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Please cite this paper as: Salmon-Mulanovich et al. (2010) Frequency of human bocavirus (HBoV) infection among children with febrile respiratory symptoms in Argentina, Nicaragua and Peru. Influenza and Other Respiratory Viruses 5(1), 1–5. Background Globally, respiratory infections are the primary cause of illness in developing countries, specifically among children; however, an etiological agent for many of these illnesses is rarely identified. Objectives Our study aimed to estimate the frequency of human bocavirus (HBoV) infection among pediatric populations in Argentina, Nicaragua and Peru. Methods We conducted a cross-sectional study using stored samples of an influenza-like illness surveillance program. Irrespective of previous diagnosis, nasopharyngeal or nasal swab specimens were randomly selected and tested using real-time PCR from three sites during 2007 from patients younger than 6 years old. Results A total of 568 specimens from Argentina (185), Nicaragua (192) and Peru (191) were tested. The prevalence of HBoV was 10·8% (95% CI: 6·3; 15·3) in Argentina, 33·3% in Nicaragua (95% CI: 26·6; 40·1) and 25·1% in Peru (95% CI: 18·9; 31·3). Conclusions These findings demonstrate circulation of HBoV in Argentina, Nicaragua and Peru among children with influenza-like symptoms enrolled in a sentinel surveillance program.

Sexual transmission represents the principal mode of transmission for human immunodeficiency virus type 1 (HIV-1) worldwide. We examined the HIV-1 seroprevalence and risk factors for infection among 613 female commercial sex workers (FCSW) in Isla Margarita, Venezuela. Recruitment was conducted in street venues and working locations. None of the FCSW tested positive for HIV; this correlated with the low self-reported rates of sexually transmitted infections (6%), drug use (20%), and alcohol abuse (12%). Condom use and safe-sex practices were found to be practiced regularly (80% of time) with clients; however, such practices were found to be very uncommon in nonclient relations (20% of the time). Understanding the sexual risk behaviors, beliefs, and drug use patterns of FCSW is important for future development of effective public prevention policies and educational campaigns aimed at decreasing the risk of infection with HIV-1 and other sexually transmitted infections among FCSW.

Acute undifferentiated febrile illnesses are common in tropical developing countries but are difficult to diagnose on clinical grounds alone. Leptospirosis is rarely diagnosed, despite evidence that sporadic cases and epidemics continue to occur worldwide. The purpose of this study was to diagnose an outbreak of acute undifferentiated febrile illness among Peruvian military recruits that developed after a training exercise in the high jungle rainforest of Peru. Of 193 military recruits, 78 developed an acute febrile illness with varied manifestations. Of these, 72 were found to have acute leptospirosis by a microscopic agglutination test (MAT). An enzyme-linked immunosorbent assay using Leptospira biflexa antigen was insensitive for the detection of anti-leptospiral IgM antibodies compared with the MAT (20 of 72, 28%). This outbreak of acute undifferentiated febrile illness among Peruvian military recruits was due to leptospirosis. High clinical suspicion, initiation of preventative measures, and performance of appropriate diagnostic testing is warranted in similar settings to identify, treat, and prevent leptospirosis.

Objetivo: Se estudiaron 141 personas con alto riesgo sexual en la ciudad de Pisco para detectar infección por HTLV-I. Material y Métodos: Se encuestaron y se tomaron muestras de sangre a 141 personas que involucró a trabajadoras sexuales (32), varones homosexuales (54), y varones bisexuales(55). Resultados: Tres de treintidós (10.4%) trabajadoras sexuales fueron positivas; uno de cincuenticuatro (1.9%) de varones homosexuales y ninguno de 55 bisexuales. Hubo una elevada frecuencia de parejas, así como el antecedente de enfermedades de transmisión sexual (ETS) en estos grupos con comportamiento de riesgo. Conclusiones: El HTLV-I es una infección frecuente en grupos de alto riesgo sexual de Pisco-Perú. (Rev Med Hered 1997; 8:104-107). Objective: One hundred and forty one high risk sexual persons were evaluated for HTLV-I infection in Pisco city. Methods and Material: 141 persons were interviewed and blood samples obtained, this group incluided sexual workers (32), homosexual men, and bisexual men. Results: Three of the 32(10.4%) female sex workers; and one of the 54(1.9%) homosexual men were positive and none of the 55 bisexuals. They had a high frecuency of partners as well as sexually transmitted diseases. Conclusion: HTLV-I is a frecuent infectious disease in high-risk sexual groups of Pisco-Peru. (Rev Med Hered 1997; 8:104-107).

