BIOLOGY IN HUMAN WELFARE
HUMAN HEALTH AND DISEASE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -Two types (species) of parasites, Plasmodium vivax and P. ovale, have liver stages and can remain in the body for years without causing sickness. If not treated, these liver stages may reactivate and cause malaria attacks (“relapses”) after months or years without symptoms.
Detailed explanation-2: -The recurrence in patients with malaria can be caused by reinfection from a new mosquito bite, recrudescence, or relapse [5]. Relapse occurs in P. vivax and P. ovale infections through the activation of hypnozoites in the human liver.
Detailed explanation-3: -Some people suffer from repeated attacks of malaria. These can occur weeks to months or longer after contracting the disease. The phenomenon is only too familiar to those who were bitten by mosquitoes carrying the type of malaria-causing organism known as Plasmodium vivax.