Subpatent Plasmodium with mutant pfmdr1, pfcrt, and pvmdr1 alleles from endemic provinces in Mindanao, the Philippines: implications for local malaria elimination.

OBJECTIVES: This study was performed to identify and characterize circulating Plasmodium species in three provinces of Mindanao approaching malaria elimination. METHODS: Rapid diagnostic tests (RDT), microscopic examination, and PCR were used to detect malaria parasites. PCR-positive isolates were genotyped for polymorphisms in loci of interest. RESULTS: A total of 2639 participants were surveyed in Mindanao between 2010 and 2013. Malaria prevalence by PCR was 3.8% (95% confidence interval (CI): 2.7-5.2%) in Sarangani, 10% (95% CI: 7.7-12.7%) in South Cotabato, and 4.2% (95% CI: 3.2-5.6%) in Tawi-Tawi. P. falciparum and P. vivax were identified in all three provinces, and there was one case of P. malariae in South Cotabato. RDT was inferior to PCR for detecting asymptomatic P. falciparum and P. vivax. In Tawi-Tawi, microscopy failed to identify 46 PCR-positive malaria infections. The presence of pfcrt haplotypes CVMNK, CVIET, and SMNT (codons 72-76), pfmdr1 haplotype NFSND (codons 86, 184, 1034, 1042, 1246), and pvmdr1 haplotype NFL (codons 91, 976, 1076) was confirmed in Mindanao. CONCLUSIONS: Asymptomatic Plasmodium infections persisted in local communities between 2010 and 2013. PCR successfully identified subpatent malaria infections, and can better characterize malaria epidemiology in communities seeking malaria control and elimination at the local level.

Understorey to canopy vertebrate fauna of a lowland evergreen forest in Mt. Makiling Forest Reserve, Philippines.

We examined the vertical stratification of forest wildlife, from the ground up to the canopy layer, within a 2-hectare permanent plot of lowland evergreen rainforest on the Mt. Makiling Forest Reserve. Our aim was to determine the species richness of the different forest layers and evaluate their ecosystem services. Understorey, sub-canopy and canopy sampling were conducted during July 2016, March to April 2017 and February to March 2018, respectively. We were able to record a total of 68 species, consisting of 11 amphibians, 15 reptiles, 25 birds and 17 mammals. Increasing species richness with increasing vertical stratification was observed for both reptiles and mammals. For birds, the peak richness was observed in the sub-canopy and then decreased in the canopy. A decreasing trend was observed with amphibians wherein the peak species richness was observed in the understorey. Increasing vertical stratification influenced vertical habitat use and species richness. For the similarity index, the same pattern was observed for all species groups. Highest similarity was observed between the sub-canopy and the canopy and the least similarity was observed between the understorey and canopy. These results indicate that the understorey and the canopy host different species groups, thus, sampling of the understorey alone, often done in biodiversity surveys, may lead to the underestimation of species richness in an area.

Plasmodium knowlesi and other malaria parasites in long-tailed macaques from the Philippines.

BACKGROUND: Macaca fascicularis (long-tailed macaque) is the most widespread species of macaque in Southeast Asia and the only species of monkey found naturally in the Philippines. The species is the natural host for the zoonotic malaria species, Plasmodium knowlesi and Plasmodium cynomolgi and for the potentially zoonotic species, Plasmodium inui. Moreover, other Plasmodium species such as Plasmodium coatneyi and Plasmodium fieldi are also natural parasites of M. fascicularis. The aims of this study were to identify and determine the prevalence of Plasmodium species infecting wild and captive long-tailed macaques from the Philippines. METHODS: A total of 95 blood samples from long-tailed macaques in the Philippines were collected from three locations; 30 were from captive macaques at the National Wildlife Rescue and Rehabilitation Center (NWRRC) in Luzon, 25 were from captive macaques at the Palawan Wildlife Rescue and Conservation Center (PWRCC) in Palawan and 40 were from wild macaques from Puerto Princesa Subterranean River National Park (PPSRNP) in Palawan. The Plasmodium spp. infecting the macaques were identified using nested PCR assays on DNA extracted from these blood samples. RESULTS: All 40 of the wild macaques from PPSRNP in Palawan and 5 of 25 captive macaques from PWRCC in Palawan were Plasmodium-positive; while none of the 30 captive macaques from the NWRRC in Luzon had any malaria parasites. Overall, P. inui was the most prevalent malaria parasite (44.2%), followed by P. fieldi (41.1%), P. cynomolgi (23.2%), P. coatneyi (21.1%), and P. knowlesi (19%). Mixed species infections were also observed in 39 of the 45 Plasmodium-positive macaques. There was a significant difference in the prevalence of P. knowlesi among the troops of wild macaques from PPSRNP. CONCLUSION: Wild long-tailed macaques from the island of Palawan, the Philippines are infected with P. knowlesi, P. inui, P. coatneyi, P. fieldi and P. cynomolgi. The prevalence of these Plasmodium spp. varied among the sites of collection and among troops of wild macaques at one site. The presence of these simian Plasmodium parasites, especially P. knowlesi and P. cynomolgi in the long-tailed macaques in Palawan presents risks for zoonotic transmission in the area.