Mosquito Vectorial Capacity Research Articles

Targeting Plasmodium ligands on mosquito salivary glands and midgut with a phage display peptide library.

Despite vast efforts and expenditures in the past few decades, malaria continues to kill millions of persons every year, and new approaches for disease control are urgently needed. To complete its life cycle in the mosquito, Plasmodium, the causative agent of malaria, has to traverse the epithelia of the midgut and salivary glands. Although strong circumstantial evidence indicates that parasite interactions with the two organs are specific, hardly any information is available about the interacting molecules. By use of a phage display library, we identified a 12-aa peptide--salivary gland and midgut peptide 1 (SM1)--that binds to the distal lobes of the salivary gland and to the luminal side of the midgut epithelium, but not to the midgut surface facing the hemolymph or to ovaries. The coincidence of the tissues with which parasites and the SM1 peptide interact suggested that the parasite and peptide recognize the same surface ligand. In support of this hypothesis, the SM1 peptide strongly inhibited Plasmodium invasion of salivary gland and midgut epithelia. These experiments suggest a new strategy for the genetic manipulation of mosquito vectorial capacity.

Variations in Malaria Transmission Rates are not Related to Anopheline Survivorship per Feeding Cycle

Anopheline survivorship, vectorial capacity, and mosquito infection probability estimates from mosquito infection rates were determined 4 times in 1 year in a Papua New Guinea village. Estimates of survivorship over the length of the extrinsic incubation period differed significantly during the year. However, survivorship per feeding cycle, individual mosquito vectorial capacity, and mosquito infection probability did not vary significantly. Estimates of these parameters were then compared to estimates of survivorship, individual vectorial capacity, and mosquito infection probability in mosquito populations in other villages in the study area. Since survivorship per feeding cycle did not vary significantly among the mosquito populations in these villages, changes in malaria transmission potential can be better gauged from estimates of survivorship over the length of the extrinsic incubation period. However, as measurements of relative inoculation rates are easier to perform and have been related to parasite prevalences in children in this area, estimates of inoculation rates are a preferred option for estimating malaria transmission in the Madang area of Papua New Guinea.

PROGNOSIS FOR INTERRUPTION OF MALARIA TRANSMISSION THROUGH ASSESSMENT OF THE MOSQUITO'S VECTORIAL CAPACITY.

Prognosis for Interruption of Malaria Transmission Through Assessment of the Mosquito's Vectorial Capacity