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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In The Gambia, 760 children less than 10 years of age with Plasmodium falciparum malaria were treated with chloroquine (25 mg/kg) and followed-up 2 and 9 d after the start of treatment. 700 children (92.1%) completed the study. The level of in vivo resistance to chloroquine varied by area from 0.4% to 16.4%. Of the 28 children found to have chloroquine resistant malaria, none was ill when seen at the 9 d follow-up and only 3 (10.3%) required further treatment with alternative antimalarials because of persistent high levels of parasitaemia. However, the fact that 30.4% of the children who completed the study had chloroquine in their urine at presentation may have masked the true level of resistance and led to underestimation of the clinical significance of these findings. The blood film at day 2 did not usefully predict resistance. 67 isolates were tested in vitro for chloroquine sensitivity. The mean EC50 was 15.5 nmol/litre, an eight-fold decrease in sensitivity from that of isolates tested in 1982. 8 (11%) of the isolates had EC50s above the WHO reference value for sensitive isolates of 18.3 nmol/litre, with values ranging from 22 to 65 nmol/litre of culture medium. Gambian isolates were sensitive to quinine (mean EC50 = 49.6 nmol/litre).
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PMID:A national survey of the prevalence of chloroquine resistant Plasmodium falciparum malaria in The Gambia. 227 59

Vanuatu, which formerly was known as the New Hebrides, is an archipelago in the southwest Pacific Ocean with a tropical humid climate. The national health system and the state of health of the population generally are satisfactory. The main diseases of public-health importance are malaria and tuberculosis. Their epidemiology and control are discussed. An epidemic of Plasmodium falciparum malaria, which commenced in 1980, is described; this possibly can be explained by an increase in chloroquine-resistant P. falciparum over the same period. Other diseases also are reviewed. Many tropical diseases of great significance elsewhere are not of much significance in Vanuatu. Medical advice for visiting travellers is provided.
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PMID:Public-health epidemiology in Vanuatu. 240 24

Immunodominant T-cell antigenic sites can so dominate a response that their presence leads to high responsiveness and their absence to low responsiveness. Therefore, it is important to locate such sites for vaccine development. Factors that lead to immunodominance include features extrinsic to the structure of the site itself, such as the major histocompatibility complex (MHC) molecules of the host and the types of fragments produced by processing of the protein antigen before the T cell sees it. They also include factors intrinsic to the structure of the T-cell site, that determine a repertoire of potential immunodominant sites from which the extrinsic factors select a subset that will be immunodominant in a given individual. We have focused on one of these intrinsic factors, helical amphipathicity, that we have found to be a common feature among both helper and cytotoxic T-cell antigenic sites, suggesting that the same physical principles apply to sites seen in association with class I and class II MHC molecules. We have used this feature to locate immunodominant epitopes on the circumsporozoite protein of the Plasmodium falciparum malaria parasite and the envelope protein of the AIDS virus. Both helper and cytotoxic T-cell epitopes were identified. At least in the case of the helper T-cell sites, it was striking that the same sites in both the malaria and AIDS proteins studied that were immunodominant in the mouse were also immunodominant in the human, an indication that the same principles apply across species, and that the animal model will be useful for identifying sites to be used in vaccines for humans. These sites have been coupled with neutralizing antibody sites to produce artificial constructs that can elicit antibodies. It is hoped that the rational design of more complex versions of these artificial constructs will produce vaccines that are more effective than the natural pathogen proteins used in subunit vaccines, since such pathogen protein antigens have been selected through evolution to evade the immune system, not to optimize immunogenicity.
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PMID:Mechanisms of immunodominance in T-cell recognition, with applications to vaccine design. 247 31

A 39-year-old Japanese male engineer who stayed in Nigeria from August 17, 1987 through January 22, 1988, presented chloroquine-resistant Plasmodium falciparum malaria. He was taking oral chloroquine prophylactically. But he suffered from P. falciparum malaria in November, 1987 and early January, 1988. He was treated in Nigeria. After his return to Japan, he was admitted to our hospital with a fever of 39 degrees C on January 29, 1988. The peripheral blood smear on admission showed the presence of ring form P. falciparum. He was diagnosed as recrudescence of P. falciparum malaria. Laboratory examination revealed severe thrombocytopenia and biologic false-positive serological tests of syphilis. The level of 50% inhibitory concentration was 0.44 nmol/ml by in vitro chloroquine sensitivity test of the strain of P. falciparum obtained from this patient. Clinically, chloroquine was not effective. The patient was treated with intravenous quinine dihydrochloride followed by sulfadoxine/pyrimethamine tablets and recovered completely. As far as we know through our survey this patient was the first case of chloroquine-resistant P. falciparum malaria brought to Japan from Nigeria.
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PMID:[Chloroquine-resistant Plasmodium falciparum malaria confirmed by semi-micro sensitivity test for chloroquine seen in a person returned from Nigeria to Japan]. 250 25

