Effect of tetracycline on the motility of microfilariae
of Brugia malayi Period of exposure in hours Tetracycline conc.
The significant percentage of animals infected by microfilariae
show that the black caiman at the Daracua community, middle Rio Negro, Amazonas state, are exposed to blood-sucking vectors and therefore occupy an ideal position to acquire blood parasites.
After mating, thousands of microfilariae
are released in to the bloodstream.
For further evaluation, Fine Needle Aspiration Cytology (FNAC) was done with 23-gauge needle, which showed microfilariae
and clusters of epithelial cells with pleomorphic nuclei (fine chromatin) and eosinophillic cytoplasm in a background of leucocytes.
Gravid female worms release microfilariae
into the reservoir host's circulation which can infect blood-feeding flies and female mosquitoes that transmit infective, third stage larvae to humans.
Adult parasites release microfilariae
into the host's bloodstream and these microfilariae
can be ingested by blood-sucking mosquitoes (genera Aedes, Anopheles, Culex) which serve as intermediate hosts and disease transmitters.
are usually recovered from peripheral blood samples.
In 2005, five species of Plasmodium genus, one of Haemoproteus genus, and two unidentified microfilariae
of different birds were reported from Pakistan .
Therefore, the iNOS/COX pathway appears to be an essential event in the rapid sequestration of microfilariae
following treatment with DEC.
The blackflies absorb the microfilariae
as they feed during the day, which further undergo developmental stages within the blackflies into infective larvae, which are then transmitted to the next human victim.
Thick and thin blood smear examination of nocturnal venous blood revealed no microfilariae
in all 5 cases.
According to the literature, horn flies (Haematobia irritans) are intermediate hosts that feed on skin lesions and ingest the microfilariae
, and in two to three weeks it develops the third larval stage (infective form), being introduced by bite in the skin of the definitive host, i.e., bovine (3).