Which of the following diseases transmitted by mosquitoes is significant to military operations?

Yellow fever is a viral disease transmitted by mosquitoes and is particularly significant to military operations due to its potential to cause widespread illness and disrupt missions. Military personnel often operate in tropical and subtropical regions where yellow fever is endemic. If soldiers are not vaccinated against the disease, they face a high risk of contracting it, which can lead to incapacitation and affect troop strength and operational effectiveness.

Vaccination against yellow fever is typically required for deployments in affected regions, and the disease's potential to cause severe symptoms, including fever, chills, loss of appetite, and muscle pain, further underscores the importance of preventive measures. In military campaigns, the health and readiness of the troops are critical, and outbreaks of diseases like yellow fever could compromise operations and mission success.

In contrast, while leptospirosis can affect military personnel, it is less commonly associated with mosquito transmission. The common cold and chickenpox are not mosquito-borne diseases and generally pose less significant threats to military readiness.