Fecha: 
01/01/2014
Linea de Investigacion: 

Abstract

A systematic review of surveys performed between 1980 and 2011 (published in MEDLINE/Pubmed and/or LILACS indexed journals, available in the baseline data from a Mass Deworming National Program (MDNP, 2005) was used to identify the prevalence, distribution and detection of risk areas for soil transmitted helminth infections (STH) in Argentina. We found 310 publications in the database using the pre-defined key-words (medical subject headings) for research purposes. Only 24 articles with 26 surveillance sites in 8 provinces and a total of 5495 surveyed individuals fulfilled the inclusion criteria. Frequency rates for STH had a wide range: Ascaris lumbricoides: 0-67%, hookworms: 0-90%, Trichuris trichiura: 0-24.6 and Strongyloides stercoralis: 0-83%. The estimated combined incidence varied from 0.8% to 88.6%. Baseline surveys from the MDNP reporting on 1943 children from 12 provinces confirmed the heterogeneity, with combined STH frequency rates ranging from 0 to 42.7%. Surveys included in this review showed that the distribution of STH in Argentina is not homogeneous, with areas of high incidence (> 20%) in the northeastern and northwestern provinces where mass deworming activities would be highly beneficial. In several surveys, the high overall incidence was mostly due to hookworms and S. stercoralis, a situation to be considered when selecting diagnostic and therapeutic control strategies. The scarcity or absence of data from various provinces and the availability of less than 8000 surveyed individuals should be considered.

Fecha: 
09/01/2014
Linea de Investigacion: 

Abstract

BACKGROUND:

The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference ("gold") standard.

METHODS:

The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests).

RESULTS:

According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2-96.9), followed by IVD-ELISA (92.3%, 87.7-96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9-100), followed by IVD-ELISA (97.4%, 95.5-99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIE-LIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains ≥70% sensitivity.

CONCLUSIONS:

NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.

Fecha: 
01/03/2014
Linea de Investigacion: 

Abstract

American tegumentary leishmaniasis (ATL) is a group of zoonotic diseases caused by kinetoplastid flagellates of the genus Leishmania. A total of 66 patients diagnosed as positive ATL cases from northwest Argentina were included in this study. Leishmania stocks were isolated in vitro and analyzed over promastigote cultures sown on FTA through nested PCR and sequence of cytochrome b (cyt b). The molecular analysis resulted in the incrimination of L. (Viannia) braziliensis as the predominant species in the studied area, identifying two genotypes of L. (V.) braziliensis, 24 cases of Ab-1 cyt b and 41 cases of Ab-2 cyt b. One L. (V.) guyanensis strain was obtained from a traveler from the Brazilian Amazon. The prevalence of different genotypes was in agreement with previous studies, suggesting the necessity for new systems to study the genetic diversity in more detail. Most of the cases typified in this study were registered in the area of Zenta Valley (Orán, Hipólito Yrigoyen, and Pichanal cities), pointing a link between genotype and geographical origin of the sample. Sex and age distribution of the patients indicate that the transmission was predominantly associated with rural areas or rural activities, although the results might not exclude the possibility of peri-urban transmission. This work represents, so far, the largest isolation and molecular characterization of ATL cases in Argentina.

Fecha: 
01/09/2013
Linea de Investigacion: 

Abstract

OBJECTIVE:

To determine the ability of recombinant antigens to detect cases of infection with Trypanosoma cruzi among cases of infection with Leishmania spp. by serological methods.

METHODS:

Sera from 41 patients infected with Leishmania spp. were evaluated with ELISA using single (FRA, CP1 and TSSAVI) or pooled (commercial Rec-ELISA) recombinant proteins or homogenate antigens (commercial H-ELISA). As there is no gold standard antigen to discriminate Chagas disease from leishmaniasis, the correlation of results between defined antigens and the homogenate was made with Kappa Index (KI), the level of correlation considered being used as a criterion of specificity.

RESULTS:

Single recombinant antigens and Rec-ELISA showed good correlation (KI > 0.8). A low correlation (KI < 0.66) was observed between the results from single recombinant antigens or the commercial recombinant kit and H-ELISA.

CONCLUSIONS:

The highly correlated results between T. cruzi single or pooled recombinant proteins are indicative of the usefulness of recombinant antigens for Chagas diagnosis. Our results also indicate that in the city of Oran in Argentina, between 12% and 17% of patients with leishmaniasis are also infected with Chagas disease. The high KI values between TSSAVI and the other recombinant proteins suggest that in these patients, the infection may be caused by T. cruzi II and/or V and/or VI lineages.

Fecha: 
09/05/2013
Linea de Investigacion: 

Páginas