Estudo comparativo entre o xenodiagnóstico natural e o artificial, em chagásicos crônicos

Abstract

In order to study the sensitivity of the xenodiagnosis technique a comparison between natural and artificial xenodiagnosis methods was performed in 57 chronic phase chagasic patients (31 female), with ages ranging from 26 to 83 years. All patients had demonstrable antibodies against Trypanosoma cruzi. Forty first instar nymphs of Dipetalogaster maximus were used for each of both methods and for each patient. The positivity of xenodiagnosis artificial was significantly higher than the routine test method. These results did show that a single application of 40 bugs by the artificial method yielded a similar result than 3 applications of 40 bugs each, by the natural method. The positivity of xenodiagnosis was significantly higher in patients between 56-65 and 66-83 years old than at other ages. Males were predominant in this age group. These results showed the viability of artificial xenodiagnosis and its use in routine laboratory testing.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

“…Silva et al 46 demonstrated that xenodiagnostic reading by this method was more efficient than abdominal compression. A reduction in mortality by approximately three times was also observed using the spontaneous deferral method 47 .…”

Comparação entre o xenodiagnóstico clássico e artificial na fase crônica da doença de Chagas

“…Considerando os resultados relatados em outros trabalhos 14 17 , a positividade acumulada de 42% por ambos os métodos foi boa. Não conseguiu-se mostrar a superioridade do xenodiagnóstico artificial encontrada por Santos et al 14 . Embora o xeno artificial tendesse a mostrar maior número de pessoas xenopositivas, não houve diferença estatisticamente significante.…”

Xenodiagnosis

“…This was the reason for the introduction of this technique which has been successfully developed (Romaña & Gil 1947, Nussenzweig & Sonntag 1953, Cedillos et al 1982b, Silva 1991. According to Santos et al (1995), it has a higher positivity than routine or natural method. Particularly interesting is the post mortem artificial XD performed in blood collected from corpses during autopsy, with a preliminary 30% positivity in individuals whose serological tests for Chagas disease -performed previously to XD -were positive (Lopes et al 1986); (e) technique for obtaining the substratum to be examined: abdominal compression (Schenone et al 1968a, 1969, 1974, Pereira JB et al 1989, Pereira VL et al 1989, Coura et al 1991; intestine dissection, grinding and homogenization (Perlowagora-Szumlewicz et al 1982, Bronfen et al 1989, Bronfen & Alvarenga 1991, Menezes, 1992; liquefaction of the whole insect, filtration of resultant material through cotton, and centrifugalization (Maekelt, 1964, Rohwedder et al 1970, Cedillos et al 1982a); examination of contents:individual (Cedillos et al 1982a, Pereira JB et al 1989, Bronfen & Alvarenga 1991, Coura et al 1991, Menezes et al 1992) and pooled (Schenone et al 1968a, Bronfen et al 1989); (f) apparently sensitivity of XD can be improved by the so-called xenoculture which consists in sowing the intestinal contents of the triatomine nymphs used in it in a modified LIT medium (Bronfen et al 1989); (g) reading: must be done by well trained and skilled personnel.…”