Adenovirus respiratory tract infections in Peru.

BACKGROUND: Currently, there is a paucity of data regarding human adenovirus (HAdv) circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru. METHODS/PRINCIPAL FINDINGS: Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI) or severe acute respiratory infection (SARI) were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected. CONCLUSIONS/SIGNIFICANCE: HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness.

Sentinel surveillance of influenza-like illness in two hospitals in Maracay, Venezuela: 2006-2010.

BACKGROUND: Limited information exists on the epidemiology of acute febrile respiratory illnesses in tropical South American countries such as Venezuela. The objective of the present study was to examine the epidemiology of influenza-like illness (ILI) in two hospitals in Maracay, Venezuela. METHODOLOGY/PRINCIPAL FINDINGS: We performed a prospective surveillance study of persons with ILI who presented for care at two hospitals in Maracay, Venezuela, from October 2006 to December 2010. A respiratory specimen and clinical information were obtained from each participant. Viral isolation and identification with immunofluorescent antibodies and molecular methods were employed to detect respiratory viruses such as adenovirus, influenza A and B, parainfluenza, and respiratory sincytial virus, among others. There were 916 participants in the study (median age: 17 years; range: 1 month--86 years). Viruses were identified in 143 (15.6%) subjects, and one participant was found to have a co-infection with more than one virus. Influenza viruses, including pandemic H1N1 2009, were the most frequently detected pathogens, accounting for 67.4% (97/144) of the viruses detected. Adenovirus (15/144), parainfluenza virus (13/144), and respiratory syncytial virus (11/144) were also important causes of ILI in this study. Pandemic H1N1 2009 virus became the most commonly isolated influenza virus during its initial appearance in 2009. Two waves of the pandemic were observed: the first which peaked in August 2009 and the second--higher than the preceding - that peaked in October 2009. In 2010, influenza A/H3N2 re-emerged as the most predominant respiratory virus detected. CONCLUSIONS/SIGNIFICANCE: Influenza viruses were the most commonly detected viral organisms among patients with acute febrile respiratory illnesses presenting at two hospitals in Maracay, Venezuela. Pandemic H1N1 2009 influenza virus did not completely replace other circulating influenza viruses during its initial appearance in 2009. Seasonal influenza A/H3N2 was the most common influenza virus in the post-pandemic phase.

Influenza and other respiratory viruses in three Central American countries.

BACKGROUND: Despite the disease burden imposed by respiratory diseases on children in Central America, there is a paucity of data describing the etiologic agents of the disease. AIMS: To analyze viral etiologic agents associated with influenza-like illness (ILI) in participants reporting to one outpatient health center, one pediatric hospital, and three general hospitals in El Salvador, Honduras, and Nicaragua Material & METHODS: Between August 2006 and April 2009, pharyngeal swabs were collected from outpatients and inpatients. Patient specimens were inoculated onto cultured cell monolayers, and viral antigens were detected by indirect and direct immunofluorescence staining. RESULTS: A total of 1,756 patients were enrolled, of whom 1,195 (68.3%) were under the age of 5; and 183 (10.4%) required hospitalization. One or more viral agents were identified in 434 (24.7%) cases, of which 17 (3.9%) were dual infections. The most common viruses isolated were influenza A virus (130; 7.4% of cases), respiratory syncytial virus (122; 6.9%), adenoviruses (63; 3.6%), parainfluenza viruses (57; 3.2%), influenza B virus (47; 2.7% of cases), and herpes simplex virus 1 (22; 1.3%). In addition, human metapneumovirus and enteroviruses (coxsackie and echovirus) were isolated from patient specimens. DISCUSSION: When compared to the rest of the population, viruses were isolated from a significantly higher percentage of patients age 5 or younger. The prevalence of influenza A virus or influenza B virus infections was similar between the younger and older age groups. RSV was the most commonly detected pathogen in infants age 5 and younger and was significantly associated with pneumonia (p < 0.0001) and hospitalization (p < 0.0001). CONCLUSION: Genetic analysis of influenza isolates identified A (H3N2), A (H1N1), and B viruses. It also showed that the mutation H274Y conferring resistance to oseltamivir was first detected in Honduran influenza A/H1N1 strains at the beginning of 2008. These data demonstrate that a diverse range of respiratory pathogens are associated with ILI in Honduras, El Salvador, and Nicaragua. RSV infection in particular appears to be associated with severe disease in infants in the region.

Changes in the viral distribution pattern after the appearance of the novel influenza A H1N1 (pH1N1) virus in influenza-like illness patients in Peru.

