Identificación de serotipos del virus dengue circulantes en el estado de Campeche, México / Identification of dengue virus serotypes circulating in Campeche state, Mexico

Introducción: el dengue en la actualidad es una arbovirosis que está impactando a los países latinoamericanos, y México no ha sido la excepción, donde de ser una región hipoendémica ha evolucionado a hiperendémica por la múltiple circulación de los serotipos. Objetivos: determinar la seroprevalencia de los virus del dengue en el Estado de Campeche, México e identificar los serotipos circulantes en los diferentes municipios que conforman el estado. Métodos: para este estudio se emplearon los métodos de ELISA de inhibición y la prueba de neutralización por reducción del número de placas. Resultados: de un total de 600 muestras obtenidas, 67,5 por ciento (405) presentó anticuerpos IgG contra virus dengue y 32,5 por ciento (195) resultó negativo. Con respecto a los serotipos se detectó que 32,3 por ciento tuvo una infección primaria con predominio del serotipo DEN-1 y 68 por ciento infección secundaria; prevaleció la secuencia DEN-1/ DEN-2 y DEN-3/ DEN-4 en 9 municipios. El grupo de edad en el que fue más frecuente la infección a los 4 serotipos resultó el de 21 a 30 años. El serotipo que resultó con mayor circulación en el estado fue DEN-1. Conclusiones: la seroprevalencia y la frecuencia de infección secundaria observada en niños y adultos, indica la elevada circulación de los virus en el Estado; este resultó un factor epidemiológico importante para la aparición de brotes epidémicos y de las formas graves de la enfermedad.

Background: at present, dengue is an arbovirosis that is greatly affecting the Latin American countries, and Mexico is not the exception, where a hypoendemic region has evolved into a hyperendemic area because of the circulation of multiple serotypes. Objectives: to determine the seroprevalence of dengue virus in Campeche state, Mexico, and to identify the circulating serotypes in its various municipalities. Methods: inhibition ELISA and plate reduction neutralizing test were the methods used in this study. RESULTS: of 600 samples, 67.5 percent (405) had IgG antibodies to dengue virus whereas 32.5 percent (195) were negative. Regarding the serotypes, 32.3 percent had primary infection with serotype DEN-1 and 68 percent showed secondary infection; the prevailing sequence was DEN-1/DEN-2 and DEN-3/DEN-4 in 9 municipalities. The infection with the 4 serotypes was mostly found in the 21-30 y age group. The most circulating serotype was DEN-1 throughout the state. Conclusions: seroprevalence and frequency of secondary infection observed in children and adults indicated an increased circulation of virus in the state and this was considered an important epidemiological factor for the emergence of outbreaks and the most severe forms of the disease.

Seroepidemiological studies of cutaneous leishmaniasis in the Campeche State of Mexico

Seroepidemiological studies of cutaneous leismaniasis were carried out in 169 individuals in a rural area of the Campeche State of Mexico. Fifty showed cutaneous lesions suggestive of leishmaniasis, 70 per cent were parasite positive and 96 per cent skin test positive. An overall 40 per cent positivity to skin test with Montenegro's antigen was found. Most of the effected individuals were males from 11 to 30 years-old. Antibodies were determined by immunoflurescent antibody test (IFA) and by Western blot. Two antigen preparations were used, one from a Leishmania mexicana strain which produced localized cutaneous leishmaniasis (LCL) and the other from a diffuse cutaneous leishmaniasis (DCL). In the general population from the area of study 19 per cent gave positive IFA tests with DCL antigen and 20 per cent with LCL antigen while for patients 67 per cent gave positive IFA tests with DCL and 71 per cent with LCL. By Western blot analysis most of the patients recognized more antigens in the DCL than in the LCL strain. In the DCL strain 78 per cent of patients recognized a 105 kDa, 34 per cent a 139 kDa and 26 per cent a 205 kDa MW antigen. In the LCL strain 40 per cent of patients recognized a 205 kDa and 22 per cent a 175 kDa antigens.