The Ecology of Ticks Transmitting Rocky Mountain Spotted Fever in the Eastern United States: Final Progress Report. Period Covered: June 1, 1963 to May 31, 1969The report summarizes data obtained on the occurrence of infection in ticks and wild vertebrate hosts collected according to the experimental field design developed and executed over a 4 year period at the Montpelier study area near Richmond, Virginia. It also includes certain new data on the occurrence of Rocky Mountain spotted fever in Virginia, based upon medical analysis case records reported to the Virginia State Health Department and the epidemiological significance of this new data upon the ecological results of our field studies at the Montpelier area and elsewhere. Also included are some reports of laboratory investigations done in support of the field investigations. Infection with Rocky Mountain spotted fever was found in 6 species of ticks native to the Montpelier study area. Dominant in importance was the American dog tick, Dermacentor variabilis, in which the annual incidence of infection varied between 2.9% and 4.4%. Infection was highest in adults (mean = 4.8%), lowest in larvae (mean = 2.3%) of this tick. In addition, infection was also recognized in 4 other species of ticks native to the area, but apparently at low incidence. Serological evidence of infection in a number of mammal and birds species provides data for assessing the seasonal associations, vector host interrelationships, and possible means of spread of the zoonosis under natural conditions. (Author). |
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Page 21
... satiated ticks ) were separated and weighed indepen- dently . A mettler Corp. microbalance held at balance room ... larvae or nymphs is used for specimens that were not allowed to complete their blood meal and were forced to drop - off by ...
... satiated ticks ) were separated and weighed indepen- dently . A mettler Corp. microbalance held at balance room ... larvae or nymphs is used for specimens that were not allowed to complete their blood meal and were forced to drop - off by ...
Page 22
... satiated larvae which remained alive molted to nymphs . All deprived larvae which has less than 60 hours of feeding ( a blood volume of approximately 81 ug . ) failed to molt . Only 8 % of the deprived larvae that remained alive in the ...
... satiated larvae which remained alive molted to nymphs . All deprived larvae which has less than 60 hours of feeding ( a blood volume of approximately 81 ug . ) failed to molt . Only 8 % of the deprived larvae that remained alive in the ...
Page 23
... larvae ) do stand better chances of survival than satiated nymphs . Although high mortality figures such as 85 % are not normal and might have been due to unfavorable conditions which the ticks might have been accidently subjected to ...
... larvae ) do stand better chances of survival than satiated nymphs . Although high mortality figures such as 85 % are not normal and might have been due to unfavorable conditions which the ticks might have been accidently subjected to ...
Contents
clinical | 7 |
Development of partially fed American dog ticks Derma | 20 |
Ibid II The effect of starvation and host species | 34 |
1 other sections not shown
Common terms and phrases
alloscutum length American dog tick americanum Amin annual attack rate Atwood average weight basis capituli blood meal blood volume clinical David Dumville decrease deprived larvae deprived nymphs depth Dermacentor variabilis dimensions dog tick Dermacentor Eastern United ecdysis ecology of ticks Endemic Typhus engorged epidemiology failed to molt females hatching heavier held at 95 host species humidities imbibe immatures Ixodidae laboratory larvae and nymphs length and width lone star tick males mean weight Montpelier Montpelier study area Mountain Spotted Fever myalgia non-starved nymphs and adults occurred patients period piedmont piedmont province population PRE-FED POST-FED pre-fed weight Rickettsial RMSF in Virginia Rocky Mountain Spotted satiated larvae satiated nymphs scutum significance Sonenshine species of ticks starved subsequent Tested thrombocytopenia tick Dermacentor variabilis tick species ticks transmitting Rocky titer total body length vector Virginia weight gains weight loss white-footed mice white-footed mouse YOUNG LAR young larvae zoonosis