Prevalence and vulnerability of homeless people to HIV infection in Sao Paulo, Brazil

OBJECTIVE: To assess the prevalence and vulnerability of homeless people to HIV infection. METHODS: Cross-sectional study conducted with a non-probabilistic sample of 1,405 homeless users of shelters in the city of Sao Paulo, southeastern Brazil, from 2006 to 2007. They were all tested for HIV and a structured questionnaire was applied. Their vulnerability to HIV was determined by the frequency of condom use: those who reported using condoms only occasionally or never were considered the most vulnerable. Multinomial and logistic regression models were used to estimate effect measures and 95% confidence intervals. RESULTS: There was a predominance of males (85.6%), with a mean age of 40.9 years, 72.0% had complete elementary schooling, and 71.5% were non-white. Of all respondents, 15.7% reported being homosexual or bisexual and 62,0% reported having casual sex. The mean number of sexual partners in the last 12 months was 5.4. More than half (55.7%) of the respondents reported lifetime drug use, while 25.7% reported frequent use. Sexually-transmitted disease was reported by 39.6% of the homeless and 38.3% reported always using condoms. The prevalence of HIV infection was 4.9% (17.4% also tested positive for syphilis) and about half of the respondents (55.4%) had access to prevention programs. Higher HIV prevalence was associated with younger age (18-29 years, OR = 4.0 [95% CI 1.54; 10.46]); past history of sexually-transmitted disease (OR = 3.3 [95% CI 1.87; 5.73]); homosexual sex (OR = 3.0 [95% CI 1.28; 6.92]); and syphilis (OR = 2.4 [95% CI 1.13; 4.93]). Increased vulnerability to HIV infection was associated with being female; young; homosexual sex; having few partners or a steady partner; drug and alcohol use; not having access to prevention programs and social support. CONCLUSIONS: The HIV epidemic has a major impact on homeless people reflecting a cycle of exclusion, social vulnerability, and limited access to prevention.

Prevalência e vulnerabilidade à infecção pelo HIV de moradores de rua em São Paulo, SP

OBJETIVO: Analisar a prevalência e o perfil de vulnerabilidade ao HIV de moradores de rua. MÉTODOS: Estudo transversal com amostra não probabilística de 1.405 moradores de rua usuários de instituições de acolhimento de São Paulo, SP, de 2006 a 2007. Foi realizado teste anti-HIV e aplicado questionário estruturado. O perfil de vulnerabilidade foi analisado pela frequência do uso do preservativo, considerando mais vulneráveis os que referiram o uso nunca ou às vezes. Foram utilizadas regressões logística e multinomial para estimar as medidas de efeito e intervalos de 95% de confiança. RESULTADOS: Houve predominância do sexo masculino (85,6%), média de 40,9 anos, ter cursado o ensino fundamental (72,0%) e cor não branca (71,5%). A prática homo/bissexual foi referida por 15,7% e a parceria ocasional por 62,0%. O número médio de parcerias em um ano foi de 5,4 e mais da metade (55,7%) referiu uso de drogas na vida, dos quais 25,7% relataram uso frequente. No total, 39,6% mencionaram ter tido uma doença sexualmente transmissível e 38,3% relataram o uso do preservativo em todas as relações sexuais. A prevalência do HIV foi de 4,9% (17,4% dos quais apresentaram também sorologia positiva para sífilis). Pouco mais da metade (55,4%) tinha acesso a ações de prevenção. A maior prevalência do HIV esteve associada a ser mais jovem (OR 18 a 29 anos = 4,0 [IC95% 1,54;10,46]), história de doença sexualmente transmissível (OR = 3,3 [IC95% 1,87;5,73]); prática homossexual (OR = 3,0 [IC95% 1,28;6,92]) e à presença de sífilis (OR = 2,4 [IC95% 1,13;4,93]). O grupo de maior vulnerabilidade foi caracterizado por ser mulher, jovem, ter prática homossexual, número reduzido de parcerias, parceria fixa, uso de drogas e álcool e não ter acesso a ações de prevenção e apoio social. CONCLUSÕES: O impacto da epidemia entre moradores de rua é elevado, refletindo um ciclo que conjuga exclusão, vulnerabilidade social e acesso limitado à prevenção.

