Bed bugs: what their bites do and do not do, why they came back and what getting rid of them involves

Qantas took a Boeing 787 out of service in Rome this month after bed bugs were found in economy seats on a flight from Perth, the Guardian reported on October 13. The return flight was canceled while the cabin was cleaned, and the paper described the culprits as small, difficult-to-eradicate insects that live on the blood of humans and some other mammals.

Both halves of that description hold up in the research: bed bugs bite, and they are hard to get rid of. What the research does not support is the fear that tends to follow a story like this one, that they spread disease. Decades of study have found germs inside bed bugs and no case of the insects passing one to a person. Their documented harms are itchy skin, lost sleep, distress, cost and, in a growing number of poison center reports, exposure to the chemicals people use against them.

What bed bugs are

Bed bugs belong to the genus Cimex, a group of closely related insect species, and two of those species feed on people. The common bed bug lives mainly in temperate regions and the tropical bed bug in warmer ones.

The Centers for Disease Control and Prevention (CDC) describes them as reddish-brown and wingless, ranging from 1mm to 7mm in size. Their flat bodies let them slip into seams and cracks, which is where they spend the day: in mattress seams, bed frames, headboards and nearby furniture. At night they come out to feed on the blood of sleeping people and animals.

They can wait a long time between meals, and they stay close to their food. The CDC says a bed bug can live several months without a blood meal and can cover over 100 feet in a night, yet the insects tend to settle within 8 feet of where people sleep.

Because they cannot fly, bed bugs travel as stowaways, tucked into the seams and folds of luggage, overnight bags and folded clothes, or carried in bedding and furniture. Michelle Power, a parasitologist at Macquarie University, told the Guardian that this is probably how the Qantas insects boarded. “They’re associated with travel. People may go to a hotel that’s infested and because they like dark spaces and are attracted to the smell of human clothes, they make their way into someone’s luggage,” Power said.

None of this has much to do with hygiene. Bed bugs turn up in five-star hotels, and the CDC says cleanliness does not determine whether bed bugs are present.

What bed bug bites do

A bed bug’s saliva contains substances that numb the skin and keep blood flowing, so the bite is not felt at the time. What follows varies from person to person. The CDC’s list runs from no physical signs at all, through small bite marks, to serious allergic reactions in rare cases, and it says the marks look similar to mosquito or flea bites.

The marks are often slow to appear. Most people notice nothing until one to several days after the bite, and the CDC says that in some people they take as long as 14 days to develop.

The standard medical description comes from a 2012 review in the journal Clinical Microbiology Reviews. It describes reactions that start as small, flat, discolored spots and can grow into intensely itchy raised welts around 5 cm in diameter, or about two inches across. The bites often run in lines along the limbs, a pattern many people recognize.

A 2026 systematic review set out to see where on the body bites land, gathering every published case report it could find. It included 84 patients, and the arms and legs, which are often uncovered in bed, were bitten most: the arms in 71.4% of cases, the legs in 59.5% and the trunk in 34.5%.

Those same authors caution that bites are easy to misread, because the skin patterns vary and can be confused with other arthropod bites (arthropods are the group that includes insects, mites and spiders). A bite mark alone does not prove bed bugs. That is why the CDC points to other evidence of an infestation, such as shed skins, live insects in the folds of mattresses, rust-colored blood spots on mattresses or furniture and a sweet, musty smell.

Doctors treat bites simply, and the treatments are largely untested. Bites usually do not require medical treatment, according to the CDC, which mentions antiseptic creams and antihistamines for itching. A systematic review in JAMA, a leading medical journal, looked for trials and found none for bites, concluding that treatments for skin and whole-body reactions have not been evaluated in clinical trials.

Do bed bugs spread disease?

This is the question with the most reassuring answer.

Bed bugs drink blood, as mosquitoes and ticks do, so it is reasonable to ask whether they carry infections from one person to the next. Researchers have looked inside them and found plenty. The 2012 review counted over 40 pathogens detected in bed bugs (a pathogen is a germ that can cause disease), yet it found no definitive evidence that the insects pass any of them to people.

A systematic review four years later took on the question directly. Its authors searched for clinical and laboratory studies from 1990 to 2016 that tested bed bugs as vectors, meaning carriers that pass an infection on, and noted that upwards of 45 pathogens had been reported in bed bugs. They were unambiguous about the result: no published study had demonstrated a causal relationship between bed bugs and the spread of infectious disease in humans.

They did not close the matter entirely. Laboratory experiments have shown that some organisms, including the parasite that causes Chagas disease, can survive inside bed bugs. The authors call those results worrisome, then warn that germs may behave very differently in laboratory conditions than in real life. They also note that studies have reported bed bugs unable to transmit hepatitis B virus and HIV.

The earlier JAMA review reached the same place, judging that evidence for disease transmission by bed bugs is lacking. In the CDC’s current wording, bed bugs “are not known to spread diseases to people.”

Other health effects of bed bugs

The absence of infection does not make bed bugs harmless.

