They come out at night to gorge on human blood, but can last a year between meals. A single female will lay 500 eggs in her lifetime. You’ll find them in sleazy digs with slobby tenants, as well as upscale apartments with conscientious landlords and fastidious residents. They’re expert hitchhikers who can catch a ride on your suitcase or clothing. No one really knows how to kill them. What are they? They’re 21st century bedbugs, and if they show up at your rental property or in your apartment, you’ll probably conclude that mold, asbestos, or even lead-based paint are benign by comparison.

Until a few days ago, it’s been reassuring to know that, unlike lead-based paint, asbestos, and some molds, bedbugs do not seriously harm your health. For sure, their bites are maddening and unsightly, and dealing with them will disrupt your life (or your landlording business) in a major way. And the psychological effects of living with bedbugs can be difficult. But you aren’t likely to get seriously sick. The Centers for Disease Control still tell us, “Bed bugs, a problem worldwide, are resurging, causing property loss, expense, and inconvenience. The good news is that bed bugs do not transmit disease. The best way to prevent bed bugs is regular inspection for signs of an infestation.”

Maybe not. In an advance electronic publication of an article slated to be published in Emerging Infections Diseases, researchers in Vancouver reported the discovery of particularly nasty bacterium on bedbugs who were taken from patients admitted to an inner-city hospital. The bugs were carrying methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). These bacterium cause serious staph infections that are very resistant to antibiotics.

The study’s authors concluded that they may have discovered a new pathway, or vector, for the transmission of these bacterium. Much like the mosquito carries malaria, perhaps the bedbug carries the bacteria, dropping it off as it bites its human host. However, further study is needed to determine whether the bugs are simple transmitters, or have the staph infection themselves; and even whether the bugs infected the humans, or the other way around. The researchers also noted that their findings occurred in an area of dense, poor housing, whose residents already had a high incidence of MRSA infections.

The implications of this study for landlords and tenants are significant. A widespread bedbug infestation qualifies as a habitability problem, which, if not addressed, will enable tenants in many states to break their leases and leave without liability for future rent, or withhold rent until the problem is fixed, or take steps to deal with it themselves and deduct the cost from the rent.

But if bedbugs are proven to be vectors for staph infections on the order of MRSA, the implications for landlords and tenants are dramatic. Tenants may be facing more than annoyance and disruption when dealing with the bugs. Landlords who fail to respond to an infestation or utilize ineffective treatments risk exposing their tenants to a devastating infection. Sickened tenants would have a lot more to sue over than just the value of their ruined belongings or the cost of having to move.