The American journal of tropical medicine and hygiene
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Am. J. Trop. Med. Hyg. · Nov 1990
Plasmodium falciparum-infected Anopheles stephensi inconsistently transmit malaria to humans.
Malaria was transmitted to only 5 of 10 volunteers bitten by 1-2 Anopheles stephensi carrying sporozoites of the 3D7 clone of the NF54 strain of Plasmodium falciparum in their salivary glands. Parasites were detectable by culture in blood taken 7-10 days following exposure and by thick blood film 14-16.5 days after exposure. Infectivity did not correlate with the numbers of sporozoites in the salivary glands.
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Am. J. Trop. Med. Hyg. · Aug 1990
Chagas' disease: lymphoma growth in rabbits treated with Benznidazole.
Administration of the trypanocidal drug, Benznidazole (N-benzyl-2-nitro-imidazoleacetamide) to Trypanosoma cruzi-infected rabbits did not arrest the destructive Chagas' heart myocarditis. A typical feature of lymphocytic infiltrates associated with non-parasitized heart cell lysis was present in both treated and untreated groups of rabbits. Benznidazole-treated rabbits had their survival time shortened, probably as a consequence of Chagas' heart disease and of the development of lymphomas. ⋯ Testicular atrophy was observed in 2 out of 10 nitroarene-treated rabbits. Benznidazole administration caused severe cell-mediated immunosuppression in T. cruzi-infected and BCG-immunized rabbits. Specific antibodies against the parasite and an unrelated antigen were detected in high levels, regardless of the nitroarene administration.
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Am. J. Trop. Med. Hyg. · May 1989
Characterization of five new phleboviruses recently isolated from sand flies in tropical America.
Five new phlebotomus fever virus serotypes (Bunyaviridae: Phlebovirus) are described. These viruses, designated Ambe, Ixcanal, Mariquita, Armero, and Durania, were isolated from sand flies (Diptera: Psychodidae) collected in Brazil, Colombia, and Guatemala. Two of the agents were recovered from pools of male sand flies. The new viruses are antigenically related to other members of the phlebotomus fever serogroup by immunofluorescence, but are distinct from the other 39 members of this serogroup by plaque reduction neutralization test.
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Am. J. Trop. Med. Hyg. · Nov 1988
Epidemiology of antimicrobial resistant cholera in Kenya and East Africa.
Strains of Vibrio cholerae O1, El Tor resistant to multiple antimicrobial agents, were isolated in Kenya between 1982 and 1985. Strains of serotype Ogawa were resistant to tetracycline, ampicillin, and trimethoprim/sulfamethoxazole. Resistance was mediated in all instances by a plasmid ca 100 mD of incompatibility group C. ⋯ This plasmid differed from plasmids in resistant V. cholerae O1 strains isolated in Tanzania, Nigeria, and Bangladesh. On Southern blot analysis of restriction endonuclease digests of chromosomal DNA using DNA probes there were no apparent differences between Kenyan V. cholerae O1 strains isolated before and after emergence of antibiotic resistance; however, a majority of El Tor strains isolated in other geographic areas had the same Southern blot pattern. Our data document the apparent endemicity of multiply antimicrobial resistant V. cholerae O1 strains in Kenya, and the persistence of a single unique resistance plasmid among isolates of serotype Ogawa.
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Am. J. Trop. Med. Hyg. · Oct 1988
California serogroup virus infections in Wisconsin domestic animals.
A serologic survey and experimental virus transmission studies were done to assess the role of domestic animals as amplifier hosts of La Crosse (LACV) and Jamestown Canyon (JCV) viruses. Serum from 319 cows, 88 dogs, 122 equines, 47 swine, 10 goats, and 4 cats were tested for neutralizing antibody to LACV, JCV, trivittatus (TVTV), and snowshoe hare (SSHV) viruses. Antibody prevalences of LACV, TVTV, and SSHV were less than 10% in all species. ⋯ None developed detectable viremias, although greater than or equal to 4-fold rises in antibody titers developed in 60% of the ponies, 17% of the calves, 50% of the dogs, and 1 of 2 ewes. None of the pigs developed corresponding rises in antibody titers. We conclude that juvenile and adult animals of the species tested are not efficient amplifier hosts of LACV or JCV, but may be useful sentinels of local virus transmission.