Acute Illnesses Associated With Insecticides Used to Control Bed Bugs --- Seven States, 2003--2010

Acute Illnesses Associated With Insecticides Used to Control Bed Bugs --- Seven States, 2003--2010Weekly
September 23, 2011 / 60(37);1269-1274

The common bed bug, Cimex lectularius, is a wingless, reddish-brown insect that requires blood meals from humans, other mammals, or birds to survive (1). Bed bugs are not considered to be disease vectors (2,3), but they can reduce quality of life by causing anxiety, discomfort, and sleeplessness (4). Bed bug populations and infestations are increasing in the United States and internationally (3,5). Bed bug infestations often are treated with insecticides, but insecticide resistance is a problem, and excessive use of insecticides or use of insecticides contrary to label directions can raise the potential for human toxicity. To assess the frequency of illness from insecticides used to control bed bugs, relevant cases from 2003--2010 were sought from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides program and the New York City Department of Health and Mental Hygiene (NYC DOHMH). Cases were identified in seven states: California, Florida, Michigan, North Carolina, New York, Texas, and Washington. A total of 111 illnesses associated with bed bug--related insecticide use were identified; although 90 (81%) were low severity, one fatality occurred. Pyrethroids, pyrethrins, or both were implicated in 99 (89%) of the cases, including the fatality. The most common factors contributing to illness were excessive insecticide application, failure to wash or change pesticide-treated bedding, and inadequate notification of pesticide application. Although few cases of illnesses associated with insecticides used to control bed bugs have been reported, recommendations to prevent this problem from escalating include educating the public about effective bed bug management.

To evaluate illnesses associated with insecticides used to control bed bugs, data from 2003--2010 were obtained from states participating in the SENSOR-Pesticides program* and from NYC DOHMH.† Acute illnesses associated with an insecticide used to control bed bugs were defined as two or more acute adverse health effects resulting from exposure to an insecticide used for bed bug control. Cases were categorized as definite, probable, possible, and suspicious based on three criteria: certainty of exposure, reported health effects, and consistency of health effects with known toxicology of the insecticide (causal relationship) (Table 1). Data were analyzed for demographics, health effects, report source, case definition category, illness severity,§ insecticide toxicity,¶ insecticide chemical class, work-relatedness, and factors contributing to illness. A 2010 case report from Cincinnati Children's Hospital Medical Center (CCHMC) in Ohio also was obtained.**

For 2003--2010, a total of 111 cases were identified in seven states (Table 2). The majority of cases occurred during 2008--2010 (73%), were of low severity (81%), and were identified by poison control centers (81%). New York City had the largest percentage of cases (58%). Among cases with known age, the majority occurred among persons aged ≥25 years (67%). The majority of cases occurred at private residences (93%); 40% of cases occurred in multiunit housing. Among cases, 39% of pesticide applications were performed by occupants of the residence who were not certified to apply pesticides. The majority of insecticide exposures were to pyrethroids, pyrethrins, or both (89%) and were in toxicity category III (58%) (Table 2). The most frequently reported health outcomes were neurologic symptoms (40%), including headache and dizziness; respiratory symptoms (40%), including upper respiratory tract pain and irritation and dyspnea; and gastrointestinal symptoms (33%), including nausea and vomiting.

Among cases, 13 (12%) were work-related. Of these, three illnesses involved workers who applied pesticides, including two pest control operators, of whom one was a certified applicator. Four cases involved workers who were unaware of pesticide applications (e.g., two carpet cleaners who cleaned an apartment recently treated with pesticides). Two cases involved hotel workers (a maintenance worker and a manager) who were exposed when they entered a recently treated hotel room, and two cases involved emergency medical technicians who responded to a scene where they found white powder thought to be an organophosphate pesticide. Contributing factors were identified for 50% of cases. Factors that most frequently contributed to insecticide-related illness were excessive insecticide application (18%), failure to wash or change pesticide-treated bedding (16%), and inadequate notification of pesticide application (11%) (Table 3).

The one fatality, which occurred in North Carolina in 2010, involved a woman aged 65 years who had a history of renal failure, myocardial infarction and placement of two coronary stents, type II diabetes, hyperlipidemia, hypertension, and depression. She was taking at least 10 medications at the time of exposure. After she complained to her husband about bed bugs, he applied an insecticide†† to their home interior baseboards, walls, and the area surrounding the bed, and a different insecticide§§ to the mattress and box springs. Neither of these products are registered for use on bed bugs. Nine cans of insecticide fogger¶¶ were released in the home the same day. Approximately 2 days later, insecticides were reapplied to the mattress, box springs, and surrounding areas, and nine cans of another fogger*** were released in the home.
On both days the insecticides were applied, the couple left their home for 3--4 hours before reentering.
Label instructions on the foggers to air out the treated area for 30 minutes with doors and windows open were not followed on either day. On the day of the second application, the woman applied a bedbug and flea insecticide††† to her arms, sores on her chest, and on her hair before covering it with a plastic cap. She also applied the insecticide to her hair the day before the second application. Two days following the second application, her husband found her nonresponsive. She was taken to the hospital and remained on a ventilator for 9 days until she died.

