Biomedical subjects

W Takken

Publications and source records attributed to W Takken.

40 records · Page 3Linked to original sources

PubMed1989

Carbon dioxide and 1-octen-3-ol as mosquito attractants.

Interval suction traps were used to study the attractant effect of CO2 and 1-octen-3-ol on trap catches of mosquito populations at 2 different locations in Florida. There was no significant increase in the numbers of mosquitoes caught when the concentration of CO2 was increased from 200 to 1,000 cc/min. One-octen-3-ol used by itself attracted mosquitoes in numbers similar to CO2 released at 200 cc/min. One-octen-3-ol and CO2 acted synergistically in attracting significantly greater numbers of Aedes taeniorhynchus, Anopheles spp. and Wyeomyia mitchellii than either bait used singly, although the response of Culex spp. to this bait combination was less pronounced. Ceratopogonidae (Culicoides furens) and Tabanidae (Diachlorus ferrugatus, Tabanus nigrovittatus and Chrysops spp.) were also attracted to the combined bait.

Aedes↗

PubMed1988

Field studies on animal trypanosomiasis in Mozambique. I. Effectiveness of the prophylactic drugs isometamidium chloride and pyrithidium bromide.

The efficacy of the trypanocides Samorin and Prothidium to protect beef cattle in areas of different trypanosome challenge was studied in Muabsa, Mozambique during an 18 month period. The performance of two groups of 1.5- to 3-year old bulls was observed, the first group in an area of high tsetse density, the second in an area of low to medium tsetse density. Glossina morsitans and G. pallidipes were present and their respective densities were determined using standard fly rounds, a mobile electric screen and biconical traps. The trypanosome challenge was determined using parameters of tsetse density and infection rates; the trypanosome risk was determined by Berenil Indices in both groups of animals. The Berenil Indices in the two study areas were not significantly different despite a great difference in apparent densities of the tsetse flies. The period of protection afforded by Samorin and Prothidium was similar in both areas which would appear to indicate that the tsetse density had no apparent effect on the degree of challenge. Samorin gave a slightly better protection than Prothidium as shown by a lower frequency of infections as well as higher packed cell volumes. There was no difference in growth rates between the treatment groups and study areas during the entire study period. It was concluded that in the study area Samorin usage is preferable to that of Prothidium. Tsetse densities obtained from standard fly rounds were found unsatisfactory in assessing the challenge, possibly because this method does not sample all components of the population. The Berenil Index, however, was found to be a useful indicator of trypanosome risk and thus frequency of treatment required.

Animals↗

PubMedDate not supplied

Differential attractiveness of isolated humans to mosquitoes in Tanzania.

Individually occupied tents, modified for sampling mosquitoes, were used to assess the attractiveness of 3 humans for Anopheles gambiae Giles s.l., A. funestus Giles, Culex quinquefasciatus Say and Mansonia spp. in north-east Tanzania. Significant differences (P < 0.025) in attractiveness were observed for the first 3 species, whereas Mansonia did not show any preference. Because of the objective sampling method used, these results provide the first conclusive evidence that isolated people vary in attractiveness to mosquitoes.

Adult↗

PubMedDate not supplied

Susceptibility of Anopheles quadriannulatus Theobald (Diptera: Culicidae) to Plasmodium falciparum.

Anopheles quadriannulatus, the cattle-feeding member of the An. gambiae complex, was fed human blood which contained cultured gametocytes of Plasmodium falciparum, using a membrane feeding system. After 7 days, 33-80% of the mosquitoes that took a blood meal contained developing oocysts. In 7 out of 12 females sporozoites were found in the salivary glands 14 days after the infectious blood meal. Control groups of An. gambiae s.s. and An. stephensi became readily infected with > 90% developing oocysts. All of the An. gambiae dissected 14 days after the infectious blood meal had sporozoites in their salivary glands. The results demonstrate that An. quadriannulatus is susceptible to infections with P. falciparum.

Animals↗