Seasonality and weather dependance of Acinetobacter baumannii complex bloodstream infections in different climates in Brazil.

Recent studies report seasonality in healthcare-associated infections, especially those caused by Acinetobacter baumannii complex. We conducted an ecologic study aimed at analyzing the impact of seasons, weather parameters and climate control on the incidence and carbapenem-resistance in A. baumannii complex bloodstream infections (ABBSI) in hospitals from regions with different climates in Brazil. We studied monthly incidence rates (years 2006-2015) of ABBSI from hospitals in cities from different macro-regions in Brazil: Fortaleza (Ceará State, Northeast region), Goiânia (Goiás State, Middle-west) and Botucatu (São Paulo State, Southeast). Box-Jenkins models were fitted to assess seasonality, and the impact of weather parameters was analyzed in Poisson Regression models. Separate analyses were performed for carbapenem-resistant versus carbapenem-susceptible isolates, as well as for infections occurring in climate-controlled intensive care units (ICUs) versus non-climate-controlled wards. Seasonality was identified for ABSSI ICUs in the Hospitals from Botucatu and Goiânia. In the Botucatu hospital, where there was overall seasonality for both resistance groups, as well as for wards without climate control. In that hospital, the overall incidence was associated with higher temperature (incidence rate ratio for each Celsius degree, 1.05; 95% Confidence Interval, 1.01-1.09; P = 0.006). Weather parameters were not associated with ABBSI in the hospitals from Goiânia and Fortaleza. In conclusion, seasonality was found in the hospitals with higher ABBSI incidence and located in regions with greater thermal amplitude. Strict temperature control may be a tool for prevention of A. baumanii infections in healthcare settings.

Burkholderia pseudomallei antibodies in individuals living in endemic regions in Northeastern Brazil.

A seroepidemiological investigation was conducted among the population of two municipalities in Northeastern Brazil. Immunoglobulin M (IgM) and IgG antibodies to Burkholderia pseudomallei were positive in 51.27% (161 in 317 samples) and 58.49% (186), respectively. IgM titers were higher in children than in adults. On the contrary, IgG increased progressively with age. We observed a significant association between agricultural occupation and raised IgM titers (P < 0.005) and IgG titers (P < 0.001), and between construction workers and raised IgG titers (P = 0.005). Antibody IgG avidities did not correlate with age. The highest titers of antibodies (1/800) showed the highest antibody avidity indexes (P < 0.01). Most of the serum samples recognized 45-kDa and 200-kDa bands by IgG1 and IgG2 subclasses. Our study showed a high seropositivity among individuals living in endemic regions of the state of Ceará, and highlights the need for further surveillance close to water courses such as dams and rivers in Northeastern Brazil.