Influenza A (H1N1): outbreak management in a dialysis unit and clinical outcomes of infection in chronic hemodialysis patients / Influenza A (H1N1): controle de surto em unidade de diálise e desfechos clínicos da infecção em pacientes em hemodiálise crônica

ABSTRACT Introduction: Chronic hemodialysis (HD) patients are considered to be at high risk for infection. Here, we describe the clinical outcomes of chronic HD patients with influenza A (H1N1) infection and the strategies adopted to control an outbreak of influenza A in a dialysis unit. Methods: Among a total of 62 chronic HD patients, H1N1 infection was identified in 12 (19.4%). Of the 32 staff members, four (12.5%) were found to be infected with the H1N1 virus. Outcomes included symptoms at presentation, comorbidities, occurrence of hypoxemia, hospital admission, and clinical evaluation. Infection was confirmed by real-time reverse transcriptase polymerase chain reaction. Results: The 12 patients who had H1N1 infection did not differ significantly from the other 50 non-infected patients with respect to age, sex, dialysis vintage, dialysis modality, or proportion of comorbidities. Obesity was higher in the H1N1-infected group (41.5 vs. 4%, p<0.002). The most common symptoms were fever (92%), cough (92%), and rhinorrhea (83%). Early empirical antiviral treatment with oseltamivir was started in symptomatic patients and infection control measures, including the intensification of contact-reduction measures by the staff members, antiviral chemoprophylaxis to asymptomatic patients undergoing HD in the same shift of infected patients, and dismiss of staff members suspected of being infected, were implemented to control the spread of infection in the dialysis unit. Conclusion: The clinical course of infection with H1N1 in our patients was favorable. None of the patients developed severe disease and the strategies adopted to control the outbreak were successful.

RESUMO Introdução: Pacientes em hemodiálise (HD) crônica apresentam risco elevado para infecções. O presente estudo descreve os desfechos clínicos de pacientes em HD crônica com infecção pelo vírus influenza A (H1N1) e as estratégias adotadas para controlar um surto de influenza A numa unidade de diálise. Métodos: Doze (19,4%) de 62 pacientes em HD crônica e quatro (12,5%) de 32 funcionários desta unidade de diálise apresentaram infecção pelo vírus H1N1. Os desfechos incluíram sintomas à apresentação, comorbidades, ocorrência de hipoxemia, internação hospitalar e avaliação clínica. A presença de infecção foi confirmada por reação em cadeia da polimerase via transcriptase reversa (RT-PCR) em tempo real. Resultados: Os 12 pacientes com infecção por H1N1 não diferiram significativamente dos 50 pacientes sem infecção no tocante a idade, sexo, tempo em diálise, modalidade de diálise e percentual de comorbidades. O percentual de obesidade foi mais elevado no grupo com infecção por H1N1 (41,5% vs. 4%, p<0,002). Os sintomas mais comuns foram febre (92%), tosse (92%) e rinorreia (83%). Os pacientes foram submetidos a tratamento antiviral com oseltamivir e medidas de controle (intensificação das medidas de redução de contato pelos funcionários da clínica, quimioprofilaxia com antiviral para pacientes assintomáticos em HD na mesma sala dos pacientes com infecção e afastamento de funcionários da clínica com suspeita de infecção) para controlar a disseminação da infecção pela unidade de diálise. Conclusão: O curso clínico da infecção por H1N1 em nossos pacientes foi favorável. Nenhum evoluiu para doença grave e as estratégias adotadas foram efetivas no controle do surto.

Colonization pressure as a risk factor for colonization by multiresistant Acinetobacter spp and carbapenem-resistant Pseudomonas aeruginosa in an intensive care unit

OBJECTIVE: To determine factors associated with colonization by carbapenem-resistant Pseudomonas aeruginosa and multiresistant Acinetobacter spp. METHODS: Surveillance cultures were collected from patients admitted to the intensive care unit at admission, on the third day after admission and weekly until discharge. The outcome was colonization by these pathogens. Two interventions were implemented: education and the introduction of alcohol rubs. Compliance with hand hygiene, colonization pressure, colonization at admission and risk factors for colonization were evaluated. RESULTS: The probability of becoming colonized increased during the study. The incidence density of colonization by carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. and colonization pressure were different between periods, increasing gradually throughout the study. The increase in colonization pressure was due to patients already colonized at admission. The APACHE II score, colonization pressure in the week before the outcome and male gender were independent risk factors for colonization. Every 1% increase in colonization pressure led to a 2% increase in the risk of being colonized. CONCLUSION: Colonization pressure is a risk factor for carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. colonization. When this pressure reaches critical levels, efforts primarily aimed at hand hygiene may not be sufficient to prevent transmission. .