Which of the following is an early stage symptom of malaria?

Low grade fever is considered an early stage symptom of malaria due to how the disease progresses within the human body. When the Plasmodium parasite, responsible for malaria, enters the bloodstream, it infects red blood cells. This leads to the body’s immune response, manifesting as mild fever, which is typically low grade in the initial stages. This fever is a response to the body's attempt to fight off the infection.

In contrast, emaciation is generally seen in chronic cases of malaria rather than early stages, as it indicates a prolonged illness and poor nutritional intake. Enlargement of the liver, or hepatomegaly, may occur later as the disease progresses and is also indicative of a more severe, prolonged infection. Bloody mucoid stools are associated with other diseases or complications and are not a symptom of early-stage malaria. Therefore, low grade fever serves as a primary indicator of the initial phase of malaria infection, highlighting the body's reaction to the invading parasites.