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New technologies in pest management prevent pathogen spread.

Historically, insect and rodent pests have been responsible for same of the most devastating disease outbreaks.

Editor's note: The following is a paper from Zia Siddiqi, Ph.D., BCE on new discoveries in the field of pest prevention.

In part because of their behavior, biology and morphology, insect and rodent pests serve as exceptional disease vehicles for harboring and rapidly transporting diseases. In the food handling environment, the three main pests that have been known to transmit pathogens are rodents, roaches and flies.

In the past century alone, more than 10 million people have died from rodent-borne diseases. At present, because of modern sanitation, antibiotics and rodent pest management programs, rodents are not the disease threat they once were. Nevertheless, because we are basically surrounded by rodents of all types, and because of their potential for carrying myriad microorganisms and ectoparasites, some of which may be pathogenic, we must constantly be alert to the potential risk of disease transmission.

The potential for mechanical transmission of pathogenic organisms by cockroaches is well documented (Mallis, 1997). Many pathogenic organisms have been isolated from cockroaches collected in and around humans, especially in food-handling environments. However, while many studies document striking transmission of pathogens in the laboratory, evidence to confirm transmission in the real world is rather limited and at times circumstantial. It has been demonstrated that cockroaches acquire pathogenic bacteria simply by walking over cultures, and that these pathogens are subsequently transferred to foodstuff via normal foraging behavior of the infested roaches.

Although flies are often undesirable nuisances, we are mostly concerned with their capability of carrying pathogens. The housefly feeds on fecal material, vomit and sputum, after which it might alight on human food. Moreover, flies commonly fall into liquid foods, thus causing contamination. Houseflies have been shown to carry many disease organisms.

Implementing a comprehensive pest management program that incorporates the principles of integrated pest management can eliminate insect and rodent pests and thus the spread of pathogens through this source. These principles place significant reliance on inspection, monitoring, establishing action threshold levels and implementing first non-chemical and then chemical measures. It also involves communication and education. The newer technologies allow us to place the control agents in precise locations, thus eliminating the possibilities of any spread of pathogens.

Pathogens and diseases associated with insect and rodent pests

Despite the fact that America's food supply is the safest in the world, the unappetizing truth is that what we eat can very well be the vehicle for food- borne illnesses that can cause a variety of unpleasant symptoms and that may be life threatening to the less healthy among us. Seventy-six million cases of foodborne diseases occur in the United States every year (FDA, 1999). The following diseases are associated with rodent pests: plague, rickettsial diseases, leptospirosis, rat bite fever, trichinosis, salmonella, hantavirus, and choriomeningitis.

Various pathogen types and pathogens associated with cockroaches include:

* Bacteria: Alcaligenes faecalis, Bacillus spp., Campylobacter jejuni, Clostridium spp., Enterobacter aerogenes, Escherichia coil, Klebsiella pneumoniae, Mycobacterium leprae, Nocardia spp., Proteus spp., Pseudomonas aeruginosa, Salmonella spp., Serratia marcescens, Shigella dysenterai, Staphylococcus aureus, Streptococcus faecalis, Vibro spp., and Yersinia pestis.

* Fungi: Asperigillis fumigatis, and Aperigilles niger.

* Helminthis: Ancylostoma duodenale, Ascaris spp., Enterobius, Hymeolopsis spp., Necator americanus, and Trichuris trichria.

* Protozoans: Entamoeba hystolytica and Giardila sp.

* Viruses: Poliomyelitis.

Houseflies have been shown to carry disease organisms causing typhoid fever, cholera, E. coil, salmonella, summer diarrhea, dysentery, tuberculosis, anthrax and ophthalmia, as well as parasitic worms. Experimental work has demonstrated the presence of the virus that causes poliomyelitis in or on files caught in endemic areas.

Most foodborne diseases come from bacterial contamination. Insects and rodent pests, especially flies and cockroaches, have been shown to be associated with several of these common bacteria. (Malls, 1997). In the United States, the Centers for Disease Control and Prevention estimates that 76 million Americans suffer foodborne illness each year. Among the nine major disease-causing agents, there were 40.7 cases per year per 100,000 people in 1999, compared with 51.2 per 100,000 four years ago (CDC, March 17, 2000). Therefore it is imperative that measures be taken to eliminate pest infestations as one source for the spread of the pathogens (CDC, 2000).

