PubMed Health⌕ Search

Biomedical subjects

J C Samantaray

Publications and source records attributed to J C Samantaray.

36 records · Page 2Linked to original sources

Trichomonal vaginitis: evaluation of serological tests and identification of immunoreactive surface peptides.

An indirect haemagglutination assay (IHA) with polysaccharide and protein antigens of Trichomonas vaginalis and an enzyme linked immunosorbent assay (ELISA) were used to test for antibodies against T vaginalis in 58 women with trichonomal vaginitis and 48 with non-specific vaginitis. Eleven antibody positive sera were used in a radioimmunoprecipitation assay (RIPA) to identify surface peptides that elicited antibody responses in infected women. The serological tests were less sensitive than biological tests (smear examination and culture); antibodies were detected in 22 of the 58 women with trichomonal vaginitis by IHA using polysaccharide as antigen, in 27 by IHA using protein antigen, and in 36 by ELISA. The ELISA was also found to be of low specificity. Only two of the 11 sera tested by RIPA showed positive reactions with surface antigens, which were confirmed by autoradiography.

Adolescent↗

A dot enzyme-linked immunosorbent assay for detection of antibodies against Entamoeba histolytica.

A visual micro-dot enzyme-linked immunosorbent assay (ELISA) based on detection of antibodies against soluble antigens of axenically grown cultures of Entamoeba histolytica is described. The antigen was spotted on a nitrocellulose sheet, the unsaturated sites blocked with bovine serum albumin (BSA) and incubated with 3-fold dilutions of patient sera followed by incubation with protein A conjugated to peroxidase. Enzymic activity was evidenced using the substrate 4-chloro-1-naphthol. A positive reaction produced a blue spot. The sensitivity of the assay was better and comparable to the indirect haemagglutination assay (IHA) and plate ELISA. The entire assay could be completed within 3 h. Antigen-loaded and pre-blocked nitrocellulose strips could be stored up to 3 months at room temperature and 37 degrees C.

Amebiasis↗

Seropositivity of Toxoplasma gondii in domestic animals.

Serum samples from 107 goats, 40 sheep, 50 cows were tested for Toxoplasma gondii antibody by indirect haemagglutination test (IHA) in dilutions of 1:10, 1:54, 1:162 and 1:486. Toxoplasma gondii-antibodies were found in 21 (19.6%), 10 (25%), 26 (52%), goat, sheep and cow sera respectively. No serum sample showed a titre higher than 1:162. All animals were kept in good hygienic condition. These results indicate that Toxoplasma gondii antibodies are widespread in animal populations which supports that toxoplasmosis is a widely spread zoonotic infection in this country.

Animal Diseases↗

Passive malaria surveillance in a low endemic area of India: validation of a clinical case definition.

BACKGROUND: In India, 2.55 million cases of malaria were reported during 1997; roughly one-third were due to Plasmodium falciparum. Malaria cases are identified by passive and active surveillance and all patients with fever are treated with chloroquine (10 mg/kg body weight). Since all fevers are not malaria, this results in overtreatment and has a bearing in terms of the parasites developing resistance. We aimed to test the validity of a clinical algorithm for passive malaria surveillance by primary care doctors (fever with pallor or splenomegaly) in a low endemic, Plasmodium vivax-predominant area of Ballabgarh block in Faridabad District, Haryana. METHODS: Passive surveillance was carried out at the general and paediatric outpatient departments (OPDs) of Ballabgarh hospital. All persons with fever attending the OPD were examined for the presence of fever, pallor and splenomegaly by the treating doctor. A blood smear was prepared and examined in all these cases. RESULTS: A total of 3119 slides for malaria were made at Ballabgarh hospital but clinical details in the requisition form were available for only 2616 patients who form the subjects of this analysis. A total of 59 malaria cases (30 P. vivax cases and 29 P. falciparum) were diagnosed. The presence of fever with pallor or splenomegaly had a sensitivity of 28.8% (95% CI: 18.1-42.3); specificity of 88.6% (95% CI: 87.3-89.8), positive predictive value of 5.5% (95% CI: 3.3-8.8) and negative predictive value of 98.2% (95% CI: 97.5-98.7). CONCLUSION: The algorithm did not have sufficient sensitivity to detect malaria cases by passive surveillance.

Algorithms↗

Plasmodium lactate dehydrogenase assay to detect malarial parasites.

