South East Asia has areas of high endemicity in Indonesia and Papua New Guinea and overall contributes 9% of the global population at risk.

Some prefer to bite outdoors or during the daytime, hampering the effectiveness of indoor insecticide and bed nets.

Several key vector species have yet to be grown in the lab for closer study, and insecticide resistance is unquantified.

Unlike P. falciparum, P. vivax can populate the bloodstream, even before a patient shows symptoms, with sexual-stage parasites—the form ingested by mosquitoes before biting the next victim.

Consequently, prompt treatment of symptomatic patients does not necessarily help stop an outbreak, as it does with falciparum malaria, in which fevers occur as sexual stages develop.

It has been known to debut with hiccups,[17] loss of taste, lack of fever, pain while swallowing, cough and urinary discomfort.

[18] The parasite can lie dormant in the liver for days to years, causing no symptoms and remaining undetectable in blood tests.

[10] A single infectious bite can trigger six or more relapses a year, leaving patients more vulnerable to other diseases.

More complications of malaria can also be impairment of consciousness, neurological abnormalities, hypoglycemia and low blood pressures caused by cardiovascular collapse, clinical jaundice, and or other vital organ dysfunctions and coagulation defects.

There are mostly three main forms in which the vector can be controlled: (1) insecticide-treated mosquito nets, (2) indoor residual spraying, and (3) antimalarial drugs.

32–100% of patients will relapse following successful treatment of P. vivax infection if a radical cure (inactivation of liver stages) is not given.

[28][29][30] Eradication of the liver stages is achieved by giving primaquine but patients with glucose-6-phosphate dehydrogenase deficiency are at risk for haemolysis.

However, it has been suggested that primaquine might, to a currently unknown extent, also inactivate noncirculating, extrahepatic merozoites (clarity in this regard is expected to be forthcoming soon).

[33] In 2013 a Phase IIb trial was completed that studied a single-dose alternative drug named tafenoquine.

Ideally, he says, researchers will be able to combine the safety data from the Army's earlier trials with the new study in a submission to the U.S. Food and Drug Administration for approval.

[10] In 2013 researchers produced cultured human "microlivers" that supported liver stages of both P. falciparum and P. vivax and may have also created hypnozoites.

In 1979, World Health Organization declared the Korean peninsula vivax malaria-free, but the disease unexpectedly re-emerged in the late 1990s and persists today.

Several factors contributed to the re-emergence of the disease, including a reduced emphasis on malaria control after 1979, floods and famine in North Korea, the emergence of drug resistance, and possibly global warming.

As such, vivax malaria offers the two Koreas an opportunity to work together on an important health problem that affects both countries.

Though, a lot of the hypothetical proteins have role in secondary metabolism, targeting them will be beneficial from two perspectives, i.e., specificity and reducing the virulence of the pathogen with no or minimal undesirable cross-reactivities.

There are situations where some of the sporozoites do not immediately start to grow and divide after entering the hepatocyte, but remain in a dormant, hypnozoite stage for weeks or months.

The duration of latency is thought to be variable from one hypnozoite to another and the factors that will eventually trigger growth are not known; this might explain how a single infection can be responsible for a series of waves of parasitaemia or "relapses".

[40] Two newly recognized, non-hypnozoite, probable contributing sources to recurrent peripheral P. vivax parasitemia are erythrocytic forms in bone marrow and the spleen.

This finding supports an intellectually insightful, paradigm-shifting viewpoint, which had prevailed since 2011 (albeit not believed between 2011 and 2018 by most malariologists and therefore ignored), that an unknown percentage of P. vivax recurrences are recrudescences (having a non-circulating or sequestered merozoite origin), and not relapses (which have a hypnozoite source).

The recent discoveries concerning bodily parasite biomass distribution did not give rise to this new theory; it was pre-existing, as explained above.

P. vivax preferentially penetrates young red blood cells (reticulocytes), unlike Plasmodium falciparum which can invade erythrocytes.

Schüffner's dots have a spotted appearance, varying in color from light pink to red, to red-yellow, as coloured with Romanovsky stains.

[citation needed] The oocyst nucleus divides repeatedly to form a large number of daughter nuclei.

[citation needed] When the mosquito bites a healthy person, thousands of sporozoites are injected into the blood along with the saliva and the cycle starts again.

A specific name – Plasmodium collinsi – has been proposed for the New World strains, but this suggestion has not been accepted to date.