In recent years, there has been a dramatic increase in the number of reported cases of both bedbug (Cimex lectularius) infestation and methicillin resistant Staphylococcus aureus (MRSA) infection in all urban areas of Canada and the United States. Previous studies have shown that bedbugs did not transmit infectious diseases to the individuals which were infested with the insects. More specifically, there have been investigations that have shown that bedbugs were not vectors for the transmission of blood borne pathogens such as HIV, and hepatitis B and C viruses. Bedbugs are known to cause a significant amount of itching and thus patients often have excoriations and open skin ulcers from scratching. Two medical microbiologists at St. Paul’s Hospital in Vancouver, Canada have reported in a letter to the CDC journal Emerging Infectious Diseases that they have isolated MRSA from bedbugs on patients. The scientists isolated five bedbugs from patients that were residents of Vancouver’s poor Downtown Eastside section, which is known to have high rates of homelessness, intravenous drug abuse, poverty, and HIV/AIDS. The five bedbugs were crushed and analyzed for infectious diseases by accepted standardized techniques. Of the five samples, three were found to contain the drug resistant staph bacteria MRSA. In humans, MRSA can cause sepsis, pneumonia, septic shock, and ultimately death and is resistant to many available antibiotics. The other two bedbug samples were found to contain vancomycin resistant Enterococcus faecium (VRE), which also causes a deadly infectious disease in humans. It is not known whether the bedbugs were able to transmit the MRSA or VRE bacteria to the patients who were infested with the insects. In addition, it is not clear if the MRSA and VRE were contained on the surface of the bedbugs, or were located within the guts of the insects. The scientists postulate that if the bedbugs caused the patients to scratch and form open wounds on their skin, the wounds could serve as an entry portal for the deadly drug resistant MRSA and VRE bacteria. The authors of the report emphasize that the sample size is small and more investigation is needed to corroborate these initial findings. In addition, they have stated that previous studies have not shown that bedbugs transmit infectious disease to the individuals which they infest.
Lowe CF, Romney MG. Bedbugs as vectors for drug-resistant bacteria [letter]. Emerg Infect Dis. 2011 Jun; [Epub ahead of print]