A total of 3,200 impressions were fixed on filter paper and were identified as containing human blood obtained from blood-sucking arthropods of the Triatoma and Panstrongylus genre. The impressions were then examined for the presence of the hepatitis B antigen (HBsAg). The immunodifusion technique showed that 12 impressions were presumably HBsAg positive, but the radioimmunoassay technique only confirmed 7 positive results. The positive samples were all obtained from Triatoma infestans nymphae.

Morphological studies of exochorial patterns of Rhodnius (Hemiptera-Reduviidae) genus were made. Ten species were studied by scanning and common microscopy, and data were described mainly for systematic purposes. The species included are Rhodnius domesticus Neiva & Pinto, 1923; R. ecuadoriensis Lent & Leon, 1958; R. nasutus Stal, 1959; R. neglectus Lent, 1954; R. neivai Lent, 1953; R. pallescens Barber, 1932; R. paraensis Sherlock, Guitton & Miles, 1977; R. pictipes Stal, 1872; R. prolixus Stal, 1859; and R. robustus Larrousse, 1927. […]

The study of the behaviour of T. cruzi strains in animals as in human beings, runs into great difficulties when the attempt is made to relate the morphology of this parasite to its biological behaviour. The thin forms are able to penetrate vertebrate cells faster than the broad forms. So, faced with the biological complexity of the T. cruzi strains and substrains it was decided to investigate the behaviour of its blood forms obtained from normal mice as biological filters. […]

The infection of several opossums Didelphis albiventris, male, female and young, by oral means by feeding them either on infected triatomines or on mice experimentally infected by Tripanosoma cruzi, is studied. After feeding uncontaminated opossums on carcasses or living specimens of baby mice, infected with the Bolivian strain of T.cruzi, a 60.0% infection index was obtained on xenodiagnoses. On the other hand, after feeding uncontaminated opossums on infected triatomines, an 83.3% index was obtained on xenodiagnoses. These results indicate that […]

Results of entomological and epidemiological investigations on the first autochthonous human case of American trypanosomiasis in the State of Acre, Brazil are presented. There are no synanthropic triatomine vectors in the area. Possibility of congenital or transfusional transmission is completely excluded. However, it is not possible to establish whether transmission was the result of house invasion of a silvatic triatomine species or contamined food. Two strains of Trypanosoma cruzi were isolated: one from humans which was called “Acre-Humana” (AH) and […]