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Background: The increase in antimicrobial resistance includes emerging mechanisms such as 16S ribosomal RNA methylases, which confer high-level resistance to aminoglycosides. In this regard, the most predominant genes observed worldwide are rmtB and armA, but their presence in Uruguay is unknown. Objectives: We describe the genomic characterization of isolates carrying rmtB and rmtC, together with blaNDM-5 and blaNDM-1, respectively, and rmtD in our country. Methology: Five isolates from patients admitted to three hospitals were studied. Identification and antibiotic susceptibility testing were performed using the Vitek2 System. Whole Genome Sequencing was conducted, and hybrid assembly was performed with Unicycler. In silico analysis using the Center for Genomic Epidemiology’s tools was undertaken to predict antibiotic resistance determinants, plasmid incompatibility groups, and sequence types. Results: We report three K. pneumoniae ST307 isolates with an IncR plasmid carrying blaNDM-5/blaCTX-M-15/blaTEM-1B/rmtB/dfrA14/dfrA12/sul1/qacEΔ1/ermB/mphA, one K. pneumoniae ST258 harboring an IncC plasmid containing rmtC/blaNDM-1/blaCMY-6/aac(6′)-Ib/sul1, and one E. cloacae ST88 isolate with an IncFIB/II plasmid hosting rmtD, within a novel Tn21-like transposon named Tn7825, alongside blaOXA-101/sul1/tet(G)/floR, and a new variant of blaTEM assigned as blaTEM-258. One of the strains, named UH_B2, also carried an IncM1 plasmid encoding qnrE1/blaTEM-1/blaCTX-M-8 associated with ISEcp1. Conclusions: This is the first description of plasmids harboring 16S rRNA methyltransferases in Uruguay. The association and dissemination of diverse antibiotic-resistant genes underpin the health threat they represent, highlighting the lack of available antibiotics effective against multidrug-resistant microorganisms.

Pseudomonas aeruginosa is a leading cause of hospital-acquired infections worldwide. Biofilm production, antibiotic resistance, and a wide range of virulence factors contribute to their persistence in nosocomial environments. We describe an outbreak caused by a multidrug-resistant P. aeruginosa strain in an ICU. Antibiotic susceptibility was determined and blaPER-1 and qnrVC were amplified via PCR. Clonality was determined using PFGE and biofilm formation was studied with a static model. A combination of antibiotics was assessed on both planktonic cells and biofilms. WGS was performed on five isolates. All isolates were clonally related, resistant to ceftazidime, cefepime, amikacin, and ceftolozane-tazobactam, and harbored blaPER-1; 11/19 possessed qnrVC. Meropenem and ciprofloxacin reduced the biofilm biomass; however, the response to antibiotic combinations with rifampicin was different between planktonic cells and biofilms. WGS revealed that the isolates belonged to ST309 and serotype O11. blaPER-1 and qnrVC6 were associated with a tandem of ISCR1 as part of a complex class one integron, with aac(6′)-Il and ltrA as gene cassettes. The structure was associated upstream and downstream with Tn4662 and flanked by direct repeats, suggesting its horizontal mobilization capability as a composite transposon. ST309 is considered an emerging high-risk clone that should be monitored in the Americas.

