Which symptoms may suggest the presence of a communicable disease?

The presence of a communicable disease can often be indicated by observable symptoms that affect a person's usual health status. Confusion of recent onset can be a significant red flag, as it may suggest an underlying illness that could be contagious, such as a viral infection or other systemic conditions affecting the brain. This symptom may indicate that the body is reacting to an infection that can impact neurological function, thus raising concerns about transmission to others, especially in a crew environment where close contact is common.

On the other hand, a stable health condition, normal body temperature, and general fatigue by themselves might not provide sufficient evidence of a communicable disease. A stable health condition and normal body temperature typically suggest that an individual is not experiencing any acute illness, and while general fatigue can be associated with various health issues, it is not specific enough to infer a communicable disease without additional context or symptoms. Only symptoms that clearly indicate a shift from normal health status, like confusion, would alert crew members to the possibility of contagion.