Dive suits could spread disease.

Divers' wetsuits can harbor bacteria that cause diseases in coral and people, a new study suggests. The finding could lead to new guidelines for cleaning gear after dives.

Coral reefs are rapidly declining worldwide, and infectious diseases of the microscopic animals living within them seem to be a major cause. Researchers have suggested a variety of reasons for the rise in infections, including increased pollution.

However, notes microbiologist Cheryl Woodley of the Charleston, S.C., office of the National Oceanic and Atmospheric Administration, few researchers suspected that divers might be harboring dangerous microbes in their suits.

To test this scenario, Woodley and her colleagues cut up a used wetsuit and sterilized the pieces. They then incubated each clean swatch in seawater mixed with a known quantity of one of three microbes: Vibrio carchariae, Serratia marcescens, and Staphylococcus aureus. V. carchariae and S. marcescens typically infect coral, whereas S. aureus infects people. The researchers measured the bacterial content of some swatches within 5 minutes of being lifted from the solution.

To simulate some common postdive scenarios, the researchers simply hung some of the contaminated swatches to dry for either 1 hour or 18 hours. The team dried other swatches after rinsing them briefly in tap water, in a 5 percent bleach solution, or in a 6 percent Lysol solution. The researchers found that simple drying only minimally reduced bacterial counts on the swatches. Swishing them in plain tap water reduced bacterial counts by 66 to 94 percent, depending on species type. However, hundreds of recoverable bacteria remained on the fabric. In comparison, rinsing with bleach or Lysol solutions knocked counts down to less than a tenth of a percent of their original numbers.

"We don't think that divers are the major vector" for disease, says Woodley. However, she adds, "the notion that bacteria can be transmitted on dive gear is real."--C.B.