Klebsiella pneumoniae is widely recognized as an opportunistic hospital and community pathogen. It is one of the priority microorganisms included in the ESKAPE group, and its antibiotic resistance related to extended-spectrum β-lactamases (ESBL) is a global public health concern. The multi-drug resistance (MDR) phenotype, in combination with pathogenicity factors, could enhance the ability of this pathogen to cause clinical infections. The aim of this study was to characterize pathogenicity factors and biofilm formation in ESBL-producing K. pneumoniae from pediatric clinical infections. Capsular types, virulence factors, and sequence types were characterized by PCR. Biofilm formation was determined by a semiquantitative microtiter technique. MDR phenotype and statistical analysis were performed. The K24 capsular type (27%), virulence factors related to iron uptake fyuA (35%) and kfuBC (27%), and sequence types ST14 (18%) and ST45 (18%) were the most frequently detected. Most of the strains were biofilm producers: weak (22%), moderate (22%), or strong (12%). In 62% of the strains, an MDR phenotype was detected. Strains with K24 capsular type showed an association with ST45 and the presence of fyuA; strains with kfuBC showed an association with moderate or strong biofilm production and belonging to ST14. Weak or no biofilm producers were associated with the absence of kfuBC. The MDR phenotype was associated with the main ESBL gene, blaCTX-M-15. The high plasticity of K. pneumoniae to acquire an MDR phenotype, in combination with the factors exposed in this report, could make it even more difficult to achieve a good clinical outcome with the available therapeutics.

Antibiotic resistance is an alarming problem throughout the world and carbapenem-resistant Pseudomonas aeruginosa has been cataloged as critical in the World Health Organization list of microorganisms in urgent need for the development of new antimicrobials. In this work, we describe two novel resistance regions responsible for conferring a multidrug resistance phenotype to two clinical isolates of P. aeruginosa (Pa873 and Pa6415) obtained from patients hospitalized in the ICU of University Hospital of Uruguay. Bacterial identification and antibiotic susceptibility tests were performed using MALDI-TOF and the Vitek 2 system, respectively. WGS was performed for both isolates using Oxford Nanopore Technologies and Illumina and processed by means of hybrid assembly. Both isolates were resistant to ceftazidime, cefepime, piperacillin–tazobactam, aztreonam, and imipenem. Strain Pa6415 also showed resistance to ciprofloxacin. Both strains displayed MICs below the susceptibility breakpoint for CAZ-AVI plus 4 mg/L of aztreonam as well as cefiderocol. Both resistance regions are flanked by the left and right inverted repeats of ISPa40 in two small regions spanning 39.3 and 35.6 kb, for Pa6415 and Pa873, respectively. The resistance region of Pa6415 includes TnaphA6, and the new Tn7516 consists of IRi, In899, qacEΔ1-sul1-ISCR1, qnrVC6-ISCR1-blaPER-1-qacEΔ1-sul1, araJ-like, IS481-like tnpA, ISPa17, and IRR. On the other hand, the resistance region of Pa873 includes Tnaph6 and the new Tn7517 (IRi, In899, qacEΔ1-sul1, ISCR1–blaPER-1–qacEΔ1-sul1, araJ-like, IS481-like tnpA, ISPa17, and IRR). It is necessary to monitor the emergence of genetic structures that threaten to invalidate the available therapeutic resources.

