Rop'ngor

Rop'ngor was a Klingon childhood virus that is comparable to Human measles.

It attacks the endocrine system, and then enters a dormant state before its host's immune system can produce enough antibodies, and then will re-emerge once white blood cell counts fall again.

Humans can be a carrier of this virus, though due to physiological differences, it only causes only mild symptoms in the Human(s) in question.

Fainting could be a symptom of this illness.

Rarely, this disease can occur in Klingon adults, who did contract this disease during childhood.

Should this happen, the Klingons consider it shameful, since the disease is considered a child-only affliction.