Belda Ketema, Tegegne Ayesheshem Ademe, Mersha Amare Mengistu, Bayenessagne Mekonnen Getahun, Hussein Ibrahim, Bezabeh Belay
World Health Organization, Oromia Region Technical Support Team.
World Health Organization Country Office, Addis Abba, Ethiopia.
Pan Afr Med J. 2017 Jun 9;27(Suppl 2):9. doi: 10.11604/pamj.supp.2017.27.2.10705. eCollection 2017.
Despite the increase of immunization coverage (administrative) of measles in the country, there are widespread outbreaks of measles. In this respect, we investigated one of the outbreaks that occurred in hard to reach kebeles of Guji Zone, Oromia region, to identify the contributing factors that lead to the protracted outbreak of measles.
We used a cross-sectional study design to investigate a measles outbreak in Guji zone, Oromia region. Data entry and analysis was performed using EPI-Info version 7.1.0.6 and MS-Microsoft Excel.
In three months' time a total of 1059 suspected cases and two deaths were reported from 9 woredas affected by a measles outbreak in Guji zone. The cumulative attack rate of 81/100,000 population and case fatality ratio of 0.2% was recorded. Of these, 821 (77.5%) cases were < 15 years of age, and 742 (70%) were zero doses of measles vaccine. Although, all age groups were affected under five years old were more affected 495 (48%) than any other age groups. In response to the outbreak, an outbreak response immunization was organized at the 11th week of the epidemic, when the epidemic curve started to decline. 6 months to14 years old were targeted for outbreak response immunization and the overall coverage was 97 % (range: 90-103%). Case management with vitamin A supplementation, active case search, and health education was some of the activities carried out to curb the outbreak.
We conclude that low routine immunization coverage in conjunction with low access to routine immunization in hard to reach areas, low community awareness in utilization of immunization service, inadequate cold chain management and delivery of a potent vaccine in hard to reach woredas/kebeles were likely contributed to the outbreak that's triggered a broad spread epidemic affecting mostly children without any vaccination. We also figured that the case-based surveillance lacks sensitivity and timely confirmation of the outbreak, which as a result outbreak response immunization were delayed. We recommend establishing reaching every child (REC) strategy in Guji zone with particular emphasis too hard reach areas to enhance the current immunization service, and furthermore to conduct data quality self-assessment or cluster coverage survey to verify the reported high vaccination coverage in some kebeles. We also recommend conducting the second opportunity as a form of supplemental immunization activities in 2-3 year interval or consider the national second dose introduction in the routine immunization system to improve population immunity. We further recommend that there is a need to boost the sensitivity of case-based surveillance system to be able to early detect, confirm and react to future epidemics.
尽管该国麻疹免疫接种覆盖率（行政统计数据）有所提高，但麻疹仍广泛爆发。在此方面，我们对奥罗米亚州古吉区难以抵达的几个社区发生的一次疫情进行了调查，以确定导致麻疹疫情长期持续的影响因素。
我们采用横断面研究设计，对奥罗米亚州古吉区的一次麻疹疫情进行调查。使用EPI-Info 7.1.0.6版本和微软Excel软件进行数据录入和分析。
在三个月的时间里，古吉区9个县共报告了1059例疑似病例和2例死亡。记录的累计发病率为81/10万，病死率为0.2%。其中，821例（77.5%）病例年龄小于15岁，742例（70%）未接种过麻疹疫苗。虽然所有年龄组均受影响，但五岁以下儿童受影响更为严重，达495例（48%）。针对此次疫情，在疫情曲线开始下降的第11周组织了疫情应对免疫接种。目标人群为6个月至14岁儿童，总体接种覆盖率为97%（范围：90%-103%）。采取了补充维生素A进行病例管理、主动病例搜索和健康教育等活动来控制疫情。
我们得出结论，常规免疫接种覆盖率低，加上难以抵达地区获得常规免疫接种的机会少、社区对免疫接种服务利用的意识低、冷链管理不足以及难以抵达的县/社区缺乏有效的疫苗供应，可能是导致此次疫情爆发的原因，引发了广泛传播的疫情，主要影响未接种疫苗的儿童。我们还发现基于病例的监测缺乏敏感性，未能及时确认疫情，导致疫情应对免疫接种延迟。我们建议在古吉区制定“覆盖每个儿童”（REC）战略，特别强调难以抵达的地区，以加强当前的免疫接种服务，此外，进行数据质量自我评估或整群覆盖率调查，以核实一些社区报告的高疫苗接种覆盖率。我们还建议每2至3年开展一次补充免疫活动形式的第二次接种机会，或考虑在常规免疫接种系统中引入国家第二剂疫苗，以提高人群免疫力。我们进一步建议，有必要提高基于病例的监测系统的敏感性，以便能够早期发现、确认并应对未来的疫情。
