Helminths and skewed cytokine profiles increase tuberculin skin test positivity in Warao Amerindians.

The immune regulatory mechanisms involved in the acquisition of Mycobacterium tuberculosis infection in children are largely unknown. We investigated the influence of parasitic infections, malnutrition and plasma cytokine profiles on tuberculin skin test (TST) positivity in Warao Amerindians in Venezuela. Pediatric household contacts of sputum smear-positive tuberculosis (TB) cases were enrolled for TST, chest radiograph, plasma cytokine analyses, QuantiFERON-TB Gold In-Tube (QFT-GIT) testing and stool examinations. Factors associated with TST positivity were studied using generalized estimation equations logistic regression models. Of the 141 asymptomatic contacts, 39% was TST-positive. After adjusting for age, gender and nutritional status, TST positivity was associated with Trichuris trichiura infections (OR 3.5, 95% CI 1.1-11.6) and low circulating levels of T helper 1 (Th1) cytokines (OR 0.51, 95% CI 0.33-0.79). Ascaris lumbricoides infections in interaction with Th2- and interleukin (IL)-10-dominated cytokine profiles were positively associated with TST positivity (OR 3.1, 95% CI 1.1-8.9 and OR 2.4, 95% CI 1.04-5.7, respectively). A negative correlation of QFT-GIT mitogen responses with Th1 and Th2 levels and a positive correlation with age were observed (all p < 0.01). We conclude that helminth infections and low Th1 cytokine plasma levels are significantly associated with TST positivity in indigenous Venezuelan pediatric TB contacts.

Carriage and invasive isolates of Streptococcus pneumoniae in Caracas, Venezuela: the relative invasiveness of serotypes and vaccine coverage.

The introduction of a pneumococcal conjugate vaccine in Venezuela needs previous studies to assess vaccine efficiency. We conducted a survey of nasopharyngeal pneumococcal carriage in urban children in Caracas and studied the distribution of serotypes. We compared these data with survey data available for invasive strains isolated in the same area and in the same time period. An overall pneumococcal carriage rate of 27% was observed. The most predominant capsular serotypes among carriage isolates were 6B (29%), 19A (13.8%), 23F (10%), 14 (8.3%), 6A (8.3%) and 15B/C (3.3%) and among invasive isolates 6B (25%), 14 (15%), and 19A, 6A, 7F, and 18 (7.5% each). The serotypes/groups 1, 5, 7F and 18, jointly covering 30% of the invasive strains, represented less than 0.7% of the carrier strains. The theoretical coverage of the pneumococcal conjugate vaccine PCV13 for carriage and invasive strains was calculated to be 74% and 90%, respectively. Our study demonstrates important differences for the serotype distribution in disease and carriage isolates and provides a key baseline for future studies addressing the prevalence and replacement of invasive and carriage serotypes after the introduction of the PCV 13 vaccine in Venezuela in the year 2010.

Fluconazol versus nistatina en niños con candidiasis orofaríngea / Fluconazole versus nystatin in children with oropharingeal candidiasis

La candidiasis orofaríngea constituye una patología frecuente en la población pediátrica. Con la finalidad de ofrecer una alternativa terapéutica segura y eficaz, se realizó un estudio multicéntrico, prospectivo, comparativo, simple ciego y de asignación aleatoria, donde se incluyeron 181 pacientes con diagnóstico clínico y micológico de candidiasis orofaríngea; fueron asignados al azar para recibir Fluconazol suspensión a 5mg/kg dosis única diaria o Nistatina suspensión 50.000 unidades/kg cada 6 horas. Se obtuvo una respuesta clínica satisfactoria al final del tratamiento con una diferencia estadística altamente significativa (p<0.001) en el grupo tratado con fluconazol (97.8 por ciento) frente al grupo de Nistatina (84.3 por ciento); y de 98.4 por ciento versus 87.9 por ciento respectivamente, un mes después de la terapia, siendo la diferencia muy significativa (p<0.01). La erradicación micológica reportó una alta significancia (p<0.0002) a favor del Fluconazol con un 74.7 por ciento contra un 35.5 por ciento de los tratados con Nistatina. El uso del Fluconazol suspensión oral, se presenta como una terapéutica eficaz, bien tolerada y de comodidad posológica en la edad pediátrica. La candidiasis albicans fue aislada en el 92 por ciento de los casos