Intensive but nonprofessional use of pesticides to control bedbugs probably contributed to the death of a 65-year-old woman in North Carolina, the CDC reported.
But most cases of illness associated with insecticides used to battle bedbugs are of low severity, the agency reported in the Sept. 23 issue of Morbidity and Mortality Weekly Report.
Although the number is probably an underestimate, the agency said, analysis of surveillance data found 111 cases of illness -- including the fatality -- in seven states from 2003 through 2010.
Most of the cases -- 73 percent -- were recorded from 2008 through 2010, the CDC reported.
New York City had the largest percentage of cases, at 58 percent.
93 percent of cases occurred at private residences and 40 percent were in multi-unit housing.
Among the cases, 39 percent involved pesticide use by occupants of a home who were not certified to apply pesticides.
Most exposures -- 89 percent -- were to pyrethroids, pyrethrins, or both, and 58 percent of the compounds used were in the Environmental Protection Agency's toxicity category III, defined as slightly toxic and slightly irritating.
The CDC said investigators identified contributing factors in half the cases, including excessive application of insecticide, failure to wash or change pesticide-treated bedding, and inadequate notification of pesticide application.
The agency cautioned that illness associated with insecticide use might be under-reported, since people with minor symptoms who do not seek treatment or advice from poison control centers would not be reported to the surveillance system.
As well, the surveillance system does not "systematically capture whether insecticides are used for bedbug control," the agency noted, so that some reported cases of poisoning might not have been counted as related to bedbugs.
On the other hand, the CDC noted, some cases might have been falsely identified as related to insecticides used to control the bugs, since the symptoms for acute illnesses linked to insecticides are nonspecific.