Peripheral blood films stained with Giemsa stain are a method of blood examination used to diagnose the presence of Plasmodium malariae, and detect quartan fever. Rapid diagnostic tests can detect the antigens which cause malaria, a sample of blood is collected from the patient and placed on a test card. After 15–20 minutes bands show up on the test card which indicate the specific species of malaria the patient is infected with. Serological tests are used in general to detect whether a patient has developed antibodies to specific microorganism, therefore serological tests are used to detect past encounters with Plasmodium virus rather than acute cases where a patient has just been infected with P. malariae and has quartan fever. Polymerase chain reactions (PCR) are used to diagnosis Plasmodium malariae (cause of quartan fever) as well as to distinguish mixed infections with different species of Plasmodium. Treatment
Chloroquine is an anti-malarial medication administered in the form of a tablet for ingestion. Chloroquine is a water-soluble drug which is used to treat quartan fever. It is ingested in a compressed tablet form and is absorbed by the gastrointestinal tract. Hydroxychloroquine, another anti-malarial, is used to treat quartan fever. Hydroxychloroquine is also typically administered to patients with lupus flares. Both hydroxychloroquine and  chloroquine have a side effect of retinal toxicity when administered to infected patients. Adverse effects  of the drug chloroquine  include agitation, anxiety, confusion, gastrointestinal discomfort, blurring vision and/or irreversible retinopathy. Sulfadoxine-pyrimethamine (SP) is administered to pregnant women.
Uninucleated merozoites can also mature into uninucleate gametocytes which can invade and infect other female Anopheles mosquitoes during feeding, thus spreading the disease onto a wider population of humans. Diagnosis
Fevers in intervals of 72 hours distinguish quartan fever from other forms of malaria where fevers range in 48 hour intervals or fever spikes that occur sporadically.Early indications of quartan fever include having irritated spots, welts, hives and burning skin, however this is dependent on individuals tolerance to mosquito bites and may not be evident on some people. With the Anopheles malaria mosquitoes, the welts are most likely to not appear unless there are severe allergic reactions.The prepatent period is the time interval for when parasites infect a host and when they can be detected on a thick blood film. For quartan fever, P. malariae has a prepatent period ranging from 16 to 59 days. Specifically in the case of quartan fever, the rupturing of liver stage schizonts releases merozoites. This stage of the P. malariae life cycle is known as the "ring stages" and are the first stages which can be detected in human blood for diagnosis. Medical procedures that diagnose a patient with quartan fever
Blood smears can be used to detect the parasites within red blood cells, thick blood smears are typically used initially to detect the parasites, then it is followed by thin blood smears which can detect the parasites as the morphology of erythrocytes is maintained through the process.