Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
PLoS Negl Trop Dis. 2018 May 31;12(5):e0006430. doi: 10.1371/journal.pntd.0006430. eCollection 2018 May.
Dengue is one of the most serious and rapidly spreading arboviral diseases in the world. Despite many acute febrile illnesses in Ethiopia, the burden of illness due to dengue in the country is largely unknown. Thus, the present study aimed to provide the first baseline data on seroprevalence and associated risk factors of dengue virus (DENV) infection in the country.
A cross-sectional study of febrile patients who were visiting Metema and Humera hospitals in Northwest Ethiopia from March 2016 to May 2017 was conducted. Blood samples were collected from each participant and serum samples were separated and tested for IgM and IgG antibodies against DENV infection by enzyme-linked immunosorbent assay (ELISA). Risk factors associated with the prevalence of anti-DENV antibodies were tested using logistic regression analysis.
Of the 600 samples tested, the overall seroprevalence against DENV infection was 33.3%, while the seroprevalence by the study area was 40% in Metema and 27.5% in Humera. The overall prevalence of IgM and IgG antibodies against DENV infection was 19% and 21% respectively. Of these, 6.7% were positive for both IgM and IgG antibodies. Residence and occupational status were significantly associated with the prevalence of anti-DENV IgM seropositivity and anti-DENV IgM-/G+serostatus. The seasonal variation was significantly associated with the prevalence of anti-DENV IgM but not with anti-DENV IgM-/G+serostatus. The prevalence of anti-DENV IgM-/G+serostatus was significantly higher in Metema than Humera. High prevalence of anti-DENV IgM seropositivity was found in the summer and spring, with a peak in the month of August. The presence of uncovered water either indoor or outdoor and lack of mosquito net use was identified as risk factors for DENV infection.
These findings provide the preliminary data on seroprevalence and associated risk factors of DENV infection in the country. The presence of antibodies against DENV infection indicates dengue as one of the causes of undifferentiated febrile illnesses in the study areas. This suggests that prevention and control measures should be designed considering the risk factors identified by this study. Furthermore, we recommend a large-scale study to include DENV infection in the differential diagnosis of all febrile illnesses in Ethiopia.
登革热是世界上最严重且传播速度最快的虫媒病毒病之一。尽管埃塞俄比亚有许多急性发热疾病，但该国因登革热导致的疾病负担在很大程度上仍不为人知。因此，本研究旨在提供该国登革病毒（DENV）感染血清流行率和相关危险因素的首批基线数据。
本研究为横断面研究，2016 年 3 月至 2017 年 5 月期间在埃塞俄比亚西北部的梅特马和胡梅拉医院就诊的发热患者参加了研究。从每位参与者采集血样，分离血清并通过酶联免疫吸附试验（ELISA）检测针对 DENV 感染的 IgM 和 IgG 抗体。使用逻辑回归分析检测与抗 DENV 抗体流行率相关的危险因素。
在检测的 600 份样本中，DENV 感染的总体血清流行率为 33.3%，按研究地区划分，梅特马的血清流行率为 40%，胡梅拉为 27.5%。针对 DENV 感染的 IgM 和 IgG 抗体的总流行率分别为 19%和 21%。其中，6.7%的患者同时检测出 IgM 和 IgG 抗体阳性。居住地和职业状态与抗 DENV IgM 血清阳性率和抗 DENV IgM-/G+血清阳性率显著相关。季节性变化与抗 DENV IgM 流行率显著相关，但与抗 DENV IgM-/G+血清阳性率无关。梅特马的抗 DENV IgM-/G+血清阳性率显著高于胡梅拉。夏季和春季发现抗 DENV IgM 血清阳性率较高，8 月份达到高峰。室内或室外有未遮盖的水以及没有使用蚊帐被确定为 DENV 感染的危险因素。
这些发现提供了该国 DENV 感染血清流行率和相关危险因素的初步数据。针对 DENV 感染的抗体的存在表明，登革热是研究地区不明原因发热疾病的原因之一。这表明应根据本研究确定的危险因素设计预防和控制措施。此外，我们建议开展一项大规模研究，将 DENV 感染纳入埃塞俄比亚所有发热疾病的鉴别诊断。
