When is parasitological confirmation not recommended?
It is always best to get a laboratory or rapid diagnostic test for malaria (parasitological confirmation) to make sure the person actually has malaria before giving treatment, and to make sure the treatment is appropriate.
There are four main types of malaria which infect humans: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. P. ovale additionally can be split into two sub-species, P. o. curtisi and P. o. wallikeri. Each of these five kinds has a subtly different life cycle which results in slight variations in symptoms and also in treatment, so knowing which one a person has is important for choosing the most appropriate treatment. For more information on this, check out the Q&As on Malaria Symptoms and malaria treatment.
Early treatment of malaria is essential to saving lives, so in communities that do not have ready access to simple lab testing, international agencies like WHO and UNICEF have developed standardized algorithms, to guide community health workers in early identification and treatment of malaria (particularly in children) without laboratory confirmation. While this approach has been taken to save lives, where possible, laboratory confirmation of malaria is recommended.