Temporal fluctuations in the sero-prevalence of Taenia solium cysticercosis in pigs in Mbeya Region, Tanzania
Temporal fluctuations in the sero-prevalence of Taenia solium cysticercosis in pigs in Mbeya Region, Tanzania
复制标题
DOI：
10.1186/s13071-014-0574-7
复制
发表时间：
2014-12-04
影响因子：
3.2
通讯作者：
Johansen, Maria Vang
中科院分区：
文献类型：
--
作者：
Braae, Uffe Christian;Magnussen, Pascal;Johansen, Maria Vang
背景：猪囊虫病是撒哈拉以南非洲地区一个新兴的农业问题。这主要是通过横断面研究记录下来的，但缺乏关于该疾病在撒哈拉以南非洲传播动态的详细知识。本研究旨在描述一个流行地区猪囊虫病抗原ELISA阳性血清流行率的季节变化。方法：在坦桑尼亚Mbeya地区进行纵向研究，包括三次横断面调查；前两个6个月（2012年3月/ 4月和2012年10月/ 11月），后8个月（2013年7月/ 8月）。采集22个村猪静脉血，采用Ag-ELISA法进行分析。结果：每次调查共采集血清样本800 ~ 1000份。第一次调查显示囊虫病血清患病率为15% （n = 822, 95% CI: 13-18%）。随访6个月时，血清患病率显著增加至24% （p < 0.001， x -2检验，n = 812, 95% CI: 21-27%）。在14个月时，血清患病率降至20% （p = 0.053， x -2检验，n = 998, 95% CI: 18-23%）。总体而言，与2007年在同一地区进行的一项研究相比，这一血清患病率有所降低，当时31%（186/600）的猪被发现呈阳性。结论：在三次调查中，禁闭猪的血清患病率并不比自由漫游猪低。若干因素可能促成了观察到的波动，如非洲猪瘟或当地作物生产做法的季节性变化。此外，由于所使用的Ag-ELISA法不是物种特异性的，因此带绦虫传播的变化可能会影响结果。观察到的波动与预测稳定平衡的理论模型相矛盾，理论模型只考虑两隔间（猪和人）模型，不包括环境的影响。该疾病是否具有地方性平衡，还是经历依赖于外在和/或社会经济因素的波动仍有待阐明。
Background: Porcine cysticercosis is an emerging agricultural problem in sub-Saharan Africa. This has been documented primarily through cross-sectional studies, however detailed knowledge of the transmission dynamics of this disease in sub-Saharan Africa is lacking. This study aims to describe seasonal variations in sero-prevalence of antigen ELISA positive porcine cysticercosis in an endemic area.Methods: A longitudinal study composed of three cross-sectional surveys was carried out in Mbeya Region, Tanzania; the first two six months apart (March/April 2012 and October/November 2012) and the last eight months later (July/August 2013). Venous blood was collected from pigs in 22 villages and analysed using Ag-ELISA.Results: In each survey between 800-1000 serum samples were collected. The first survey revealed a cysticercosis sero-prevalence of 15% (n = 822, 95% CI: 13-18%). The sero-prevalence had significantly increased to 24% (p < 0.001, X-2-test, n = 812, 95% CI: 21-27%) at the time of the 6 month follow-up. At 14-months the sero-prevalence had dropped to 20% (p = 0.053, X-2-test, n = 998, 95% CI: 18-23%). Overall, this was a reduction in sero-prevalencecompared with a study conducted in 2007 in the same area, where 31% (186/600) of pigs were found positive.Conclusion: Confined pigs did not have a lower sero-prevalence compared to free roaming pigs in any of the three surveys. Several factors may have contributed to the observed fluctuations such as African swine fever or seasonal variation in local crop production practices. Also, as the Ag-ELISA assay used is not species specific, variation in transmission of Taenia hydatigena could potentially influence the results. The observed fluctuations contradict a theoretical model which predicts a stable equilibrium, which only considers a two-compartment (pig and human) model excluding the effect of the environment. Whether the disease has an endemic equilibrium, or undergoes fluctuations dependent on extrinsic and/or socio-economic factors remains to be elucidated.