Guam Hazard Mitigation Plan - Western States Seismic Policy Council

SECTIONFIVERisk AssessmentSeveral cases of zoonotic diseases have been documented on Guam. In 1967 a rabies incidentaffected 89 animals over a 7-month period. No human infections were reported, but the controlmeasures employed resulted in the elimination of 13,406 dogs on Guam. In the nine-year periodof 2000 to 2009, 21 people contracted leptospirosis. Cases have been reported in reference to theCross-Island Road area, Sigua Falls and Talofofo River. Leptospirosis is a disease caused byexposure to bacteria that can be found in freshwater contaminated by animal urine.No data are readily available regarding animal disease outbreaks on Guam. However, Guam hasexperienced large, adverse effects from invasive animal species. The brown treesnake on Guamis often considered an example of how a nonnative species can proliferate and destroy theecology of an area. This animal is presumed to be responsible for the extinction of severalendemic bird and lizard species on Guam and is also responsible for millions of dollars indamage each year by causing power failures throughout Guam. Some of the other large pestsintroduced to Guam from outside are water buffalo, feral pigs, and deer. The large African landsnail and a species of flatworm that was introduced to reduce the population of this snail are bothconsidered invasive pests on Guam. In December 2003, a nonnative insect known as cycadAulocapsis scale was detected in Guam on an ornamental cycad (a palm-like tree). Over the next2 years it spread throughout the northern two-thirds of Guam, infesting and killing bothornamental and indigenous cycads. Cycas micronesica, the indigenous cycad unique toMicronesia, seems particularly susceptible, with mortality rates of 100 percent in infested areasand causing it to be added to the Red List of Threatened Species maintained by the InternationalUnion for the Conservation of Nature and Natural Resources.In Fall 2007, the CRB was first detected on Guam at Tumon Bay. This large scarab beetle posesa serious threat to palm trees; adult beetles bore deep into the crowns of coconuts and otherpalms to feed on sap. Trees are killed when beetles bore through the meristematic tissue and bysecondary infection by pathogens. The dead trees then provide breeding sites for futuregenerations of CRBs. An eradication program was implemented, by the Guam Department ofAgriculture and the United States Department of Agriculture Animal and Plant Health InspectionServices, which established a quarantine area covering over 28,000 acres. As of March 2011, thelargest number of CRBs have been caught in Asan, portions of Piti and Yona, Tamuning, andSouthern Dededo.Probability of Future EventsThe probability of a disease, particularly an epidemic, occurring on Guam is difficult to evaluatedue to the wide variation in disease characteristics, including variation in the rates of spread,morbidity, and mortality; detection and response time; and the availability of vaccines and otherforms of prevention. A review of the historical record (as described above) indicates that diseaserelateddisasters have occurred in humans with some regularity and occasional severity. Forexample, MRSA appears to have affected approximately 250 people on Guam annually, whileLeptospirosis in most years only affected one person per year. Due to a lack of historicalinformation, it is difficult to make a similar conclusion for animals and plants. Today, concern isalso growing about emerging infectious diseases and the possibility of a bioterrorism attack,although the probability and magnitude of such events cannot be predicted.5-14