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

Although malaria and hookworm disease appear to be on the decline, another dreaded parasitic disease-schistosomiasis-is on the increase. Presently, the number of infected individuals with schistosomes is estimated to be 250 million, and even though only a small proportion of them become sick and die, schistosomiasis remains a medical problem of great significance. The high incidence of infection of man with Schistosoma mansoni, Schistosoma japonicum or Schistosoma haematobium, as well as the chronic debilitating diseases produced, places these organisms among the world's most important infectious agents. This paper discusses the nature of immunity to schistosomiasis.
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PMID:Immunobiology of schistosomiasis. 11 64

The assessment of morbidity caused by chronic parasitic infections in the populations of endemic areas has remained difficult and controversial. Contributing to this predicament is the frequent occurrence of multiple infections with agents that can cause a wide range of clinical manifestations, from the frequent symptomless carrier state to overt disease with more or less specific clinical manifestations. In the interpretation of the complex morbidity patterns found in rural populations of tropical countries, it is often difficult to make a clear determination of cause and effect. The situations is further complicated by the low degree of pathognomicity of the clinical manifestations of even the advanced stages of certain parasitic diseases. The paper gives examples that illustrate the interaction between endemic malaria and schistosomiasis as important causes of hepatosplenomegaly. Also shown in the paper are the inter-relationships between the nutritional status and the number of multiple infections with parasites found in African villages as well as the association between habitual coca leaf chewing, malnutrition and hookworm disease in a Peruvian community of mixed ethnic origin. The paper describes micro-epidemiological features of poly-parasitism by comparing the prevalence and intensity of infection with Onchocerca volvulus, Schistosoma mansoni and S; haematobium between sub-groups in the village population who have different sources of domestic water supply. In two African villages with endemic schistosomiasis where mass treatment will be administered, only 25% of the residents with parasitologically confirmed S. haematobium infection and 12% of those with S. mansoni had single infection; the remaining majority had at least one additional patent parasitic infection of public health importance.
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PMID:Epidemiology of poly-parasitism. IV. Combined effects on the state of health. 72 41

1. The effect on anaemia in mice given Plasmodium berghei yoelii 3 and 5 weeks after exposure to Schistosoma mansoni cercariae, was investigated. 2. Haematological criteria (PCV and haemoglobin levels), reticulocytosis, parasitaemia and splenomegaly were used as indices. 3. Anaemia was severe in the animals given P. b. yoelii and in those with mixed infection (P. b: yoelii plus S. mansoni). Malaria was found to dominate the picture until the clearance of the parasitaemia. The effect of the interaction between the diseases on the anaemia was nil. 4. Toward the end of the experiment, moderate splenomegaly was observed in the mice with mixed infection.
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PMID:Anaemia in mice with concomitant Schistosoma mansoni and Plasmodium berghei yoelii infection. 109 78

Experiences with population-based chemotherapy and other methods for the control of schistosomiasis mansoni in two subsaharan foci are described. In the forest area of Maniema (Zaire), intense transmission of Schistosoma mansoni, high prevalences and intensities of infection, and important morbidity have been documented. Taking into account the limited financial means and the poor logistic conditions, the control strategy has been based mainly on targeted chemotherapy of heavily infected people (> 600 epg). After ten years of intervention, prevalences and intensities have hardly been affected, but the initial severe hepatosplenic morbidity has almost disappeared. In Burundi, a national research and control programme has been initiated in 1982. Prevalences, intensities and morbidity were moderate, transmission was focal and erratic in time and space. A more structural control strategy was developed, based on screening and selective therapy, health education, sanitation and domestic water supply. Prevalences and intensities have been considerably reduced, though the results show focal and unpredictable variations. Transmission and reinfection were not significantly affected by chemotherapy alone, and the eventual outcome of repeated selective treatment appears to be limited by the sensitivity of the screening method. Intestinal morbidity was strongly reduced by community-based selective treatment, but hepatosplenic enlargement was hardly affected; this is possibly due to the confounding impact of increasing malaria morbidity. The experiences show the importance of local structures and conditions for the development of an adapted control strategy. It is further concluded that population-based chemotherapy is a highly valid tool for the rapid control of morbidity, but should in most operational conditions not be considered as a tool for transmission control.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Experiences with the control of schistosomiasis mansoni in two foci in central Africa. 134 93

We have expressed two cDNA sequences encoding 121 and 230 amino acids of the C-terminus of the Schistosoma mansoni Hsp 70 in Escherichia coli. The products were synthesized as polypeptides fused to the RNA polymerase of bacteriophage MS2, and their reactivities were tested in ELISAs, using sera from human and murine infections. Anti-Hsp70 antibodies were detected in a significant number of individuals suffering from chronic schistosomiasis mansoni, but not in patients with known recent infections. This, together with the finding that antibodies directed at S. mansoni-specific Hsp70 determinants during the course of infection of experimental mice were not detectable until 5-6 weeks post-infection, suggests that the protein may be a useful marker for distinguishing late and early infections. The diagnostic specificity of Hsp70 was evaluated with sera from humans infected with different schistosome species and other parasitic diseases. While some subjects infected with S. haematobium produced antibodies which recognized the S. mansoni Hsp70, no such antibodies were generated in S. japonicum infected individuals. However, cross-reactive antibodies were elicited in donors with other parasitic diseases such as filariasis and malaria. The absence of antibodies in early infection and the observed cross-reactivities led us to conclude that Hsp70 will be of limited value in the diagnosis of schistosomiasis.
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PMID:The humoral response to heat shock protein 70 in human and murine Schistosomiasis mansoni. 211 91

