Dr. Stafford Tick Management Handbook - Newtown, CT

StaffordThe Connecticut Agricultural Experimentation Stationantibiotic treatment is important for suspected cases. The tetracyclines are the drug of choice withchloramphenicol an alternative in some cases. RMSF is made more severe with inadvertent use ofsulfonamides. In recent years, about 1-4% of cases in the U.S. have been fatal. A clinical diagnosismay be con. rmed by molecular tests or serologically by an indirect . uorescent antibody (IFA) test,but antibodies may not yet be present when a physician sees a patient early in the illness (85% ofpatients lack diagnostic titers the . rst week after illness and 50% lack diagnostic titers 7-9 days afteronset of illness).Tick ParalysisA toxin produced by certain Dermacentor ticks during feeding can cause a progressive, ascendingparalysis, which is reversed upon removal of the tick. Recovery is usually complete. Paralysisbegins in the extremities of the body with a loss of coordination and inability to walk. It progressesto the face with corresponding slurred speech, and . nally shallow, irregular breathing. Failure toremove the tick can result in death by respiratory failure. Cases appear more frequently in younggirls with long hair where the tick is more easily overlooked. Most cases of tick paralysis are causedby the Rocky Mountain wood tick (Dermacentor andersoni) in northwestern states. The Americandog tick also has been known to cause tick paralysis.TularemiaThe bacterium, Francisella tularensis, that causes tularemia (Rabbit Fever or Deer Fly Fever) istransmitted by bites from deer . ies and horse . ies and from several species of ticks. The Americandog tick, D. variabilis is one of the principal vectors for F. tularensis. Other ticks associated withtularemia include the lone star tick, A. americanum, Rocky Mountain wood tick, D. andersoni,and certain Ixodes ticks. Most cases occur during the summer (May-August), when arthropodtransmission is common. The disease also may be contracted while handling infected dead animals(particularly while skinning rabbits), eating under cooked infected meat, or by an animal bite,drinking contaminated water, inhaling contaminated dust, or having contact with contaminatedmaterials. Transmission does not occur between people. Natural reservoirs of infection includerabbits, hares, voles, mice, muskrats, water rats, andsquirrels. A recent study conducted in Connecticut showedthat cats carried antibodies to the pathogen. Tularemia wasremoved from the list of reportable diseases after 1994, butwas reinstated in January 2000 because of its potential as abioterrorism agent.Tularemia occurs throughout the United States as well asEurope, Russia, and parts of the Middle East, northern coastof Africa, Asia, China and Japan. There have been fewer than 200 cases reported each year duringthe . rst half of the 1990s, and again in 2000-2001, and less than 100 in 2002. Most cases havebeen reported from the central states of Missouri, Arkansas, and Oklahoma. With the exception ofoutbreaks of pneumonic tularemia on Martha’s Vineyard that appear related to gardening or mowingactivities that may have stirred up contaminated dust, reports of this disease are not common in NewEngland, although sporadic cases do occur.All persons are susceptible to tularemia. The clinical symptoms of tularemia depend uponthe route of infection. With infection by a tick, an indolent ulcer often occurs at the site of thebite followed by swelling of the regional lymph nodes and usually a fever. Fever is the mostcommonly reported symptom. Diagnosis usually is made clinically and con. rmed by an antibodytest. Antimicrobials with demonstrable clinical activity against F. tularensis include the . uorinated32Bulletin No. 101063