Temporal Dynamics of Subclinical Malaria in Different Transmission Zones of Myanmar.

Countries in the Greater Mekong Subregion have committed to eliminate Plasmodium falciparum malaria by 2025. Subclinical malaria infections that can be detected by highly sensitive polymerase chain reaction (PCR) testing in asymptomatic individuals represent a potential impediment to this goal, although the extent to which these low-density infections contribute to transmission is unclear. To understand the temporal dynamics of subclinical malaria in this setting, a cohort of 2,705 participants from three epidemiologically distinct regions of Myanmar was screened for subclinical P. falciparum and P. vivax infection using ultrasensitive PCR (usPCR). Standard rapid diagnostic tests (RDTs) for P. falciparum were also performed. Individuals who tested positive for malaria by usPCR were followed for up to 12 weeks. Regression analysis was performed to estimate whether the baseline prevalence of infection and the count of repeated positive tests were associated with demographic, behavioral, and clinical factors. At enrollment, the prevalence of subclinical malaria infection measured by usPCR was 7.7% (1.5% P. falciparum monoinfection, 0.3% mixed P. falciparum and P. vivax, and 6.0% P. vivax monoinfection), while P. falciparum prevalence measured by RDT was just 0.2%. Prevalence varied by geography and was higher among older people and in those with outdoor exposure and travel. No difference was observed in either the prevalence or count of subclinical infection by time of year, indicating that even in low-endemicity areas, a reservoir of subclinical infection persists year-round. If low-density infections are shown to represent a significant source of transmission, identification of high-risk groups and locations may aid elimination efforts.

Microbial transformation of diosgenin to diosgenone by Wickerhamomyces anomalus JQ-1 obtained from Naxi traditional Jiu Qu.

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been considered as a potential therapeutic alternative remedy for malaria. An efficient and economical approach of microbial transformation with diosgenin to diosgenone by the yeast strain Wickerhamomyces anomalus JQ-1 from Naxi traditional Jiu Qu was developed in this study. Chromatographic analysis confirmed that 85% of 0.1 mM diosgenin was transformed to diosgenone within 72 h. This research demonstrates that diosgenin could be converted to diosgenone through two-step pathway including 3ß-hydroxyl oxidation and double bond isomerization rather than through one-step pathway, which prompted a further inference that the oxidation activity in W. anomalus JQ-1 has the same function with the Oppenauer-type oxidation which can convert diosgenin into diosgenone. Gaining specific functional strains from traditional fermented products will be a potential direction and ethnobotanical researches could provide helps with discovery and utilization of microbial resources.

Skincare plants of the Naxi of NW Yunnan, China.

The Naxi of Northwest Yunnan, China use medicinal plants to treat skin conditions related to traditional lifestyles in extreme environments. However, modernization endangers both the medicinal plants used to treat skin conditions and traditional knowledge. Therefore, investigation and documentation of the medicinal plants used and associated traditional knowledge is necessary. In this study, we conducted an ethnobotanical survey in 12 Naxi communities in Northwest Yunnan. For this purpose, we used semi-structured surveys to interview 840 informants from Naxi communities. We used informant consensus factor and use frequency as quantitative indices to evaluate the importance of medicinal plant species. A total of 161 medicinal plant species belonging to 69 families were documented. The highest informant consensus factor (ICF) values were recorded for skin nourishing (ICF = 0.849), frostbite and chapped skin (ICF = 0.833). These skin treatments are highly related to the environment and lifestyle of Naxi communities. The main active compounds of plants used to treat skin conditions in Naxi communities are known to have skin-treating properties. This study reveals that the skin conditions treated by the Naxi are associated with traditional medicine culture and social economic development. In addition, this study uses ethnobotanical indices to explain how skin condition treatments are linked to the natural environment of Naxi communities.