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

Twelve children, 2 to 15 years of age, with falciparum malaria (parasitaemia 4,500 to 170,000/mm3) have taken 24 mg/kg body weight of halofantrine hydrochloride (Halfan) per os in three divided doses given within 12 hours. The symptomatology improved after 24 to 48 hours, with no more fever 5 to 90 hours after treatment and with a decrease of splenomegaly in 80% of the cases. The parasitic clearance was obtained after 24 to 60 hours. The haematocrit started raising again in 58% of the cases. Halofantrine hydrochloride is an efficient antimalarial drug in semi-immune patients. It is well tolerated and well accepted, thus representing an alternative for the cure of chloroquine-resistant falciparum malaria.
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PMID:[Halofantrine in the treatment of malaria. Clinical trial in a semi-rural zone of Cameroon]. 267 Feb 89

From April 1988 to March 1989, 903 randomly chosen children were examined in the Maternal and Child Health Department of the Central Hospital of Yaounde (Cameroon) to determine the importance of malaria in general morbidity, the relation between clinical symptoms and parasite densities and to have some idea of the population's self-medication behaviour. We adopted the criteria formerly worked out in West Africa, i.e. a fever (t degree higher than 37.9 degrees C) without any obvious febrile disease and a parasitaemia higher than 10,000 red blood cells parasitized by Plasmodium falciparum/mm3. In the sample under investigation, the average plasmodic index was 32.5%, mainly P. falciparum (98% of all infections), while 120 children had a parasitaemia higher than the critical level of 10,000 par./mm3 (i.e. 13.3% of the whole sample and 40.1% of Plasmodium carriers. 559 of the 903 children were actually febrile and among them 94 had a so-called malaria crisis (i.e. 16.8% of fevers and 10.4% of all consultations). It was confirmed that not one single clinical symptom is pathognomic for malaria crisis but fever, splenomegaly and anaemia seemed to occur more frequently among sick children. It also appeared that the proportion of children with fever increased as their parasitaemia exceeded the critical threshold of 10,000 par./mm3, while splenomegaly tends to drop with very high parasitaemia. Faced with fever as a clinical symptom, self-medication is a common behaviour (65% of people interviewed admitted such practice); it is mainly based upon chloroquine tablet ingestion but at a subcurative dosage. Such self-medication could induce an underestimation of malaria morbidity from clinical statistics and, on the other hand, a growing drug pressure, which could play a role in the current spread of P. falciparum chloroquine resistant strains in Central Africa and elsewhere in sub-saharan regions.
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PMID:[Malaria morbidity at the Center for Maternal and Child Prevention of the Central Hospital, Yaounde, Cameroon. Observations of a sample of 903 infants]. 269 23

Specific malaria and total IgM antibody responses were measured in 2 linguistically distinct coastal Papua New Guinean populations living in the same endemic malarious area, but exhibiting different adult female spleen rates (51% and 30%), in order to establish whether the higher spleen rates in the former group were due to hyper-reactive malarious splenomegaly (HMS). Malaria parasite rates were comparable, and geometric mean titres of IgG malaria antibody were the same, in both groups, indicating comparable exposure to malaria. A higher mean total IgM was observed in the high spleen (HS) rate group (6.07 g/litre, compared with 4.62 g/litre), a higher proportion was seropositive for IgM antibody to Plasmodium falciparum (63% compared with 54%), and HMS was found rather more frequently (4.7% compared with 2.6%). In both groups total IgM concentrations increased significantly with rising parity, and the mean level of 5.27 g/litre in young nulliparous women from the HS group suggested that IgM levels in this group at least were elevated from childhood. In both groups a rise in total IgM was associated with higher P. falciparum IgM geometric mean titres of antibody activity, a fall in parasite rates (HS group: 30% to 15%, P = 0.02; LS group: 24% to 0%, P = 0.034), and higher spleen rates (HS group: 38% to 65%, P = 0.001; LS group: 20% to 67%, P = 0.00012). It is concluded that the difference in spleen rates between the 2 groups was the result of differing degrees of acquired immunity to malaria, probably due to genetic differences in immune responses.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Two populations of women with high and low spleen rates living in the same area of Madang, Papua New Guinea, demonstrate different immune responses to malaria. 269 94