Introdução: O vírus da imunodeficiência humana (HIV) continua sendo um importante problema de saúde pública global. Estima-se que 38,4 milhões [33,9 milhões – 43,8 milhões] de pessoas no mundo vivem com HIV e 28,7 milhões de pessoas tem acesso à terapia antirretroviral. Contudo, a terapia antirretroviral (TARV) vem apresentando avanços importantes nos últimos anos com uma mudança de paradigma de tripla para dupla terapia com um impacto significativo na efetividade e segurança. A terapia antirretroviral simplificada melhora a adesão e os desfechos clínicos, reduzem o número de antirretrovirais que as pessoas que vivem com HIV (PVHIV) estão expostas e podem potencialmente diminuir a toxicidade e os custos associados ao tratamento. Objetivos: Avaliar a efetividade dos esquemas de tratamento antirretroviral simplificado em um Hospital Universitário de Salvador- Bahia. Material e Método: Trata-se de uma coorte retrospectiva, com uma abordagem quantitativa, realizado no Ambulatório Magalhães Neto vinculado ao Hospital Universitário Professor Edgard Santos da Universidade Federal da Bahia (UFBA). Os dados foram coletados de janeiro de 2017 a agosto 2022. Foram incluídos pacientes soropositivos com 18 anos ou mais que já haviam sido submetidos a esquemas terapêuticos antirretrovirais no passado, inclusive pacientes que já faziam utilização da TARV simplificada antes do início do estudo, sem distinção de sexo; o esquema ARV simplificado foi definido, como mudança de um regime terapêutico prescrito, para reduzir a posologia e/ou o número total de medicamentos por dia variando de 1 ou 2 medicamentos prescritos. O desfecho virológico foi avaliado a partir de 16 semanas em uso da terapia antirretroviral simplificada, definida como a efetividade da terapia antirretroviral (TARV) por carga viral < 50 cópias/ml sem alteração de TARV. Resultados: Os resultados desse estudo de mundo real envolvendo 244 pacientes em 5 anos de seguimento , demonstra uma manutenção da supressão virológica correspondente a 98% dos pacientes com carga viral indetectável, com uma mediana de tempo de supressão virológica de 60,5 (29,25-160,25) semanas e uma mediana das células CD4 cel/ mm3 de 675 (478,5-925,25) ,outrossim,89,7% dos pacientes prescritos o esquema Dolutegravir 50mg/Lamivudina 300mg não tinham histórico de falha terapêutica prévia, contudo, 47,5% dos pacientes submetidos a outros esquemas terapêuticos já haviam apresentado histórico de falha. Ademais, 96,7% dos pacientes não mudaram de esquemas simplificado o que demonstra uma certa efetividade e otimização terapêutica. Discussão e Conclusões: Os resultados corroboram com a literatura demonstrando uma boa resposta da supressão virológica em esquemas simplificados, com boa efetividade imunológica, durante 5 anos de seguimento, fortalecendo a teoria que os esquemas de dupla terapia constituem uma alternativa segura e efetiva mesmo em pacientes com histórico de falha terapêutica prévia.

Objectives Infections by SARS-CoV-2 variants of concern (VOCs) might affect children and adolescents differently than earlier viral lineages. We aimed to address five questions about SARS-CoV-2 VOC infections in children and adolescents: (1) symptoms and severity, (2) risk factors for severe disease, (3) the risk of infection, (4) the risk of transmission and (5) long-term consequences following a VOC infection.Design Systematic review.Data sources The COVID-19 Open Access Project database was searched up to 1 March 2022 and PubMed was searched up to 9 May 2022.Eligibility criteria We included observational studies about Alpha, Beta, Gamma, Delta and Omicron VOCs among ≤18-year-olds. We included studies in English, German, French, Greek, Italian, Spanish and Turkish.Data extraction and synthesis Two reviewers extracted and verified the data and assessed the risk of bias. We descriptively synthesised the data and assessed the risks of bias at the outcome level.Results We included 53 articles. Most children with any VOC infection presented with mild disease, with more severe disease being described with the Delta or the Gamma VOC. Diabetes and obesity were reported as risk factors for severe disease during the whole pandemic period. The risk of becoming infected with a SARS-CoV-2 VOC seemed to increase with age, while in daycare settings the risk of onward transmission of VOCs was higher for younger than older children or partially vaccinated adults. Long-term symptoms following an infection with a VOC were described in