Highly debilitating natural Trypanosoma vivax infections in Brazilian calves: epidemiology, pathology, and probable transplacental transmission

Clinical, epidemiological, and pathological aspects of trypanosomiasis caused by Trypanosoma vivax in calves were reported for the first time in northeast Brazil. Clinical and epidemiological data, packed cell volumes (PCV), and parasitemia were assessed in 150 calves in May 2009 (rainy season-survey 1) and in 153 calves in November 2009 (dry season-survey 2) in three farms (A, B, and C). Prevalence of T. vivax in calves examined in the survey 1 was 63.3%, 65.0%, and 80.0% in farms A, B, and C, respectively. Morbidity varied from 63.3% to 80%, mortality from 15% to 30% and lethality from 23% to 37.5%. In survey 1, for all farms, high parasitemia (from 30.3 to 26.2x10(6) parasites/mL), fever (from 39.8 to 40.3 degrees C), low PCV (from 15.7% to 18.1%), and body score (from 2.5 to 3.5) were detected. Calves showed depression, weight loss, pale mucous membranes, enlarged lymph nodes, edema of the dewlap, cough, coryza, and diarrhea. The animals from farms A and B were treated with diminazene aceturate. Six months after, in survey 2, non-treated calves from farm C showed values for prevalence (81.82), morbidity (81.82), mortality (12.73), and lethality (15.55) similar to those in survey 1 (P>0.05). Also in survey 2, four calves aging merely 1-3 days old presented high parasitemia levels (from 32x10(6) to 74x10(6) parasites/mL), suggesting transplacental transmission. In conclusion, trypanosomiasis by T. vivax constitutes high prevalent disease for calves raised in Brazilian semiarid and may have transplacental transmission.

Human immunodeficiency virus prevalence, incidence, and residual risk of transmission by transfusions at Retrovirus Epidemiology Donor Study-II blood centers in Brazil

BACKGROUND: In Brazil nationally representative donor data are limited on human immunodeficiency virus (HIV) prevalence, incidence, and residual transfusion risk. The objective of this study was to analyze HIV data obtained over 24 months by the Retrovirus Epidemiology Donor Study-II program in Brazil. STUDY DESIGN AND METHODS: Donations reactive to third-and fourth-generation immunoassays (IAs) were further confirmed by a less-sensitive (LS) IA algorithm and Western blot (WB). Incidence was calculated for first-time (FT) donors using the LS-EIA results and for repeat donors with a model developed to include all donors with a previous negative donation. Residual risk was projected by multiplying composite FT and repeat donor incidence rates by HIV marker-negative infectious window periods. RESULTS: HIV prevalence among FT donors was 92.2/ 105 donations. FT and repeat donor and composite incidences were 38.5 (95% confidence interval [CI], 25.651.4), 22.5 (95% CI, 17.6-28.0), and 27.5 (95% CI, 22.0-33.0) per 100,000 person-years, respectively. Male and community donors had higher prevalence and incidence rates than female and replacement donors. The estimated residual risk of HIV transfusion transmission was 11.3 per 106 donations (95% CI, 8.4-14.2), which could be reduced to 4.2 per 106 donations (95% CI, 3.2-5.2) by use of individual-donation nucleic acid testing (NAT). CONCLUSION: The incidence and residual transfusion risk of HIV infection are relatively high in Brazil. Implementation of NAT will not be sufficient to decrease transmission rates to levels seen in the United States or Europe; therefore, other measures focused on decreasing donations by at-risk individuals are also necessary.