BACKGROUND: Microscopic examination of blood smears remains the gold standard for the diagnosis of malaria. However, it is labour-intensive and requires skilled operators. Immunochromatographic dipstick assays provide a potential alternative. One such dipstick, the Plasmodium lactate dehydrogenase assay (pLDH), is based on detection of the Plasmodium intracellular metabolic enzyme, LDH. The differentiation of malarial parasites is based on the antigenic differences between the pLDH isoforms. This study was designed to assess the sensitivity and specificity of pLDH assays in detecting and differentiating between various malarial species compared with microscopy. METHODS: Blood samples (n = 124) submitted to our laboratory for routine diagnosis of malaria were included in this study. From each blood sample, two thin films and a quantitative buffy coat (QBC) were made for microscopy. Thin films were stained with Giemsa and acridine orange. The pLDH assay was performed on all the samples according to the manufacturer's instructions. RESULTS: Of the 124 blood samples, 84 were negative by all methods (Giemsa, acridine orange, QBC and pLDH assay). Of the 38 samples positive for Plasmodium falciparum on microscopy, pLDH assay correctly identified 36 at parasite counts as low as < 40 parasites/microl and had a sensitivity and specificity of 94.3% and 97.6%, respectively. Of the 21 samples positive for Plasmodium vivax, pLDH assay correctly identified 19 at parasite counts as low as < 80/microl, and had a sensitivity and specificity of 90.4% and 100%, respectively. However, it failed to identify two Plasmodium vivax infections at parasite counts of 5000/microl and > 200/microl, suggesting that plasmodial gene deletions could be responsible for non-expression of pLDH. CONCLUSIONS: Our data demonstrate that pLDH assay, given its accuracy, rapidity (10-15 minutes), ease of performance and interpretation, can be a useful tool for the detection of malaria in countries where both plasmodial species are co-endemic and where laboratory support is limited.

Animals↗

Detection of Entamoeba histolytica using polymerase chain reaction in pus samples from amebic liver abscess.

BACKGROUND AND OBJECTIVE: Direct demonstration of Entamoeba histolytica by conventional microscopy and in vitro culture in pus obtained from amebic liver abscess (ALA) is often unsuccessful. We evaluated polymerase chain reaction (PCR) for detection of E. histolytica DNA in such pus. METHODS: Species-specific primers were used for the amplification of E. histolytica DNA from liver pus obtained from 30 patients with ALA. Patients with pyogenic liver abscess and sterile (autoclaved) pus spiked with Entamoeba dispar and bacteria (Escherichia coli, Klebsiella spp. and Bacteroides spp.) were used as negative controls. RESULTS: PCR was positive in 83% of pus specimens from patients with ALA, and was negative in all 25 pus specimens obtained from pyogenic abscess and autoclaved pus spiked with known bacteria. Sensitivity and specificity of PCR were 83% and 100%, respectively. The overall positivity of PCR was higher compared to serological tests. CONCLUSION: PCR may be a more reliable and better alternative diagnostic modality for ALA.

Animals↗

Spirochetal dysentery: a case report and review of literature.

Spiral shaped bacteria have frequently been demonstrated from human faeces. Their role in causation of disease is, however, controversial; as they have been found to colonise the lower gastrointestinal tracts of both symptomatic and asymptomatic individuals. Here we report a case in which spiral shaped motile, gram negative and nonflagellated bacteria, probably belonging to the genus Borrelia, were demonstrated and associated with acute bloody diarrhea in a cardiac patient. The condition could successfully be treated with short course of Metronidazole. The relevant and up to date literature on this problem is also reviewed.

Adolescent↗

Parasitic gut flora in a north Indian population with gastrointestinal symptoms.

Intestinal parasitosis is a major health problem in India. More than 3000 million people have one or more parasites in their gut at any given time. There have been various studies in India to elucidate the prevalence rate of intestinal parasitosis in health and disease. In present study, data from 8000 stool samples examined over a period of 4 years from April 1984 to March 1988 at All India Institute of Medical Sciences was processed and analysed in a computer. Of the 8000 samples screened more than 25% were positive for one or more parasites. Females predominated over males and the most affected age group was 20-29 years in both sexes. Pain abdomen was the leading clinical manifestation. Of the parasite positive samples 54.19% had one parasite, 26.05% two, 14.61% three, 4.40% four and 0.74% had five or more intestinal parasites. Amongst the various pathogenic protozoan parasites, Giardia lamblia was most frequently encountered, while hookworm was the commonest amongst helminthic parasites. The non-pathogenic protozoan parasites E. nana and E. coli were the most frequent in all groups.

Adult↗