In a cluster of hutments, many people are suffering from malaria. Mention the unhygienic conditions that must be prevailing in that locality. How does a doctor confirm malaria?

Stagnant water (of ponds (in the locality is the habitat of larvae of many types of mosquitoes and the are vector of a disease, called malaria.
Doctor confirms malaria if the patients have following symptoms: headache, nausea, muscular pain and high fever. Doctor also checks the presence of malarial parasite in the human body by blood test.