Components of an integrated pest management program

The meaning of Integrated Pest Management (IPM) has developed differently in agriculture and in urban or structural pest control. It started out in agriculture as a method of control with monitoring to see if pesticides were even needed, where to use them and when to use them. It's the same idea in urban or structural pest control, but some activist groups have led people to believe that IPM can control pests without any pesticides. The traditional agricultural definition of IPM sets action thresholds for use of pesticides, but that does not always work in structural or urban situations. Sometimes we have large buildings with perpetual pest populations, and it may be practical to tolerate a certain number. However, it may not be possible to set a threshold level that two or three cockroaches are OK. The consumer's expectation is often that no pests are acceptable. They have zero tolerance--especially for food safety issues.

Today's emphasis on IPM techniques almost gives the impression that it's a radical new idea. Actually, the practice known today as IPM involves essentially the same methods that progressive pest control operators have used for many years. What has changed is that consumers now take a more active role in the management of pests, and the professional tools are more sophisticated and effective. Urban pest control, like other industries based on research and development, has changed dramatically due to new technology and techniques. The image of pest control of years past, with a heavy reliance on pesticides applied throughout the structure, remains strong. Today, however, structural pest control involves the use of pesticides as well as other pest management options: mechanical and physical controls, structural repairs, preventive maintenance, non-toxic materials, targeted pesticides, sophisticated applications and the active involvement of consumers. IPM brings all these elements together.

IPM is a process, not an event

Respect for nature and knowledge of a pest's living habits are not just the job of a PCO practicing IPM techniques. Homeowners and consumers too should become involved in the process, which includes changing human behavior, modifying pest habitats, sharing decisions with the PCO and monitoring over an extended period of time. An effective IPM program relies on the knowledge of a pest's survival habits, biological cycles and natural enemies. Treatment plans typically combine changes in sanitation and maintenance, structural repairs, biological or physical controls, spot application of pesticides, evaluation and long-term monitoring. These elements together can dramatically reduce pest populations and remove any incentives for them to return.

According to the National Pest Control Association, IPM offers several advantages. However, it does require time and effort to assure that treatment strategies are effective. IPM is a process of pest management, not a one-time event.

The best IPM programs combine several strategies, taking into consideration time, cost and other relevant factors. Education is vital because the consumer must understand pest behavior to help prevent future infestations. To be considered successful, IPM strategies should be simple to maintain, cost-effective over time and the most effective way to permanently reduce pest populations.

Many IPM programs include changes to both pest and human habitats, which experts call "indirect suppression" techniques. Take away a pest's food, shelter, water and other survival needs, and its population will decline. Typical methods include drying up pools of water that harbor mosquito eggs, caulking cracks against roaches and breaking the wood-to-soil contact conducive to termite migration.

Often, indirect suppression techniques are not enough for control. That's when direct suppression methods, both physical and mechanical, come into play. Physical controls include manually removing pests or forming barriers to pest entry with screens in doors or on chimneys, using new wood or other materials to seal entrances, caulking cracks and crevices against crawling pests, or placing drain covers over pipes to block rodents. Mechanical traps or light traps also work well in an IPM program.

Many buildings and structures offer the perfect sanctuary for pests, partly because there are seldom natural predators indoors. Structural, sanitary and maintenance practices also influence pest populations, but many cases require pesticide treatments to bring the pest problems under control. Today's pesticides go far beyond those used in the blanket treatments of pests. They are formulated for use on specific pests, under specific conditions. Government safety regulations strictly limit their use to the conditions listed on the label, and PCOs must be licensed and knowledgeable about pesticide application.

Proper use of pesticides plays a critical role in the effectiveness of an IPM program. New formulations of pesticides are less toxic or environmentally persistent, but more toxic to targeted pests. They use fewer active ingredients and are less harmful to non-target species. Also, new equipment design gives PCOs greater accuracy and effectiveness for applications to limited access areas.

The last step of IPM success is continual maintenance and monitoring. Recommendations for sanitation and maintenance must be followed to make it difficult for pests to survive.

