RESUMO
Assuntos
Malária/epidemiologia , Adolescente , Adulto , Altitude , Criança , Estudos Transversais , Feminino , Humanos , Malária/etiologia , Malária/transmissão , Masculino , Fatores de Risco , Fatores Socioeconômicos , Iêmen/epidemiologia , Adulto JovemRESUMO
Leishmanial antigen in circulating immune complexes (CIC) from sera of cotton-rats experimentally infected with Leishmania donovani and visceral leishmaniasis patients (VLP) was detected using a polyethylene glycol (PEG) enzyme-linked immunosorbent assay (PEG-ELISA). The immune complexes were precipitated in the cold with 12% PEG (average M(r) 6000) and then dissociated with glycine-HCl buffer. The dissociated antigen bound to the plate was then detected by peroxidase-labelled rabbit antibody raised to either amastigotes or to CIC. Serum samples from either controls or patients infected with heterologous organisms were used to define the sensitivity and specificity of the test. Leishmanial antigen was detected in the CIC from all experimentally infected animals (100% sensitivity) and in 22 of 25 of the CIC from VLP (88% sensitivity), using either conjugate. Immunoblotting of PEG-precipitated CIC from infected animals with both rabbit antisera revealed multiple antigen components. Antigens of 40, 42 and 45 kDa appeared to be specifically recognized by both antibodies; the components of 40 and 42 kDa were common to amastigote extracts and CIC from infected animals.
Assuntos
Complexo Antígeno-Anticorpo/sangue , Antígenos de Protozoários/sangue , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , Animais , Western Blotting , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos/sangue , Humanos , Polietilenoglicóis , Sensibilidade e Especificidade , SigmodontinaeRESUMO
This paper describes a new latex agglutination test ('KATEX') for the detection of leishmanial antigen in the urine of patients with visceral leishmaniasis. In preliminary laboratory trials, using urine collected from well-defined cases and controls from Brazil, Yemen and Nepal, the test had 100% specificity and a sensitivity between 68 and 100%. When used in a time-course experiment in cotton rats infected with Leishmania donovani, the test became positive 1 week after inoculation and antigen levels in urine declined rapidly after chemotherapy (the test was negative before the end of the course of treatment). Finally, in an integrated study performed in Sudan, KATEX was compared to microscopy and four different serological tests in a group of 73 patients having presented with clinical manifestations suggestive of visceral leishmaniasis. Compared to microscopy, KATEX performed better than any single serological test in predicting positivity and a particularly good result was obtained by combining KATEX and the direct agglutination test (DAT).
Assuntos
Antígenos de Protozoários/urina , Testes de Fixação do Látex/métodos , Leishmania donovani/imunologia , Leishmaniose Visceral/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Gluconato de Antimônio e Sódio/administração & dosagem , Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/administração & dosagem , Antiprotozoários/uso terapêutico , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Leishmania donovani/isolamento & purificação , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/urina , Proteínas de Protozoários , Coelhos , Sensibilidade e Especificidade , Sigmodontinae , SudãoRESUMO
Full text is available as a scanned copy of the original print version.
RESUMO
We studied the profile of malaria and intestinal parasitosis among children presenting to the Paediatric Health Centre in Sana'a from January 1998 to December 2000. In stool samples from 9014 children, Ascaris lumbricoides, Entamoeba histolytica, Giardia lamblia and Trichuris trichiura were the most common. Infection with parasites of direct life-cycle were similar in boys and girls. Schistosome infection was significantly higher in boys than girls, but girls were more infected with ascariasis. The only species of malaria parasite found in blood samples from 753 children with suspected malaria was Plasmodium falciparum, with the highest rates in April-June. The majority of positive cases were Yemeni children, but 10.8% were Sudanese or Ethiopian.
