National Tick Surveiiiance Program 

 Caiendar Year 1 983 



During calendar year 1983, the collection and submis- 

 sion of ticks from native and imported animals plus 

 plant and animal material was 12 percent greater than 

 in 1982. There were 10,207 collections in 1983, 9,086 

 in 1982, 9,381 in 1981, 7,763 in 1980, and 11,553 in 

 1979. 



Lyme Disease 



Lyme disease is a tick-borne disease of humans 

 transmitted by Ixodes ofamm/n/ which is characterized 

 by a skin lesion (erythema chronicum migrans) that 

 may be accompanied by headache, stiff neck, fever, 

 malaise, fatigue, aching muscles and joints, and swol- 

 len lymph nodes. Weeks or months later some patients 

 develop brain and heart infections, central and peri- 

 pheral nervous disorders, and migratory musculoskele- 

 tal pain. Still later arthritis may develop and persist for 

 several years resulting in erosion of the cartilage and 

 bone.^ 



The disease was first recognized in 1975 in children in 

 Lyme, Connecticut. The rural setting and seasonal na- 

 ture of the cases suggested possible arthropod involve- 

 ment. Investigations soon incriminated a newly recog- 

 nized tick species Ixodes dammini as one of the vec- 

 tors. Interestingly /. dammini has in recent years been 

 shown to vector another disease in humans. In 1976 

 Spielman incriminated /. scapularis (later recognized as 

 the new species, /. dammini) in the transmission of Ba- 

 besia microti \n humans on Nantucket Island, Mas- 

 sachusetts.^ 



The etiologic agent for Lyme disease was suspected as 

 possibly being bacterial when it was noted that when 

 penicillin or tetracycline was given early in the illness 

 the duration of the skin lesion was shortened and the 

 arthritis was either prevented or attenuated. In 1982 a 

 new spirochete was isolated from /. dammini in New 

 York. In 1983 the same spirochete was isolated from 

 the blood, skin, and cerebrospinal fluid of patients ill 

 with Lyme disease. 



In 1983 three employees of Plant Pest Quarantine, Otis 

 Methods Development Center, Otis Air Force Base, 

 Massachusetts, were diagnosed as having Lyme 

 disease. The three cases were recognized in late June 

 and early July 1983 in employees involved with testing 



^Steer, Allen C. et al. 1983. The Spirochetal Etiology of Lyme 

 Disease. New England J. Med., Vol. 308, No. 13:733-742. 

 ^Spielman, Andrew. 1976. Human Babesiosis on Nantucket Is- 

 landi'Transmission By Numphal Ixodes Ticks. Am. Jour. Trop. 

 Med. Hyg. Vol. 25, No. 6: 784-787. 



Gypsy Moth pheromones at Otis Air Force Base. Re- 

 portedly these clinical cases coincided with the period 

 of greatest seasonal activity for ticks in that area. 



Since Lyme disease is now known to occur in at least 

 14 States, Europe, and Australia, it is important to be 

 aware of the etiology, transmission, symptoms, clinical 

 signs, and treatment of the disease. Other endemic tick 

 species may possibly play a significant role in the 

 maintenance and transmission of the disease agent. 



Update on Heartwater in the Caribbean 



Throughout 1983 there was continued interest and 

 concern regarding the presence of heartwater, the 

 tick-borne disease caused by the rickettsial organism, 

 Cowdria ruminantium. This disease was reported from 

 Guadeloupe in 1980. In late 1983 official correspon- 

 dence was received in Washington, D.C. from the Chief 

 Veterinary Officer of Antigua confirming the presence 

 of heartwater in livestock on Antigua. 



Other islands in the West Indies, such as Puerto Rico, 

 St. Kitts, and Martinique, are especially concerned 

 since they also presently have established populations 

 of Amblyomma variegatum, a primary vector of heart- 

 water. In 1983 there were 39 laboratory confirmed col- 

 lections of A. variegatum from Puerto Rico. It is strong- 

 ly emphasized, however, that there were no reports of 

 heartwater form Puerto Rico in 1983 or earlier years. 



There is a potential threat for the introduction of heart- 

 water into the continental United States since one of 

 the experimental vectors, Amblyomma maculatum, is 

 endemic in 10 States. These are primarily Gulf of Mexi- 

 co or Atlantic Ocean coastal States. Increased illicit 

 drug and animal traffic, along with the influx of illegal 

 aliens, increases the threat of introducing A. variega- 

 tum and heartwater in coastal States such as Florida. It 

 is important that Federal and State regulatory officials 

 improve the surveillance program to rapidly detect and 

 eliminate heartwater should it be introduced onto the 

 mainland of the United States. 



African Swine Fever 



In light of the recently demonstrated potential for the 

 soft tick, Ornithodoros puertoricensis, to transmit swine 

 fever (ASF) virus, a great deal of interest has centered 

 around this tick.^ In July 1983 a team of USDA, Agri- 

 cultural Research Service (ARS), and Animal and Plant 



^Butler JF, and Gibbs EPJ. 1983. Distribution of Potential Soft 

 Tick Vectors of African Swine Fever in the Caribbean Region. 

 Prev Vet Med: In press. 



