Are bedbugs disease vectors?

May 4, 2011 7:06 PM

Bitten by bedbugs at a hostel, worried about disease. Most answers here say that they're not vectors. How come they're not, what's the mechanism? How can I ease my mind?
posted by Tom-B to Health & Fitness (8 answers total)

Apparently, they don't carry disease, but no one knows why.

Via the NY Times, "South African researchers have fed them blood with the AIDS virus, but the virus died. They have shown that bugs can retain hepatitis B virus for weeks, but when they bite chimpanzees, the infection does not take. Brazilian researchers have come closest, getting bedbugs to transfer the Chagas parasite from a wild mouse to lab mice."

And, if you prefer a touch more snark, Gothamist's write-up of the Times article.

The CDC also says, "Although bed bugs are not known to transmit disease, they are a pest of significant public health importance. Bed bugs fit into a category of blood-sucking ectoparasites (external parasites) similar to head lice (Pediculus humanus capitis). Bed bugs, like head lice, feed on the blood of humans but are not believed to transmit disease."
posted by tip120 at 7:37 PM on May 4, 2011 [2 favorites]

Yeah, I'm not clear on the science either but Vancouver has lately been a "hot bed" of bed bug concern and one point that the experts are always keen to make is that, nasty as they are, they are not a disease threat.
posted by philip-random at 7:47 PM on May 4, 2011

I used to manage a backpackers' hostel and we got bedbugs after an influx of Bonnaroo-goers. We did have one guest who had an allergic reaction to the bites, and when I called to check on him after he left, he told me he was fine after some Benadryl. Out of the hundreds of people who stayed at our hostel that awful summer, he was the only one who had a reaction.

That seems to be the worst that happens, other than the pure hell of waking up to bedbugs or taking them home with you. Oh god... the smell... like Sharpies... [rocks back and forth in corner]
posted by Toothless Willy at 8:07 PM on May 4, 2011

Don't know for sure, but probably for the similar reasons to why mosquitoes do not transmit HIV.

They probably bite without injecting major secretions/saliva.

(if you are really bored)
posted by Meta-4 at 8:28 PM on May 4, 2011

Best answer: Vectors in the disease sense are animals that transfer parasites from one host to another. Diseases like malaria have to evolve to survive (or require) both the vector and the ultimate host. I don't know why bedbugs don't pass on diseases to human except they perhaps haven't been around long enough or been abundant enough for diseases to have an advantage to using them. I wonder if they transfer disease among other species (like bird ticks passing on bird parasites that don't effect humans because they are not adapted to our system).
posted by hydrobatidae at 8:30 PM on May 4, 2011

Best answer: Building on what hydrobatidae said, it's actually very unusual for disease to be able to survive in two species as wildly different as insects and humans. There are a few diseases that have evolved to do it, but they are very small in number, extremely specialized, and highly dependent on both species. Thinking about it slightly differently: Nobody ever worries about catching a disease from a sneezing cat.

So in some ways you're asking the wrong question. The question is not "What's special about bed bugs that they don't pass diseases to humans?" The question is "What's special about malaria and west nile virus that they actually CAN infect both insects and humans? Because that is friggin' weird, man...."
posted by yeolcoatl at 9:19 PM on May 4, 2011 [3 favorites]

Best answer: For a disease to be transmitted via an insect vector, it must be adapted to that vector. While bedbug feeds on blood like mosquito, and when they bite, they also inject their saliva into the bite to thin blood/anesthetize; there are no pathogen which can move from the stomach of the bedbug to its saliva gland. The malaria protozoa, on the other hand, was able to move from the blood meal inside the stomach of the mosquito to its saliva gland, allow itself to be injected into the next victim. From what I know, the malarial protozoa use the mosquito to infect many other warm blooded animals too, not just human; and it probably evolved for some host other than human. Mosquito are also more mobile and indiscriminate about which species it feeds on, whereas bedbug was adapted to feed only on human. This could be a factor as to why no pathogen has evolved to take advantage of bedbug as a vector yet.
posted by curiousZ at 10:21 PM on May 4, 2011 [1 favorite]

Yeah, don't worry about getting a disease. But be very worried about taking them home.

Treat everything (wash/dry very hot) and/or throw stuff away before re-entering your house, that's my advice.
posted by hungrytiger at 12:27 AM on May 5, 2011