The main objective of this study is to evaluate the prevalence of resistance-associated mutations to reverse transcriptase (RT) and protease (PR) inhibitors (I) 2 years after the introduction of antiretroviral treatment in Cuba, analyzing the mutations corresponding to different HIV-1 genetic forms circulating in Cuba. A total of 425 plasma samples were collected in 2003, corresponding to 175 (41.2%) subtype B and 250 (58.8%) non-B genetic forms, including 56 (22.4 %) non-B subtypes, 112 (44.8%) circulating recombinant forms (CRFs), and 82 (32.8%) unique RFs (URFs). Of these, 175 (41.2%) patients were under highly active antiretroviral therapy (HAART) and 250 (58.8%) were treatment-naive. The presence of RT and PR resistance-associated mutations was established by sequencing. Levels of resistance were evaluated according to the Stanford Database program (http://hivdb.stanford.edu). The prevalence of resistance to RTI was 52.2% among RTI-treated patients, 51.5% for subtype B, and 53.2% for non-B genetic forms, including CRF18_cpx, CRF19_cpx, subtype C, and BG URF. In treatment-naive patients it was 6.4% in subtype B and 4.2% in non-B subtypes and RFs. The prevalence of resistance to PRI was 30% among PRI-treated patients, 28% in subtype B and 31% in non-B genetic forms, and 3.2% among treatment-naive subjects, mostly BG recombinants. In conclusion, significant differences in the prevalence of resistance to RTI and PRI were not detected among the most frequent genetic forms from treated patients, suggesting that the genetic diversity of HIV-1 in Cuba does not play a main role in the development of resistance to antiretroviral drugs. The presence of transmitted resistance mutations supports the study of resistance at baseline of treatment.

BG intersubtype recombinants represented 11.6% of HIV-1 isolates in a recent survey in Cuba based on pol sequences, most of them forming a single clade further subdivided into 3 subclades. Here, we analyze 8 near full-length genomes and 1 gag-pol sequence from epidemiologically unlinked Cuban BG recombinants from these 3 subclades (3 from each). Near full-length sequences were also obtained from 3 subtype G and 2 subtype B Cuban viruses. Phylogenetic relationships were estimated via maximum likelihood, and mosaic structures of the recombinants were inferred with the bootscanning, MaxChi, Genconv, and GARD methods. For the near full-length genomes, all recombinants formed a strongly supported clade further subdivided into the same subclades previously defined in pol. Mosaic structures were identical within each subclade and different among subclades, although 5 breakpoints were coincident among all recombinants. Individual phylogenetic trees for nonrecombinant fragments (concatenated B and G subtype segments) indicated a common ancestry for the parental viruses and their relationships to local subtype B and G strains. These results allow us to identify 3 new BG intersubtype circulating recombinant forms in Cuba derived from a common recombinant ancestor, which originated from B and G subtype parental strains circulating in Cuba.

Highly diverse HIV-1 genetic forms are circulating in Cuba, including subtypes B and G and two recombinant forms of African origin (CRF18_cpx and CRF19_cpx). Here we phylogenetically analyze pol sequences from a large collection of recent samples from Cuba, corresponding to 425 individuals from all Cuban provinces, which represents approximately 12% of prevalent infections in the country. RNA from plasma was used to amplify a pol segment by reverse transcription-polymerase chain reaction; phylogenetic analyses were performed with neighbour-joining trees and bootscanning. The distribution of genetic forms was subtype B, 41.2%; CRF19_cpx, 18.4%; BG recombinants, 11.6%; CRF18_cpx, 7.1%; subtype C, 6.1%; subtype G, 3.8%; B/CRF18 recombinants, 2.6%; subtype H, 2.1%; B/CRF19 recombinants, 1.7%; and others, 5.4%. Seventy-five (17.6%) viruses were recombinant between genetic forms circulating in Cuba. In logistic regression analyses, adjusting by gender and region, subtype B was more prevalent (OR 5.0, 95% CI 2.0-12.3) and subtype G less prevalent (OR 0.1, 95% CI 0.0-0.5) among men who have sex with men (MSM) than among heterosexuals. Within the main genetic forms of Cuba there were phylogenetic subclusters, several of which correlated with risk exposure or region. BG recombinants formed three phylogenetically related subclusters, corresponding to three different mosaic structures; most of these recombinants were from MSM from Havana City, among whom they have expanded recently, reaching 31% HIV-1 infections diagnosed in 2003. This study confirms the high HIV-1 diversity and frequent recombination in Cuba and reveals the recent expansion of diverse related BG recombinant forms in this country.