BACKGROUND: We describe the temporal variation in viral agents detected in influenza like illness (ILI) patients before and after the appearance of the ongoing pandemic influenza A (H1N1) (pH1N1) in Peru between 4-January and 13-July 2009. METHODS: At the health centers, one oropharyngeal swab was obtained for viral isolation. From epidemiological week (EW) 1 to 18, at the US Naval Medical Research Center Detachment (NMRCD) in Lima, the specimens were inoculated into four cell lines for virus isolation. In addition, from EW 19 to 28, the specimens were also analyzed by real time-polymerase-chain-reaction (rRT-PCR). RESULTS: We enrolled 2,872 patients: 1,422 cases before the appearance of the pH1N1 virus, and 1,450 during the pandemic. Non-pH1N1 influenza A virus was the predominant viral strain circulating in Peru through (EW) 18, representing 57.8% of the confirmed cases; however, this predominance shifted to pH1N1 (51.5%) from EW 19-28. During this study period, most of pH1N1 cases were diagnosed in the capital city (Lima) followed by other cities including Cusco and Trujillo. In contrast, novel influenza cases were essentially absent in the tropical rain forest (jungle) cities during our study period. The city of Iquitos (Jungle) had the highest number of influenza B cases and only one pH1N1 case. CONCLUSIONS: The viral distribution in Peru changed upon the introduction of the pH1N1 virus compared to previous months. Although influenza A viruses continue to be the predominant viral pathogen, the pH1N1 virus predominated over the other influenza A viruses.

Distribución de los subtipos del VIH-1 en nueve países de América del Sur, 1995-2002 / Distribution on HIV-1 subtypes in nine countries of South America, 1995-2002

Objetivo: Determinar la distribución de los subtipos del virus de la inmunodeficiencia humana (VIH-1) y la presencia de cepas recombinantes en Argentina, Bolivia, Colombia, Chile, Ecuador, Paraguay, Perú, Uruguay y Venezuela a través de estudios epidemiológicos y de genotipificación. Materiales y Métodos: Se incluyeron a los participantes de los protocolos realizados en los nueve paises, incluyendo poblaciones de trabajadoras sexuales (TS), hombres que tienen sexo con hombres (HSH), individuos VIH positivos, gestantes y pacientes con tuberculosis (TB). Se utilizó la prueba de movilidad heteroduplex de envoltura (env HMA), ProRT, secuenciamiento completo o ambas para determinar los subtipos de VIH 1. Resultados: Se identificaron 3081 individuos positivos al VIH (de un total de 42 290voluntarios), las prevalencias oscilaban entre menos de 1 por ciento a 29 por ciento según población estudiada, siendo mayor en los HSH. Un total de 1654 muestras (54 por ciento) fueron genotipificadas. Se encontró el subtipo B en 1380 (83 por ciento) muestras, el subtipo F en 218 (13 por ciento), así como los subtipos A y C en 0,1 por ciento y 0,4 por ciento respectivamente. Se hallaron subtipos recombinantes BF en 39 muestras (2 por ciento) y formas recombinantes CRF01_AE(0,1 por ciento), CRF17_BF(0,4 por ciento) y CRF02_AG(0,1 por ciento). En Venezuela, Colombia, Ecuador, Perú, Bolivia y Chile (paises andinos) predominó el subtipo B, mientras en Argentina, Uruguay y Paraguay hubo un alto porcentaje del subtipo F. Conclusiones: En la mayoría de países andinos la epidemia de VIH-1 se concentró en los HSH con un predominio del subtipo B. El subtipo F es másfrecuente en las TS en Argentina y Uruguay. Esta información es útil para implementar planes de prevención y futuros ensayos de vacunas en esta región.

Objectives: To determine human immunodeficiency virus type 1 (HIV-1) subtype distribution, and the presence of recombinant strains in Argentina, Bolivia, Colombia, Chile, Ecuador, Paraguay, Peru, Uruguay, and Venezuela using epidemiological and genotyping studies. Materials and Methods: Participants in the studies performed in nine countries were included, amongst them female sex workers, men who have sex with men (MSM), HIV-positive individuals, pregnant women, and patients with tuberculosis (TB) were included. Envelope-base heteroduplex mobility assay (env HMA) testing was used, as well as ProRT, complete sequencing, or both for determining HIV-1 subtypes. Results: 3081 HIV positive individuals were identified (out of 42 290 volunteers), prevalences from less than 1% to 29% in the different populations studied, and it was higher among MSM. 1654 samples (54%) underwent genotyping. B subtype was found in 1380 (83%) samples, F subtype was found in 218 (13%) samples, and A and C subtypes were found in 0,1% and 0,4%, respectively. BF recombinant serotypes were found in 39 samples (2%), and CRF01_AE (0,1%), CRF17_BF (0,4%), and CRF02_AG (0,1%) were also found. In Venezuela, Colombia, Ecuador, Peru, Bolivia, and Chile (Andean countries) subtype B predominated, while in Argentina, Uruguay, and Paraguay there was a high frequency of F subtype. Conclusions: In most Andean countries, HIV-1 epidemic concentrated among MSM, who are predominantly infected with B subtype. F subtype is more frequent among female sex workers in Argentina and Uruguay. This is useful information in order to implement prevention plans and future vaccine tests in this region.