Joshi Anand B, Luman Elizabeth T, Nandy Robin, Subedi Bal K, Liyanage Jayantha B L, Wierzba Thomas F
Institute of Medicine, Kathmandu, Nepal.
Bull World Health Organ. 2009 Jun;87(6):456-65. doi: 10.2471/blt.07.050427.
To estimate the case-fatality ratio (CFR) for measles in Nepal, determine the role of risk factors, such as political instability, for measles mortality, and compare the use of a nationally representative sample of outbreaks versus routine surveillance or a localized study to establish the national CFR (nCFR).
This was a retrospective study of measles cases and deaths in Nepal. Through two-stage random sampling, we selected 37 districts with selection probability proportional to the number of districts in each region, and then randomly selected within each district one outbreak among all those that had occurred between 1 March and 1 September 2004. Cases were identified by interviewing a member of each and every household and tracing contacts. Bivariate analyses were performed to assess the risk factors for a high CFR and determine the time from rash onset until death. Each factor's contribution to the CFR was determined through multivariate logistic regression. From the number of measles cases and deaths found in the study we calculated the total number of measles cases and deaths for all of Nepal during the study period and in 2004.
We identified 4657 measles cases and 64 deaths in the study period and area. This yielded a total of about 82 000 cases and 900 deaths for all outbreaks in 2004 and a national CFR of 1.1% (95% confidence interval, CI: 0.5-2.3). CFR ranged from 0.1% in the eastern region to 3.4% in the mid-western region and was highest in politically insecure areas, in the Ganges plains and among cases < 5 years of age. Vitamin A treatment and measles immunization were protective. Most deaths occurred during the first week of illness.
To our knowledge, this is the first CFR study based on a nationally representative sample of measles outbreaks. Routine surveillance and studies of a single outbreak may not yield an accurate nCFR. Increased fatalities associated with political insecurity are a challenge for health-care service delivery. The short period from disease onset to death and reduced mortality from treatment with vitamin A suggest the need for rapid, field-based treatment early in the outbreak.
估算尼泊尔麻疹的病死率（CFR），确定政治不稳定等风险因素在麻疹死亡中的作用，并比较使用全国具有代表性的疫情样本与常规监测或局部研究来确定全国病死率（nCFR）。
这是一项针对尼泊尔麻疹病例和死亡情况的回顾性研究。通过两阶段随机抽样，我们按各地区的地区数量比例选取概率，选择了37个地区，然后在每个地区内从2004年3月1日至9月1日期间发生的所有疫情中随机选取一次疫情。通过对每户家庭的一名成员进行访谈并追踪接触者来确定病例。进行双变量分析以评估高CFR的风险因素，并确定从出疹开始到死亡的时间。通过多变量逻辑回归确定每个因素对CFR的贡献。根据研究中发现的麻疹病例和死亡数量，我们计算了研究期间以及2004年尼泊尔全国所有麻疹病例和死亡的总数。
在研究期间和地区内，我们确定了4657例麻疹病例和64例死亡。这得出2004年所有疫情的病例总数约为82000例，死亡900例，全国病死率为1.1%（95%置信区间，CI：0.5 - 2.3）。病死率范围从东部地区的0.1%到中西部地区的3.4%，在政治不稳定地区、恒河平原以及5岁以下病例中最高。维生素A治疗和麻疹免疫具有保护作用。大多数死亡发生在疾病的第一周。
据我们所知，这是第一项基于全国具有代表性的麻疹疫情样本的病死率研究。常规监测和单一疫情研究可能无法得出准确的nCFR。与政治不稳定相关的死亡人数增加对医疗服务提供构成挑战。从疾病发作到死亡的时间较短以及维生素A治疗降低了死亡率，这表明在疫情早期需要快速的现场治疗。
