scholarly journals Diagnosing human asymptomatic visceral leishmaniasis in an urban area of the State of Minas Gerais, using serological and molecular biology techniques

2006 ◽  
Vol 39 (5) ◽  
pp. 421-427 ◽  
Author(s):  
Elizabeth Castro Moreno ◽  
Maria Norma Melo ◽  
José Roberto Lambertucci ◽  
José Carlos Serufo ◽  
Antero S.R. Andrade ◽  
...  

A population-based cross-sectional study was set up in Sabará country, Southeastern Brazil, to identify asymptomatic human visceral leishmaniasis in an urban area of low disease prevalence. Blood was collected on filter paper (n=1,604 inhabitants) and examined by indirect immunofluorescent test, enzyme-linked immunosorbent assay and immunochromatographic strip test. The prevalence rates of infection ranged from 2.4 to 5.6% depending on the test used. One year later, venous blood was collected in a subset of 226 participants (102 seropositive and 124 seronegative). The tests performed were IFAT, ELISA, rk39-ELISA, polymerase chain reaction and hybridization with Leishmania donovani complex probe. No clinical signs or symptoms of leishmaniasis were observed. Using hybridization as a reference test, the sensitivity and specificity of serology were respectively: 24.8 and 71% (ELISA); 26.3 and 76.3% (rk-39); 30.1 and 63.4% (IFAT). Due to disagreements, different criteria were tested to define the infection and hybridization should be considered in epidemiological studies.

2021 ◽  
Vol 15 (8) ◽  
pp. e0009571
Author(s):  
Priscila de Oliveira Azevedo ◽  
Susana Zevallos Lescano ◽  
Rogério Giuffrida ◽  
Louise Bach Kmetiuk ◽  
Andrea Pires dos Santos ◽  
...  

Toxocariasis is worldwide endemic parasitic anthropozoonosis with high risk to those in in vulnerable populations and particularly during pregnancy and childhood. Although the prevalence of anti-Toxocara spp. antibodies has been extensively studied, risk factors of pregnant women of different ages remains to be established. This study was designed to i) assess the presence of anti-Toxocara spp. antibodies in pregnant women that presented to the public health system in a city of southeastern Brazil, and ii) determine the risk factors for toxocariasis in adolescent and adult pregnant women. This cross-sectional study included 280 pregnant women (71 aged up to and including 17 years [adolescents] and 209 aged 18 years and older [adults]). Pregnant women voluntarily agreed to complete a socioeconomic questionnaire and provide serum samples. Anti-Toxocara IgG antibodies were screened by Enzyme-Linked Immunosorbent Assay (ELISA). Univariable and multivariable logistic regression models were performed to assess the risks for toxocariasis. Overall, 20.7% of pregnant women were seropositive (33.8% of adolescents and 16.3% of adults). Prevalence in pregnant adolescents was 2.6-fold higher than in adults (Odds ration [OR]: 2.63; 95% CI: 1.42–4.86, p = 0.003). Multivariate analysis revealed that contact with soil (p = 0.01; OR = 4.76) and being in the first trimester of pregnancy (p = 0.03; OR = 0.17) had significantly greater risk of toxocariasis for adolescents, and attainment of elementary through middle school education level (p = 0.05; OR = 8.33) was a risk factor in adult pregnant women. Toxocariasis is likely underreported and neglected in adolescent pregnant women; this age group should always be monitored for toxocariasis and correspondent clinical signs, particularly at late pregnancy.


2019 ◽  
Vol 40 (6Supl2) ◽  
pp. 3313
Author(s):  
Valéria Régia Franco Sousa ◽  
Álvaro Felipe de Lima Ruy Dias ◽  
Juliana Yuki Rodrigues ◽  
Mariana de Medeiros Torres ◽  
Janaína Marcela Assunção Rosa Moreira ◽  
...  

