Thirty-two patients reporting to the Lundu District Hospital, Sarawak, Malaysian Borneo, with uncomplicated falciparum malaria were recruited into a multifaceted study to assess treatment response. Following combined chloroquine and sulphadoxine/pyrimethamine treatment the patients were followed for 28 days according to the World Health Organisation in vivo drug response protocol. The in vivo study revealed that 13 (41%) of the patients had a sensitive response to treatment, five (16%) cleared asexual stage parasites but had persistent gametocytes, 11 (34%) had RI type resistance and three (9%) had RII type resistance requiring quinine intervention before day 7 for parasite clearance. Although clinically insignificant, patients with persistent gametocytes, surviving chloroquine and sulphadoxine/pyrimethamine treatment during maturation, were placed in the reduced response to treatment group for analysis. Allelic typing detected 100% prevalence of the pfcrt K76T marker associated with chloroquine resistance and 78% prevalence of the pfdhfr NRNL haplotype associated with sulphadoxine/pyrimethamine treatment failure. High serum chloroquine levels and pfdhfr haplotypes with
The blood filtration method was used as the gold standard to determine the detection level of simple blood-spot sampling and nested-polymerase chain reaction (PCR) for Brugia malayi. Of 100 samples, 48 were filtration-positive. Of these, 26 had microfilaria counts that were low enough (<1-29 microfilariae/ml) to accurately assess the limit of detection by nested-PCR. Nested-PCR consistently detected B. malayi DNA in samples with > or = 10 microfilariae/ml. Post-filtration, microfilaria-depleted, blood-spots from microfilaria-positive samples were screened by nested-PCR and B. malayi specific 'free' DNA was detected in 51.7% of these samples. There was no evidence for 'free' DNA in microfilaria-negative individuals from this endemic community.
Nipa (Nypa fruticans Wurmb.) is an important mangrove palm species, but it is understudied due to lack of information on genetic patterns within its distribution range. In this study, we identified 18 informative microsatellite markers to assess genetic variations among local populations in the Indo-West Pacific (IWP). Results showed population stratification based on high genetic differentiation (FST = 0.22131) with the Mantel test indicating significance to isolation-by-distance. We found a pronounced differentiation between the west populations in Sri Lanka and east populations in Southeast Asia. The east populations around the South China Sea were more genetically similar than those along the Malacca Strait and Java Sea. These genetic clines were shaped by ocean circulations and seasonal monsoon reversals as plausible factors. The Malacca Strait was confirmed as both a genetic and a geographic barrier rather than a corridor according to the Monmonier plot. Simulations of directional migration indicated a statistically strong contemporary genetic connectivity from west to east where Sri Lankan immigrants were detected as far as central Philippines via long-distance dispersal. This is the first report on the recent migration patterns of nipa using microsatellites. Assignment of first-generation (F0) immigrants suggested Mainland Southeast Asia as a melting pot due to the admixture associated with excess of homozygosity. The western populations were recent expansions that emerged in rapid succession based on a phylogram as supported by footprints of genetic drift based on bottleneck tests.