By excluding as many pests as possible, denying harborage, food and water to those that do enter, and actively eliminating or catching those that otherwise survive, an environment can be maintained with no pest population above the predetermined threshold level. Neglecting any of these methods strengthens the pest's ability to survive and flourish. None of these methods are easy, and they do require commitment from both the pest control company and the customer. Most IPM programs fail because certain IPM techniques require time and money. It takes commitment and follow-up to maintain an IPM program, but the rewards are worth the effort. Pests will always be around to threaten our health and property, but a sound IPM program will ensure a safe, clean environment in which to live and work.

Integrated Pest Management is a thought process and a joint venture between the pest control company and the customer about how to solve pest problems. The key is to offer conditions that are not favorable to pest survival. Pesticides, when used, must begin with the least toxic formulations.

Newer techniques

In the field of pest management, newer techniques include computer-aided monitoring methodology and the introduction of non-volatile, non-repellent insecticide bait formulations. This is especially important after the removal of certain pesticides from the market in recent years. Several insecticide formulations are now available as gel baits that are applied into cracks and crevices and into precise locations to successfully control insects, especially cockroaches.

Computerized monitoring methods allow for accurate and timely data management to be proactive in eliminating a pest population, thus preventing any pathogen transmission in a food-handling environment. At the present time, various versions of handheld systems are available that allow a pest control technician to inspect, monitor and record data (observations and findings) and provide a real-lime scenario of the location where pests may be a problem (Brenner, et. al. 1998 and Focks, et. al. 1999).

Spatial analysis is another example of how new technologies can help in preventing pathogen transmission by precision targeting of pesticide application. This program was developed and field tested by Dr. Richard Brenner, UDSA & ARS, Center for Medical, Agricultural & Veterinary Entomology in Gainesville, Fla. Trap counts of target pests are entered over time on a schematics of the site. The program shows the specific location of pest population concentration. This information is helpful in precision application of control strategies. The system uses ArcView and GIS-based platform to compute the precise location of pest populations in any given area. This research unit develops reduced-risk integrated management strategies for domestic and peridomestic arthropods of consequence to human and animal health.

It allows the user to precisely document in real time the location of field survey data or pesticide applications. These data are directly filed in an ArcView[delta] database. Data can be easily stored, retrieved and shared with others. Users can collect and immediately record georeferenced data with an attached Global Positioning System (GPS) unit, or they can use the coordinate system inherent in GIS-ready serial photos or satellite imagery, available from many sources.

When the software is run on a pentablet computer, the user can record data directly by handwriting the entries onto the pentablet screen. The software provides an easy method to visualize the distribution of an insect or pest population by conducting a simple spatial analysis of the data. The software also creates a "spatial map" that can be used to target the location of the pest population with integrated pest management interventions.

In addition, the software includes the ability to apply pest thresholds in the analysis, and to compare pre- and post-treatment pest distribution maps as a measure of treatment efficacy. It can be used to analyze pest management data along with other GIS data sets ("themes" and "coverages") that may be useful in predicting pest populations, likely treatment successes or failures, and plant, animal and human populations at risk from pests and disease vectors. Such data sets may include locations of buildings and utilities, natural resource features of soil types and hydrology, land use classifications, plant biotypes and human demographics.

In advanced applications, the software can analyze data sets through specific predictive models that have been specially written for spatial analyses. For example, Dr. Dana Focks of the Imported Fire Ant and Household Insects Research Unit at CMAVE is completing spatial models for container breeding mosquitoes and the risk of dengue transmission (Brenner, et. al. 1998).

The current version of the Integrated Pest Management Information System (IPMIS) is also included on CD and may be run from the PT/SA software. IPMIS is the standard reporting system in the Department of Defense for pesticide use. This permits the user to easily record pesticide use if the pesticide applicator determined that a pesticide application was needed after running the precision targeting and spatial analysis.

Extensive online help has been created that allows new users of this GIS system to gain an understanding of the importance of collecting and analyzing data.
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Comment:New technologies in pest management prevent pathogen spread.
Author:Siddiqi, Zia
Publication:Food Processing
Geographic Code:1USA
Date:Feb 1, 2001
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