First case of a naturally acquired human infection with Plasmodium cynomolgi

Abstract

Since 1960, a total of seven species of monkey malaria have been reported as transmissible to man by mosquito bite: Plasmodium cynomolgi, Plasmodium brasilianum, Plasmodium eylesi, Plasmodium knowlesi, Plasmodium inui, Plasmodium schwetzi and Plasmodium simium. With the exception of P. knowlesi, none of the other species has been found to infect humans in nature. In this report, it is described the first known case of a naturally acquired P. cynomolgi malaria in humans.The patient was a 39-year-old woman from a malaria-free area with no previous history of malaria or travel to endemic areas. Initially, malaria was diagnosed and identified as Plasmodium malariae/P. knowlesi by microscopy in the Terengganu State Health Department. Thick and thin blood films stained with 10% Giemsa were performed for microscopy examination. Molecular species identification was performed at the Institute for Medical Research (IMR, Malaysia) and in the Malaria & Emerging Parasitic Diseases Laboratory (MAPELAB, Spain) using different nested PCR methods.Microscopic re-examination in the IMR showed characteristics of Plasmodium vivax and was confirmed by a nested PCR assay developed by Snounou et al. Instead, a different PCR assay plus sequencing performed at the MAPELAB confirmed that the patient was infected with P. cynomolgi and not with P. vivax.This is the first report of human P. cynomolgi infection acquired in a natural way, but there might be more undiagnosed or misdiagnosed cases, since P. cynomolgi is morphologically indistinguishable from P. vivax, and one of the most used PCR methods for malaria infection detection may identify a P. cynomolgi infection as P. vivax.Simian Plasmodium species may routinely infect humans in Southeast Asia. New diagnostic methods are necessary to distinguish between the human and monkey malaria species. Further epidemiological studies, incriminating also the mosquito vector(s), must be performed to know the relevance of cynomolgi malaria and its implication on human public health and in the control of human malaria.The zoonotic malaria cannot be ignored in view of increasing interactions between man and wild animals in the process of urbanization.

Strict tropism for CD71+/CD234+ human reticulocytes limits the zoonotic potential of Plasmodium cynomolgi

“…(C) Inhibition of P cynomolgi countries. [19][20][21] By contrast, to date, only 1 case of zoonotic P cynomolgi has been reported recently from Malaysia, 22 and it came to light solely through careful molecular analysis. Three interrelated factors might account for the disparity in the observed prevalence of zoonotic infections for these 2 species that have similar high prevalence in their natural hosts.…”

Ethnobotany of Medicinal Plants Used to Treat Malaria by Traditional Healers from Ten Indigenous Colombian Communities Located in Vaupes Medio

“…4 This parasite is transmitted to humans by the bite of the Anopheles mosquito. Once inside the organism, the parasite causes clinical symptoms that can range from mild to grave, or even lead to fatal.…”

From the Fifth to the Seventh Human Malarial Species: A New Concern in Infectious Medicine

“…In 2014, the sixth malarial species, P. cynomolgi, was identified in Southeast Asia, with a single case reported in Malaysia (3). Malaria caused by P. cynomolgi is very difficult to differentiate from that caused by P. vivax (3). In 2015, Lalremruata et al (4) reported the seventh human malarial species, P. brasilianum, this time in South America.…”

“…Based on 18S rRNA gene sequencing, Lalremruata et al (4) identified 12 patients harboring malaria parasites, which were 100% identical to those of P. brasilianum isolated from the monkey Alouatta seniculus. Indeed, P. brasilianum malaria is important monkey malaria, and the chance for human cross-species infection had already been highlighted (3). Of interest, other carriers of malaria, such as the monkeys P. eylesi, P. inui, P. schwetzi, and P. simium, provide an opportunity for cross-species infection.…”