Solar and Climate Effects Explain the Wide Variation of Legionellosis Incidence Rates in the United States.

This study examined environmental effects on the 2014-2016 average annual legionellosis incidence rates in the US states through correlative analyses with long-term precipitation, temperature, solar ultraviolet radiation, and sunshine hours. The continental states west of ∼95°W showed low incidence rates of 0.51 to 1.20 cases per 100,000 population, which corresponded to low precipitation below annual 750 mm. For the eastern states, where precipitation was higher, solar effects were prominent and mixed, leading to wide incidence variation. Robust regressions suggested a dividing line at 40°N: north of this line, rising temperature, mainly from solar heat, raised legionellosis incidence, to the peak of 4.25/100,000 in Ohio; south of this line, intensifying sunlight in terms of high ultraviolet indices and long sunshine hours prevailed to limit incidence, gradually to 0.99/100,000 in Louisiana. On or near the 40°N line were 15 eastern states that had leading legionellosis incidence rates of >2.0/100,000. These states all showed modest environmental parameters. By contrast, the frigid climate in Alaska and the strong year round solar ultraviolet in Hawaii explained the least incidence of 0.14/100,000 and 0.47/100,000 in these states respectively. The findings of solar and climate effects explain the wide variation of legionellosis incidence rates in the US and may offer insights on the potential exposure and prevention of the infection.Importance Legionellosis, caused by...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research