Assuntos
Enteropatias Parasitárias/epidemiologia , Malária/epidemiologia , Saúde da População Urbana/estatística & dados numéricos , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , Centros Comunitários de Saúde/estatística & dados numéricos , Etiópia/etnologia , Fezes/parasitologia , Feminino , Parasitologia de Alimentos , Humanos , Lactente , Enteropatias Parasitárias/parasitologia , Enteropatias Parasitárias/prevenção & controle , Enteropatias Parasitárias/transmissão , Malária/parasitologia , Malária/prevenção & controle , Malária/transmissão , Masculino , Pediatria , Vigilância da População , Prevalência , Características de Residência/estatística & dados numéricos , Fatores de Risco , Estações do Ano , Distribuição por Sexo , Sudão/etnologia , Água/parasitologia , Iêmen/epidemiologiaRESUMO
Antihydatid cyst antibodies from sera of infected Yemeni patients were detected using indirect haemagglutination assay (IHA). Antihydatid cyst antibodies were detected in 34 out of 38 serum samples (89% sensitivity). The specificity of the assay was defined to be 97.0% as cross reactivity only noticed with serum from one patient with Schistosoma mansoni out of 11 Schistosoma positive patients examined. Results were discussed.
Assuntos
Equinococose/diagnóstico , Animais , Especificidade de Anticorpos , Antígenos de Helmintos/análise , Reações Cruzadas , Echinococcus/imunologia , Testes de Hemaglutinação , Humanos , Schistosoma mansoni/imunologia , IêmenRESUMO
Levels of circulating antigen in a group of cotton rats infected with Leishmania donovani were followed over a 28-week period, using a modified, polyethylene-glycol (PEG) ELISA. Circulating antigen could be detected from 1 week post-infection and gradually increased over time. In infected cotton rats treated with a curative dose of Pentostam at 12 weeks post-infection, antigen levels peaked and then declined. Antigen was still detected in some of the treated animals at 28 weeks post-infection. The antibodies used in the PEG-ELISA were also used in a capture ELISA to detect parasite antigens in urine. Urine samples which were positive by capture ELISA were also analysed by western blotting, in an attempt to identify the parasite antigens present. Three components, of 45, 47 and 58 kDa, were detected.
Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/sangue , Leishmania donovani , Leishmaniose Visceral/imunologia , Sigmodontinae/parasitologia , Animais , Antígenos de Protozoários/química , Antígenos de Protozoários/urina , Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/uso terapêutico , Western Blotting , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Leishmaniose Visceral/tratamento farmacológico , Estudos Longitudinais , Ratos , Sigmodontinae/imunologia , Fatores de TempoRESUMO
As part of an attempt to develop an effective method for the serodiagnosis of visceral leishmaniasis (VL), the sera from 43 Yemeni cases of the disease were screened both for antileishmanial IgG antibodies and for Leishmania-specific antigens. Indirect ELISA and capture ELISA were used to test each serum for the antibodies and antigens, respectively. Sera from patients with diseases other than leishmaniasis (29 for the antibody-detection assays and 42 for the antigen-detection) and from apparently healthy volunteers were also tested. For each type of assay, the threshold for seropositivity was set three standard deviations above the mean absorbance value for the sera from the healthy volunteers. Thirty-seven of the 43 VL sera were found positive for Leishmania-specific IgG antibodies and 37 were found positive for Leishmania-specific antigens. The sensitivities of the antibody- and antigen-detection assays were both therefore 86%. The overall specificity of the antibody-detection ELISA (67%) was, however, slightly higher than that of the capture-ELISA (64%).
Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/sangue , Imunoglobulina G/sangue , Leishmaniose Visceral/imunologia , Animais , Especificidade de Anticorpos/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Reações Falso-Positivas , Humanos , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , IêmenRESUMO
We studied the profile of malaria and intestinal parasitosis among children presenting to the Paediatric Health Centre in Sana'a from January 1998 to December 2000. In stool samples from 9014 children, Ascaris lumbricoides, Entamoeba histolytica, Giardia lamblia and Trichuris trichiura were the most common. Infection with parasites of direct life-cycle were similar in boys and girls. Schistosome infection was significantly higher in boys than girls, but girls were more infected with ascariasis. The only species of malaria parasite found in blood samples from 753 children with suspected malaria was Plasmodium falciparum, with the highest rates in April-June. The majority of positive cases were Yemeni children, but 10.8% were Sudanese or Ethiopian