Visceral Leishmaniasis (VL) is a parasitic zoonosis expanding in Brazil. Several municipalities in the state of Mato Grosso including those on the river Cuiabá have reported the incidence of both human and canine cases and the identification of sandfly vector, Lutzomyia longipalpis and Lu. cruzi. Dogs are considered the main reservoir of Leishmania chagasi in the urban areas, hence, we devised a cross-sectional study aimed at assessing the prevalence of the infection in the dogs of riverside communities on Cuiabá River watershed by parasitological (parasitic isolation in culture), serological, and molecular methods. Of the 248 surveyed dogs, 24 were positive in enzyme linked immunosorbent assay (ELISA) or immunofluorescence antibody test (IFAT), with a prevalence of 9.7%. The riverside communities located in the town of Santo Antonio do Leverger displayed a higher prevalence of the disease than the cities of Cuiabá and Várzea Grande; however, the difference was not statistically significant (p > 0.05). Dogs born in the communities had a 3.24-fold higher risk of acquiring the infection. Promastigote were isolated in the axenic culture from the bone marrow samples and intact skin. Further, DNA of Leishmania sp. was detected in the bone marrow samples, lymph nodes, leukocyte cover, and skin of only one examined dog. These samples were sequenced and they showed 99% homology to L. infantum. To conclude, we observed a higher prevalence of infection in Riverside communities of Santo Antonio do Leverger and the confirmation of autochthony in these areas justifies the surveillance actions to minimise the risk of transmission within the riverine community itself, besides its dissemination to other areas by tourism.


2019 ◽  
Vol 6 (1) ◽  
pp. 12-15
Author(s):  
Ishrat Sharmin ◽  
AKM Quamruzzaman ◽  
Rezina Parveen ◽  
M Abdulah Yusuf ◽  
Rashida Akter Khanam

Background: Newly developed KAtex test can be used as a non invasive tool for diagnosis of Kala-azar. Objectives: The aim of the present study was to compare KAtex, Bone marrow aspiration and DAT to diagnose VL. Methodology: This cross-sectional study was carried out in the Department of Microbiology at Dhaka Medical College, Dhaka, Bangladesh in collaboration with the Department of Parasitology, Institute of Epidemiology, Disease Control and Research (IEDCR), Dhaka, Bangladesh for a period of one year. Clinically suspected Kala-azar (VL) cases of different age and sex attending IEDCR, Dhaka from different Kala-azar endemic areas of Bangladesh were selected for this study. Patients having fever for more than 2 weeks, with or without splenomegaly, having history of loss of body weight following onset of fever were clinically suspected as Kala-azar cases. Microscopy and culture was performed in bone marrow (BM). KAtex was performed with urine sample. Agglutination of sensitized latex indicated presence of Leishmania donovani antigen in urine and thereby visceral leishmaniasis. No agglutination indicates absence of antigen in urine. DAT was done with serums of all cases. Result: Among 130 clinically suspected VL cases, 70 (53.85%) cases were BM positive and 60(46.15%) cases were BM negative. All the 70 BM positive cases were positive by KAtex and DAT. Among 60 BM negative cases, 15 were positive by KAtex and 23 were positive by DAT. The sensitivity of KAtex was 100.0% and specificity was 75.0%. The sensitivity of DAT was 100.0% and specificity is 61.6%. Conclusion: In conclusion, KAtex test is a good diagnostic tool for the detection of VL in comparison with DAT. Bangladesh Journal of Infectious Diseases, June 2019;6(1):12-15


2008 ◽  
Vol 15 (5) ◽  
pp. 836-842 ◽  
Author(s):  
Ayan Dey ◽  
Pawan Sharma ◽  
Naresh Singh Redhu ◽  
Sarman Singh

