Trombiculiasis in domestic goats and humans in the state of Maranhão, Brazil / Trombiculíase em caprinos domésticos e humanos no Estado do Maranhão, Brasil

Abstract Trombiculiasis is an infestation caused by larval mites (chiggers) of the family Trombiculidae. Here, we provide the first report on parasitism by the chigger species Eutrombicula alfreddugesi (Oudemans) and Eutrombicula batatas (Linnaeus) in goats and humans on farms in the state of Maranhão, northeastern Brazil. Severe itching and dermatitis caused by the chiggers' bites were seen. From a total of 779 examined goats, 214 of them showed clinical signs of infestation, as well as family members of three farms of the region. Most of the cases occurred during the rainy season, from March to September.

Resumo Trombiculíase é uma infestação causada por larvas de ácaros da família Trombiculidae. Nós reportamos pela primeira vez parasitismo por ácaros das espécies Eutrombicula alfreddugesi (Oudemans) and Eutrombicula batatas (Linnaeus) em cabras e humanos em fazendas no estado do Maranhão, nordeste do Brasil. Foram observadas dermatite e coceiras severas causadas pelas picadas de trombiculídeos. De um total de 779 cabras examinadas, 214 delas apresentaram sinais clínicos de infestações, assim como membros de três famílias de fazendeiros da região. A maioria dos casos ocorreu durante a estação chuvosa, de março a setembro.

A study of small mammals in the Ciloto field station area, West Java, Indonesia, with special reference to vectors of plague and scrub typhus.

From June 1977 to June 1978 a study of smal mammals was carried out in the Ciloto field station area, West Java, Indonesia by the WHO Vector Biology and Control Research Unit-II. The objectives of the investigations were to determine the diversity and density of rodent species, to find potential plague and scrub typhus vectors and to study their host-parasite relationships. In the 13 month period a total of 6 species of murids were identified; two species of campestral rats (R. tiomanicus and R. argentiventer), one species of peri-domestic (R. exulans), one species of domestic (R.r. diardii), and two species of forest rats (R. bartelsii and R. bukit). In addition, three species of insectivores (Suncus murinus, Hylomys suillus and Crocidura monticola), and one species of carnivore were found. Of the three habitats studies (mixed, ricefield and lalang), 10 species of small mammals were found in the mixed while four species of commensal murids were found in both the ricefield and the lalang. Of the four commensal murid species R. exulans had the highest density. R. tiomanicus was common but not abundant, and least common was R. argentiventer. R.r. diardii was occasionally found in the field. The mean litter size of gravid R. tiomanicus was 7.1, R. exulans 4.3, R. argentiventer 7.5 and R.r. diardii 9. Male R. tiomanicus, R. argentiventer and R.r. diardii with spermatozoa present in animals over 55 gm. Animals of less than 50 gm had no sperm. In R. exulans spermatozoa were present in specimens weighing 24-66 gm. No sperm were detected in those below 20 gm. The flea index of Xenopsylla cheopis and Stivalius cognatus as determined for R. tiomanicus was 0.3 and 2.3;l for R.r. diardii 2.2 and 1.7; for R. exulans 0.3 and 0.5; and for R. argentiventer 0.4 and 1.7 respectively. S. cognatus had a significantly higher density than X. cheopis among the campestral and peridomestic rats, but the density of X. cheopis was significantly in the domestic rat. Overall infestation rates were equally high in both mixed and lalang habitats, but low in the ricefield. Flea indices were highest in the mixed habitat, lower in lalang, and lowest in ricefield. The putative vector of scrub typhus (Leptotrombidium (L.) deliense) was quite prevalent on campestral rats, less so on domestic ones and least on peridomestic. Overall infestation rates were equally high in both mixed and lalang habitats and low in the ricefield. Chiggers load per animal was significantly higher in the mixed habitat, lower in lalang and lowest in the ricefield.