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Biomedical subjects

C F Curtis

Publications and source records attributed to C F Curtis.

At least 127 records · Page 7Linked to original sources
PubMed1984

Two cases of falciparum malaria acquired in Britain.

Two cases of severe falciparum malaria contracted in the United Kingdom occurred in residents of Sussex, living 10 and 15 km from Gatwick airport. One patient was the landlord of a public house much frequented by aircrew, and the other was the wife of a worker at the airport, who travelled close to the public house on the probable date she contracted her infection. Transmission was most probably due to the bite of an infected imported tropical anopheline mosquito transported in a vehicle from the aircraft to the site of transmission during the very hot and humid weather of July 1983. Prevention of further cases depends on increased diligence in "blocks-away" destruction of insects in aircraft flying from endemic areas, but there is a need for more study of acceptable alternative ways of delivering the insecticide. This "airport malaria" is well recognised on the continent, and physicians should be aware of its existence in those who have not travelled abroad but live or work near international airports.

Aircraft↗
PubMed1984

Genetic linkage between malathion and dieldrin resistance in Anopheles arabiensis.

A strain of Anopheles arabiensis resistant to both malathion and dieldrin was crossed and backcrossed to a susceptible strain. The progeny were tested on each insecticide in turn. Less than 50% mortality in the second insecticide exposure among the backcross progeny indicated linkage between the resistance genes. In a backcross of A. gambiae X A. arabiensis hybrids a recombination rate of 7.5% was observed. A Y-translocation strain of A. arabiensis showed less than 2.8% recombination between the resistance genes. It is impossible to confirm the genotype of apparent recombinants using existing stocks, but the two resistance mechanisms are biochemically distinguishable. If the two genes are very closely linked, linkage disequilibrium could influence the consequences of switching to malathion spraying after dieldrin resistance has evolved.

Animals↗
PubMed1982

Entomological studies of on-site sanitation systems in Botswana and Tanzania.

A survey of various types of on-site sanitation systems in Dar es Salaam and Gaborone showed that many were infested with larvae of flies (mainly Chrysomya putoria) and Culex mosquitoes (mainly Cx quinquefasciatus). The mosquitoes only occurred where the pit contents had a free water surface but the flies were found in both wet and scum covered pits. The infestation rate was much higher where the latrine vent pipe had no insect-proof screen. Exit traps were placed on the vent pipes and drop holes to determine by which route the emerging flies and mosquitoes left the pit. Provided that the latrine door was kept closed (thus producing a relatively greater light intensity in the vent pipe), over 90% of flies went up the vent pipe. In most cases about 80% of Cx quinquefasciatus did the same, but in two pits very dense mosquito infestations were found and over 1000 mosquitoes per night were caught leaving the pit through the drop hole. In such cases traps on the drop holes might be used as a semi-permanent control method. Entry traps were placed on the vent pipe and drop hole to catch females attempting to enter to lay eggs. All the flies and the majority of the mosquitoes caught were trying to enter the vent pipe which indicates that odour from this source is attractive to these insects. Various possible modifications to the methods of using latrines to minimize associated insect problems are discussed; the simplest and most important is to ensure that all vent pipes are effectively screened.

Animals↗
PubMed1982

Tests for the existence of genetic variability in the tendency of Anopheles culicifacies species B to rest in houses and to bite man.

Experiments were carried out in Sri Lanka on the malaria vector Anopheles culicifacies using the mark-release-recapture technique. Collections were made in cattle-baited huts fitted with exit traps, and in nightbiting catches on human subjects. The same individual mosquitos were caught biting cattle and man on different occasions and the numbers caught demonstrated an overall preference for the cattle. The mean interval between successive blood meals in the field was estimated to be 2.3 days.Following blood-feeding on a cow in a hut, A. culicifacies were found to rest in the hut for 1 or 2 days, whereas A. subpictus and A. varuna generally exited on the night of feeding or on the following night. The same individual A. culicifacies were recorded resting in a hut for 1 or 2 days on different occasions. The apparent absence of genetic variability in host choice or indoor resting behaviour is considered encouraging for the prospects of control of malaria transmitted by A. culicifacies.

Animals↗
PubMed1981

Tests of susceptibility of Liberian Culex quinquefasciatus to Tanzanian Wuchereria bancrofti.

Culex quinquefasciatus strains of Liberian and Tanzanian origin were fed on Tanzanian donors with Wuchereria bancrofti microfilaraemias. 11 to 17 days later the mosquitoes were dissected and scored for the presence and numbers of immature and mature filarial larvae. In one experiment a significantly lower susceptibility was found in a Liberian compared with a Tanzanian strain, but in the other cases there was no significant difference. The susceptibility of the Liberian strains was higher than in published data on the same mosquito strains tested with Liberian W. bancrofti. It is doubtful whether the Liberian mosquito strains could be a useful source of genes for the construction of a refractory strain with which to replace an East African vector population.

Animals↗