A longitudinal analysis of methicillin-resistant and sensitive Staphylococcus aureus incidence in respect to specimen source, patient location, and temperature variation
文摘
The results indicate a gradual but steady increase in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) infections, with outpatient cases representing the majority of infections. The top three most common infections in order of prevalence were wound, respiratory tract, and urinary sources. The rate of infection was distributed equally between males and females. Although there was a slight increase in inpatient and nursing home MRSA cases, these cases consistently contributed to a smaller fraction of the total cases over the 5 years. If present, the cyclical nature of MRSA infections was directly related to the specimen source and patient location, with wound infections from outpatients more prevalent in warmer months, and respiratory infections among inpatients commonly observed during the colder months. This seasonal variation was absent among the nursing home population. The current report provides a longitudinal analysis of staphylococcal epidemiology, and in the process, identifies the staphylococcal seasonality to be multifactorial and to depend on various environmental factors, such as patient subpopulation and specimen source.