ABSTRACT Introduction: The CVA24 antigenic variant is the causal agent of epidemics of acute hemorrhagic conjunctivitis that has prevailed to date. To study the transmission dynamics and evolution of this variant, we molecularly characterized Cuban isolates obtained in 5 epidemic periods between 1986 and 2009. Methods: Using the BEAST v1.8.4 program, it was performed the phylogenetic and phylodynamic analysis of the partial genomic regions of 54 Cuban sequences and 83 sequences from 17 countries for the 3C genomic region and 35 Cuban sequences with 95 sequences from 18 countries for the VP1 region. They were analyzed the amino acid changes of the Cuban sequences and they were compared the sequences obtained from conjunctival exudates and feces. Results: It was identified that each epidemic period was caused by different genetic variants, and homologous to variants that circulated in the Americas, Africa, and Asia, and that could circulate up to 2 years prior to the epidemic peaks. The virus showed a stable effective population over time, increasing in pandemic periods, with a nucleotide substitution rate (substitutions/site/year) of 4.39 × 10-3 for the 3C region and 5.80 × 10-3 for VP1. They were obtained 19 viral transmission routes for the 3C genomic region and 25 routes for VP1. They were inferred the routes of introduction of the virus to Cuba in the epidemic periods of the years 1986, 1997, 2003 and 2008-2009 by the ancestral relationships of the Cuban sequences with sequences of destination countries of some routes, endorsed by viral transmission networks. Amino acid changes in both genomic regions could be involved in the evolution of CVA24v and it was obtained evidence that supports the use of feces to identify this viral variant. The conclusions were new knowledge in the molecular epidemiology of CVA24v that circulated in Cuba and the world for 23 years after its global emergence.

RESUMEN Introducción: La variante antigénica del CVA24 constituye el agente causal de epidemias de conjuntivitis hemorrágica aguda que ha prevalecido hasta la actualidad. Para estudiar la dinámica de transmisión y la evolución de esta variante, caracterizamos molecularmente aislamientos cubanos obtenidos en 5 periodos epidémicos entre 1986 y 2009. Métodos: Mediante el programa BEAST v1.8.4 se realizó el análisis filogenético y filodinámico de las regiones genómicas parciales de 54 secuencias cubanas y 83 secuencias de 17 países para la región genómica 3C y 35 secuencias cubanas con 95 secuencias de 18 países para la región VP1. Se analizaron los cambios aminoacídicos de las secuencias cubanas y se compararon las secuencias obtenidas de exudados conjuntivales y heces. Resultados: Se identificó que cada periodo epidémico fue causado por variantes genéticas diferentes, y homólogas a variantes que circularon en Las Américas, África y Asia, y que pudieron circular hasta 2 años previos a los picos epidémicos. El virus mostró una población efectiva estable en el tiempo, aumentando en los periodos pandémicos, con una tasa de sustitución nucleotídica (sustituciones/sitio/año) de 4,39 × 10-3 para la región 3C y 5,80 × 10-3 para VP1. Se obtuvieron 19 rutas de transmisión viral para la región genómica 3C y 25 rutas para VP1. Las rutas de introducción del virus a Cuba en los periodos epidémicos de los años 1986, 1997, 2003 y 2008-2009 se infirieron por las relaciones de ancestralidad de las secuencias cubanas con secuencias de países destinos de algunas rutas, avaladas por redes de transmisión viral. Los cambios aminoacídicos en ambas regiones genómicas pudieran involucrarse en la evolución del CVA24v y se obtuvieron evidencias que apoyan el uso de las heces para identificar esta variante viral. Las conclusiones fueron nuevos conocimientos en la epidemiología molecular del CVA24v que circuló en Cuba y el mundo durante 23 años a partir de su emergencia global.

To determine the prevalence rates and serovar distribution of Chlamydia trachomatis cervical infections in Cuban women, two different groups were selected. Group I consisted of 60 human immunodeficiency virus (HIV-1) seropositive women from different regions of Cuba and group II of 60 randomly selected women HIV seronegative and apparently healthy. C. trachomatis was detected in cervical scrapes by mean of nested polymerase chain reaction (PCR) specific for major out membrane protein. The overall prevalence rate of C. trachomatis in cervical scrapes determined by nested PCR was 10% in group I and the estimated prevalence was 6.6% for group II; 83.3% of HIV seropositive women with C. trachomatis infection reported history of pelvic inflammatory disease followed by cervicitis (50%). The control group C. trachomatis-infected women referred a history of cervicitis in 75% of cases. Other reports in the latter group included infertility and pelvic inflamatory disease in 50%. The present study is the first report of C. trachomatis prevalence in Cuba. It showed that there was not significantly difference in the prevalence rate of C. trachomatis between both groups.