Hyperreactive malarious splenomegaly (HMS) represents an abnormal immune response to recurrent malaria, characterized by excessive production of both IgM and IgG antibodies. It has both a racial and a familial distribution in various parts of the world. Immune responses to many foreign antigens, including those of malaria, are under genetic control of the major histocompatibility locus (MHC), through the influence of HLA antigens on regulatory T-lymphocyte activity. It is therefore likely that this region also contains the genetic determinants for HMS, which would be reflected in associations between HMS and particular HLA antigens or haplotypes. Genetic studies of the Watut people of Papua New Guinea have not shown any association between HMS and a wide range of red cell and serum polymorphisms. However, HMS in this group is associated with the class II HLA antigen DR2, and with high levels of HLA heterozygosity. Formal genetic analysis of family data also points to a sex-linked gene as a further determinant of overresponsiveness to malaria in the Anga. These findings suggest that more than one genetic system may be involved in the development of HMS, and that the combined effects of several genetic determinants may be responsible for the extraordinarily high frequency of HMS found in the Upper Watut Valley.
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PMID:The genetic basis of hyperreactive malarious splenomegaly. 269 22

Hyperreactive malarious splenomegaly (HMS) represents an abnormal immune response to recurrent malarial infection. In the Upper Watut Valley of Papua New Guinea, where over 80% of adult inhabitants are known to develop the disease, human leucocyte antigen (HLA) studies have demonstrated an association between the antigen DR2 and gross splenomegaly. To test the hypothesis that the magnitude of the individual immune response to malaria is also influenced by the number of different HLA antigens present, we have studied the correlation of the level of observed heterozygosity at HLA-A, -B, -C and -DR loci with the degree of splenomegaly in adult Watut subjects. Heterozygosity per se provides additional antigens for the formation of complexes between HLA and foreign antigenic epitopes, considered crucial to mounting an immune response. Multiply heterozygous individuals were found to exhibit more intense immune responses to recurrent malarial infections than did individuals with low multiple-locus heterozygosity. On the basis of the analysis presented here, we suggest that the degree of immune response to malaria is also influenced by the level of HLA heterozygosity, although the exact mechanisms remain unclear.
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PMID:HLA heterozygosity and hyperreactive malarious splenomegaly in the Upper Watut Valley of Papua New Guinea. 269 23

The Malaria Research Unit of the Madagascar Pasteur Institute and the local health authorities carried out a study in the Sainte Marie Island in August 1988. Epidemiological results were in agreement with those previously reported in areas of endemic malaria. Parasite and splenomegaly rates were 34.6 and 35.9% respectively, by both active and passive cases detection. Analysis of parasite densities and clinical symptoms in the various age groups demonstrates that protective immunity is absent in infants and young children, and appears by the age of 2 to 9 years. An in vivo study of the sensitivity of Plasmodium falciparum to chloroquine was conducted in 41 patients. 39% of the infections were normally sensible (S) to WHO standard therapy (25 mg chloroquine/kg in 3 days), while 32% of the patients presented with a thick blood smear negative by D7, but positive by D14 (S/R1). Parasite resistance was observed in 29% of the infections: in 10% at the R1 level, and in 19% at the R2 level. Frequency and level of resistance to chloroquine are higher than those we observed in the East Coast in 1983 and 1985. However, chloroquine consistently achieves a high reduction in parasite densities and is still clinically active.
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PMID:[Malaria in Ile de Sainte Marie in 1988. Epidemiological approach. Chloroquine sensitivity of Plasmodium falciparum]. 269 21

We studied 521 serum samples collected in 1987-88 in the Highland Plateaux and the East coast of Madagascar, two areas presenting different levels of malaria endemicity. Total anti-Plasmodium falciparum antibodies were investigated by an indirect immunofluorescence assay (IFA). Antibodies directed to the ring-infected erythrocyte surface antigen (RESA) were investigated by a modified IFA (MIFA). Results were analysed in regards to malariological parameters (parasite and splenomegaly rates) collected simultaneously. IFA appears as a good epidemiological tool as it closely parallels the classical malariological parameters. In selected studies, the presence of P. falciparum parasites in blood was less frequent in individuals presenting with anti-RESA antibody, as detected by MIFA, than in the other individuals were consistently lower in subjects with anti-RESA antibody than in others.
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PMID:[Antimalarial serology in 1987-1988 in the Highland Plateaux, the East coast and the South of Madagascar]. 269 22