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.

BackgroundTropical countries are thought to play an important role in the global behavior of respiratory infections such as influenza. The tropical country of Ecuador has almost no documentation of the causes of acute respiratory infections. The objectives of this study were to identify the viral agents associated with influenza like illness (ILI) in Ecuador, describe what strains of influenza were circulating in the region along with their epidemiologic characteristics, and perform molecular characterization of those strains.Methodology/findingsThis is a prospective surveillance study of the causes of ILI based on viral culture of oropharyngeal specimens and case report forms obtained in hospitals from two cities of Ecuador over 4 years. Out of 1,702 cases of ILI, nine viral agents were detected in 597 patients. During the time of the study, seven genetic variants of influenza circulated in Ecuador, causing six periods of increased activity. There appeared to be more heterogeneity in the cause of ILI in the tropical city of Guayaquil when compared with the Andean city of Quito.Conclusions/significanceThis was the most extensive documentation of the viral causes of ILI in Ecuador to date. Influenza was a common cause of ILI in Ecuador, causing more than one outbreak per year. There was no well defined influenza season although there were periods of time when no influenza was detected alternating with epidemics of different variant strains.

The epidemiology of HTLV-I infection in female prostitutes was studied in a survey of 395 prostitutes from Callao, Peru (the port city of Lima), 72 prostitutes from Iquitos, Peru (another port city on the Amazon River), and 510 prenatal clinic patients from Lima. Prostitutes reported a mean of 8.8 years (range, 1-39 years) of active prostitution and a mean of 205 sexual contacts during the month prior to the study. The percentage of prostitutes with HTLV-I antibody (21.8%) was significantly higher than patients attending a prenatal clinic (3.1%; P less than .0001). The prevalence of HTLV-I antibody increased steadily with age in prostitutes, but no age trend was noted in prenatal patients. By multiple logistic regression analysis, an independent association was found between HTLV-I seropositivity and a history of prostitution in Callao, age, and positive syphilis serology when all 977 study subjects were evaluated. When prostitutes alone were analyzed, the number of years of exposure as a practicing prostitute was associated with HTLV-I seropositivity after controlling for age. These data indicate a greatly increased risk of HTLV-I infection in prostitutes in Callao, Peru, and suggest an association between sexual activity and HTLV-I transmission.

BACKGROUND: Acute respiratory illnesses and influenza-like illnesses (ILI) are a significant source of morbidity and mortality worldwide. Despite the public health importance, little is known about the etiology of these acute respiratory illnesses in many regions of South America. In 2006, the Peruvian Ministry of Health (MoH) and the US Naval Medical Research Center Detachment (NMRCD) initiated a collaboration to characterize the viral agents associated with ILI and to describe the clinical and epidemiological presentation of the affected population. METHODOLOGY/PRINCIPAL FINDINGS: Patients with ILI (fever > or =38 degrees C and cough or sore throat) were evaluated in clinics and hospitals in 13 Peruvian cities representative of the four main regions of the country. Nasal and oropharyngeal swabs, as well as epidemiological and demographic data, were collected from each patient. During the two years of this study (June 2006 through May 2008), a total of 6,835 patients, with a median age of 13 years, were recruited from 31 clinics and hospitals; 6,308 were enrolled by regular passive surveillance and 527 were enrolled as part of outbreak investigations. At least one respiratory virus was isolated from the specimens of 2,688 (42.6%) patients, with etiologies varying by age and geographical region. Overall the most common viral agents isolated were influenza A virus (25.1%), influenza B virus (9.7%), parainfluenza viruses 1, 2, and 3, (HPIV-1,-2,-3; 3.2%), herpes simplex virus (HSV; 2.6%), and adenoviruses (1.8%). Genetic analyses of influenza virus isolates demonstrated that three lineages of influenza A H1N1, one lineage of influenza A H3N2, and two lineages of influenza B were circulating in Peru during the course of this study. CONCLUSIONS: To our knowledge this is the most comprehensive study to date of the etiologic agents associated with ILI in Peru. These results demonstrate that a wide range of respiratory pathogens are circulating in Peru and this fact needs to be considered by clinicians when treating patients reporting with ILI. Furthermore, these data have implications for influenza vaccine design and implementation in South America.

