[Technically Speaking] Priming the Pump Or Poisoning the Well?

On April 9, 2003, the following headline was posted to the National Pest Management Association/Professional Pest Management Alliance Web site: "Pest management officials find link between SARS and cockroaches consistent with cockroach disease-carrying patterns. Responding to two international wire service reports, NPMA officials state that there is a consistent pattern in the way cockroaches spread disease and the purported (or alleged) connection to the spread of Severe Acute Respiratory Syndrome (SARS)."

A LITTLE BACKGROUND. In 1960, Roth and Willis compiled a list of 47 pathogens and other organisms biologically associated with cockroaches that are potentially pathogenic to vertebrates. These organisms include those associated with wound infections, leprosy, gangrene, pneumonia, food poisoning, respiratory infections, typhoid, polio and plague. Imagine the publicity that could be gained by exploiting the association of cockroaches with these diseases. I find some of them far more disconcerting than SARS.

There is no doubt that the potential for cockroaches as mechanical vectors of disease has been well established. Unfortunately, the reality of the situation is that a direct causal relationship (disease transmission) at best has been poorly demonstrated.

Benson and Zungoli (1997) accurately summarize disease transmission by cockroaches by stating, "...while many studies document striking transmission of pathogens in the laboratory, evidence to confirm transmission in real world settings is limited and often circumstantial. Thus, the true magnitude of cockroaches as vectors of pathogens is controversial."

Thus, is it not foolhardy for our industry to capitalize on the unsubstantiated suggestion by the Hong Kong Deputy Director of Health, Leung Pakyin, that cockroaches may be the mode of transmission for SARS? This is analogous to suggesting that mosquitoes may be involved in the transmission of AIDS (a hypothesis promulgated during the early 1990s). Let’s stick with the well documented fact about cockroaches and human health also pointed out by NPMA, i.e., the many significant scientific studies that demonstrate how cockroach allergens can trigger asthma in children and the elderly population.

A RELIABLE SOURCE. If we want to promote the professionalism of our industry we must remain a credible resource for the media and the public. We should not lower our standards to gain publicity for the industry, these are tactics frequently used by anti-pesticide groups to draw attention to their cause. In many cases this has backfired, damaging the credibility of authors and their organizations.

It reminds me of the days of the Fenske, et al., studies attacking chlorpyrifos. It also reminds me of subsequent studies of electromagnetic radiation associated with high-tension lines and the extrapolation of data implicating some pesticides in childhood diseases. Most recently I read a statement by the Pesticide Action Network (PANUPS) quoting the American Bird Conservancy, Defenders of Wildlife, Farm Worker Justice Fund, National Wildlife Federation and others (January 28, 2003 Press Release):

"EPA re-registration review, brodifacoum, (the active ingredient of the rodenticide D-Con) has killed a number of endangered San Joaquin kit foxes in California as well as golden eagles. This same pesticide has been responsible for the vast majority of the more than 48,000 recent rodenticide poisoning cases of children under six years old reported to poison control centers across the nation."

When I questioned PANUPS regarding data to support their statement they referred me back to the American Bird Conservancy. The point is if you make a broad statement it should be supported by data, i.e., instead of "reported cases," let’s have the data on documented cases.

JUST THE FACTS. Facts we can work with include:

• West Nile Virus: In 2002, there were 3,389 human cases reported to the Centers for Disease Control and Prevention, including 201 deaths. There were 14,122 dead birds infected with the virus and 9,144 horses were found infected.

• Malaria: Two confirmed cases of local transmission were reported in Virginia.

• Lyme Disease: Since 1982, more than 145,000 cases have been reported to CDC. The last year for which data is complete is 1999, when 16,273 cases were reported.

• Hantavirus: Since 1993, 335 cases have been reported to CDC and 38 percent of the cases have resulted in death.

There are many facts our industry can work with to demonstrate our role and value as protectors of health, food, property and the environment. NPMA, PPMA, and all pest management professionals should always be a credible public information resource. In the process of priming the pump we want to be careful not to poison the well.

The author is technical director of American Pest Management, Takoma Park, Md. He can be reached at 301/891-2600 or rkramer@pctonline.com.