Zoonotic Diseases

Each year as Summer arrives, Utahns of all ages head into the great outdoors for hiking, biking, cookouts, camping, boating and an array of other activities. While enjoying the outdoors, it is important to be aware of the infectious agents that we may be exposed to and take the precautions necessary to prevent exposure to viruses, bacteria and animal parasites that could cause infectious diseases. The following is a summary of a few of the diseases that could be encountered in the outdoors and some of the ways we can prevent exposure and detect and treat illness early. This is not a comprehensive list but includes those we might be more likely to be exposed to in Utah.

Hantavirus Pulmonary Syndrome

Hantavirus can be found in approximately 1/3 of the deer mouse population in the state of Utah. Utah has seen 17 cases of hantavirus in humans with a fatality rate of approximately 30%. The rodents shed the virus in their urine, droppings and saliva. It is most often transmitted to humans when they breathe air that is contaminated with the virus. The incubation period for Hantavirus Pulmonary Syndrome (HPS) can range from a few days to six weeks with an average of two weeks. Patients with HPS typically present in a very nonspecific way with a relatively short febrile prodrome lasting 3-5 days. In addition to fever and myalgias, early symptoms include headache, chills, dizziness, non-productive cough, nausea, vomiting, and other gastrointestinal symptoms. Malaise, diarrhea, and lightheadedness are reported by approximately half of all patients, with less frequent reports of arthralgias, back pain, and abdominal pain. Patients may report shortness of breath, (respiratory rate usually 26 - 30 times per minute). The diagnosis is seldom made at this stage, as cough and tachypnea generally do not develop until approximately day seven. Once the cardiopulmonary phase begins, however, the disease progresses rapidly, necessitating hospitalization and often ventilation within 24 hours.

Also, while hiking or camping, you should avoid rodents and rodent burrows. Use tents with floors. All food and trash should be stored away from rodents. Cabins, sheds, or other buildings that are only used periodically should be aired out and carefully cleaned using the same precautions as in the home.

Plague
Plague is an infection in humans and animals caused by the Yersinia Pestis bacteria. In the past 10 years, Utah has had six confirmed human Plague cases. Plague appears in one of three forms. Bubonic plague, the most common, septicemic plague and pneumonic plague. Clinical features of each are similar with fever, chills and prostration. Bubonic plague includes enlarged, tender lymph nodes called buboes. Pneumonic plague includes cough and difficulty breathing. Pneumonic plague is also considered to be the most serious since it is the only type that is communicable from person to person. If plague patients are not given specific antibiotic therapy, the disease can progress rapidly to death. Streptomycin is the antibiotic of choice. Gentamicin is used when streptomycin is not available. Tetracyclines and chloramphenicol are also effective. Persons who have been in close contact with a plague patient, particularly a patient with plague pneumonia or those with possible exposure to plague in animals, should be identified and considered for antibiotic prophylaxis. The incubation period from exposure to onset of symptoms is generally two to six days. The preferred specimen for microscopic examination and isolation from a bubonic case is material from the affected bubo. Blood cultures should be taken whenever possible. Specimens intended for culture should be taken before initiation of antibiotic treatment.

Rabies
Rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal. The vast majority of rabies cases reported to the Centers for Disease Control and Prevention (CDC) each year occur in wild animals such as raccoons, skunks, bats, and foxes. Domestic animals account for less than 10% of the reported rabies cases, with cats, cattle, and dogs most often reported rabid. In Utah, bats are the only animals that have tested positive for rabies since 1995. An average of 11 bats test positive each year.

Giardiasis
Giardiasis is a diarrheal illness caused by Giardia intestinalis (also known as Giardia lamblia), a one-celled, microscopic parasite that lives in the intestine of people and animals. Giardia has become recognized as one of the most common causes of waterborne disease (drinking and recreational) in humans in the United States. Symptoms include diarrhea, loose or watery stool, stomach cramps, and upset stomach. These symptoms may lead to weight loss and dehydration. Some cases may be asymptomatic. Giardia can be spread by swallowing drinking water or recreational water contaminated with the parasite. Recreational water is water in swimming pools, hot tubs, jacuzzis, fountains, lakes, rivers, springs, ponds or streams that can be contaminated with sewage or feces from humans or animals. Giardia can also be contracted by eating uncooked food contaminated with Giardia. Prevention includes the following:

These are just a few examples of diseases we should be aware of as we head outside this summer. Many of the same prevention strategies listed above can be applied in prevention of other outdoor diseases such as Rocky Mountain Spotted Fever and Colorado Tick Fever which are spread by ticks and Tularemia, which can be spread through deer fly bites. It is advisable to stay away from dead or sick animals, use insect repellent and check for ticks and remove them promptly after entering areas where ticks could be present. Information on these and other diseases may be obtained on the Utah Department of Health website- http//www.health.state.ut.us/els/epidemiology/comdisease.html.

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Don’t Miss the Olympic Fun Because of the Flu!

Preparation for the 2001/2002 influenza season in Utah will present unique challenges due to the influenza season coinciding with the 2002 Winter Olympics. Olympic activities will increase the possibility for importation of influenza viruses and increase the possibility of exposure through crowd settings. Therefore, it will be more important than ever to attain high levels of vaccination coverage with influenza and pneumococcal vaccines.

People Who Can Transmit Influenza to Those at High Risk:

In the United States, seasonal influenza activity can begin to increase as early as November or December but has not reached peak levels in the majority of recent seasons in Utah until January through February. Adults develop peak antibody protection against influenza infection two weeks after vaccination. Therefore vaccine administered after November is likely to be beneficial in most influenza seasons. Persons who are not at high risk are encouraged to seek influenza vaccine in November and later when additional vaccine supply becomes available.

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Seminar Announcement

The Utah Association of Local Health Officers and the Utah Department of Health announce an upcoming workshop entitled, “Seminar in Public Health Communications and Response”. This three-day workshop will unite public health stakeholders to formulate communication networks and plans for emergency preparedness and response. Participants will have the opportunity to work with other response organizations within their communities to discuss planning efforts. Various local, state, and federal experts will also speak about current efforts in preparation and response. Participants will also have the opportunity to perform case studies in epidemiology and surveillance.

Registration Information: On-line registration and workshop information is available at http://www.health.state.ut.us/hanconf/. For further information, please contact Susan Lester or Lee Anne Wessol at 801-370-8737.

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