Alejandro Krolewiecki

Experticia en Ciencia y Técnica

Mi carrera se desarrolla en el campo de las enfermedades infecciosas, inicialmente la misma se centró en el desarrollo y ejecución de investigación clínica en HIV con estudios epidemiológicos y ensayos clínicos de fase II a IV. Actualmente y desde hace más de 10 años, el foco de mis proyectos está en el campo de las enfermedades infecciosas desatendidas, con aquellas prevalentes en el norte de Argentina como el sujeto de los distintos proyectos. La experticia desde mi etapa formativa se centró en el testeo de drogas antiparasitarias y estudios clínicos para el testeo de estas drogas en terreno. Actualmente la actividad está focalizada en el desarrollo de herramientas diagnósticas, terapéuticas y de medición de morbilidad para geohelmintiasis y leishmaniasis tegumentaria en el ámbito de salud pública. Estos desarrollos, que tienen el objetivo último de ser trasladados al ámbito público, han permitido ganar experiencia en la implementación de desarrollos de ciencia básica aplicados a campañas de salud pública, adquiriendo en etapas más reciente, capacitaciones en biología molecular.

Fecha: 
16/11/2018
Linea de Investigacion: 

Abstract

Background

Some sand flies are of medical importance because they are vectors of Leishmania parasites that are responsible for leishmaniasis. The aim of this study was to make a retrospective epidemiological analysis of tegumentary leishmaniasis (TL), to identify Leishmania spp. from patient isolates and to describe the diversity of sand flies from a border area between Bolivia and Argentina.

Methods

TL cases included in the study were diagnosed in an endemic area of the north of Argentina from 1985 to 2017. The parasites isolated were characterized by the cytochrome B method. Sandflies were captured with Centers for Disease Control traps in Aguas Blancas and Media Luna-Algarrobito localities.

Results

A total of 118 cases of TL were analysed. Eight isolates were characterized as Leishmania (Viannia) braziliensis. A total of 1291 sandflies were captured, including Nyssomyia neivai, Cortelezzii complex, Evandromyia sallesiMigonemyia migonei and Micropygomyia quinquefer. Within the area, sandflies were found in the backyards of houses.

Conclusions

In this region there exists the possibility of peridomestic transmission of TL in the neighbourhoods peripheral to the urban area and in rural environments as well as the risk of transmission to travellers that pass through the customs offices.

Fecha: 
25/09/2018
Linea de Investigacion: 

Cutaneous leishmaniasis is endemic in Salta province, which belongs to the northwest of Argentina. Leishmania spp. DNA from Giemsa-stained slides of up to 12 years in storage of patients from Salta was characterized through PCR-restriction fragment length polymorphism. One hundred smears positive for microscopy, classified in a semiquantitative scale for amastigote density, were analyzed. Also, Leishmanin skin test (LST) results were included. DNA extraction was carried out applying lysis buffer with proteinase K, and then DNA was amplified with ribosomal internal transcribed spacer 1 primers. PCR products were digested with HaeIII enzyme. All PCR-positive smears (74/100) belonged to Viannia subgenus. A statistically significant, directly proportional relationship between semiquantitative microscopy and PCR results was detected. All patients had LST-positive results (induration ≥ 5 mm), and the smears of those with smaller induration (LST < 19 mm) gave a higher proportion of positive PCR results. This study determined that smear age did not affect PCR positivity, which allows retrospective analyzes and suggests smears might be useful for molecular complementary diagnosis. Because Leishmania (Viannia) braziliensis is the main circulating species in the study area, determining Viannia subgenus in all analyzed samples confirms previous findings. PCR positivity showed statistically significant differences according to semiquantitative microscopy, highlighting the importance of parasite burden in the diagnostic sensitivity of the method. Considering that smears of patients with smaller LST induration were more positive in PCR, a negative smear from patients with positive LST response, but < 19 mm, could actually represent a false-negative result.

 

© The American Society of Tropical Medicine and Hygiene