An HIV seroprevalence and molecular study was conducted among 935 subjects: 723 female commercial sex workers, 92 men who have sex with men and 120 HIV-positive volunteers. The reported injection drug use rates were 0.7% in female commercial sex workers and 3% in men who have sex with men. Sexually transmitted infections were reported in 265 (37%) of the female commercial sex workers and 38 (41%) of the men who have sex with men. A total of 20 (2.8%) female commercial sex workers and 12 (13%) men who have sex with men became HIV infected during the study period. A history of sexually transmitted infection increased the risk of subsequent HIV infection twofold (adjusted odds ratio of 2.5) among the female commercial sex workers, while cocaine use had an adjusted odds ratios of 6.61 among men who have sex with men. From 130 samples, and based on heteroduplex mobility assaying for the env gene, with sequencing of part of pol and/or full genomes, subtype B was the predominant subtype identified (66%); followed by subtype F (22%) and subtype C (4%). Recombinant CRF12-BF strains were identified in 6% and CRF17_BF was identified in 2%. Um estudo de soroprevalência e de avaliação molecular do HIV foi realizado com 935 indivíduos: 723 mulheres que trabalhavam no comércio do sexo, 92 homens que mantinham relações sexuais com outros homens e com 120 voluntários HIV-positivos. O relato de uso de drogas injetáveis foi de 0,7% nas mulheres que trabalhavam no comércio do sexo e de 3% nos homens que mantinham relações sexuais com outros homens. Infecções sexualmente transmitidas foram relatadas por 265 (37%) das mulheres que trabalhavam no comércio do sexo e em 38 (41%) dos homens que mantinham relações sexuais com homens. Um total de 20 (2,8%) mulheres que trabalhavam no comércio do sexo e 12 (13%) homens que mantinham relações sexuais com homens se infectou com HIV durante o período do estudo. História prévia de infecção sexualmente transmitida aumentou em duas vezes o risco de infecção subseqüente por HIV (odds ratio ajustado de 2,5) entre as mulheres que trabalhavam no comércio do sexo, enquanto cocaína apresentou odds ratio ajustado de 6,61 entre os homens que mantinham relações sexuais com outros homens. De 130 amostras, com base no ensaio da mobilidade heteroduplex para o gene env, com sequenciamento de parte do pol e/ou genomas completos, o subtipo B foi o subtipo mais identificado (66%); seguido pelo subtipo F (22%) e subtipo C (4%). Cepas recombinantes CRF12-BF foram identificadas em 6% e CRF17_BF foi identificada em 2%.

Background: Transfusion-transmitted infections (TTIs) constitute a major health problem worldwide where routine screening of blood or blood products is improperly done, and where non-medical injecting medications and/or drug use are prevalent. Prevalence and risk factors vary by geographic location and by the specific TTI (including HIV-1, HBV, HCV and HTLV-I). Objective: To determine theprevalence and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru. Study design: A cross-sectionalmulti-center study was conducted across seven major hospitals in Peru from February 2003 to September 2004. Self-reported behavior information (medical procedures, number of sexual partners, and drug use history) was analyzed, along with a review of exposure history from hospital medical records. Prevalences were calculated by TTI for different exposures, along with unadjusted and adjusted odds ratios for infection risk. Results: Overall, 192 (54.7%) of 351 multi-transfused patients were found infected with one or more TTIs.Number of transfusion units, years of transfusion history (6 or more), and number of treatment facilities (2 or more) were associated with HCV infection. Hemodialysis history was a common risk factor associated with HBV, HCV and HTLV-I infection. HIV infection was associated only with total number of transfusion units received. Conclusions: High prevalences of HBV and HCV infection were foundamong Peruvian multi-transfused patients and were associated with a past history and number of blood transfusions, as well as with past hemodialysis procedures. TTIs continue to represent a significant public health problem in Peru. Continued vigilant attention to blood safety procedures, including universal screening and health care provider education, is recommended.