Another example of insecticide misuse to control bed bugs occurred in Ohio in 2010. An uncertified pesticide applicator applied malathion to an apartment five times over the course of 3 days to treat a bed bug infestation. The malathion product was not registered for indoor use and was applied liberally such that beds and floor coverings were saturated. A family resided in the apartment that consisted of a father, mother, four children, and an adult roommate. One of the children, aged 6 years, attended kindergarten and arrived home around the time of the afternoon malathion applications. The father and roommate also were in the home during the applications. The child began experiencing diarrhea on the first application day, and headache and dizziness began on the second application day. The two adults present during the applications reported nausea, vomiting, headaches, and tremors. During the malathion applications, three younger children were in child care while their mother was at work, and they did not exhibit symptoms of insecticide poisoning. Each night following application of malathion, the children slept on sheets placed on the floor to avoid sleeping on saturated beds.

Because symptoms in the child aged 6 years persisted on the third application day, he was taken to a community hospital emergency department (ED) and decontaminated. Because the hospital did not have pediatrics specialty care, he was transferred to CCHMC by ambulance for evaluation and treatment. His pseudocholinesterase level was within normal limits. He received 1 dose of pralidoxime and was observed in the CCHMC ED before release. The two adults were seen in a community hospital ED, treated, and released. The family did not return to the contaminated residence following the ED visits. The incident was investigated by the Cincinnati fire department and the Ohio Department of Agriculture. The applicator pled guilty to criminal charges, resulting in a fine and probation.

Reported by
James B. Jacobson, MPH, Katherine Wheeler, MPH, Robert Hoffman, MD, New York City Dept of Health and Mental Hygiene, New York; Yvette Mitchell, New York State Dept of Health. John Beckman, California Dept of Public Health; Louise Mehler, MD, PhD, California Dept of Pesticide Regulation. Prakash Mulay, Florida Dept of Health. Abby Schwartz, MPH, Michigan Dept of Community Health. Rick Langley, MD, Div of Public Health, North Carolina Dept of Health and Human Svcs. Brienne Diebolt-Brown, MA, Texas Dept of State Health Svcs. Joanne Bonnar Prado, MPH, Washington Dept of Health. Nicholas Newman, DO, Cincinnati Children's Hospital/Univ of Cincinnati, Ohio. Geoffrey M. Calvert, MD, Div of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health; Naomi L. Hudson, DrPH, EIS Officer, CDC. Corresponding contributor: Naomi L. Hudson, nhudson1@cdc.gov, 513-841-4424.

Editorial Note
Bed bug populations and infestations are increasing in the United States and internationally (3,5). Contributing factors are thought to include increased bed bug resistance to insecticides, increased domestic and international travel, rooms with more clutter, and greater prevalence of bed bug--friendly furnishings (e.g., wooden bed frames) (5). Insecticides containing pyrethroids are used widely to control bed bugs; however, pyrethroid-resistant bed bug populations have been found in five states (California, Florida, Kentucky, Ohio, and Virginia) (5). Given the increasing resistance of bed bugs to insecticides approved for bed bug control, at least one state has requested an emergency exemption from the Environmental Protection Agency (EPA) to use propoxur, a carbamate, to control bed bugs indoors.

CDC and EPA promote integrated pest management (IPM) for bed bug control (3,6). IPM is an effective pest control method that uses information on the life cycle of the pest and incorporates nonchemical and chemical methods (6). Nonchemical methods to effectively control bed bugs include heating infested rooms to 118°F (48°C) for 1 hour or cooling rooms to 3°F (-16°C) for 1 hour by professional applicators (7); encasing mattresses and box springs with bed bug--excluding covers; and vacuuming, steaming, laundering, and disposing of infested items (6). Any effective control measure for bed bugs requires support from all residents in affected buildings and ongoing monitoring for infestation from other housing units (3). Often, multiple inspections and treatments are needed to eradicate bed bugs (4).

The findings in this report are subject to at least four limitations. First, acute illness associated with insecticide use might be underreported in the regions covered by the surveillance systems. Case identification in SENSOR-Pesticides relies on a passive surveillance system, so persons experiencing minor symptoms who do not seek medical treatment or advice from poison control centers are not reported to the system. Second, cases might have been excluded if insufficient information was provided to meet the case definition§§§ or to determine that the insecticide was used for bed bug control (e.g., surveillance systems do not systematically capture whether insecticides are used for bed bug control). Cases were identified only if available narrative information contained the term "bed bug." Third, false positives might be included as cases. Symptoms for acute illnesses associated with insecticides are nonspecific; illnesses might be coincidental and not caused by insecticide exposure. Among the 111 cases described in this report, only 16% were categorized as either definite or probable. Finally, contributing factors were identified for only 50% of the cases; complete knowledge of contributing factors might alter the interpretation presented in this report.