Sleep and mental health. The CDC lists insomnia and anxiety among the effects of bites, but few studies have measured exposure across a general population. One comes from Montreal, where researchers analyzed a housing survey of 5,000 adult tenants. Four percent said they had been exposed to bed bugs during the year preceding the survey. Those tenants had about 1.7 times the odds of reporting anxiety or depression, after taking sociodemographic factors and housing conditions into account. When the figures were weighted to represent the city’s tenants as a whole, the gap narrowed to about 1.5 times the odds, with a range from slightly lower odds to 2.5 times, which is no clear difference.

Because the survey was a snapshot, it cannot show whether bed bugs came before the anxiety. Its authors nonetheless argue that the biggest health impacts of bed bugs are likely psychological. They also describe who is exposed: infestations are more common in high-density multi-unit housing, and they disproportionately affect people facing vulnerability. Power made the same point to the Guardian, saying that people already facing health inequities may be unable to afford pesticides or the hot water needed to kill the insects.

Blood loss. In heavy, long-running infestations the feeding itself can matter. The 2012 review warns that anemia, a shortage of red blood cells, may result when bed bugs are numerous, and that their allergens can set off asthma. The 2026 review of case reports found such problems confined to severe infestations in neglected patients. Across its cases, psychological effects showed up in a small subset of cases, and complications affecting the whole body were rare.

Poisoning from treatments. The 2012 review foresaw a harm that comes from people and not from the insects, warning that misusing chemicals and other technologies for controlling the insects could damage human health.

French data bear that out. Between 1999 and 2021, poison control centers in France logged 1056 cases of exposure to bed bug insecticide products, with a marked rise from 2016. Of the patients whose age was known, 16% were under 18. The reports showed people repeatedly misusing insecticides, including substances banned or not approved for use against bed bugs. About three in four patients had symptoms, nearly all of them mild, and one case was fatal.

Why bed bugs came back

For a few decades bed bugs were rare in wealthy countries. According to the 2012 review, both species, Cimex lectularius and Cimex hemipterus, have staged a worldwide resurgence since the late 1990s.

A 2022 review in the Annual Review of Entomology, co-written by the lead author of the 2012 paper, gives the leading explanation. The insects have evolved to survive chemicals that once killed them, and the authors attribute the resurgence primarily to the development of insecticide resistance, with global travel and poor pest management also playing a part.

The practical result is that sprays alone often fail. Back in 2009 the JAMA review called control challenging due to insecticide resistance, a shortage of effective products, and worries about spraying mattresses with pesticides.

What getting rid of bed bugs involves

US agencies describe a slow process that uses several methods at once. The Environmental Protection Agency (EPA), which regulates pesticides, opens its guidance by warning that treatment is complex and can take weeks to months, with the timeline set by how big the infestation is. Success, it says, depends on how many insects there are, how much clutter gives them cover, whether neighbors have them and whether everyone in the building takes part.

The EPA’s guidance covers the following methods.

• Heat. For fabrics, the agency says a person can use a clothes dryer on high heat. It says steam cleaners can treat carpets, baseboards and bed frames if the steam reaches at least 130 degrees Fahrenheit. It warns against trying to heat a home with a thermostat, space heater or fireplace, which it calls ineffective and dangerous.
• Cold. Freezing works only at 0 degrees Fahrenheit for three days, and the EPA warns that many home freezers are not cold enough to kill bed bugs.
• Barriers and traps. The guidance includes sealing cracks and crevices with caulk to remove hiding places. Sealing covers for mattresses and box springs trap insects inside. Interceptor traps set under the legs of furniture catch bed bugs as they climb.
• Pesticides. The EPA points to products registered with it that list bed bugs on the label. It is cautious about foggers, also called bug bombs, because their spray will not reach the cracks and crevices where the insects hide. It describes desiccants, powders that kill by drying the insect out, as a class the bugs cannot become resistant to, though they can take months to work.
• Things that do not work. Under treatments to avoid, the EPA lists rubbing alcohol, kerosene and gasoline, which it says can harm people and easily ignite. It says sticky traps are not meant for bed bugs.

Checking continues for at least a year after treatment ends, under the agency’s guidance, and the CDC points people who suspect an infestation toward a professional pest control company.

Entomologists call this layered approach integrated pest management. The 2012 review described it as combining nonchemical means of control with the judicious use of insecticides. How well any one method works is less certain than the lists suggest. The JAMA search turned up only 2 clinical trials concerning bed bugs, both of pest control methods, and the reviewers found no evidence-based way to eradicate the insects or prevent bites.

What the bed bug evidence cannot show

That transmission is impossible. No study has shown bed bugs infecting people. That is an absence of evidence after a long search. Some viruses have never been specifically tested.

How common bed bugs are. Good counts are scarce. The Montreal figure of 4% covers tenants in one city in 2017 and relies on people’s own reports.

Whether bed bugs cause anxiety. The survey measures both at a single moment, and people in poor housing face many other strains.

What bites typically do. The 2026 review drew on 84 published cases, and doctors write up unusual cases more often than ordinary ones.

Which control methods work best. The 2009 search found only two trials, and the 2022 review calls for better insecticide test protocols and management strategies.

Age of the main review. The main clinical review dates from 2012. Its description of bites has held up, while the control picture has moved on.

Whether a skin reaction in a particular person needs treatment is assessed by their doctor.

Bed bugs remain a pest of skin, sleep and peace of mind, and the evidence so far has not shown them passing disease to people.