During a 6 month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined a fever >102oF lasting >2 days with three or more symptoms (i. e. chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or felling ill). A laboratory-confimed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest and rainfall was 0.5 cm compared with 7-10 cm during each of the previous three years. Required:
a. What is the significance of the rainfall?
b. The etiologic agent of the disease is:
c. This is an example of:

a. What is the significance of the rainfall? These bacteria resist desiccation, and its dispersion is favored by winds. A decrease in rainfall means a dryer environment, which the bacteria can resist and makes it easier for the cell to be carried somewhere else by winds.  

b. The etiologic agent of the disease is Coxiella burnetii

c. This is an example of  a zoonosis  

Explanation:

Q fiber Pneumonia is a zoonosis world-widely distributed and of global importance, which etiologic agent is Coxiella bunetti.

Populations in contact with goats, sheep, and cattle, use to have a positive result for antibodies against Coxiella burnetii. This bacteria is transmitted to humans orally and by inhalation. The microorganisms resist extreme conditions and are highly infectious. The inhalation of only one cell can produce an important infection in the host. It resists desiccation and any other environmental degradation. They can persist for several months and be transported by winds to farther places. This makes it even more difficult to determine the epidemiologic origin.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.