Human Brucella canis Infections Diagnosed by Blood Culture

This report demonstrates an apparently paradoxical inverse relationship between a positive RDT result and severity of illness among patients with pandemic (H1N1) 2009. This observation cannot be explained by differences in the time to access to medical care, performance of RDT (7), or prior antiviral therapy. Variants of pandemic (H1N1) 2009 virus may preferentially infect the lower respiratory tract in certain hosts (8). Invasive properties of pandemic (H1N1) 2009 virus and severity of illness may be more closely related to heterogeneity in host immunity than to viral load (9). US Centers for Disease Control and Prevention guidance advises that “hospitalized patients with suspected infl uenza should receive immediate empiric antiviral treatment..., a negative RIDT or DFA test result does not exclude infl uenza virus infection...” (10). Moreover, this guidance also recommends that collection of lower respiratory tract specimens may be useful for reverse transcription–PCR testing to improve diagnosis for patients suspected of having severe lower respiratory tract disease caused by pandemic (H1N1) 2009 virus. The current fi ndings strongly support this recommendation, particularly for severely ill patients.