Previous pandemics and related lockdowns have had a deleterious impact on pregnant women’s mental health. We studied the impact of the SARS-CoV-2/Covid-19 pandemic and France’s first lockdown on pregnant women’s mental health. A cross-sectional study was conducted in July 2020 using a web-questionnaire completed by 500 adult women who were pregnant during the first lockdown in France (March-May 2020). Questions focused on their self-perceived psychological state and affects they felt before and during the lockdown and anxiety symptomatology (HAD) two months after it ended. A robust variance Poisson regression model was used to estimate adjusted prevalence ratios (aPR) for anxiety and self-perceived psychological state evolution. One in five respondents (21.1%) reported psychological deterioration during lockdown. Associated determinants were: i) little or no social support (self-perceived) (aRP = 1.77, 95%CI[1.18–2.66]), ii) increased workload (1.65, [1.02–2.66]), and iii) poor/moderate knowledge about SARS-CoV-2 transmission (1.60, [1.09–2.35]). Seven percent of women reporting psychological deterioration had access to professional psychological support during lockdown, while 19% did not despite wanting it. Women reported heightened powerlessness (60.3%), frustration (64%) and fear (59.2%) during lockdown. One in seven respondents (14.2%, 95%CI[10.9–18.2]) had anxiety symptoms. Determinants associated: i) at least one pregnancy-related pathology (aPR = 1.82, 95%CI[1.15–2.88]), ii) overweightness or obesity (1.61, [1.07–2.43]), iii) one child under the age of six years in the household during the lockdown (3.26, [1.24–8.53]), iv) little or no social support (self-perceived) during the lockdown (1.66, [1.07–2.58]), v) friend or relatives diagnosed with Covid-19 or with symptoms of the disease (1.66; [1.06–2.60]), vi) no access to medication for psychological distress (2.86, [1.74–4.71]), and vii) unsuccessfully seeking exchanges with healthcare professionals about their pregnancy during the pandemic (1.66, [1.08–2.55]). Our results can guide prevention and support policies for pregnant women during pandemics, current or future, with or without lockdowns. Preventing perinatal mental health problems is essential to ensure a supportive environment for the child’s development.

Abstract Background In the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, consultations and pregnancy monitoring examinations had to be reorganised urgently. In addition, women themselves may have postponed or cancelled their medical monitoring for organisational reasons, for fear of contracting the disease caused by SARS-CoV-2 (COVID-19) or for other reasons of their own. Delayed care can have deleterious consequences for both the mother and the child. Our objective was therefore to study the impact of the SARS-CoV-2 pandemic and the first lockdown in France on voluntary changes by pregnant women in the medical monitoring of their pregnancy and the associated factors. Methods A cross-sectional study was conducted in July 2020 using a web-questionnaire completed by 500 adult (> 18 years old) pregnant women during the first French lockdown (March–May 2020). A robust variance Poisson regression model was used to estimate adjusted prevalence ratios (aPRs). Results Almost one women of five (23.4%) reported having voluntarily postponed or foregone at least one consultation or pregnancy check-up during the lockdown. Women who were professionally inactive (aPR = 1.98, CI95%[1.24–3.16]), who had experienced serious disputes or violence during the lockdown (1.47, [1.00–2.16]), who felt they received little or no support (1.71, [1.07–2.71]), and those who changed health professionals during the lockdown (1.57, [1.04–2.36]) were all more likely to have voluntarily changed their pregnancy monitoring. Higher level of worry about the pandemic was associated with a lower probability of voluntarily changing pregnancy monitoring (0.66, [0.46–0.96]). Conclusions Our results can guide prevention and support policies for pregnant women in the current and future pandemics.

Abstract Background Outbreaks of infectious diseases generate outbreaks of scientific evidence. In 2016 epidemics of Zika virus emerged, and in 2020, a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic of coronavirus disease 2019 (COVID-19). We compared patterns of scientific publications for the two infections to analyse the evolution of the evidence. Methods We annotated publications on Zika virus and SARS-CoV-2 that we collected using living evidence databases according to study design. We used descriptive statistics to categorise and compare study designs over time. Results We found 2286 publications about Zika virus in 2016 and 21,990 about SARS-CoV-2 up to 24 May 2020, of which we analysed a random sample of 5294 (24%). For both infections, there were more epidemiological than laboratory science studies. Amongst epidemiological studies for both infections, case reports, case series and cross-sectional studies emerged first, cohort and case-control studies were published later. Trials were the last to emerge. The number of preprints was much higher for SARS-CoV-2 than for Zika virus. Conclusions Similarities in the overall pattern of publications might be generalizable, whereas differences are compatible with differences in the characteristics of a disease. Understanding how evidence accumulates during disease outbreaks helps us understand which types of public health questions we can answer and when.

