Dammann D F, Solarsh G C
Department of Paediatrics, Edendale Hospital, Pietermaritzburg.
S Afr Med J. 1992 Aug;82(2):118-23.
A repeat vaccination coverage survey has been conducted in the Edendale/Vulindlela district of KwaZulu. The survey data were processed using the Coverage Survey Analysis System (COSAS) developed by the World Health Organisation (WHO) through its Expanded Programme on Immunisation (EPI). A modified random cluster sampling method was used to select 281 children between the ages of 12 and 23 months. Of the children surveyed, 83% were in possession of Road-to-Health cards (RTHCs). The best estimate of overall coverage for doses up to and including the second doses of polio and diphtheria, pertussis and tetanus (DPT) was 85% or higher, but estimates for polio 3 and measles, at 72% and 67% respectively, remain suboptimal. Stratification of coverage into urban, peri-urban and rural categories revealed that the major contribution to the fall-off in coverage, after the second dose of polio and DPT, came from children in the peri-urban category with estimates of 52% for polio 3 and 38% for measles. The fact that coverage in the peri-urban population for doses up to and including polio 2 was 78% or higher indicated that the peri-urban influence responsible for this drop-out effect occurred between the approximate ages of 5 and 8 months. This identified populations in informal peri-urban settlements as a priority group for urgent intervention and further study. The estimation of missed opportunities at visits when vaccinations are normally given, found in this survey to occur in 17% of children, was a useful feature of COSAS and provided a basis for a specific intervention.
在夸祖鲁省的伊登代尔/武林德莱拉区开展了一次重复疫苗接种覆盖率调查。调查数据使用世界卫生组织（WHO）通过其扩大免疫规划（EPI）开发的覆盖率调查分析系统（COSAS）进行处理。采用改良的随机整群抽样方法选取了281名年龄在12至23个月之间的儿童。在接受调查的儿童中，83%持有《健康之路卡》（RTHC）。对于包括脊髓灰质炎和白喉、百日咳、破伤风（DPT）第二剂及之前各剂次的总体覆盖率的最佳估计为85%或更高，但脊髓灰质炎第三剂和麻疹疫苗的覆盖率估计分别为72%和67%，仍未达到理想水平。将覆盖率按城市、城郊和农村类别进行分层显示，在脊髓灰质炎和DPT第二剂之后覆盖率下降的主要原因来自城郊类别的儿童，脊髓灰质炎第三剂的覆盖率估计为52%，麻疹疫苗为38%。城郊人口中直至包括脊髓灰质炎第二剂的各剂次覆盖率为78%或更高，这一事实表明导致这种漏种效应的城郊影响发生在大约5至8个月龄之间。这确定了城郊非正规住区的人群为急需干预和进一步研究的优先群体。本次调查发现，在通常进行疫苗接种的就诊时错过接种机会的比例为17%，这是COSAS的一个有用功能，并为具体干预措施提供了依据。
