, Ali Sadia, Chelene Imelda, Monteiro Vanessa Onofre, Guiliche Onélia, Muianga Argentina Felisbela, Mula Flora, António Virgílio, Chongo Inocêncio, Oludele John, Falk Kerstin, Paploski Igor A, Reis Mitermayer G, Kitron Uriel, Kümmerer Beate M, Ribeiro Guilherme S, Gudo Eduardo Samo
Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, BA, Brazil.
Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Ministério da Saúde, Salvador, BA, Brazil.
PLoS One. 2018 Feb 7;13(2):e0192110. doi: 10.1371/journal.pone.0192110. eCollection 2018.
In January 2016, health authorities from Zambézia province, Mozambique reported the detection of some patients presenting with fever, arthralgia, and a positive result for chikungunya in an IgM-based Rapid Diagnostic Test (RDT). We initiated a study to investigate a potential chikungunya outbreak in the city of Quelimane.
METHODS/PRINCIPAL FINDINGS: From February to June 2016, we conducted a cross-sectional study enrolling febrile patients attending five outpatient health units in Quelimane. Serum from each patient was tested for CHIKV and DENV, using IgM and IgG ELISA and qRT-PCR. Patients were also tested for malaria by RDT. Entomological surveys were performed around patients' households, and we calculated the proportion of positive ovitraps and the egg density per trap. A total of 163 patients were recruited, of which 99 (60.7%) were female. The median age was 28 years. IgM and IgG anti-CHIKV antibodies were identified in 17 (10.4%) and 103 (63.2%) patients, respectively. Plaque reduction neutralization assay confirmed the presence of anti-CHIKV antibodies in a subset of 11 tested patients with positive IgG results. IgM anti-DENV antibodies were found in 1 (0.9%) of 104 tested patients. Malaria was diagnosed in 35 (21.5%) patients, 2 of whom were also IgM-positive for CHIKV. Older age and lower education level were independently associated with the prevalence of IgG anti-CHIKV antibodies. Immature forms of Aedes aegypti were collected in 16 (20.3%) of 79 surveyed households. We also found that 25.0% (16/64) of the traps were positive, with an average of 90.8 eggs per pallet.
Our investigation demonstrated that no CHIKV outbreak was ongoing in Quelimane; rather, endemic transmission of the virus has been ongoing. Aedes aegypti mosquitoes are abundant, but dengue cases occurred only sporadically. Further population-based cohort studies are needed to improve our understanding of aspects related to the dynamics of arboviral transmission in Mozambique, as well as in other parts of Sub-Saharan Africa.
2016年1月，莫桑比克赞比西亚省的卫生当局报告称，检测到一些出现发热、关节痛且基于IgM的快速诊断检测（RDT）中基孔肯雅病毒检测呈阳性的患者。我们启动了一项研究，以调查在克利马内市是否存在潜在的基孔肯雅热疫情。
方法/主要发现：2016年2月至6月，我们开展了一项横断面研究，纳入了在克利马内市五家门诊卫生机构就诊的发热患者。使用IgM和IgG酶联免疫吸附测定（ELISA）以及定量逆转录聚合酶链反应（qRT-PCR）对每位患者的血清进行基孔肯雅病毒（CHIKV）和登革病毒（DENV）检测。患者还通过RDT进行疟疾检测。在患者家庭周围进行了昆虫学调查，并计算了阳性诱蚊产卵器的比例和每个诱蚊产卵器的卵密度。共招募了163名患者，其中99名（60.7%）为女性。年龄中位数为28岁。分别在17名（10.4%）和103名（63.2%）患者中检测到IgM和IgG抗CHIKV抗体。蚀斑减少中和试验在11名IgG检测结果为阳性的受试患者亚组中证实了抗CHIKV抗体的存在。在104名受试患者中的1名（0.9%）检测到IgM抗DENV抗体。35名（21.5%）患者被诊断为疟疾，其中2名患者CHIKV的IgM检测也呈阳性。年龄较大和教育水平较低与IgG抗CHIKV抗体的流行独立相关。在79户接受调查的家庭中的16户（20.3%）收集到了埃及伊蚊的未成熟形态。我们还发现，25.0%（16/64）的诱蚊产卵器呈阳性，每个托盘平均有90.8枚卵。
我们的调查表明，克利马内市并未发生CHIKV疫情；相反，该病毒一直在进行地方性传播。埃及伊蚊数量众多，但登革热病例仅偶尔出现。需要开展进一步的基于人群的队列研究，以增进我们对莫桑比克以及撒哈拉以南非洲其他地区虫媒病毒传播动态相关方面的了解。
