Feliciangeli M Dora, Carrasco Hernán, Patterson James S, Suarez Benny, Martínez Clara, Medina Mehudy
Facultad de Ciencias de la Salud, BIOMED, Universidad de Carabobo, Núcleo Aragua, Apartado 4873, Maracay, Venezuela.
Am J Trop Med Hyg. 2004 Oct;71(4):501-5.
Mixed infestation of nymphs and adults of Rhodnius prolixus Stal, 1859 and Panstrongylus geniculatus Latreille, 1811 was detected in 3 (15%) of 20 dwellings in El Guamito, an endemic focus of Chagas disease in Lara State, Venezuela. In one of the houses, both species were positive for Trypanosoma cruzi: 14.3% (R. prolixus) and 20% (P. geniculatus ). The overall infection rate in 143 of 352 R. prolixus was 16.1%. Parasites isolated from R. prolixus were identified as T. cruzi I by random amplified polymorphic DNA analysis. Dot-enzyme-linked immunosorbent assays of 36 R. prolixus showed that 58.3% of the R. prolixus had fed on humans. The gut contents of one fifth-instar nymph of P. geniculatus that was positive for T. cruzi also reacted with anti-human serum. A questionnaire was used to gather data on the demographic and socioeconomic characteristics of the population. An indirect immunofluorescent test, an indirect hemaglutination test, and an ELISA were used to detect the presence of antibodies against T. cruzi in 84 of 86 inhabitants and in 15.5% of people more than 20 years old. The relative risk (RR) of infection was greater in men than in women (RR = 1.61, 95% confidence interval = 0.54-4.80). Of the people more than 15 years old, 36.6% had no formal education. All respondents recognized triatomine bugs, but they did not relate them to Chagas disease transmission. A total of 85.7% of the houses were "ranchos" suitable for the colonization of triatomine bugs. The possible domiciliation of P. geniculatus and the implications of competition with R. prolixus for resources are discussed. Since there is no clear separation of food sources, abiotic factors such as microclimatic variation within houses may be critical to predict the outcome of the process of competition and potential domestication of this generally sylvatic species.
在委内瑞拉拉腊州恰加斯病的地方性疫源地埃尔瓜米托，20所住宅中有3所（15%）检测到1859年的红带锥蝽若虫和成虫与1811年的膝状锥猎蝽混合侵染。在其中一所房屋中，两种锥蝽均检测出克氏锥虫阳性：红带锥蝽为14.3%，膝状锥猎蝽为20%。352只红带锥蝽中有143只的总体感染率为16.1%。通过随机扩增多态性DNA分析，从红带锥蝽中分离出的寄生虫被鉴定为克氏锥虫I型。对36只红带锥蝽进行斑点酶联免疫吸附试验表明，58.3%的红带锥蝽吸食过人血。一只克氏锥虫阳性的膝状锥猎蝽五龄若虫的肠道内容物也与抗人血清发生反应。使用问卷调查收集了关于人群人口统计学和社会经济特征的数据。采用间接免疫荧光试验、间接血凝试验和酶联免疫吸附测定法，在86名居民中的84名以及20岁以上人群中的15.5%中检测到了抗克氏锥虫抗体。男性感染的相对风险（RR）高于女性（RR = 1.61，95%置信区间 = 0.54 - 4.80）。在15岁以上的人群中，36.6%没有接受过正规教育。所有受访者都认识锥蝽，但他们并未将其与恰加斯病传播联系起来。共有85.7%的房屋是适合锥蝽栖息的“棚屋”。文中讨论了膝状锥猎蝽可能的家居化以及与红带锥蝽资源竞争的影响。由于食物来源没有明显区分，房屋内微气候等非生物因素对于预测这一通常生活在野外的物种竞争过程和潜在家居化结果可能至关重要。
