Simian malaria in wild macaques: first report from Hulu Selangor district, Selangor, Malaysia

Abstract

BackgroundMalaria is a vector-borne parasitic disease which is prevalent in many developing countries. Recently, it has been found that Plasmodium knowlesi, a simian malaria parasite can be life-threatening to humans. Long-tailed macaques, which are widely distributed in Malaysia, are the natural hosts for simian malaria, including P. knowlesi. The aim of the present study was to determine the prevalence of simian malaria parasites in long-tailed macaques in the district of Hulu Selangor, Selangor, Malaysia.MethodsA total of 70 blood samples were collected from Macaca fascicularis dwelling in the forest of Hulu Selangor by the Department of Wildlife and National Parks Peninsular Malaysia, Kuala Lumpur, Malaysia. DNA was extracted using PureLink™ Genomic DNA Kits. Conventional and nested PCR were used to detect the genus and species of Plasmodium parasites respectively. In addition, phylogenetic analysis was carried out to confirm the species of Plasmodium parasites.ResultsThirty-five (50 %) of the 70 samples were positive for Plasmodium using genus-specific primers. These positive samples were then subjected to nested PCR targeting the 18S ribosomal RNA genes to detect all five simian malaria parasites: namely, P. knowlesi, Plasmodium inui, Plasmodium cynomolgi, Plasmodium fieldi, and Plasmodium coatneyi. All five species of simian malaria parasites were detected. Of these, P. inui was the predominant (65.7 %), followed by P. knowlesi (60 %), P. cynomolgi (51.4 %) P. coatneyi (45.7 %) and P.fieldi (2.9 %). A total of nine macaques had mono-infection with P. knowlesi (four), P. cynomolgi (two), P. coatneyi (two) and P. fieldi (one). Eleven of the macaques had dual infections while 12 had triple infections. Three macaques were infected with four species of Plasmodium. Molecular and phylogenetic analysis confirmed the five species of Plasmodium parasites.ConclusionThis study has provided evidence to elucidate the presence of transmission of malaria parasites among the local macaques in Hulu Selangor. Since malaria is a zoonosis, it is important to determine the new control strategies for the control of malaria.

Distribution and prevalence of malaria parasites among long-tailed macaques (Macaca fascicularis) in regional populations across Southeast Asia

“…A comparison with multiple studies using molecular methods to detect Plasmodium infections in macaques from other locations indicates that the prevalence of malaria and of the different species of Plasmodium vary according to the sampling site, even on a small island like Singapore [18–20, 22–26]. Comparing the Singaporean samples screened from this study, which were collected from 2007, with the Singaporean samples reported from 2011 [20], there was a decrease in the prevalence of P. knowlesi infection.…”

Phylogenetic analysis of simian Plasmodium spp. infecting Anopheles balabacensis Baisas in Sabah, Malaysia

“…Previous studies in Malaysia have shown that the long-tailed macaques harbor at least five species of simian Plasmodium [14,15], all of which have also been detected in An . balabacensis [9,16].…”

Ancestry, Plasmodium cynomolgi prevalence and rhesus macaque admixture in cynomolgus macaques (Macaca fascicularis) bred for export in Chinese breeding farms

“…Because these parasites’ infections in humans are likely to originate from close proximity between humans and wild macaques, a thorough understanding of the distribution of the zoonotic malaria parasite in nature is essential in the control and prevention of malaria disease in countries and regions under high risk. Recent studies have shown that P. cynomolgi is one of the most common malarial parasites among wild cynomolgus macaques and is uniformly and widely distributed throughout cynomolgus macaque populations in Southeast Asia . Infections in experimentally infected rhesus macaques result in much more severe clinical manifestations than in cynomolgus macaques .…”

“…Recent studies have shown that P. cynomolgi is one of the most common malarial parasites among wild cynomolgus macaques and is uniformly and widely distributed throughout cynomolgus macaque populations in Southeast Asia. 38,[42][43][44] Infections in experimentally infected rhesus macaques result in much more severe clinical manifestations than in cynomolgus macaques. 36 Furthermore, previous studies reported a significantly higher count of parasites in rhesus macaques than in cynomolgus macaques within the same duration after infection.…”