A number of arthropods and vertebrates have a magnified reputation and status as pests due to their involuntary participation in the spread of disease-causing organisms (pathogens and parasites) among humans and domesticated animals. Therefore, pest management professionals play an important role in preserving public health through their efforts in reducing or eliminating pest populations in both urban and rural settings. The importance of pest management in public health is often difficult to quantify due to:

1) the effectiveness of pest management efforts in this country,

2) the limited likelihood of sufficient exposure by a susceptible host to an infected or contaminated pest,

3) variability in the fraction of pest populations which actually carry pathogens,

4) the high percentage of pest-borne and pest-vectored cases which go unreported or are misdiagnosed, and

5) the potential for introduction of new pathogens from abroad and the occasional resurfacing and spread of existing (endemic) pathogens in select parts of the country.

Pest management professionals may never know how often their IPM efforts have averted a public health disaster. However, for the sake of addressing the questions and concerns of an inquiring public and defending the reputation of a noble profession, they should be aware of the health conditions, causal pathogens and known carriers which pose a threat to the public well-being.

Carrier or Vector?

Carriers are organisms (like cockroaches and house flies) that pick up pathogens (like Salmonella bacteria) on their tarsi and mouthparts and, during the course of contacting food and other items handled by humans, spread those pathogens by contamination. Vectors are organisms (such as anopheline mosquitoes) which play an important role in the life cycle of certain pathogens (such as malaria-causing sporozoans, Plasmodium species). Vectors serve to transfer infective stages of a pathogen from one host to another or from an intermediate (reservoir) host to a definitive host, while providing acceptable conditions for their further development.

Pest management professionals, by the very nature of their work, may place themselves at considerable risk while performing inspections and implementing control measures for pests that are known carriers or vectors of pathogens. The information provided here should serve as a reminder to inspectors and technicians to exercise caution by wearing appropriate clothing and using the recommended personal protective equipment (PPE) while in close proximity to these organisms, their harborages and nesting sites. The following PPE and products are strongly recommended if working in potentially hazardous areas:

• Full-face or half-mask respirator fitted with a HEPA (="P-100") filter
• Disposable latex or vinyl gloves
• Clean, long-sleeve coveralls
• Disinfectant (sprayable liquid)
• Pest vacuum cleaner fitted with a HEPA filter
• Plastic trash bags and ties
• Soap, clean water and paper towels
• A proven insect repellent product

References

1. Acha, P.N., and B. Szyfres. 2nd ed. Zoonoses and Communicable Diseases Common to Man and Animals. Scientific Publication No. 503, Pan American Health Organization, Washington, DC.
   
2. Chin, J. (ed.). 2000. 17th ed. Control of Communicable Diseases Manual. Amer. Publ. Health Assn., Washington, DC.
   
3. McClelland, G.A.H. 1987. 11th ed. Medical Entomology; An Ecological Perspective. Univ. of Calif., Davis, CA.
   
4. James, M.T., and R.W. Harwood. 1969. 6th ed., Herms' Medical Entomology, Macmillan Publ. Co., New York, NY.