RESUMO
An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A total of 126 cases and 62 controls were included in the analysis. The odds of developing gastroenteritis were 6.0 times greater among holiday makers than residents (95% confidence interval (CI) 2.0-17.7). Swimming in the lagoon increased the odds of developing gastroenteritis by 3.3 times (95% CI 1.06-10.38). Lagoon water samples tested positive for norovirus (NoV) GI.6, GII.3 and GII.6, astrovirus and rotavirus. Eleven (55%) stool specimens were positive for NoV with eight genotyped as GI.1 (n = 2), GI.5 (n = 3), GI.6 (n = 2), and GI.7 (n = 1). A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. Restriction to swimming in the lagoon was apparently ineffective at preventing the outbreak, possibly due to inadequate enforcement, communication and signage strategies.
Assuntos
Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Gastroenterite/epidemiologia , Norovirus/genética , Norovirus/isolamento & purificação , Adolescente , Adulto , Praias , Infecções por Caliciviridae/microbiologia , Infecções por Caliciviridae/transmissão , Estudos de Casos e Controles , Criança , Pré-Escolar , Água Potável , Fezes/microbiologia , Feminino , Gastroenterite/microbiologia , Genótipo , Férias e Feriados , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco , Esgotos/microbiologia , África do Sul/epidemiologia , Natação , Microbiologia da Água , Poluentes da Água , Adulto JovemRESUMO
BACKGROUND: Rates of healthcare-associated infections (HAIs) among babies born in developing countries are higher than among those born in resource-rich countries, as a result of suboptimal infection prevention and control (IPC) practices. Following two reported deaths of neonates with carbapenem-resistant Klebsiella pneumoniae bloodstream infections (BSIs), we conducted an outbreak investigation in a neonatal unit of a regional hospital in Gauteng Province, South Africa. OBJECTIVES: To confirm an outbreak of K. pneumoniae BSIs and assess the IPC programme in the neonatal unit. METHODS: We calculated total and organism-specific BSI incidence risks for culture-confirmed cases in the neonatal unit for baseline and outbreak periods. We conducted a clinical record review for a subset of cases with K. pneumoniae BSI that had been reported to the investigating team by the neonatal unit. An IPC audit was performed in different areas of the neonatal unit. We confirmed species identification and antimicrobial susceptibility, and used polymerase chain reaction for confirmation of carbapenemase genes and pulsed-field gel electrophoresis (PFGE) for typing of submitted clinical isolates. RESULTS: From January 2017 to August 2018, 5 262 blood cultures were submitted, of which 11% (560/5 262) were positive. Of 560 positive blood cultures, 52% (n=292) were positive for pathogenic organisms associated with healthcare-associated BSIs. K. pneumoniae comprised the largest proportion of these cases (32%; 93/292). The total incidence risk of healthcare-associated BSI for the baseline period (January 2017 - March 2018) was 6.8 cases per 100 admissions, and that for the outbreak period (April - September 2018) was 10.1 cases per 100 admissions. The incidence risk of K. pneumoniae BSI for the baseline period was 1.6 cases per 100 admissions, compared with 5.0 cases per 100 admissions during the outbreak period. Average bed occupancy for the entire period was 118% (range 101 - 133%), that for the baseline period was 117%, and that for the outbreak period was 121%. In a subset of 12 neonates with K. pneumoniae bacteraemia, the median (interquartile range (IQR)) gestational age at birth was 27 (26 - 29) weeks, and the median (IQR) birth weight was 1 100 (880 - 1 425) g. Twelve bloodstream and 31 colonising K. pneumoniae isolates were OXA-48-positive. All isolates were genetically related by PFGE analysis (89% similarity). Inadequate IPC practices were noted, including suboptimal adherence to aseptic technique and hand hygiene (57% overall score in the neonatal intensive care unit), with poor monitoring and reporting of antimicrobial use (pharmacy score 55%). CONCLUSIONS: Overcrowding and inadequate IPC and antimicrobial stewardship contributed to a large outbreak of BSIs caused by genetically related carbapenemase-producing K. pneumoniae isolates in the neonatal unit.