[Public Health] They're Not Spider Bites

Consider this scenario that gets played out repeatedly in the United States. A PCO or facility IPM official gets called out to a prison, long-term heath care facility or military base because many of the inmates, residents or military personnel are complaining about being bitten by spiders. No one can catch a spider in the act of biting nor remember a spider actually associated with the wound in any of the incidents. Inspection of the grounds reveals either no spiders or only a few harmless spiders, yet the pest specialist is supposed to provide eradication services for something that is undeterminable and nebulous.
In the last decade or so, an emerging health problem that occasionally is the actual cause of these “spider bites” has become recognized by the medical community. This problem is methicillin-resistant Staphylococcus aureus, which currently is designated in two forms: MRSA (pronounced “mersa”) and community-acquired MRSA (CA-MRSA). These infections typically are no worse than other staphylococcal infections in the scope of their manifestations, but they are resistant to many antibiotics, so treating them can be much more difficult. The correct assessment of this condition as a bacterial infection instead of rampant spider bite activity can have critical implications for pest management professionals.

LIKELY INFECTIONS. CA-MRSA is probably the greater concern for pest control personnel because it can conspicuously involve many people in a non-home facility; hence, eradication services will be sought. It is found in places where people are housed close together for great lengths of time, including prisons, other correctional facilities, sports camps, long-term health facilities, nursing homes, military barracks and on-board ships. It may occur after the use of recreational drugs. The infection is contagious, and may erupt in singular or multiple boils. In the case of multiple eruptions, skin lesions can occur simultaneously or sequentially on the same person and be readily spread to other people. In prisons, the bacteria were circulated when the wounds were popped with fingernails or with nail clippers that were passed amongst inmates. Often, people can carry the infection around with them unknowingly because they show no symptoms of the bacteria and hence, spread it easily to others.
In a Texas study, 10 patients at an indigent health-care clinic were treated for CA-MRSA. All had some association with prison (i.e., as an inmate, a visitor, having recently lived with someone who was recently incarcerated, etc.). Of these 10 Texas CA-MRSA patients, five had been either self-diagnosed or medically diagnosed with spider bites. Four of these also reported six additional people associated with them suffering from or treated for “spider bites.”
This scenario is being played out in other prisons across the country. In Ohio, inmates spread the bacteria by tattooing themselves with contraband needles (at least one inmate reportedly died in this episode). More than 1,000 inmates in a Los Angeles prison claimed “spider bites” and in a San Diego prison, a lawsuit claiming negligence of spider control was initiated on behalf of the inmates until it was learned that the true cause was most likely bacterial. An East Coast military entomologist was contacted in 2004 to address the problem of multiple personnel “being bitten by spiders” in a barracks situation. After conferring with the author, it was suggested that they should consider CA-MRSA — it turned out it was, in fact, CA-MRSA.
Additionally, an encampment of homeless people in southern California caused an advocate for the group to raise a ruckus about “brown recluse spider bites” in an area where no brown recluses have ever been found. Although not officially confirmed, a contagious bacterial infection was a far more likely scenario than bites from non-existent spiders. Long-term health care facilities and nursing homes also are ripe breeding grounds for CA-MRSA due to the close and continual contact of the inhabitants. Because of advanced age, in combination with compromised or failing immune systems, nursing home residents are more likely to suffer from mysterious skin lesions of unknown origin. Requests for “spider bite” information in similar scenarios have originated from military housing areas and recreational or sports camps as well.
The initial consideration of spider involvement should not be made in most of these cases because spiders typically bite only once and rarely do they leave a medically significant skin lesion. Therefore, one can almost assuredly rule out spider bite when there are multiple lesions on one person at the same time or over a period of time or multiple people showing lesions.
The way to determine CA-MRSA is to culture the skin for the bacteria. It is proliferated by poor hygiene, so the way to reduce the spread of CA-MRSA is to invoke more frequent hand washings and showers, institute more frequent changes of clean clothes/bed linens and use proper antibiotics. CA-MRSA is resistant to some of the common antibiotics such as penicillin, cephalexin and amoxicillin; however, other antibiotics like clindamycin and trimethoprim-sulfa can be very effective for eradicating CA-MRSA with immediate resolution of lesions.
MRSA often is more difficult to deal with than CA-MRSA because it is often contracted in a hospital and usually acquires resistance to a broader range of antibiotics. Therefore, fewer antibiotics are effective for MRSA. Typically, it occurs after some invasive procedure like a surgery, the use of intravenous needles in a hospital setting, prolonged antibiotic treatment, a stay in ICU or a burn unit, and the treatment of heart and lung disease.
Sometimes the patient returns home from the hospital and several weeks later develops a “spider bite.” Because of the lengthy incubation time after leaving the hospital and the tendency for the general public to blame spiders for so many mysteriously developing lesions instead of making a hospital association, MRSA may not be considered by either the patient or the physician. When several antibiotics are prescribed by a physician and the lesion remains the same, the catch-all diagnosis of “spider bite” is sometimes made, taking the physician off the correct course while the condition continues unabated. In some cases, children have died because MRSA was not correctly diagnosed early.
WHAT THIS MEANS FOR PCOs. All of these situations can be detrimental to the pest management professional’s reputation and client confidence. A request for spraying insecticide will do nothing to reduce or eliminate the bacterial infection, which will continue unchecked until the proper antibiotics are administered and behavioral changes in hygiene are made. Another problem is the psychological aspect of arachnophobia, which can spread quickly via word-of-mouth by the residents of a nursing home, prison or other similar facility. This reinforces an incorrect notion of “spider bites” in the minds of the inhabitants. Making matters worse is when physicians throw in their opinions that spiders are the source of the wounds, adding further erroneous conviction to the people suffering from the lesions. Because these bacterial infections are contagious, the infections then can continue to spread to other facility inhabitants or to unaffected family members. At this point, the PCO may shoulder the entire blame for the continuation of the disease, when, in fact, the PCO is faultless.
The forms of MRSA are a recently-emerging medical condition that is gaining recognition in the medical community. Lesions due to these bacterial infections are frequently misdiagnosed as spider bites. The psychological mythologies associated with spider bites are deeply entrenched in both the medical community and general public, and can lead to incorrect and detrimental opinions being formed by the client. Word-of-mouth misconceptions involving spiders run deep, and are persistent and difficult to correct. However, as more people in medicine, pest control and the general public become aware of MRSA and CA-MRSA, there will be less reliance on spiders as scapegoats for mysterious skin lesions. Additional benefits will be improved health care as well as reduction of superfluous pest control measures.
One warning must be given: Although awareness of MRSA as misdiagnosed spider bites is becoming more widely circulated, people should not make the mistake of just claiming all previous “spider bites” are now MRSA infections. There are a multitude of medical conditions that are mistaken for spider bite, MRSA just being one of many other possibilities.
If PCOs can offer more educated and more probable causative agents to their clients as to the culprits behind their skin lesions, it can only increase the stature of the PCO in the public’s eye.

The author is a staff research associate in the department of entomology at the University of California-Riverside and can be reached at rvetter@giemedia.com.