ABSTRACT Arboviruses are one of the leading causes of health emergencies due to their morbidity and mortality and the sanitary stress they bring about. Cuba has not been free from risk, and the response first to dengue fever and then to other arboviruses has been and still is a priority for the country's top authorities. Laboratory surveillance of dengue fever was implemented in the 1970s, though its aims and strategies have evolved in keeping with the national and regional epidemiological situation, and the available diagnostic technology. Four stages stand out in the development of dengue laboratory surveillance. The present paper summarizes the strategies developed for laboratory surveillance of dengue fever and other arboviruses in the period 1970-2017. A description is also provided of the role played by Pedro Kourí Tropical Medicine Institute (IPK) as a national reference laboratory.

RESUMEN Los arbovirus constituyen una de las principales causas de emergencia en salud por la morbilidad y mortalidad que producen y el estrés sanitario que conllevan. Cuba no ha estado excenta de riesgo, y el enfrentamiento del dengue inicialmente y de otros arbovirus después, ha sido, y es, una prioridad de las máximas autoridades del país. La vigilancia de laboratorio de dengue se estableció desde inicios de la década del 70 aunque sus objetivos y estrategias han cambiado según la situación epidemiológica nacional y regional y la tecnología de diagnóstico disponible. Se destacan cuatro etapas en su desarrollo. En este trabajo se resumen las estrategias desarrolladas para la vigilancia de laboratorio de dengue y de otros arbovirus en el periodo de 1970 a 2017. Se describe además el papel desempeñado por el Instituto de Medicina Tropical, ¨Pedro Kouri¨ (IPK) como Laboratorio Nacional de Referencia.

The association between colorectal cancer and human papillomavirus (HPV) infection is still unproven. The aim of this study was to investigate the presence of high-risk HPV (HR-HPV) DNA in colorectal tissues from Cuban patients. A total of 63 colorectal formalin-fixed paraffin-embedded tissues were studied (24 adenocarcinoma, 18 adenoma, and 21 colorectal tissues classified as benign colitis). DNA from colorectal samples was analysed by quantitative real-time polymerase chain reaction to detect the most clinically relevant high HR-HPV types (HPV-16, -18, -31, -33, -45, -52, and -58). Associations between histologic findings and other risk factors were also analysed. Overall, HPV DNA was detected in 23.8% (15/63) of the samples studied. Viral infections were detected in 41.7% of adenocarcinoma (10/24) and 27.7% of adenoma cases (5/18). HPV DNA was not found in any of the negative cases. An association between histological diagnosis of adenocarcinoma and HPV infection was observed (odd ratio = 4.85, 95% confidence interval = 1.40-16.80, p = 0.009). The only genotypes identified were HPV 16 and 33. Viral loads were higher in adenocarcinoma, and these cases were associated with HPV 16. This study provides molecular evidence of HR-HPV infection in colorectal adenocarcinoma tissues from Cuban patients.

The objective of the present study is to standardize a real-time based polymerase chain reaction system in order to detect and quantify 7 high risk human papillomavirus in different clinical samples from patients suspected of this type of infection. The validation of a 5´ exonuclease fluorescent probe real-time PCR assay (TaqMan format) for the detection and quantification of the 7 most frequent HR-HPV types (16, 18, 31, 33, 45, and 58) which account for over 87% of cervical carcinomas world-wide was carried out. Simultaneous PCR reactions are required to detect the designated HPV types. Specificity tests for each HPV type and other DNA viruses were performed. Standard external curve constructions were achieved, which allow determining the number of target DNA copies in the previously HPV tested samples. HPV 16 and 18 standard curves were obtained from purified genomic DNA of SiHa and HeLa cell lines, respectively. The pattern curves were constructed on the basis of each of the resulting standard DNA, which showed good linear correlation (r = -0, 99) and low error values. The lower detection limit was 10 copies for both HPV 16 and 18. No cross reactions between HPV types and other DNA viruses were observed. Real-Time Polymerase Chain Reaction system, standardized for 7 HPV types, proved to be a rapid, specific and highly sensitive system for better diagnosis and follow-up of patients with high grade intraepithelial lesions. In addition, this assay will allow the development of coming researches in relation with the prevalence and pathogenesis of human papillomavirus infections in different samples from Cuban patients.

El objetivo de este trabajo fue normalizar e implementar un sistema de reacción en cadena de la polimerasa en tiempo real, para determinar la carga viral de 7 genotipos de papilomavirus humano (PVH) de alto riesgo oncogénico. Se evaluó la especificidad del sistema y se construyeron las curvas estándar para PVH 16 y 18, que se emplearon para la cuantificación de ADN viral en diferentes muestras de pacientes identificados como positivos a PVH, mediante reacción en cadena de la polimerasa (RCP) cualitativa y secuenciación nucleotídica. Se obtuvieron dos curvas estándar para PVH 16 y 18, a partir del ADN genómico de las líneas celulares SiHa y HeLa, las que mostraron una buena correlación lineal ( r = -0,99) y valores bajos de error. El límite inferior de detección a partir del ADN de las líneas celulares fue de hasta 10 copias para ambos genotipos. No se obtuvo reacción cruzada entre los diferentes tipos de PVH ni con otros virus ADN. La reacción en cadena de la polimerasa en tiempo real (RCP-TR) normalizada probó ser un sistema simple, rápido, específico y altamente sensible. Además, permitirá desarrollar investigaciones sobre la prevalencia de infección por PVH en Cuba, con vistas a la aplicación de las vacunas que se encuentran disponibles en el mercado internacional, así como la evaluación de otros candidatos vacunales diseñados en el futuro.