20.下列何者不是飛沫（droplet）傳染疾病？
(A)腮腺炎（Mumps）
(B)鏈球菌性肺炎（Streptococcal pneumonia）
(C)水痘（Varicella）
(D)百日咳（Pertussis）

飛沫（droplet）傳染疾病

(A)腮腺炎（Mumps）

(B)鏈球菌性肺炎（Streptococcal pneumonia）

 (D)百日咳（Pertussis）

空氣傳染

(C)水痘（Varicella）

varicella can be transmitted by air droplet according to  WHO POSITION PAPER 2014

therefore i think , all OF THE ABOVE CHOICES can be transmitted by droplet. SO  suggested the answer should be " 以上皆非" . 

What is transmission by droplet contact?

Some diseases can be transferred by infected droplets contacting surfaces of the eye, nose, or mouth. This is referred to as droplet contact transmission. Droplets containing microorganisms can be generated when an infected person coughs, sneezes, or talks. Droplets can also be generated during certain medical procedures, such as bronchoscopy. Droplets are too large to be airborne for long periods of time, and quickly settle out of air.

Droplet transmission can be reduced with the use of personal protective barriers, such as face masks and goggles. Measles and SARS are examples of diseases capable of droplet contact transmission.

 What is airborne transmission?

Airborne transmission refers to situations where droplet nuclei (residue from evaporated droplets) or dust particles containing microorganisms can remain suspended in air for long periods of time. These organisms must be capable of surviving for long periods of time outside the body and must be resistant to drying. Airborne transmission allows organisms to enter the upper and lower respiratory tracts. Fortunately, only a limited number of diseases are capable of airborne transmission.

Diseases capable of airborne transmission include:

• Tuberculosis
• Chickenpox
• Measles

Department of Microbiology, Mount Sinai Hospital, Toronto, Canada. All rights reserved.