Division of Tsetse Control Services, Ministry of Lands, Agriculture, Water and Rural Resettlement, Harare, Zimbabwe.
Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa.
Parasit Vectors. 2021 Jan 14;14(1):50. doi: 10.1186/s13071-020-04555-8.
In the 1980s and 1990s, great strides were taken towards the elimination of tsetse and animal African trypanosomiasis (AAT) in Zimbabwe. However, advances in recent years have been limited. Previously freed areas have been at risk of reinvasion, and the disease in tsetse-infested areas remains a constraint to food security. As part of ongoing control activities, monitoring of tsetse and AAT is performed regularly in the main areas at risk. However, a centralized digital archive is missing. To fill this gap, a spatially explicit, national-level database of tsetse and AAT (i.e. atlas) was established through systematic data collation, harmonization and geo-referencing for the period 2000-2019.
The atlas covers an area of approximately 70,000 km, located mostly in the at-risk areas in the north of the country. In the tsetse component, a total of 33,872 entomological records were assembled for 4894 distinct trap locations. For the AAT component, 82,051 samples (mainly dry blood smears from clinically suspicious animals) were collected at 280 diptanks and examined for trypanosomal infection by microscopy.
Glossina pallidipes (82.7% of the total catches) and Glossina morsitans morsitans (17.3%) were the two tsetse species recorded in the north and northwest parts of the country. No fly was captured in the northeast. The distribution of AAT follows broadly that of tsetse, although sporadic AAT cases were also reported from the northeast, apparently because of transboundary animal movement. Three trypanosome species were reported, namely Trypanosoma brucei (61.7% of recorded infections), Trypanosoma congolense (28.1%) and Trypanosoma vivax (10.2%). The respective prevalences, as estimated in sentinel herds by random sampling, were 2.22, 0.43 and 0.30%, respectively.
The patterns of tsetse and AAT distributions in Zimbabwe are shaped by a combination of bioclimatic factors, historical events such as the rinderpest epizootic at the turn of the twentieth century and extensive and sustained tsetse control that is aimed at progressively eliminating tsetse and trypanosomiasis from the entire country. The comprehensive dataset assembled in the atlas will improve the spatial targeting of surveillance and control activities. It will also represent a valuable tool for research, by enabling large-scale geo-spatial analyses.
在 20 世纪 80 年代和 90 年代，津巴布韦在消灭采采蝇和动物非洲锥虫病（AAT）方面取得了巨大进展。然而，近年来的进展有限。以前已解放的地区有再次受到感染的风险，而采采蝇出没地区的疾病仍然是粮食安全的一个制约因素。作为正在进行的控制活动的一部分，在主要的高危地区定期监测采采蝇和 AAT。然而，目前缺少一个集中的数字化档案。为了填补这一空白，通过对 2000-2019 年期间的数据进行系统整理、协调和地理参考，建立了一个具有空间明确性的国家一级的采采蝇和 AAT 数据库（即地图集）。
该地图集覆盖了大约 70000 平方公里的区域，主要位于该国北部的高危地区。在采采蝇部分，共收集了 33872 项昆虫学记录，涉及 4894 个不同的诱捕器位置。在 AAT 部分，在 280 个诱捕器中收集了 82051 份样本（主要是来自临床疑似动物的干血涂片），并通过显微镜检查检测锥虫感染情况。
在该国北部和西北部记录到的采采蝇物种为 G. pallidipes（占总捕获量的 82.7%）和 G. morsitans morsitans（17.3%）。东北部没有捕捉到苍蝇。AAT 的分布大致与采采蝇的分布相同，尽管也有报道称东北部偶尔会出现 AAT 病例，这显然是由于动物跨界移动造成的。报告了三种锥虫物种，即布氏锥虫（记录感染的 61.7%）、刚果锥虫（28.1%）和冈比亚锥虫（10.2%）。通过随机抽样估计，在哨点牛群中的各自患病率分别为 2.22%、0.43%和 0.30%。
津巴布韦的采采蝇和 AAT 分布模式是由生物气候因素、历史事件（如 20 世纪之交的牛瘟流行）以及广泛和持续的采采蝇控制等因素共同作用的结果，后者旨在逐步从全国范围内消除采采蝇和锥虫病。地图集中汇编的综合数据集将提高监测和控制活动的空间针对性。它还将成为研究的宝贵工具，通过实现大规模的地理空间分析。