HIV cross-sectional studies were conducted among high-risk populations in 9 countries of South America. Enzyme-linked immunosorbent assay screening and Western blot confirmatory testing were performed, and env heteroduplex mobility assay genotyping and DNA sequencing were performed on a subset of HIV-positive subjects. HIV prevalences were highest among men who have sex with men (MSM; 2.0%-27.8%) and were found to be associated with multiple partners, noninjection drug use (non-IDU), and sexually transmitted infections (STIs). By comparison, much lower prevalences were noted among female commercial sex workers (FCSWs; 0%-6.3%) and were associated mainly with a prior IDU and STI history. Env subtype B predominated among MSM throughout the region (more than 90% of strains), whereas env subtype F predominated among FCSWs in Argentina and male commercial sex workers in Uruguay (more than 50% of strains). A renewed effort in controlling STIs, especially among MSM groups, could significantly lessen the impact of the HIV epidemic in South America.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Acute undifferentiated febrile illnesses are common in tropical developing countries but are difficult to diagnose on clinical grounds alone. Leptospirosis is rarely diagnosed, despite evidence that sporadic cases and epidemics continue to occur worldwide. The purpose of this study was to diagnose an outbreak of acute undifferentiated febrile illness among Peruvian military recruits that developed after a training exercise in the high jungle rainforest of Peru. Of 193 military recruits, 78 developed an acute febrile illness with varied manifestations. Of these, 72 were found to have acute leptospirosis by a microscopic agglutination test (MAT). An enzyme-linked immunosorbent assay using Leptospira biflexa antigen was insensitive for the detection of anti-leptospiral IgM antibodies compared with the MAT (20 of 72, 28%). This outbreak of acute undifferentiated febrile illness among Peruvian military recruits was due to leptospirosis. High clinical suspicion, initiation of preventative measures, and performance of appropriate diagnostic testing is warranted in similar settings to identify, treat, and prevent leptospirosis.

The circumsporozoite (CS) protein of Plasmodium vivax consists of a central repeat region flanked by highly conserved non-repeat regions. Serum samples from 33 individuals with naturally acquired infections of P. vivax were tested for antibodies to four antigens representing the vivax CS protein. Three recombinant proteins containing different overlapping sequences in the non-repeat regions and either the entire central repeat region (vivax-1 and vivax-2) or two of the repeat sequences (vivax-3) were used as antigens in an enzyme-linked immunosorbent assay (ELISA). Antibodies to two other proteins, one (NS1(81)V20) containing the entire predominant repeat region (GDRAA/DGQPA) and the other (Pvk247) containing the variant repeat sequence (ANGAGNQPG) that was recently reported from Thailand were also measured by ELISA. Immunoglobulin G antibodies to the antigen representing the predominant repeat were present in 15% of the patients on the first day of treatment (day 0) and in 24% of the patients two weeks later (post-treatment). Six and 12% of the patients had IgG antibodies to the antigen containing the variant repeat on day 0 and post-treatment, respectively. A larger proportion of the sera had antibodies to the three antigens containing the non-repeat sequences; on the first day of treatment and two weeks later, 79 and 97% of the patients, respectively, had antibodies to vivax-1, vivax-2, and vivax-3. In this sample of Peruvians naturally infected with P. vivax, the most prevalent antibody responses were targeted to epitopes in the non-repeat region of the CS protein rather than to epitopes in the repeat region.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: A prospective study was conducted to determine the prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection among healthy Japanese migrants and their descendents in Peru.Methods: A total of 407 persons were enrolled at the Peruvian-Japanese Medical Center in Lima during routine visits for health evaluations. Each study volunteer was interviewed to obtain clinical and epidemiologic data, and a blood sample was obtained for HTLV-I testing. Sera samples were initially tested for antibody by enzyme-linked immunosorbent assay (ELISA). All ELISA reactive sera were further tested by Western Blot assay, and the results were recorded in accordance with the manufacturer's recommendations.Results: Among the 407 study volunteers, HTLV-I infection was demonstrated in 6.8% (19280) of females and 3.2% (4127) of males. Infection rates significantly increased with age, with 28.5% of volunteers over 80 years of age being positive (P < 0.05). The migrants from Japan had the highest infection rate (15.8%), whereas none of the second generation volunteers were positive (P < 0.05). The incidence among those with ancestors from Okinawa was 9.3%, and for those with ancestors from the central zone of Japan, 1.2% (P < 0.05).Conclusions: These data indicated that HTLV-I infection rates were highest among the older volunteers from Okinawa and Kyushu, and that evidence of infection was not found among their offspring.