Nsereko Godfrey, Kadobera Daniel, Okethwangu Denis, Nguna Joyce, Rutazaana Damian, Kyabayinze Daniel J, Opigo Jimmy, Ario Alex R
Uganda Public Health Fellowship Program, Ministry of Health, Kampala, Uganda.
National Malaria Control Division, Ministry of Health, Kampala, Uganda.
J Environ Public Health. 2020 Apr 22;2020:5802401. doi: 10.1155/2020/5802401. eCollection 2020.
Malaria is a leading cause of morbidity and mortality in Uganda. In April 2018, malaria cases surged in Nwoya District, Northern Uganda, exceeding expected limits and thereby requiring epidemic response. We investigated this outbreak to estimate its magnitude, identify exposure factors for transmission, and recommend evidence-based control measures.
We defined a malaria case as onset of fever in a resident of Anaka subcounty, Koch Goma subcounty, and Nwoya Town Council, Nwoya District, with a positive rapid diagnostic test or microscopy for malaria from 1 February to 25 May 2018. We reviewed medical records in all health facilities of affected subcounties to find cases. In a case-control study, we compared exposure factors between case-persons and asymptomatic controls matched by age and village. We also conducted entomological assessments on vector density and behavior.
We identified 3,879 case-persons (attack rate [AR] = 6.5%) and two deaths (case-fatality rate = 5.2/10,000). Females (AR = 8.1%) were more affected than males (AR = 4.7%) ( < 0.0001). Of all age groups, 5-18 years (AR = 8.4%) were most affected. Heavy rain started in early March 2018, and a propagated outbreak followed in the first week of April 2018. In the case-control study, 55% (59/107) of case-persons and 18% (19/107) of controls had stagnant water around households for several days following rainfall (OR = 5.6, 95% CI = 3.0-11); 25% (27/107) of case-persons and 51% (55/107) of controls wore full extremity covering clothes during evening hours (OR = 0.30, 95% CI = 0.20-0.60); 71% (76/107) of case-persons and 85% (91/107) of controls slept under a long-lasting insecticide-treated net (LLIN) 14 days before symptom onset (OR = 0.43, 95% CI = 0.22-0.85); 37% (40/107) of case-persons and 52% (56/107) of controls had access to at least one LLIN per 2 household members (OR = 0.54, 95% CI = 0.30-0.97). Entomological assessment indicated active breeding sites in the entire study area; species were the predominant vector.
Increased vector-breeding sites after heavy rainfall and inadequate malaria preventive measures were found to have contributed to this outbreak. We recommended increasing coverage for LLINs and larviciding breeding sites in the area.
疟疾是乌干达发病和死亡的主要原因。2018年4月，乌干达北部的Nwoya区疟疾病例激增，超过预期限度，因此需要采取疫情应对措施。我们对此次疫情进行了调查，以评估其规模，确定传播的暴露因素，并推荐基于证据的控制措施。
我们将2018年2月1日至5月25日期间，Nwoya区Anaka乡、Koch Goma乡和Nwoya镇议会居民中出现发热，且疟疾快速诊断检测或显微镜检查呈阳性的情况定义为疟疾病例。我们查阅了受影响乡所有卫生设施的医疗记录以查找病例。在一项病例对照研究中，我们比较了病例组和按年龄及村庄匹配的无症状对照组之间的暴露因素。我们还对媒介密度和行为进行了昆虫学评估。
我们确定了3879例病例（发病率[AR]=6.5%），2例死亡（病死率=5.2/10000）。女性（AR=8.1%）比男性（AR=4.7%）受影响更严重（<0.0001）。在所有年龄组中，5 - 18岁（AR=8.4%）受影响最严重。2018年3月初开始下大雨，随后在2018年4月的第一周出现了疫情蔓延。在病例对照研究中，55%（59/107）的病例组和18%（19/107）的对照组在降雨后数天家庭周围有积水（比值比[OR]=5.6，95%置信区间[CI]=3.0 - 11）；25%（27/107）的病例组和51%（55/107）的对照组在夜间穿着覆盖全身的衣物（OR=0.30，95%CI=0.20 - 0.60）；71%（76/107）的病例组和85%（91/107）的对照组在症状出现前14天睡在长效杀虫剂处理蚊帐（LLIN）下（OR=0.43，95%CI=0.22 - 0.85）；37%（40/107）的病例组和52%（56/107）的对照组每2名家庭成员至少有一顶LLIN（OR=0.54，95%CI=0.30 - 0.97）。昆虫学评估表明整个研究区域有活跃的繁殖场所； 物种是主要媒介。
发现暴雨后媒介繁殖场所增加以及疟疾预防措施不足是此次疫情的原因。我们建议增加该地区LLIN的覆盖率并对繁殖场所进行杀幼虫处理。
