Plasmodium vivax: transmission-blocking immunity in a malaria-endemic area of Colombia.
Plasmodium vivax transmission-blocking activity was assessed in sera from acutely infected patients from a malaria-endemic area in Colombia. We measured reduction in the number of oocysts that developed in the midguts of Anopheles albimanus mosquitoes artificially fed with blood from these patients. Of 88 mosquito batches that developed infections when parasites were mixed with normal AB human serum, one-third (36.4%) showed full transmission-blocking activity (>or= 90% inhibition) when mixed with autologous sera, 29.6% showed partial activity (50-89%), 17.0% did not block transmission (0-50%), and 17% did not enhance transmission. Transmission-blocking activity correlated with antibody titer by an immunofluorescent antibody test and decreased with the serial dilution of the sera. This activity disappeared at a 1:4 dilution in most sera tested. Afro-Colombian individuals showed lower activity than other ethnic groups and febrile patients produced stronger inhibition than those without fever.
Arévalo-Herrera
Myriam
M
Instituto de Inmunología del Valle, Cali, Colombia. marevalo@inmuno.org
Solarte
Yezid
Y
Zamora
Felipe
F
Mendez
Fabián
F
Yasnot
Maria Fernanda
MF
Rocha
Leonardo
L
Long
Carole
C
Miller
Louis H
LH
Herrera
Sócrates
S
D000328:Adult; D000818:Animals; D000852:Anopheles / Q000469:parasitology; D000913:Antibodies, Protozoan / Q000097:blood; D003105:Colombia / Q000453:epidemiology; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D016780:Malaria, Vivax / Q000453:epidemiology / Q000276:immunology* / Q000635:transmission*; D008297:Male; D010966:Plasmodium vivax / Q000276:immunology*
D000913:Antibodies, Protozoan; D007106:Immune Sera