Abstract Medication reconciliation is a strategy to minimize medication errors at the transition points of care. This study aimed to demonstrate the effectiveness of medication reconciliation in identifying and resolving drug discrepancies in the admission of adult patients to a university hospital. The study was carried out in a 300-bed large general public hospital, in which a reconciled list was created between drugs prescribed at admission and those used at pre-admission, adapting prescriptions from the pharmacotherapeutic guidelines of the hospital studied and the patients’ clinical conditions. One hundred seven patients were included, of which 67,3% were women, with a mean age of 56 years. Two hundred twenty-nine discrepancies were found in 92 patients; of these, 21.4% were unintentional in 31.8% of patients. The pharmacist performed 49 interventions, and 47 were accepted. Medication omission was the highest occurrence (63.2%), followed by a different dose (24.5%). Thirteen (26.5%) of the 49 unintentional discrepancies included high-alert medications according to ISMP Brazil classification. Medication reconciliation emerges as an important opportunity for the review of pharmacotherapy at transition points of care, based on the high number of unintentional discrepancies identified and resolved. During the drug reconciliation process, the interventions prevented the drugs from being misused or omitted during the patient’s hospitalization and possibly after discharge.

Background: We aimed to describe pregnant women’s worry about the SARS-CoV-2 pandemic, the associated reasons, their perceived vulnerability to this infection, and factors influencing continued poor/non-existent or decreased implementation of preventive measures over time. Method: A cross-sectional study was conducted in July 2020 using a web-questionnaire completed by 500 women who were pregnant during the first lockdown in France (March–May 2020). Questions focused on worry caused by the pandemic, perceived vulnerability to infection by SARS-CoV-2 and implementation of preventive measures during and after lockdown. A robust variance Poisson regression model was used to estimate adjusted prevalence ratios (aPR) for perceived vulnerability and continued poor/non-existent or decreased implementation of preventive measures. Results: Participants felt significantly more vulnerable to infection than women of childbearing age who were included in a parallel study on the French general population, but were significantly less worried about the pandemic. Obese participants and those who unsuccessfully sought exchanges with healthcare professionals about their infection risk felt significantly more vulnerable (aPR = 1.32 95%CI[1.05–1.64] and 1.88 [1.43–2.48], respectively). Participants with continued poor/non-existent or decreased implementation of preventive measures two months after the lockdown ended were more likely to have experienced violence during the lockdown (2.06, [1.32–3.22]), or to live in areas less affected by the pandemic (1.66 [1.05–2.62]). A good knowledge of viral transmission (0.54 [0.30–0.97]) and a high perceived vulnerability score (0.66 [0.44–0.99]) were associated with maintained/increased implementation of preventive measures. Conclusions: Our results can guide prevention and support policies for pregnant women during pandemics, current or future.