Morbidity due to infection with Schistosoma mansoni was investigated in a recently discovered highland focus around Lake Cohoha, Burundi. The distribution of the infection was very focal and morbidity patterns in populations from an endemic area A (prevalence 38%, mean egg load of positive subjects 231 eggs per gram [epg]), a less affected area B (16%, 90 epg) and a virtually non-endemic area C (5%, 45 epg), were compared; apart from schistosomiasis, the profiles of these populations were highly similar. The overall frequencies of diarrhoea were 36%, 25%, and 19%, respectively; of abdominal pain 86%, 78%, and 83%; of fatigue 7%, 2%, and 1%; of left lobe hepatomegaly 30%, 18%, and 9%; of right lobe hepatomegaly 18%, 10%, and 5%; of splenomegaly 18%, 10%, and 7%. Organomegaly was generally mild, even in area A. Within area A, the association between the presence of infection and diarrhoea, fatigue, hepatomegaly and splenomegaly was significant, but far less impressive than the results of the community-based comparison with areas B and C. The correlation with intensity was limited to an increased prevalence of diarrhoea and fatigue in the highest egg count group, and a more gradual increase (varying with age) in hepatomegaly and splenomegaly. The data are compared to other morbidity studies in subsaharan Africa, in particular one in the nearby Rusizi Plain. The lesser impact of malaria, the higher egg loads, the recent establishment of the focus and possibly parasite strain differences may account for the more apparent and more important schistosomiasis morbidity in the Cohoha focus.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The morbidity of schistosomiasis mansoni in the highland focus of Lake Cohoha, Burundi. 212 66

Antigens containing phosphocholine (PC) circulate in the blood during chronic filarial infection. Because of the wide occurrence of such PC epitopes, we examined their specificity by evaluating 10 common parasites of humans for the presence of PC epitopes, and sera from patients infected with these parasites for circulating antigens containing PC. Immunoblot analysis of extracts from various parasites using an anti-PC monoclonal antibody (CA101) demonstrated the presence of PC epitopes on the protozoa Leishmania major and Trypanosoma cruzi, and on the helminths Schistosoma mansoni and Strongyloides stercoralis, in addition to those previously described on Trichinella spiralis, Onchocerca volvulus and Brugia malayi. They were not detected on the protozoa Entamoeba histolytica, Giardia lamblia or Plasmodium falciparum. Sera from 163 individuals with single protozoan or helminth infections were assayed for PC-bearing circulating antigens in a two-site immunoassay; such antigens were found in almost all patients infected with Wuchereria bancrofti; in half of those infected with S. stercoralis; and in 7-15% of those with S. mansoni, T. cruzi or L. donovani; none was detected in those with Trichinella, hookworm, Echinococcus, malaria, Giardia or amoebic infections. Thus, while detection of circulating PC-antigen as an immunodiagnostic assay for filariasis could result in some 'false positives', it appears to be a potentially valuable immunodiagnostic tool that deserves wider field testing to determine its practical usefulness.
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PMID:Phosphocholine epitopes on helminth and protozoal parasites and their presence in the circulation of infected human patients. 248 59

An enzyme-linked immunosorbent assay was used to quantify soluble interleukin 2 receptor (IL-2R) in the serum of patients with helminthic and protozoal infections. The results demonstrated that levels of IL-2R were normal in patients with helminthic infections limited to the intestinal tract (ascariasis, trichuriasis), but significantly elevated in patients with systemic or long-lasting infections (strongyloidiasis, schistosomiasis, fascioliasis, opisthorchiasis). In patients infected with Schistosoma mansoni levels of IL-2R were higher in those with the hepatosplenic than in those with the intestinal form of the disease. Patients with malaria also showed increased serum levels of IL-2R, irrespective whether the infection was caused by Plasmodium falciparum or P. vivax. No difference was observed between patients with acute or history of malaria. The highest levels of IL-2R were observed in patients with visceral leishmaniasis. Interestingly, in these patients the concentration of IL-2R correlated to specific antibody titre. The results are discussed in the context of preferential activation of T lymphocytes, B lymphocytes and/or macrophages during the course of the different parasitic infections investigated.
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PMID:Interleukin 2 receptor in patients with localized and systemic parasitic diseases. 313 58

Plasmodium berghei yeolii infection in mice suppressed granuloma formation around Schistosoma mansoni eggs in the lungs. This suppressive effect was observed as early as 4 days after schistosome eggs were injected into malaria-infected mice and the maximum suppressive effect was seen by the 16th day. At this time granulomas in control mice than in mice infected with malaria. These data suggest that malaria has a direct influence on an immunologic reaction of the delayed hypersensitivity type. There was no significant difference in the level of antibodies, specific for schistosome eggs, in the sera of the malaria-infected mice as compared to mice injected with S. mansoni eggs alone.
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PMID:Suppression of schistosome granuloma formation by malaria in mice. 461 97

In this review article, some recent developments in the immunology of parasitic infections are presented. After an introduction in which the major human parasitic infectious diseases, including malaria, african and american trypanosomiasis, leishmaniasis, filariasis an schistosomiasis are mentioned, a description of the host/parasite relationship in malaria presented. The possibility for the development of vaccins against malaria are described. The close relation between the immunological responses and the inflammatory reactions present both in Schistosoma mansoni and Trichinella spiralis infections is stressed. Particularly the recently recognized direct anti-parasitic activity of eosinophils was emphasized. Next, ways of escape of parasites from the host defence were described, with special emphasis on the immunomodulating properties of parasitic infections. Finally, the development and improvement of new immunodiagnostic methods, including the detection of circulating antigens were discussed.
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PMID:Immunological aspects of some parasitic infections. 699 58


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