SEASONALITY OF VIRAL RESPIRATORY INFECTIONS IN SOUTHEAST OF BRAZIL: THE INFLUENCE OF TEMPERATURE AND AIR HUMIDITY

Viruses are the major cause of lower respiratory tract infections in childhood and the main viruses involved are Human Respiratory Syncytial Virus (HRSV), Human Metapneumovirus (HMPV), Influenzavirus A and B (FLUA and FLUB), Human Parainfluenza Virus 1, 2 and 3 (HPIV1, 2 and 3) and Human Rhinovirus (HRV). The purposes of this study were to detect respiratory viruses in hospitalized children younger than six years and identify the influence of temperature and relative air humidity on the detected viruses. Samples of nasopharyngeal washes were collected from hospitalized children between May/2004 and September/2005. Methods of viral detection were RT-PCR, PCR and HRV amplicons were confirmed by hybridization. Results showed 54% (148/272) of viral positivity. HRSV was detected in 29% (79/272) of the samples; HRV in 23.1% (63/272); HPIV3 in 5.1% (14/272); HMPV in 3.3% (9/272); HPIV1 in 2.9% (8/272); FLUB in 1.4% (4/272), FLUA in 1.1% (3/272), and HPIV2 in 0.3% (1/272). The highest detection rates occurred mainly in the spring 2004 and in the autumn 2005. It was observed that viral respiratory infections tend to increase as the relative air humidity decreases, showing significant association with monthly averages of minimal temperature and minimal relative air humidity. In conclusion, viral respiratory infections vary according to temperature and relative air humidity and viral respiratory infections present major incidences it coldest and driest periods.

Epidemiology and predictors of a poor outcome in elderly patients with candidemia

Background: Candidemia affects patient populations from neonates to the elderly. Despite this, little information is available about the epidemiology of candidemia in elderly patients. Methods: We performed a retrospective analysis of 987 episodes of candidemia in adults (>14 years of age) from the databases of three laboratory-based surveys of candidemia performed at 14 tertiary care hospitals. Patients aged >= 60 years were considered elderly (group 1, n = 455, 46%) and were compared to younger patients (group 2, n = 532, 54%) regarding demographics, underlying diseases, comorbidities, exposure to medical procedures, species, treatment, and outcome. Results: The median APACHE II score was significantly higher in the elderly patients (19 vs. 15, p = 0.03). Variables that were observed significantly more frequently in elderly patients included admission to an intensive care unit, diabetes mellitus, renal failure, cardiac disease, lung disease, receipt of antibiotics or H2 blockers, insertion of a central venous catheter, mechanical ventilation, and candidemia due to Candida tropicalis. The 30-day mortality of elderly patients was significantly higher than that of younger patients (70% vs. 45%, p < 0.001). Factors associated with higher mortality by multivariate analysis included APACHE II score and being in group 1 (elderly). Factors associated with mortality in elderly patients were lung disease and the receipt of mechanical ventilation. Conclusions: Elderly patients account for a substantial proportion of patients with candidemia and have a higher mortality compared to younger patients. (C) 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Molecular epidemiology of extended-spectrum-beta-lactamase-producing Klebsiella pneumoniae over a 10 year period in Calgary, Canada

A study was designed to investigate the molecular epidemiology of extended-spectrum -lactamase (ESBL)-producing Klebsiella pneumoniae isolated in a centralized region over a 10 year period (200009). Molecular characterization was done using isoelectric focusing, PCR and sequencing for bla(CTX-M), bla(TEM) and bla(SHV) genes and plasmid-mediated quinolone resistance determinants. Genetic relatedness was determined with PFGE using XbaI and multilocus sequencing typing. A total of 89 patients with incident infections were identified; the majority presented with hospital-onset urinary tract infections. The absolute number of ESBL-producing isolates remained very low until 2003, increased slightly in 2004, remained stable until 2008 and then in 2009 there was an abrupt increase in the numbers of ESBL producers identified. The majority of K. pneumoniae produced CTX-M-14 and -15, and have replaced SHV-12-producing isolates since 2005. We identified four different major sequence types (STs) among 32 of isolates (i.e. ST17, ST20, and the new ST573 and ST575) and provided insight into their clinical and molecular characteristics. The ST isolates were more likely to produce community-onset infections, were associated with bla(CTX-M) and emerged during the latter part of the study period. ST17 produced CTX-M-15 and SHV-12, and was more likely to be positive for qnrB; ST20 produced CTX-M-14 and was positive for qnrS. The multiresistant ST575 that produced CTX-M-15 appeared in 2009. Our study highlights the importance of molecular epidemiology in providing insight into the emergence, characteristics and distribution of STs among ESBL-producing K. pneumoniae.