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Studies on the periodicity and intravascular distribution of Wuchereria bancrofti microfilariae in paired samples of capillary and venous blood from Recife, Brazil
Author(s) -
Dreyer Gerusa,
Pimentael Agueda,
Medeiros Zulma,
Béliz Fatima,
Moura Izolda,
Coutinho Amaury,
Andrade Luiz Dias,
Rocha Abraham,
Silva Luiz Mauricio,
Piessens Willy F.
Publication year - 1996
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.1996.tb00037.x
Subject(s) - wuchereria bancrofti , venous blood , parasite hosting , filariasis , medicine , blood film , bancroftian filariasis , biology , pathology , veterinary medicine , helminths , immunology , malaria , world wide web , computer science
Summary We examined the periodicity and intravascular distribution of Wuchereria bancrofti microfilariae (mf) and determined the effect of these parasite properties on the accuracy of blood filming and filtration methods for diagnosis of bancroftian filariasis in the endemic area of Recife, Brazil. Microfilariae in both venous and capillary blood exhibited a nocturnal periodicity pattern with a relatively high amplitude. Overall, capillary blood contained ˜ 1.25 times the number of mf present at the same time in the same volume of venous blood. However, the ratio of mf present in capillary and venous blood varied over a 24‐hour period, so that the fewest mf were present in the capillary bed of the skin at the time when biting activity of the local Culex vector is the lowest. Twenty or 60 μl blood films did not reliably detect carriers with fewer than 100 or 60 mf/ml venous blood, respectively, and were thus inadequate for the identification of low density mf carriers. In contrast, all carriers with > I mf/20 or 60 μl blood smear at night could be identified during daytime hours by filtration of I ml venous blood