ABSTRACT Visceral leishmaniasis (VL) is one of the important parasitic diseases, with approximately 350 million people at risk. Due to the nonavailability of an ideal drug, development of a safe, effective, and affordable vaccine could be a solution for control and prevention of this disease. The present study was carried out to examine the immunological potential of kinesin protein from the microtubule locus of Leishmania donovani as a suitable vaccine candidate. In silico analysis of this region revealed clusters of major histocompatibility complex class I and II binding epitopes in its motor domain region. A recombinant protein was expressed from this region and named rLvacc. The antigenicity and immunogenicity studies of this protein by Western blot analysis revealed that rLvacc is strongly recognized by sera from acute VL patients. To evaluate its immunogenicity, peripheral blood mononuclear cells from cured VL patients were separated, and a lymphocyte proliferation assay was carried out in the presence of rLvacc. After lymphocyte proliferation, the pooled culture supernatant was assayed for anti-rLvacc antibody titers using an enzyme-linked immunosorbent assay. The results showed that immunoglobulin G2 (IgG2) subtype antibodies were predominant, while IgG1 subtype antibodies were produced in very low titers. On the basis of these ex vivo preliminary findings, its immunogenicity was studied in BALB/c mice. Vaccination with the DNA construct generated a good cellular immune response with significant increases in gamma interferon and interleukin-2 (IL-2) cytokine levels (Th1), but no increase in IL-4 levels (Th2). Taken together, our findings suggest the kinesin motor domain region of L. donovani as a potential vaccine candidate against visceral leishmaniasis.


2002 ◽  
Vol 9 (4) ◽  
pp. 789-794 ◽  
Author(s):  
Mohammad Zahidul Islam ◽  
Makoto Itoh ◽  
S. M. Shamsuzzaman ◽  
Rusella Mirza ◽  
Farzana Matin ◽  
...  

ABSTRACT A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.


2007 ◽  
Vol 14 (12) ◽  
pp. 1592-1595 ◽  
Author(s):  
Durria Mansour ◽  
Elfadil M. Abass ◽  
Mohamed el Mutasim ◽  
Abdelhafeiz Mahamoud ◽  
Abdallah el Harith

ABSTRACT Corroboration of serology results is essential for restricting the risk of inappropriate antileishmanial prescription. A direct agglutination test (DAT) and a recently developed β-mercaptoethanol-modified enzyme-linked immunosorbent assay (β-ME ELISA) based on the use of antigen prepared as described for the DAT were applied to 416 sera from two Sudanese populations with and without clinical evidence of visceral leishmaniasis (VL). Of 285 sera with the lowest antileishmanial DAT titers (≤1:100 to 1:1,600), 270 (94.7%) scored comparable minimum β-ME ELISA absorbance values (≤0.1 to 0.26). In 117 sera that demonstrated the highest DAT titers (1:12,800 to ≥1:25,600), 86 (73.5%) scored maximum (0.81 to ≥1.35) and 30 (25.6%) medium (0.27 to 0.80) β-ME ELISA absorbance values. VL diagnosis was established for 142 (44.1%) patients in the VL-symptomatic group (n = 322), based on positive microscopy for Leishmania donovani in lymph node aspirates or positive DAT (titer, ≥1:3,200). Of the 125 sera from the symptomatic patients for whom microscopy was positive for VL, 111 (88.8%) had comparable positive DAT and β-ME ELISA readings. In all 17 sera from the symptomatic DAT-positive patients for whom leishmaniasis was not established by microscopy but who responded favorably to antileishmanial therapy, absorbance values (≥0.27) indicative of VL were obtained by β-ME ELISA. Of 197 symptomatic patients for whom microscopy was negative for VL, 172 (87.3%) tested negative in β-ME ELISA and 180 (91.4%) in DAT. Based on the high reliability demonstrated here for VL detection, β-ME ELISA fulfills the requirement of confirming DAT results in patients manifesting suspected VL.


1997 ◽  
Vol 12 (4) ◽  
pp. 127-135 ◽  
Author(s):  
C J. Evans ◽  
F. G. R. Fowkes ◽  
C. V. Ruckley ◽  
P. L. Allan ◽  
M. N. Carson ◽  
...  

Objective: To describe the methods required to conduct a large epidemiological study of venous disease in the general population, and the resulting response. Design: Cross-sectional study. Setting: University of Edinburgh. Participants: Men and women aged 18–64 years, randomly selected from general practice registers. Methods: Subjects were invited for the following procedures: questionnaire, height and weight measurement, classification of varices and chronic venous insufficiency, duplex measurement of duration of venous reflux and venous blood sampling. A questionnaire survey of non-responders was carried out. Results of response: A total of 1566 subjects attended, a final response rate of 53.8%. The response rate increased with age. The distribution of ethnic origin and social class of attenders was similar to that of the general Edinburgh population. Study participants were generally older, from more affluent areas and more often female than non-responders ( p ≤ 0.001). Conclusions: Large epidemiological studies of venous disease in the community are feasible but the level of response illustrates the importance of obtaining information on the disease status of non-responders.


