Plasmodium vivax is the most widespread human
malaria, putting 2.5 billion people at risk of
infection. Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum Unlike P. falciparum, P. vivax
infections have typically low blood-stage
parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses. These traits affect both its geographic distribution and transmission patterns.
Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review. Despite relatively low prevalence measurements and
parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign. Plasmodium vivax can be associated with severe and even fatal illness. Spreading resistance to
chloroquine against the acute attack, and the operational inadequacy of
primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the
tens of millions suffering from
infection each year. Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic
malaria transmission will be substantially impeded.