BackgroundDebate about the level of asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection continues. The amount of evidence is increasing and study designs have changed over time. We updated a living systematic review to address 3 questions: (1) Among people who become infected with SARS-CoV-2, what proportion does not experience symptoms at all during their infection? (2) What is the infectiousness of asymptomatic and presymptomatic, compared with symptomatic, SARS-CoV-2 infection? (3) What proportion of SARS-CoV-2 transmission in a population is accounted for by people who are asymptomatic or presymptomatic?Methods and findingsThe protocol was first published on 1 April 2020 and last updated on 18 June 2021. We searched PubMed, Embase, bioRxiv, and medRxiv, aggregated in a database of SARS-CoV-2 literature, most recently on 6 July 2021. Studies of people with PCR-diagnosed SARS-CoV-2, which documented symptom status at the beginning and end of follow-up, or mathematical modelling studies were included. Studies restricted to people already diagnosed, of single individuals or families, or without sufficient follow-up were excluded. One reviewer extracted data and a second verified the extraction, with disagreement resolved by discussion or a third reviewer. Risk of bias in empirical studies was assessed with a bespoke checklist and modelling studies with a published checklist. All data syntheses were done using random effects models. Review question (1): We included 130 studies. Heterogeneity was high so we did not estimate a mean proportion of asymptomatic infections overall (interquartile range (IQR) 14% to 50%, prediction interval 2% to 90%), or in 84 studies based on screening of defined populations (IQR 20% to 65%, prediction interval 4% to 94%). In 46 studies based on contact or outbreak investigations, the summary proportion asymptomatic was 19% (95% confidence interval (CI) 15% to 25%, prediction interval 2% to 70%). (2) The secondary attack rate in contacts of people with asymptomatic infection compared with symptomatic infection was 0.32 (95% CI 0.16 to 0.64, prediction interval 0.11 to 0.95, 8 studies). (3) In 13 modelling studies fit to data, the proportion of all SARS-CoV-2 transmission from presymptomatic individuals was higher than from asymptomatic individuals. Limitations of the evidence include high heterogeneity and high risks of selection and information bias in studies that were not designed to measure persistently asymptomatic infection, and limited information about variants of concern or in people who have been vaccinated.ConclusionsBased on studies published up to July 2021, most SARS-CoV-2 infections were not persistently asymptomatic, and asymptomatic infections were less infectious than symptomatic infections. Summary estimates from meta-analysis may be misleading when variability between studies is extreme and prediction intervals should be presented. Future studies should determine the asymptomatic proportion of SARS-CoV-2 infections caused by variants of concern and in people with immunity following vaccination or previous infection. Without prospective longitudinal studies with methods that minimise selection and measurement biases, further updates with the study types included in this living systematic review are unlikely to be able to provide a reliable summary estimate of the proportion of asymptomatic infections caused by SARS-CoV-2.Review protocolOpen Science Framework (https://osf.io/9ewys/).

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic lockdown, communication between pregnant women and health professionals may have become complicated due to restrictions on movement and saturated health services. This could have impacts on pregnancy monitoring and women's wellbeing. We aimed to i) describe the unmet need of pregnant women living in France to communicate with health professionals about the pandemic and their pregnancy during the lockdown, ii) assess the socio-demographic, medical and contextual factors associated with this unmet need. The Covimater cross-sectional study, conducted in July 2020, includes data on 500 adult women's experiences of pregnancy during the first lockdown period in France (i.e., from March to May 2020). The women, all residents in metropolitan France, answered a web-based questionnaire about their conversations with health professionals during the lockdown, as well as their social and medical characteristics. A robust variance Poisson regression model was used to estimate crude or adjusted prevalence ratios (aPRs) for their unmet need to communicate with health professionals about the pandemic and their pregnancy. Forty-one percent of participants reported an unmet need to communicate with a health professional during the lockdown, mainly about the risk of transmitting SARS-CoV-2 to their baby and the consequences for the latter. Factors associated were: i) being professionally inactive (aPR = 1.58,CI95%[(1.14-2.21]), ii) having an educational level below secondary school diploma (1.38,[1.05,-1.81]), iii) having experienced serious arguments/violence (2.12,[1.28-3.52]), iv) being very worried about the pandemic (1.41,[1.11-1.78]), v) being primiparous (1.36,[1.06-1.74]) and vi) having had pregnancy consultations postponed/cancelled by health professionals during the lockdown (1.35,[1.06-1.73]). These results can be used to develop targeted strategies that ensure pregnant women are able to i) communicate with health professionals about the potential impact of the SARS-CoV-2 pandemic on their pregnancy, and ii) access up-to-date and reliable information on the consequences of SARS-CoV-2 for themselves and their child.