In 1988, the Malaria Research Unit of the Madagascar Pasteur Institute settled an out-patients clinic in Manarintsoa, a village of the Highland Plateaux where epidemic malaria appeared recently. 2776 consultants presented between January and June. In addition, the 200 schoolchildren were examined thrice. For each individual, clinical examination and thick and thin blood smears were performed. In the out-patients, parasite rates were above 50% each month and in each age group; the mean parasite rate being 74%. Splenomegaly rates were above 60% in individuals less than 15 years of age, and around 20% in adults. In schoolchildren, parasite and splenomegaly rates are consistently above 50%. Gametocyte indexes were 7.5% and 7% in May and October, respectively. Plasmodium falciparum is the most encountered species (in 85% of the cases), but P. vivax and P. ovale are also present. P. malariae is very rare. Early diagnosis and adequate therapy were very effective against mortality. During the high transmission time, monthly mortality rates varied from 12% before our arrival to 0.66% after. The number of malaria attacks was estimated at 2 per man and per year. In this area of unstable malaria, presence of fever appears to be of poor predictive value of the malaria infection. Systematic chloroquine therapy of fevers would be adapted to only 43% of the cases.
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PMID:[Malaria in 1988 in a village of the Malagasy Highland Plateaux. Epidemiological findings]. 269 26

The effects of three separate antimalarial prophylactic regimens (proguanil, sulfisoxazole, and proguanil plus sulfisoxazole) and of vitamins in a control group were compared in a study population of 380 children living in a malaria endemic area along the Thai-Burmese border. The subjects, aged 5-16 years, were matched for age, weight, and presence of splenomegaly, then randomly assigned to one of the four groups. All medications were administered daily by the investigators and malaria smears were performed on a weekly basis. Among 99 subjects taking proguanil plus sulfisoxazole for a total of 1464 man-weeks, there was only one case of falciparum and no vivax malaria. Statistically, this regimen proved superior to each of the other groups against both Plasmodium falciparum and P. vivax. The data show that proguanil alone, as a causal or suppressive prophylatic, has poor efficacy against P. falciparum. Side-effects were infrequent and generally mild, except for two subjects whose sulfisoxazole prophylaxis was discontinued because of urticarial rash.
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PMID:Malaria prophylaxis with proguanil and sulfisoxazole in children living in a malaria endemic area. 270 27

The level of resistance to infection in inbred mice with the murine malaria species Plasmodium chabaudi AS is genetically determined. Resistant C57BL/6, which are able to eliminate the parasite by 4 weeks, develop marked splenomegaly and survive the infection. Susceptible A/J mice, which succumb to infection (mean survival time = 10 days), develop only minimal splenomegaly. In order to determine if gross differences in the organization, number, and type of spleen cells are related to the outcome of infection with P. chabaudi AS, the development of splenomegaly was examined by enzyme and immunohistochemical methods during the first week after infection. Cryostat sections of spleens removed from normal animals of both strains and at 4 and 7 days after intraperitoneal infection with 10(6) parasitized erythrocytes were stained for enzyme (acid phosphatase and nonspecific esterase) and immunohistochemistry with conventional monoclonal antibodies against T cells, B cells, and macrophages as well as with novel rat anti-mouse monoclonal antibodies which define discrete subpopulations of macrophages in the mouse spleen. The livers of normal and infected animals of each strain were also examined. The results of this study demonstrate (1) differences between normal, uninfected B6 and A/J mice in the organization and number of one subpopulation of macrophages in the spleen, the marginal metallophilic macrophages, and (2) marked histological changes in the spleen and liver during the course of infection in both resistant C57BL/6 and susceptible A/J mice. These changes include depletion of cells from the marginal zone of the spleen which, in the case of the marginal metallophilic macrophages, appears to be more severe in susceptible A/J mice.
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PMID:Histological changes in the spleen and liver of C57BL/6 and A/J mice during Plasmodium chabaudi AS infection. 278 81


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