Although the number of acute illnesses from insecticides used to control bed bugs does not suggest a large public health burden, increases in bed bug populations that are resistant to commonly available insecticides might result in increased misuse of pesticides. Public health recommendations to prevent illnesses associated with insecticides used to control bed bugs include media campaigns to educate the public about bed bug--related issues, including nonchemical methods to control bed bugs, methods to prevent bed bug infestation (e.g., avoiding the purchase of used mattresses and box springs), and prudent use of effective insecticides (3). Persons who have a bed bug infestation should be encouraged to seek the services of a certified applicator¶¶¶ who uses an IPM approach to avoid pesticide misuse. Persons applying insecticides should follow product instructions for safe and appropriate use. Insecticide labels that are easy to read and understand also can help prevent illnesses associated with bed bug control.

References
1.Thomas I, Kihiczak GG, Schwartz RA. Bedbug bites: a review. Int J Dermatol 2004;43:430--3.
2.Goddard J, deShazo R. Bed bugs (Cimex lectularius) and clinical consequences of their bites. JAMA 2009;301:1358--66.
3.CDC, Environmental Protection Agency. Joint statement on bed bug control in the United States from the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Environmental Protection Agency (EPA). Atlanta, GA: US Department of Health and Human Services; 2010.
4.Wang C, Gibb T, Bennett GW. Evaluation of two least toxic integrated pest management programs for managing bed bugs (Heteroptera: Cimicidae) with discussion of a bed bug intercepting device. J Med Entomol 2009;46:566--71.
5.Romero A, Potter MF, Potter DA, Haynes KF. Insecticide resistance in the bed bug: a factor in the pest's sudden resurgence? J Med Entomol 2007;44:175--8.
6.Environmental Protection Agency. Bed bug information. Washington, DC: Environmental Protection Agency; 2011. Available at http://www.epa.gov/bedbugs/#treat. Accessed September 16, 2011.
7.Benoit JB, Lopez-Martinez G, Teets NM, Phillips SA, Denlinger DL. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins. Med Vet Entomol 2009;23:418--25.

* The SENSOR-Pesticides program consists of 12 states that conduct surveillance of pesticide-related illness. California, Florida, Michigan, North Carolina, New York, Texas, and Washington reported cases of acute illness associated with insecticides used for bed bug control. The other five states participating in the SENSOR-Pesticides program (Arizona, Iowa, Louisiana, New Mexico, and Oregon) did not identify any cases of acute illness associated with insecticides used for bed bug control during 2003--2010. The California Department of Public Health reported one case of acute illness associated with insecticides used for bed bug control. The other case in California was reported through the California Department of Pesticide Regulation.
† New York City Poison Control Center, a component of NYC DOHMH, contributed data from 2003--2010, in addition to data received from New York State Department of Health and Mental Hygiene. Because the New York City Poison Control Center does not report data to the New York State Department of Health, their data were reported separately.
§ Low severity cases usually resolve without treatment and cause minimal time lost from work (<3 days). Moderate severity cases are non--life threatening but require medical treatment and result in <6 days lost from work. High severity cases are life threatening, require hospitalization, and result in >5 days lost from work.
¶ The toxicity category of an insecticide is determined by the Environmental Protection Agency (EPA) under guidance from CFR Title 40 Part 156. Insecticides in category I have the greatest toxicity, and insecticides in category IV have the least toxicity.
** This case was not included in the analysis because Ohio does not participate in the SENSOR-Pesticides program. However, this case received media coverage in Ohio and represents misuse and excessive application of pesticides. The case demonstrates the need for consumers to be diligent in choosing a certified or licensed pesticide applicator.
†† Ortho Home Defense Max (Ortho Business Group), EPA registration number: 239-2663, with the active ingredient bifenthrin.
§§ Ortho Lawn and Garden Insect Killer (Ortho Business Group), EPA registration number: 239-2685, with the active ingredient bifenthrin.
¶¶ Hot Shot Fogger (Spectrum Group), EPA registration number: 9688-254-8845, with active ingredients tetramethrin and cypermethrin.
*** Hot Shot Bedbug and Flea Fogger (Spectrum Group), EPA registration number: 1021-1674-8845, with the active ingredient pyrethrins, piperonyl butoxide, MGK 264 (an insecticide synergist), and pyriproxyfen.
††† Hot Shot Bed Bug and Flea Killer (Chemisco), EPA registration number: 9688-150-8845, with active ingredients pyrethrins and piperonyl butoxide.
§§§ Among New York City cases, 33 were excluded because the affected persons each had only one reported symptom.
¶¶¶ Restricted-use pesticides may only be applied by licensed or certified applicators. States are responsible for the training, certification, and licensing of pesticide applicators. A certified applicator is a pesticide applicator who has been determined to have the knowledge and ability to use pesticides safely and effectively. Some states also require that certified pesticide applicators be licensed. In such states, a license is required to purchase, use and/or supervise the application of restricted-use pesticides. Information on certification of pesticide applicators is available at http://www.epa.gov/oppfead1/safety/applicators/applicators.htm. EPA guidance for consumers on choosing a pest control company and on pesticide safety and nonchemical means of control is available at http://www.epa.gov/oppfead1/Publications/Cit_Guide/citguide.pdf . Consumers who have questions about the licensing or certification of a pesticide applicator should contact their state's agriculture department or agricultural extension service for information.

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Acute Illnesses Associated With Insecticides Used to Control Bed Bugs --- Seven States, 2003--2010