Bed bugs back in view
In 2023, widespread reporting of bed bug infestations in France and South Korea, alongside frenzied social media attention, has raised the profile of these troublesome arthropods once again. Bed bugs are considered a nuisance, but does the “ick factor” surpass the legitimate public health concerns, or should there be renewed emphasis on their prevention and control? This blog provides some context to this issue and highlights recent information and resources for environmental public health professionals (EPHPs), including an updated NCCEH subject guide on bed bugs.
What are bed bugs?
Bed bugs are small, reddish-brown, wingless, flat-bodied insects, which can grow up to 10 mm in length. They live on the blood of animals or humans and they can survive several months without a blood meal. They thrive in warm indoor places (e.g., 21-31°C), and under optimal conditions, a population can double every 16 days. Two species are responsible for most outbreaks globally: Cimex lectularius L. is most common in Canada and other northern countries, and C. hemipterus is more common in tropical climates.
Why the resurgence?
Although bed bugs have lived among human dwellings for millennia, they were likely first introduced into Canada by early European settlers. They were nearly eradicated in many developed countries following World War II with the use of pesticides such as dichlorodiphenyltrichloroethane (DDT), which killed bugs and provided a residual effect that prevented re-emergence. Pesticides such as DDT are now long banned from use, but other pesticides have since taken their place. A global bed bug resurgence began around the early 2000s, and many Canadian cities from the south to the north have observed increasing bed bug prevalence since then. The bed bug resurgence is driven by many factors:
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Pesticide resistance: Bed bugs have developed resistance to many pesticides, including pyrethroid insecticides commonly used today, making chemical control increasingly difficult. |
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Increased international trade and travel: Bed bugs can hide in clothing, furniture, and luggage, and can survive being transported long distances. Reduced international travel during the COVID-19 pandemic coincided with a decline in bed bug infestations, which are now increasing. Outbreaks in the UK increased by 65% between 2022 and 2023, with a rise in post-pandemic travel. |
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Media attention: Periodic media coverage of bed bugs, fuelled by viral social media posts, can heighten awareness among the public and cause an uptick in reporting. |
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Fragmented responsibilities: Responsibility for addressing bed bugs in some jurisdictions may be assigned to municipal bylaw enforcement, landlords, tenants, or housing agencies, and does not always come under the purview of public health. Surveillance may be patchy and control measures may be inappropriate or incomplete, leading to persistence and spread. |
Which locations are most at risk?
Infestations can be persistent and spread easily in any building or facility where people gather or sleep particularly housing and hotels. Public buildings, university accommodation, COVID isolation centres, libraries, and other locations have also been affected in recent years. Apartment buildings, particularly low-income housing, are often the most affected, and bed bug infestations can be challenging to eradicate. Children, the elderly, disabled persons, immigrant families, and people in socioeconomically challenging situations may be most at risk of exposure, and least able to respond. Costs associated with treatment can be a barrier, and lack of follow up or periodic monitoring throughout a building can contribute to chronic issues.
What are the health concerns?
Bed bugs are not considered a vector for human pathogens but they are a pest of public health concern. They have been shown to harbour some infectious bacteria, fungi, viruses and parasites, including antimicrobial resistant bacteria such as MRSA. There is no evidence yet of human disease transmission via bites or feces, but they can cause adverse health impacts ranging from irritation and allergic reactions, to more serious psychological impacts.
People living in bed bug infested conditions can suffer loss of sleep, anxiety, depression, and social isolation. Some of the most serious adverse health events linked to bed bugs have been due to psychological distress, poor living conditions, and neglect. For example, Burrows et al. (2013) reported on a case of suicide of a woman whose negative psychological state was likely triggered by a bed bug infestation. Neglectful care was determined to have caused the deaths of a prisoner in a bed bug infested jail cell in Georgia and a 96-year-old Pennsylvania woman, who developed sepsis from multiple bed bug bites while living in an infested home.
Serious adverse health effects have also occurred due to use of unregistered pesticides or unsafe practices for controlling infestations. In 2015, an eight-month-old baby and a two-year-old boy died and other family members became ill following the use of an illegally imported phosphine pesticide to treat bed bugs in an apartment in Fort McMurray, Alberta. This prompted a Health Canada warning on the use of unregistered bed bug control products. In 2018, a UK couple died while on holiday in Egypt due to carbon monoxide poisoning when lambda-cyhalothrin was sprayed in an adjacent hotel room to treat bed bugs. The pyrethroid pesticide had been diluted with dichloromethane, causing the formation of carbon monoxide vapour.
What are the most effective control strategies?
Chemical controls are often sought to provide a quick fix, but waning effectiveness due to pesticide resistance and the health risks from improper pesticide use make prevention and non-chemical control measures more appealing. Prevention and non-chemical controls are safer and may be less expensive. The US EPA Collaborative Strategy on Bed Bugs emphasizes four priority areas for addressing bed bugs, which have been adopted by many agencies as part of a comprehensive and collaborative approach. These priority areas include:
- Prevention: Prevention includes raising awareness of risk factors for bed bugs entering a property through luggage, furniture, or other goods, and advice on ensuring bed bugs do not become established (e.g., frequent vacuuming, isolating luggage, beds or furniture, reduction of clutter). Disclosure of bed bug infestations by landlords to public health or housing departments may help prevent spread in rented accommodation by prompting landlords to undertake control and prevention measures. This was one factor suggested to facilitate a 50% reduction in monthly bed bug complaints in New York City between 2014—2020, where annual disclosure is required.
- Surveillance and Integrated Pest Management (IPM): Detecting infestations as soon as possible increases the likelihood of eradication and lowers control costs. Surveillance measures include monitors, traps, resident surveys, or even sniffer dogs to detect infestations. Using an IPM approach means employing a multipronged approach, deploying non-chemical control methods and considering using pesticides safely only if necessary. Non-chemical methods range widely from various forms of heat treatment to kill off adult bed bugs and eggs, to desiccant sprays such as diatomaceous earth, to glue traps, essential oils, or emerging biological controls. Health Canada warns against the use of ozone generators. Difficult to treat objects (e.g., electronics) or settings (e.g., vehicles, storage containers) may require other techniques such as fumigation.
- Education and communication: Many groups affected by bed bug infestations may be unaware of prevention and control measures. Communicating clearly both the risks and best practices for dealing with bed bugs can assist the appropriate deployment of DIY controls. An excellent example is the State of Alaska’s step-by-step guide to “Controlling Bed Bugs” with detailed pictures and a DIY checklist. Maintaining lines of communication, periodic inspections, and follow-up measures can help address persistent bed bug infestations.
- Research: As bed bugs continue to develop resistance to chemical treatments, further research on bed bug biology and control measures is needed, including how climate change could affect bed bug species distribution or persistence. Further study of the health impacts of bed bug bites, and the role in transmission of diseases, including antimicrobial resistant pathogens is also needed.
Keeping up to date with best practice approaches and research on bed bugs can assist public health inspectors who provide education and guidance to the public on prevention, control measures, and hazards. EPHPs also have an important role to play in developing strategies for addressing persistent infestations that require collaboration between many groups, including residents, building managers, pest control professionals, and others.
For additional information and resources on bed bugs for EPHPs, see the NCCEH subject guide on Bed bugs