2006 ◽  
Vol 11 (12) ◽  
pp. 1792-1799 ◽  
Author(s):  
Karl Schenkel ◽  
Suman Rijal ◽  
Siddhartha Koirala ◽  
Shekhar Koirala ◽  
Veerle Vanlerberghe ◽  
...  

2021 ◽  
Vol 71 (Suppl-1) ◽  
pp. S102-05
Author(s):  
Ambreen Rehman ◽  
Naveed Asif ◽  
Saima Shakeel Malik ◽  
Waqas Sheikh ◽  
Quratulain . ◽  
...  

Objective: To identify effect of pre-analytical variables on serum thyroid stimulating hormone. Study Design: Cross sectional study. Place and Duration of Study: Armed Forces Institute of Pathology (AFIP) Rawalpindi, Department of Chemical Pathology & Endocrinology, from Mar 2018 to Aug 2018. Methodology: Hundred subjects with ages ranging from 18 to 34 years, irrespective of gender, were randomly selected for this study. Five milliliters venous blood sample was collected from each subject in a serum separator and divided into two aliquots. First aliquot was centrifuged and analyzed immediately for TSH, while second aliquot was stored for 24 hours and was then analyzed. TSH was measured by third generation assay usingchemiluminescence technique on ADVIA Centaur® XP. Serum TSH levels were also analyzed twice daily; in the morning (0800 to 0900 hours) and afternoon (1400 to 1600 hours). Data was analyzed using SPSS version 24. Frequency and percentages were calculated for qualitative variables like gender and pre-analytical variables. Test of significance Mann-Whitney U-test was applied and p-value <0.05 was taken as significant. Results: Mean age of subjects was 23 ± 3.4 years. Change in circadian rhythm was observed in 17 (28%) males and 14 (36%) females. Statistically significant association was found between morning and evening TSH levels, while no change was observed in TSH level by early and late centrifugation of samples. Conclusion: TSH levels vary significantly between blood samples collected at different timings of the day from the same person. TSH is resistant to degradation, immunologically stable, and reasonably insensitive to potential problems associated with routine specimen handling, when measured by immunoassay technique. Therefore, it is helpful in large epidemiological studies and small size laboratory, which require long transportation time and storage.


2011 ◽  
Vol 20 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Márcia Mariza Gomes Jusi ◽  
Wilma Aparecida Starke-Buzetti ◽  
Trícia Maria Ferreira de Sousa Oliveira ◽  
Michely da Silva Tenório ◽  
Lúcio de Oliveira de Sousa ◽  
...  

Leishmaniasis is a zoonotic disease that affects 12 million people worldwide. Several mammalian species can serve as a reservoir for this disease. Dogs are the main reservoir for visceral leishmaniasis in urban areas, which has become a serious public health concern in Brazil. The aim of this study was to evaluate the presence of Leishmania spp. in captive wild animals from Ilha Solteira, São Paulo, Brazil. Blood and various tissues samples were collected from animals of five different species: Speothos venaticus, Chrysocyon brachyurus, Cerdocyon thous, Pseudalopex vetulus, and Procyon cancrivorus. Antibodies against Leishmania spp. were detected in three wild canids by indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). PCR analyses of blood and bone marrow from all animals were negative, but Leishmania DNA was found in the tissues and skin of seropositive animals. Positive PCR samples were also positive for Leishmania donovani complex. Analysis of sequenced PCR products showed similarities with different regions of Leishmania (Leishmania) infantum and Leishmania (Leishmania) chagasi kinetoplastids. Measures to control visceral leishmaniasis in wild animals kept in Brazilian zoos should be established, as no disease control programs are currently available.


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