Vigilancia de laboratorio de dengue y otros arbovirus en Cuba, 1970-2017 / Laboratory surveillance of dengue fever and other arboviruses in Cuba, 1970-2017

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(AU)

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(AU)

Molecular evidence of high-risk human papillomavirus infection in colorectal tumours from Cuban patients

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.

Molecular evidence of high-risk human papillomavirus infection in colorectal tumours from Cuban patients.

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.

Normalización de un sistema de reacción en cadena de la polimerasa en tiempo real para la cuantificación de papilomavirus humano de alto riesgo oncogénico / Standardization of a real-time based polymerase chain reaction system for the quantification of human papilomavirus of high oncogenic risk

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(AU)

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(AU)

Isolation of Coxsackievirus A24 variant from patients with hemorrhagic conjunctivitis in Cuba, 2008-2009.

BACKGROUND: An outbreak of acute hemorrhagic conjunctivitis occurred in Cuba in 2008 and 2009. OBJECTIVE: To determinate the etiological agent associated with the Cuban outbreaks of acute hemorrhagic conjunctivitis during 2008 and 2009. STUDY DESIGN: Conjunctival swabs and/or faecal samples from 382 patients with clinical diagnosis suggestive of acute hemorrhagic conjunctivitis were subject to viral culture in HEp-2 human laryngeal epidermoid carcinoma cells. Positive samples were identified by a specific Coxsackievirus A24 variant PCR and the 3C protease region of 16 isolates was sequenced for phylogenetic analysis. RESULTS: Enterovirus cytopathic effect was observed in 138 cases (36%). A higher percent of CA24v was recovered from faecal samples, 19 out of 45 cases (42.2%), than from conjunctival swabs, 127 out of 355 samples (35.8%). All isolates were identified as Coxsackievirus A24 variant. Phylogenetic analysis revealed that 2008 and 2009 Cuban outbreaks were caused by the same virus strains and that isolates were closely related to those from Taiwan (2006-2007), China (2007-2008) and Singapore (2005) with a bootstrap value of 71%. CONCLUSIONS: Outbreaks of acute hemorrhagic conjunctivitis occurred in Cuba in 2008 and 2009 were caused by Coxsackievirus A24 variant. The faecal-oral route is another mode of transmission of CA24v in the acute hemorrhagic conjunctivitis outbreaks. Phylogenetic analysis of Cuban CA24v strains involved in an acute hemorrhagic conjunctivitis outbreak in 2008 and 2009 confirms a new introduction of the CA24 variant into the Americas from South-east Asia.

Kaposi's sarcoma-associated herpesvirus load in asymptomatic contacts of Cuban epidemic KS patients.

To evaluate the pathogenic mechanisms and transmission routes involved in KSHV infection in 22 Cuban individuals who maintained close contact with epidemic KS patients, real-time PCR was used to quantify KSHV-DNA in clinical samples of plasma, saliva and peripheral blood mononuclear cells (PBMC). KSHV-DNA was detected in 72.7% (16/22) of the contacts. The highest levels of KSHV load were detected in saliva, followed by PBMC (average log copies/100 ng DNA = 1.28 and 1.12), while significantly lower levels were detected in plasma (average log copies/ml = 0.37). Two of three intra-domiciliary and two serodiscordant sexual contacts of AIDS-KS patients were infected with KSHV. The rate of KSHV-DNA detection in saliva and PBMC samples in men who have sex with men (MSM) was significantly higher than in heterosexuals (HT) (p = 0.014). MSM were more likely to harbor KSHV-DNA in saliva when compared with HT individuals (OR 4.33; 95% CI 1.117-16.8). These results emphasize that, in Cuba, KSHV horizontal transmission through saliva may occur, although homosexual behavior may predispose an individual to KSHV acquisition. Even in the absence of disease, KSHV could cause an asymptomatic systemic infection in individuals who maintain close contact with AIDS-KS patients.

Diagnosis and screening for cytomegalovirus infection in pregnant women in Cuba as prognostic markers of congenital infection in newborns: 2007-2008.

BACKGROUND: Human cytomegalovirus (HCMV) has established itself as the most significant cause of congenital infection in the developed world. The objective of this research was prenatal identification of pregnant women at risk for developing active infection due to HCMV as well as to diagnose congenitally infected newborns. METHODS: A diagnostic algorithm based on specific immunoglobulin G (IgG), IgM, and, IgG avidity was used to screen serum from 1131 pregnant women enrolled prospectively from 3 municipalities from Havana City, Cuba during 2007-2008. Qualitative multiplex nested PCR and quantitative real time-based PCR testing for HCMV DNA were performed on urine and saliva specimens from women detected with active infection and from their newborns. RESULTS: Most women were seropositive to HCMV (92.7%), with 2.38% (27 women) having active infection. Primary infection was detected in 20 pregnant women (1.77%) while 7 patients (0.62%) had active nonprimary infection. HCMV DNA was detected in specimens from 9 of the 27 pregnant women by both PCR methods. HCMV congenital infection was diagnosed in 12 (1.06%) of the 26 live children born from 25 mothers with active infection, for a vertical transmission rate of 46.2%. Two fetal deaths were reported from 2 women with active infection; furthermore 2 newborns were symptomatic at birth and 2 showed sequelae during the follow-up done until 6 months age. CONCLUSIONS: Mothers with active infection during the pregnancy and with HCMV excretion had significant risks, RR = 1.16 and RR = 1.35, respectively, to have congenitally infected children.

The effect of highly active antiretroviral therapy on outcome of central nervous system herpesviruses infection in Cuban human immunodeficiency virus-infected individuals.

With the rapid progress in the development of highly active antiretroviral therapy (HAART), the observed patterns in human immunodeficiency virus (HIV) encephalitis has changed, allowing herpesvirus (HV) infection to be controlled. HAART was first administered to HIV patients in Cuba in 2001. Consequently with the aim of investigate the behavior of the HVs causing neurological disorders in this population in the post-HAART era, the authors perform a clinical evaluation by a multiplex nested polymerase chain reaction (PCR) assay for simultaneous detection of human HVs--herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and Epstein-Barr virus (EBV). The authors studied 241 samples of cerebrospinal fluid (CSF) received at the Sexually Transmitted Diseases Laboratory between 2001 and 2005 inclusive. Of the 241 CSF studied, 10.4% resulted positive for HV infections. Of these, 92% of patients were acquired immunodeficiency syndrome (AIDS) individuals at the C3 stage. CMV (44%), EBV (28%), and dual-HV (16%) infections were the most important agents identified. The principal clinical manifestations were fever, headache, vomiting, and focal abnormalities; the latter being associated with an increased risk of death. A statistically significant result was observed when central nervous system (CNS) disease evolution was compared between patients who were under HAART against those who were not, before they developed encephalitis. It was therefore concluded that it is more likely that HIV individuals receiving HAART have a better recovery of CNS infections than those who are not receiving it.