Background: During the 1994–1995 season, an increase in the circulation of influenza type B was observed in our infantile population, according to serological studies (hemagglutination-inhibition). We reported the case of four children (<1 year old) that were diagnosed with influenza-like illness, who developed a severe disease (rapid progressive encephalopathy) with high fever, drowsiness and recurrent convulsions, and were presumptively diagnosed with encephalomyocarditis. Brain and lung necropsies were carried out. Materials and methods: Initial laboratory diagnosis was done by immunofluorescence assay on brain and lung samples, followed by viral isolation in MDCK cells and chicken eggs. The isolates were characterized antigenically by haemagglutination-inhibition assay (HI) with post-infection ferret antisera. Results: For the immunofluorescence technique, four samples were positive. In MDCK and chicken eggs, six haemagglutinating agents characterized by hemagglutination-inhibition were similar to the B/Beijing/184/93-like reference strain (four from the lungs and two from the brain). Data from the morbidity report will be presented. Serological studies (monosera and pair sera) showed an increase in the circulation of influenza B in our infantile population. Conclusions: The pathogenesis of encephalopathy is still not clarified. However, we believe that viremia is the key to initiation. There is an urgent need to promote vaccination against influenza in young children to prevent these devastating disease conditions.

Background: In Cuba, flu is the first cause of infectious diseases and the fifth general cause of death associated with pneumonia. Lung necropsies were carried out on 15 fatal cases, between 20–54 years old, and dengue was presumptively diagnosed during an epidemic outbreak in 1997. According to virological evaluation, it was demonstrated that the causative agent in nine of these cases was influenza virus. Techniques and Methods: Indirect Immunofluorescence (IFI); immunoperoxidase staining (IPS); RT-PCR; nucleotide sequence. Culture was in MDCK cells and chicken eggs and hemagglutination inhibition was used for antigenic characterization. Results: With the IFA technique, nine cases (60%) were positive and with IPS, seven cases were positive (46.7%). In MDCK and chicken eggs, six hemagglutinating agents characterized by hemagglutination inhibition were similar to the reference strain A/Johannesburg/33/94 (H3N2). Type and subtype A(H3N2) were demonstrated by RT-PCR, too. Nucleotide sequences were determined and compared. Serological studies showed that the isolated A/Santiago de Cuba/193/97 strain was circulating in the population studied. Morbidity reports during January to May showed an average of 19 600 cases per month; however, morbidity during June and July rose to 39 800 per month. Conclusion: This is the first report about the co-circulation of influenza and dengue viruses in Cuba. It also reinforces the necessity of developing prophylactic, clinical and epidemiological actions against flu during dengue virus epidemics.

The paper presents the case of a female patient who was admitted to "Calixto García" General Hospital with respiratory distress and hypovolemic or septic shock. She was diagnosed with viral hemorrhagic pneumonia. From the endotracheal secretion taken as a sample, the influenza virus was isolated as etiological agent, which, through the hemaglutination inhibition technique, was characterized as a strain belonging to H3N2 subtype, very similar to strain A/Johannesburg/33/94 from the antigenic viewpoint. The patient recovered satisfactorily after being treated with rivabirin.

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.

An increase in the reported cases of viral meningoencephalitis (VME) was detected in October and November, 1995, compared with the same period of 1994. 43 stock specimens from children with this diagnosis were received at the Laboratory of Enterovirus from the "Pedro Kourí" Institute of Tropical Medicine. 23 isolations (53.4%) were obtained and identified as Coxsackievirus B5. Besides, in 43 matched sera investigated by the neutralization test against some Enteroviruses, 21 proved to be positive (48.8%) to the isolated agent. This allowed us to affirm, supported by the clinical picture and by epidemiology, that we are in the presence of an VME outbreak produced by Coxsackievirus B5.

The NCI-H292 continual line of mucoepidermoid cells of the human lungs has been reported to be useful for the propagation of many viruses, mainly Adenovirus and Paramyxovirus. It is stated the possible substitution of primary cultures of monkey kidney for NCI-H292 in order to isolate such agents. In the present paper it is evaluated the utility of this line for multiplying the respiratory syncytial viruses Adenovirus 3 and 7, and the parainfluenza viruses 1, 2, and 3, in comparison with the continual cellular lines traditionally used for the propagation of these viruses, whose strains were inoculated this time in the Vero, HEp-2, and HeLa lines, according to their know sensitivities as well as in NCI-H292 simultaneously. The viral multiplication was detected by the appearance of the cytopathic effect or by hemadsorption. As a result, it was demonstrated the multiplication capacity of the NCI-H292 line for Adenoviruses 3 and 7 and parainfluenza 3, being more useful for their multiplication than the traditionally used lines.