Enquadramento: O baixo peso ao nascer é um fator de risco para a morbi-mortalidade neonatal, e um indicador geral do nível de saúde de uma população. Associa-se a baixos níveis de desenvolvimento socioeconómico, características maternas e de assistência materno-infantil. Objetivos: Analisar a influência das variáveis sociodemográficas, obstétricas e de assistência pré-natal ao baixo peso ao nascer. Participantes: 1846 puérperas, em que 161 apresentam recém-nascidos de baixo peso ao nascer. Métodos: Estudo transversal, descritivo correlacional e prospetivo com uma amostra não probabilística intencional. Foi utilizado um questionário aplicado entre Março de 2010 e Maio de 2012, em 26 instituições de saúde públicas portuguesas. Resultados: O baixo peso ao nascer, foi associado a: idade gestacional ≥41semanas (p0,001), idade materna de risco*número gestações de risco (p=0,021); baixa escolaridade*rendimentos ≤1000€ (p=0,036), baixa escolaridade*desemprego (p=0,044), número filhos de risco*idade gestacional de termo (p0,001), patologias na gravidez*idade gestacional de termo (p0,001), patologias prévias*idade gestacional de termo(p0,001), e com erro de 10% à baixa escolaridade (p=0,074) e não planeamento da gravidez (p=0,089). A prevalência de BPN foi de 8,7%. Conclusão: A determinação dos fatores que favorecem o aparecimento do baixo peso ao nascer é fundamental para o planeamento e desenvolvimento de ações no âmbito da saúde materno-infantil.

Este trabalho registra aspectos de uma pesquisa que objetivou analisar o currículo de uma escola municipal, situada na cidade de Natal/RN, com vistas à inclusão de alunos com deficiência intelectual. Com base num estudo de caso, apresentamos algumas reflexões acerca das concepções de currículo escolar, sob a ótica da inclusão escolar. Assim, destacamos a compreensão das professoras, coordenadoras e gestora sobre a inserção dessa temática no projeto político-pedagógico, a concepção de currículo, bem como as diretrizes curriculares expressas no projeto político pedagógico. Constatamos que as diretrizes curriculares expressam uma visão ampla de currículo e são desconhecidas pelos profissionais da instituição de ensino.

OBJECTIVES: To determine the HIV vertical transmission rate (VTR) and associated risk factors by use of zidovudine and infant care education in Brazil. METHODS: Since 1995, a prospective cohort of HIV infected pregnant women has been followed at the Federal University of Rio de Janeiro. A multidisciplinary team was established to implement the best available strategy to prevent maternal-infant HIV transmission. Patients with AIDS or low CD4 and high viral load received anti-retroviral drugs in addition to zidovudine. Children were considered infected if they had 2 positive PCR-RNA tests between 1 and 4 months of age, or were HIV antibody positive after 18 months. Education regarding infant treatment and use of formula instead of breast feeding was provided. RESULTS: Between 1995 and August, 2000, HIV status was determined for 145 infants. Compliance with intra-partum treatment, infant treatment and use of formula was 88.2%. Intra-partum zidovudine treatment was completed in 134/145 (92.6%) of patients; 88.1% had rupture of membranes < 4 hours; 85.4% of mothers were asymptomatic. The mean CD4 count was 428.4 cells and mean viral load 39,050 copies. HIV vertical transmission rate was 4/145 (2.75%; CI: 0.1%-5.4%). The only risk factor significantly associated with transmission was a failure to use zidovudine intra-partum in 2 of the 4 mothers (50% versus 6.4% in non-transmitting mothers). A trend toward low CD4 and high viral load at entry, and rupture of membranes > 4 hours were associated with increased HIV transmission. CONCLUSION: HIV vertical transmission in Brazil was reduced to a level similar to other countries with the most effective prevention programs using a multidisciplinary team approach. A high level of compliance for use of anti-retroviral drugs, the provision of health education to mothers, and use of formula for all exposed infants.