A comparison of Rhodnius prolixus, Triatoma infestans and Panstrongylus megistus in the xenodiagnosis of a chronic Trypanosoma (schizotrypanum) cruzi infection in a rhesus monkey (Macaca mullatta).

Fifth instar Rhodnius prolixus, Triatoma infestans and Panstrongylus megistus were fed on a rhesus monkey (Macaca mullatta) with a chronic infection of Peru strain Trypanosoma cruzi and examined 30 days later for the presence of trypanosomes in the rectum. No correlation could be demonstrated between either blood meal size or sex and the subsequent development of a rectal infection with T. cruzi. As T. infestans and P. megistus were more highly infected than R. prolixus in terms of both percentage infected and degree of infection, the two former species can be regarded as more suitable for the xenodiagnosis of this particular strain of T. cruzi in M. Mullatta.

Miles MA ，Patterson JW ，Marsden PD ，Minter DM ... -  《TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE》

Comparative xenodiagnosis with three triatomine species of different hosts with natural and experimental chronic infections with Trypanosoma (Schizotrypanum) cruzi.

Simultaneous xenodiagnosis was made of 29 patients with chronic Chagas's disease, six naturally infected opossums (Didelphis azarae) and of a Rhesus monkey with an experimental chronic infection with Trypanosoma (Schizotrypanum) cruzi (Peru strain). Patients and opossums were from an endemic area in the state of Bahia, Brazil, where Panstrongylus megistus is the sole domiciliary vector of the disease to man. Various instars of P. megistus Triatoma infestans and Rhodnius prolixus were used. The proportion of bugs infected with compared with bloodmeal intake by a computer programme using linear logistic analysis. The analysis showed that there are intrinsic interspecific differences in susceptibility to infection with Trypanosoma cruzi between the three triatomine species used and that subsequent infection of bugs with T. cruzi is correlated with the quantity of blood ingested. The results show that interspecific differences of bloodmeal size and intrinsic differences in susceptibility to T. cruzi between triatomine species are limiting factors for the standardization and interpretation of the results of xenodiagnosis.

Minter DM ，Minter-Goedbloed E ，de C Marshall TF 《TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE》

[Comparative study of the susceptibility of 5 triatomine species (Insecta: Reduviidae) to Trypanosoma cruzi infection].

In order to determine the most suitable species of triatomine for xenodiagnosis of the Chagas disease, five species triatomine (Triatoma barberi, T. infestans, T. pallidipennis, T. phyllosoma, and Rhodnius prolixus) in third and fourth instars were used to evaluate their susceptibility to one T. cruzi strain isolated in Mexico. The susceptibility was determined by: a) percentage of infected triatomines, b) amount of flagellates in bug feces and c) amount of blood ingested. We found that in most species of triatomines tested the third instar was more susceptible than fourth instar. The order of susceptibility to T. cruzi was: T. pallidipennis > T. barberi > T. phyllosoma > T. infestans > R. prolixus.

Alejandre-Aguilar R ，Nogueda-Torres B ，Calvo-Méndez ML ，Cortés-Jiménez M ... -  《-》

Attempts to improve xenodiagnosis: comparative test of sensibility using Rhodnius neglectus, Panstrongylus megistus, Triatoma vitticeps and Triatoma infestans in endemic areas of Brazil.

From June 1984 to July 1992, 392 xenodiagnostic tests were applied on 264 patients with chronic Chagas disease from Brazilian endemic areas of Virgem da Lapa and Coronel Murta, situated in the Jequitinhonha Valley, in the State of Minas Gerais. The susceptibilities of Rhodnius neglectus, Panstrongylus megistus, Triatoma vitticeps and Triatoma infestans were compared. Most of the time 20 nymphs (fourth instar) of each species were applied to 161 women and 103 men aged between 5 and 83 years of age. The tests were prepared to compare the susceptibilities of two species at a time, using the same patients for each test. Results showed a xenopositiveness of 26.28% (103 tests) being 27.98% in women (68 positive in 243 applied tests) and 23.49% in men (35 positive in 149 applied tests). The relative frequency of xenopositiveness displayed a great superiority of P. megistus and T. vitticeps. In tests from type 1, for example, P. megistus was the unique responsible for 10.73% of positive xenodiagnosis vs only 0.98% in T. infestans. Other parameters analized in this work confirm this superiority, and corroborate that T. infestans can be replaced by P. megistus and/or T. vitticeps in order to upgrade the efficacy of xenodiagnosis.

Moreira CJ ，Perlowagora-Szumlewicz A 《MEMORIAS DO INSTITUTO OSWALDO CRUZ》

[Susceptibility of Rhodnius neglectus, Rhodnius robustus and Triatoma infestans (Hemiptera, Reduviidae, Triatominae) to infection by two strains of Trypanosoma cruzi (Kinetoplastidae, Trypanosomatidae) using artificial xenodiagnosis].

The susceptibility of 3rd instar nymph of Triatominae Rhodnius neglectus, R. robustus and Triatoma infestans to Trypanosoma cruzi Y and AMJM strains was verified using artificial xenodiagnosis. After the accomplishment of the xenodiagnosis, the faeces of the Triatominae were analyzed on two-day intervals from day 5 until day 31 post infection, using the abdominal compression technique. The results showed differences in the susceptibility of the Triatominae for the two strains studied, and the optimal period reading differed from day 11 to day 19 for the Y strain and from day 11 to day 15 for the AMJM strain. For the Y strain, all three Triatominae species showed good susceptibility, whereas in the AMJM strain, the highest susceptibility was observed with R. neglectus, followed by T. infestans and R. robustus.

Martins LP ，da Rosa JA ，Castanho RE ，Sauniti GL ，Medeiros H Jr ... -  《Revista da Sociedade Brasileira de Medicina Tropical》