Nine Adenovirus (Ad) strains isolated in Cuba, from 128 nasopharingeal swab specimens of children below five years old, with acute respiratory diseases, during 1996 and 1997, were studied by restriction enzyme analysis of genomic DNA with two endonucleases BamH I and Sma I. All different fragment patterns were compared with the respective prototypes. The identified adenoviruses were Ad 1 (n=4), Ad 2 (n=1) and Ad 6 (n=4). Males were more frequently infected than females. The analysis of the occurrence of these Adenovirus strains of subgenus C revealed that Ad 1 and Ad 6 were the predominant serotypes in 1996 and in 1997, respectively.

The polymerase chain reaction technique was applied to detect sequences of human Papillomavirus (HPV) by controls of cellular lines of cervical cancer and of tissues obtained through biopsy with a HPV-positive clinical diagnosis. A set of consensus oligonucleotides, which are complementary to a highly conserved region within the open reading frame El of the viral genome of HPV affecting the cervical mucosa, was used. With these primers it was possible to amplify DNA sequences corresponding to HPV 6 and 11, considered in the low risk group, and to HPV 16, 18, 31 and 33, included in the high risk group. The study of the sensitivity of the amplification technique showed a level of detection of 3,5 viral particles per each cellular diploid genome.

Se aplicó la técnica de reacción en cadena de la polimerasa para la detección de secuencias de Papillomavirus humano (PVH) mediante controles de líneas celulares de cáncer cervical y tejidos obtenidos por biopsia con diagnóstico clínico positivo a PVH. Se utilizó un juego de oligonucleótidos consenso, que son complementarios a una región altamente conservada dentro del marco de lectura abierta E1 del genoma viral de los PVH que afectan la mucosa cervical. Con este juego de cebadores fue posible amplificar secuencias de ácido desoxirribonucleico (ADN) correspondientes a los PVH 6 y 11, considerados dentro del grupo de bajo riesgo y de los PVH 16, 18, 31 y 33 comprendidos en el grupo de alto riego. El estudio de la sensibilidad de la técnica de amplificación arrojó como resultado un nivel de detección de 3,5 partículas virales por cada genoma diploide celular.

The immune response of a group of patients with epidemical neuropathy and of controls was studied by the immunoblotting technique against proteins of the Coxsackie virus and the proteins of slow effect isolated in our laboratory. 13 sera of patients with epidemical neuropathy and 9 sera of controls were studied. Of the 13 sera studied, 8 (61.5 %) recognized protein VPI and 2 sera (15.3 %) protein VP0 of the strain 47.93. Of the 9 controls studied, 4 (44.4 %) recognized protein VPI and 3 (33.3 %) protein VP0 only. With the antigen prepared from the slow effect strain it was obtained a specific signal in 5 (38.5 %) sera of patients and in 2 sera (22.5 %) of controls. It should be stressed that in this last case the protein observed had a molecular weight of 41 300 D, and that its size was smaller than that of the preceeding protein detected against the strain 47.93 was of 45 000 D.

Se estudió la respuesta inmune de un grupo de pacientes con neuropatía epidémica y de individuos controles mediante la técnica de inmunoblotting frente a las proteínas del virus Coxsackie y a las proteínas de la cepa de efecto lento aislada en nuestro laboratorio. Se estudiaron 13 sueros de pacientes con neuropatía epidémica y 9 sueros controles. De los 13 sueros estudiados, 8 (61,5 %) reconocieron a la proteína VP1 y 2 sueros (15,3 %) a la proteína VP0 de la cepa 47/93. De los 9 controles estudiados, 4 (44,4 %) reconocieron la proteína VP1 y 3 sueros (33,3 %) la proteína VP0 solamente. Con el antígeno preparado a partir de la cepa de efecto lento, en 5 (38,5 %) sueros de pacientes y 2 sueros (22,5 %) de controles se obtuvo una señal específica. Es de destacar en este último caso que la proteína observada tenía un peso molecular de 41 300 D, era de menor talla que la proteína precursora detectada frente a la cepa 47/93, que fue de 45 000 D.