Swimming with salmonella
It’s summer and thus time for the National Resources Defense Council’s annual report on the state of the nation’s beaches. In other words, where you enjoy a nice, safe dip and where the scariest menaces in the water are not big, bad sharks.
Rather, they’re tiny, terrible, teeming pathogens like salmonella bacteria, pictured above invading a cultured human cell in this false-colored micrograph from the National Institute of Allergy and Infectious Diseases.
Salmonella are indicator bacteria, a microbe used to detect and estimate the level of fecal contamination in water. A gram of human feces contains approximately 100 billion bacteria, not to mention pathogenic viruses, protozoa and parasites. Exposure to salmonella (which can come as well from tainted food or certain animals) can cause a host of ailments, from gastrointestinal disorders to typhoid fever.
The NRDC’s report was not encouraging. It found that the number of days that beaches around the country were closed or under health advisories reached 23,481 last year, slightly better than the previous year but still the third-highest total in the report’s 22-year history.