Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil.
A Z Nunes & Cia Ltda, Itu, Brazil.
Vector Borne Zoonotic Dis. 2019 Oct;19(10):711-716. doi: 10.1089/vbz.2019.2479. Epub 2019 May 23.
The bacterium causes Brazilian spotted fever (BSF), a highly lethal disease that is transmitted by ticks in areas where capybaras () are the tick's major hosts. In this study, we evaluated the expansion of a capybara population in a residential park in São Paulo state, and the implications of such expansion to the occurrence of ticks and BSF. The capybara population was quantified during 2004-2013. In 2012, there was a BSF human case in the area, culminating in the complete fencing of the residential park and the official culling of all capybaras. Quantification of ticks in the environment was performed by dry ice traps from 2005 to 2018. Domestic dogs in 2006-2011 and capybaras in 2012 were serologically tested for the presence of anti- antibodies. Our results show that capybara numbers increased ≈5 times from 2004 (41 capybaras) to 2012 (230 capybaras). Dry ice traps collected and The number of adult ticks was generally higher than adults during 2005-2006; however, during 2012-2013, outnumbered by a large difference. During 2016-2018 (after capybara culling), the number of both species fell close to zero. The low numbers of adult ticks during 2005-2006 coincided with relatively low capybara numbers (<80). Thereafter, in 2012, we counted the highest numbers of both ticks and capybaras (230 animals). All 40 canine blood samples were seronegative to , in contrast to the 48.3% seropositivity (83/172) among capybaras. Our results support that the emergence of BSF in the residential park was a consequence of the increase of the local capybara population, which in turn, provided the increment of the population. Culling the entire capybara population eliminated the risks of new BSF cases.
这种细菌引起巴西斑疹热（BSF），这是一种高度致命的疾病，通过在水豚（）是蜱虫的主要宿主的地区的蜱虫传播。在这项研究中，我们评估了圣保罗州一个居民区中水豚种群的扩张，以及这种扩张对蜱虫和 BSF 发生的影响。2004-2013 年期间对水豚种群进行了量化。2012 年，该地区出现了一例 BSF 人类病例，最终该居民区完全被围起来，所有水豚被官方扑杀。2005 年至 2018 年，通过干冰陷阱对环境中的蜱虫进行了量化。2006-2011 年对家犬进行了血清学检测，以检测抗抗体的存在，2012 年对水豚进行了血清学检测。我们的结果表明，2004 年（41 只水豚）到 2012 年（230 只水豚），水豚数量增加了约 5 倍。干冰陷阱共收集到 ，在 2005-2006 年期间，成年蜱虫的数量通常高于幼蜱虫；然而，在 2012-2013 年，幼蜱虫的数量远远超过成年蜱虫。2016-2018 年（水豚扑杀后），两种蜱虫的数量都接近零。2005-2006 年期间成年蜱虫数量较少，这与水豚数量较低（<80）相对应。此后，在 2012 年，我们记录到了蜱虫和水豚的数量最高（230 只动物）。所有 40 份犬血样本对 均为阴性，而水豚的血清阳性率为 48.3%（83/172）。我们的结果支持这样的观点，即居民区 BSF 的出现是当地水豚种群增加的结果，而水豚种群的增加又反过来导致了 种群的增加。扑杀整个水豚种群消除了新 BSF 病例的风险。