Numerical alterations of circulating lymphocytes were investigated in 37 Brazilian patients with uncomplicated Plasmodium falciparum malaria and in a group of 15 healthy controls. The number of CD4+ T helper/inducer cells was significantly lower in patients than controls, whereas absolute numbers of CD8+ suppressor/cytotoxic T cells did not differ between the groups. TNF and neopterin levels were markedly increased in the plasma of patients and remained slightly elevated after chemotherapy with clindamycin. Neopterin, but not TNF levels, were significantly correlated with parasitaemia. TNF was inversely related to monocyte counts. Interferon gamma could not be detected in the plasma of control subjects and was observed in only one patient. We conclude that in uncomplicated falciparum malaria the distribution of phenotypes of circulating lymphocytes are altered slightly and that the high plasma levels of TNF and neopterin indicate excessive release of these molecules by activated macrophages and the activation of cellular immune mechanisms during the infection.
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PMID:Immunological alterations in uncomplicated Plasmodium falciparum malaria. Relationship between parasitaemia and indicators of macrophage activation. 257 70

Forty cases of imported malaria (1978 to 1988) are reviewed and management principles are discussed. All 15 cases of Plasmodium falciparum malaria were acquired in Africa, 5 of which were probably chloroquine-resistant. Most cases of Plasmodium vivax (80%) were acquired on the Indian subcontinent, including 2 cases of congenital malaria. Six children developed P. falciparum malaria despite chemoprophylaxis. All children had a history of fever, usually with other influenza-like symptoms. Two-thirds had splenomegaly, and one-third were afebrile on admission. Thrombocytopenia (70%) and anemia (70%) were often present. Forty-five percent received previous wrong diagnoses and treatments. Quinine or quinidine with either Fansidar or clindamycin were used to treat P. falciparum malaria. Clindamycin may be more effective if given for 7 instead of 3 days. There were no deaths or residual complications. As the prevalence and severity of drug-resistant P. falciparum spreads, prophylaxis and treatment choices become more difficult. Diagnosis requires a travel history and a high index of suspicion.
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PMID:Review of 40 children with imported malaria. 259 48

A 27-year-old man was admitted to the hospital with a seven-day history of fever, nausea, vomiting, diarrhea, and pruritic rash. He was not diagnosed as having malaria until a history was obtained of Plasmodium falciparum malaria two years previous to this admission, and a review of the peripheral blood smear confirmed the diagnosis. The patient was admitted for inpatient therapy. He responded well and was discharged on the fourth hospital day to complete the remainder of the therapy as an outpatient. This case is a somewhat atypical presentation and reemphasizes several key points in the prophylaxis, diagnosis, and treatment of malaria.
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PMID:It's not a viral syndrome, it's malaria. 264 81

In countries where malaria is not endemic the diagnosis of the disease is often delayed or overlooked, particularly if the clinical symptoms are atypical and if automated cell analyzers are used instead of blood films for leucocyte differential counts. We report 2 cases of severe Plasmodium falciparum malaria with unusual clinical features: a 46-year-old man with an exceptionally long incubation period and a 22-year-old woman with presenting symptoms suggesting viral hepatitis. In both cases the diagnosis of malaria was unexpectedly made by observant laboratory technicians examining stained blood films for differential counts.
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PMID:Diagnosis of falciparum malaria delayed by long incubation period and misleading presenting symptoms: life-saving role of manual leucocyte differential count. 265 17

During the past decade the incidence of Plasmodium falciparum malaria in the United States has increased 10-fold. Treatment may be delayed because the therapy recommended for severe or complicated disease, intravenous quinine dihydrochloride, is available only from the Centers for Disease Control. We studied 17 patients who were treated for severe or complicated P. falciparum malaria in the United States between 1985 and 1987. Five patients were treated with a continuous infusion of quinidine gluconate, 10 with an exchange transfusion in addition to the continuous infusion of quinidine gluconate, and 2 with intermittently administered intravenous quinine dihydrochloride and an exchange transfusion. All 16 patients with P. falciparum malaria (1 patient had P. vivax malaria) had hyperparasitemia at the time of diagnosis (6 to 54 percent of the erythrocytes infected; median, 13 percent). Three patients with marked hyperparasitemia (54, 38, and 30 percent) and multiple other indicators of a poor prognosis, including advanced age, died. The 13 patients who completed their courses of quinidine with or without exchange transfusion had a parasitemia level of 1.1 percent or less 28 to 72 hours (mean, 44.4 hours) after the start of therapy. Side effects of quinidine treatment were observed in only two patients, one of whom had a serum quinidine concentration above the toxic level. We conclude that the continuous infusion of quinidine gluconate is well tolerated alone and with exchange transfusion and is effective in the treatment of severe and complicated malaria.
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PMID:Treatment of severe malaria in the United States with a continuous infusion of quinidine gluconate and exchange transfusion. 240 49

Spreading from 2 countries in 1978 to at least 29 in 1988, chloroquine-resistant Plasmodium falciparum malaria has become a significant concern for travelers to Africa. The spread of chloroquine resistance has been documented by sporadic case reports and by isolated population surveys, which do not always completely reflect the risk of infection for travelers using chloroquine prophylaxis. Surveillance of Peace Corps volunteers in West Africa indicates that as of January 1, 1989, P falciparum malaria resistant to chloroquine prophylaxis had spread as far west as Liberia, with only limited risk in Sierra Leone and to the north and west of Sierra Leone. Monitoring the incidence of malaria in highly exposed expatriates provides early warning of the emergence of drug-resistant P falciparum malaria and can provide data to guide recommendations for travelers.
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PMID:The spread of chloroquine-resistant malaria in Africa. Implications for travelers. 266 66


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