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 27
... feeding larval mean weight increased to 0.566 mg ( N = 170 ) ; 12.6 times as much as the pre - fed weight . At the time of molting to nymphs the mean weight declined to 0.315 mg ( N = 48 ) ; a loss of 44.3 % from the post - fed weight ...
... feeding larval mean weight increased to 0.566 mg ( N = 170 ) ; 12.6 times as much as the pre - fed weight . At the time of molting to nymphs the mean weight declined to 0.315 mg ( N = 48 ) ; a loss of 44.3 % from the post - fed weight ...
Page 28
... pre - fed weight to reach 10.08 mg ( N = 53 ) . The females undergo a tremendous increase to 562.739 mg ( N = 85 ) , 64.4 times the pre - fed weight , which is near the nymphal weight increase of 72.5 , but higher than the larval weight ...
... pre - fed weight to reach 10.08 mg ( N = 53 ) . The females undergo a tremendous increase to 562.739 mg ( N = 85 ) , 64.4 times the pre - fed weight , which is near the nymphal weight increase of 72.5 , but higher than the larval weight ...
Page 35
... Weight change pattern 1. The effect of starvation ( Tables 1,2 ) . Table 1 shows the effect of starvation on the ... pre - fed weight while the pre - starved larvae showed a relatively heavier mean weight of 0.575 mg : 14.4 timesheavier ...
... Weight change pattern 1. The effect of starvation ( Tables 1,2 ) . Table 1 shows the effect of starvation on the ... pre - fed weight while the pre - starved larvae showed a relatively heavier mean weight of 0.575 mg : 14.4 timesheavier ...
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