Bedbugs may carry MRSA and other diseases, but do they spread them? Don't panic yet

Los Angeles Times
Thursday, May 12, 2011

Not only can bedbugs harbor MRSA, they could potentially, just maybe, spread the drug-resistant bacteria, researchers - and resulting headlines - are speculating.

The thought is a scary one, but not much different than what we already knew about the threat from these generally nocturnal parasites.

It's certainly plausible that a blood-sucking bug can spread blood-transmitted diseases, but scientists haven't found much evidence they do so. Here's the low-down on what's known on bedbugs and disease.

The Entomology Department at Purdue University says this:

"At least 27 agents of human disease have been found in bed bugs, including viruses, bacteria, protozoa, and parasitic worms. None of these agents reproduce or multiply within bed bugs, and very few survive for any length of time inside a bed bug. There is no evidence that bed bugs are involved in the transmission (via bite or infected feces) of any disease agent, including hepatitis B virus and HIV, the virus that causes AIDS. "

Again, there's that "no evidence" of disease transmission-just the plausibility. A report in the Centers for Disease Control and Prevention journal Emerging Infectious Diseases in 2005 has this to say about bedbugs and disease transmission:

"Although bed bugs could theoretically act as a disease vector, as is the case with body lice, which transmit Bartonella quintana (the causal agent of trench fever) among homeless persons, bed bugs have never been shown to transmit disease in vivo. Hepatitis B viral DNA can be detected in bed bugs up to 6 weeks after they feed on infectious blood, but no transmission of hepatitis B infection was found in a chimpanzee model. Transmission of hepatitis C is unlikely, since hepatitis C viral RNA is not detectable in bed bugs after an infectious blood meal. Live HIV can be recovered from bed bugs up to 1 hour after they feed on infected blood, but no epidemiologic evidence for HIV transmission by this route exists."

An article from Medscape echoes that HIV spread is unlikely but that anaphylaxis, a severe allergic reaction, has been documented. 

And the article raises the possibility of itchy ("pruritic") bug bites becoming infected:

"Sometimes, if the bite reactions are intensely pruritic, scratching with excoriations may be complicated by impetigo."

Impetigo is a skin infection caused by strep or staph bacteria-and that includes MRSA, according to PubMed Health.

That's the hypothetical situation-scratching a bug bite that leaves the skin vulnerable to infection by MRSA-researchers suggested this week.

That's not to say researchers aren't still working on trying to quantify the potential threat of bedbugs. A clinical trial is underway in France.

But again, the threat remains largely theoretical. Interesting, but theoretical.