The American journal of tropical medicine and hygiene
-
Am. J. Trop. Med. Hyg. · Jul 1993
Comparative StudyRegression of hepatic lesions after treatment of Schistosoma mansoni or Schistosoma japonicum infection in mice: a comparative study.
Experimental infections with Schistosoma mansoni and S. japonicum differ in several aspects and post-treatment resorption of fibrosis might be one of them. To investigate this point, mice infected with each of these schistosome species were treated with praziquantel and the evolution of hepatic lesions was sequentially followed for five months. Parasitologic data showing destruction of worms and eggs and biochemical findings of progressively decreased collagen concentration after cure indicated that the lesions caused by S. mansoni and S. japonicum involuted in a similar fashion following chemotherapy. The time sequence of the histologic changes indicative of decreasing inflammation and progressive matrix degradation and resorption was also similar in both cases.
-
Am. J. Trop. Med. Hyg. · Feb 1993
Should yellow fever vaccine be included in the expanded program of immunization in Africa? A cost-effectiveness analysis for Nigeria.
The cost-effectiveness of preventive yellow fever vaccination versus emergency mass vaccination campaigns for epidemic control remains a matter of controversy. Until recently, Nigeria and other anglophone countries in West Africa most severely afflicted by yellow fever epidemics have followed a policy of emergency control. The effects of including yellow fever 17D vaccine in the Expanded Program of Immunization (EPI) on the immune status of the Nigerian population was studied under conservative assumptions of vaccine coverage and efficacy. ⋯ In large epidemics, such as that occurring over successive years (1986-1991) in Nigeria, cost-effectiveness of the EPI exceeded that of emergency control. The EPI may also play an important role in the prevention of endemic yellow fever. Assuming annual rates of endemic yellow fever predicted by serologic surveys, routine vaccination would significantly reduce morbidity and mortality at cost-effectiveness ratios within the range for other diseases prevented by the EPI, including polio, tetanus, and diphtheria.(ABSTRACT TRUNCATED AT 400 WORDS)
-
Am. J. Trop. Med. Hyg. · Mar 1992
Community participation in malaria surveillance and treatment. I. The Volunteer Collaborator Network of Guatemala.
The Volunteer Collaborator Networks (VCNs) of Latin America are one of the oldest and most successful examples of community participation in malaria control. They are made up of unpaid community volunteers, known as Volunteer Collaborators, who are selected by their neighbors and are trained and supervised by a member of the National Malaria Service (NMS). When a febrile patient visits the home of a Volunteer Collaborator, the volunteer worker takes a thick blood smear, completes a patient report form, and administers a presumptive treatment for malaria. ⋯ With modifications tailored to meet the objectives of a malaria control program and the local epidemiologic setting, the VCN can serve as an excellent model for community participation in malaria case detection and treatment in other regions of the world. In particular, in areas where the primary goal of the malaria program is to prevent mortality and morbidity through the provision of readily accessible, appropriate drug therapy, VCNs are an attractive alternative to self-medication and an effective adjunct to treatment of malaria at health posts which are often located at a considerable distance from the patient's village. Experience gained with this system can be valuable in developing approaches to community involvement in other efforts to improve the health of villagers in developing countries.
-
Am. J. Trop. Med. Hyg. · Oct 1991
Central nervous system involvement during infection by Phlebovirus toscana of residents in natural foci in central Italy (1977-1988).
Central nervous system (CNS) involvement was detected during infection caused by the sand fly-transmitted Phlebovirus Toscana. One hundred fifty-five cases of Toscana virus-associated meningitis or meningoencephalitis were identified in a survey that lasted ten years, conducted in two regions of central Italy. Diagnosis was performed by different serologic tests. ⋯ A few strains of Toscana virus were isolated from the cerebrospinal fluid of seropositive patients. Toscana virus-associated CNS disease occurred during the summer, reaching a peak value in August, when the maximum activity of the sand fly vector occurs and virus isolates are obtained in their natural foci. The results suggest that Toscana virus should be considered as a possible cause of CNS disease in Mediterranean countries where sand flies of the genus Phlebotomus are known to be present.
-
Am. J. Trop. Med. Hyg. · Oct 1991
Halofantrine for the treatment of mefloquine chemoprophylaxis failures in Plasmodium falciparum infections.
Thai soldiers who became slide-positive for malaria while receiving mefloquine chemoprophylaxis were treated with halofantrine to study its efficacy against mefloquine-resistant falciparum malaria. Thirty-two patients received three doses of 500 mg (1,500 mg total) of halofantrine at six-hr intervals, and were then observed for four weeks. Parasite recrudescence following treatment (median 21 days) occurred in seven of 23 patients (30%) who had mefloquine serum concentrations indicative of regular prophylaxis (greater than 500 ng/ml). ⋯ The halofantrine serum concentrations were higher in patients cured by halofantrine than in patients with drug failure, but this was not statistically significant. Patients who were cured by halofantrine had parasites that were more sensitive in in vitro testing to mefloquine (mean [inhibitory concentration] IC50 = 12.5 ng/ml) than in patients whose parasitemias recrudesced (mean IC50 = 23.8 ng/ml) (P less than 0.01, by Wilcoxon rank sum test). These observations suggest that the current formulation and regimen of halofantrine are not optimal for the treatment of multiple drug-resistant falciparum malaria from Thailand.