Deforestation inhibits malaria transmission in Lao PDR: a spatial epidemiology using Earth observation satellites.

BACKGROUND: The present study aimed to analyze the impact of deforestation on the malaria distribution in the Lao People's Democratic Republic (Lao PDR), with consideration of climate change. METHODS: Malaria distribution data from 2002 to 2015 were obtained from the Ministry of Health of Lao PDR and each indicator was calculated. Earth observation satellite data (forested area, land surface temperature, and precipitation) were obtained from the Japan Aerospace Exploration Agency (JAXA). Structured equation modeling (SEM) was conducted to clarify the relationship between the malaria incidence and Earth observation satellite data. RESULTS: As a result, SEM identified two factors that were independently associated with the malaria incidence: area and proportion of forest. Specifically, malaria was found to be more prevalent in the southern region, with the malaria incidence increasing as the percentage of forested land increased (both p < 0.01). With global warming steadily progressing, forested areas are expected to play an important role in the incidence of malaria in Lao PDR. This is believed because malaria in Lao PDR is mainly forest malaria transmitted by Anopheles dirus. CONCLUSION: To accelerate the elimination of malaria in Lao PDR, it is important to identify, prevent, and intervene in places with increased forest coverage (e.g., plantations) and in low-temperature areas adjacent to malaria-endemic areas, where the vegetation is similar to that in malaria-endemic areas.

Impact of precipitation on the prevalence of schistosomiasis mekongi in Lao PDR: Structural equation modelling using Earth observation satellite data.

Increasing attention is being given to the effect of climate change on schistosomiasis, but the impact is currently unknown. As the intermediate snail host (Neotricula aperta) of Schistosoma mekongi inhabits the Mekong River, it is thought that environmental factors affecting the area of water will have an impact on the occurrence of schistosomiasis mekongi. The aim of the present study was to assess the impact of precipitation on the prevalence of human schistosomiasis mekongi using epidemiological data and Earth observation satellite data in Khong district, Champasak province, Lao PDR. Structural equation modelling (SEM) using epidemiological data and Earth observation satellite data was conducted to determine the factors associated with the number of schistosomiasis mekongi patients. As a result, SEM identified 3 significant factors independently associated with schistosomiasis mekongi: (1) a negative association with mass drug administration (MDA); (2) negative association with total precipitation per year; and (3) positive association with precipitation during the dry season. Precisely, regardless of MDA, the increase in total yearly precipitation was suggested to decrease the number of schistosomiasis patients, whereas an increase in precipitation in the dry season increased the number of schistosomiasis patients. This is probably because when total precipitation increases, the water level of the Mekong River rises, thus decreasing the density of infected larvae, cercaria, in the water, and the frequency of humans entering the river would also decrease. In contrast, when precipitation in the dry season is higher, the water level of the Mekong River also rises, which expands the snail habitant, and thus water contact between humans and the snails would also increase. The present study results suggest that increasing precipitation would impact the prevalence of schistosomiasis both positively and negatively, and precipitation should also be considered in the policy to eliminate schistosomiasis mekongi in Lao PDR.

Detection of Schistosoma mekongi DNA in Human Stool and Intermediate Host Snail Neotricula aperta via Loop-Mediated Isothermal Amplification Assay in Lao PDR.

Schistosomiasis mekongi infection represents a public health concern in Laos and Cambodia. While both countries have made significant progress in disease control over the past few decades, eradication has not yet been achieved. Recently, several studies reported the application of loop-mediated isothermal amplification (LAMP) for detecting Schistosoma DNA in low-transmission settings. The objective of this study was to develop a LAMP assay for Schistosoma mekongi using a simple DNA extraction method. In particular, we evaluated the utility of the LAMP assay for detecting S. mekongi DNA in human stool and snail samples in endemic areas in Laos. We then used the LAMP assay results to develop a risk map for monitoring schistosomiasis mekongi and preventing epidemics. A total of 272 stool samples were collected from villagers on Khon Island in the southern part of Laos in 2016. DNA for LAMP assays was extracted via the hot-alkaline method. Following the Kato-Katz method, we determined that 0.4% (1/272) of the stool samples were positive for S. mekongi eggs, as opposed to 2.9% (8/272) for S. mekongi DNA based on the LAMP assays. Snail samples (n = 11,762) were annually collected along the riverside of Khon Island from 2016 to 2018. DNA was extracted from pooled snails as per the hot-alkaline method. The LAMP assay indicated that the prevalence of S. mekongi in snails was 0.26% in 2016, 0.08% in 2017, and less than 0.03% in 2018. Based on the LAMP assay results, a risk map for schistosomiasis with kernel density estimation was created, and the distribution of positive individuals and snails was consistent. In a subsequent survey of residents, schistosomiasis prevalence among villagers with latrines at home was lower than that among villagers without latrines. This is the first study to develop and evaluate a LAMP assay for S. mekongi detection in stools and snails. Our findings indicate that the LAMP assay is an effective method for monitoring pathogen prevalence and creating risk maps for schistosomiasis.

A Drug-Drug Interaction Study to Evaluate the Effect of TAS-303 on CYP3A Activity in the Small Intestine and Liver.

TAS-303 (4-piperidinyl 2,2-diphenyl-2-[propoxy-1,1,2,2,3,3,3-d7 ] acetate hydrochloride) is a novel selective noradrenaline reuptake inhibitor being developed for the treatment of stress urinary incontinence. An in vitro study and a physiologically based pharmacokinetic model simulation showed that TAS-303 had inhibitory potential against cytochrome P450 (CYP) 3A. This open-label, single-group study investigated the effect of TAS-303 on CYP3A activity by evaluating the pharmacokinetics (PK) of single-dose oral simvastatin 5 mg or intravenous midazolam 1 mg after repeated oral administration of TAS-303 3 mg in 12 healthy participants. TAS-303 plus simvastatin resulted in a 1.326-fold and a 1.420-fold increase of simvastatin in peak plasma concentration and area under the plasma concentration-time curve from time zero to time t, where t is the final time of detection (AUC0-t ), respectively. The addition of midazolam resulted in a 1.090-fold increase in the midazolam AUC0-t . TAS-303 had a weak PK interaction with simvastatin but no apparent interaction with midazolam. TAS-303 at 3 mg/day is a weak inhibitor of intestinal but not hepatic CYP3A activity. No clinically important safety concerns related to TAS-303 were raised.

A Double-Blind, Randomized, Crossover Comparative Study for Evaluating the Clinical Safety of Ephedrine Alkaloids-Free Ephedra Herb Extract (EFE).

Ephedra Herb is an important crude drug; it is used in various Traditional Japanese Medicine (Kampo) formulations. Its significant pharmacological effects have been believed to be attributed to ephedrine and pseudoephedrine, which sometimes induce adverse effects. On the other hand, it has been reported that some of these pharmacological effects are not dependent on ephedrine or pseudoephedrine. Ephedrine alkaloids-free Ephedra Herb extract has been newly developed. It has been reported to have analgesic, anti-influenza, and antimetastatic effects. This clinical trial was aimed at verifying the noninferiority of EFE's safety compared to that of Ephedra Herb extract (EHE) in humans. This was a single-institution, double-blinded, randomized, two-drug, two-stage, crossover comparative study. Twelve healthy male subjects were equally and randomly allocated into two groups: prior administration of EFE (EFE-P) and prior administration of EHE (EHE-P). In Stage 1, EFE and EHE were orally administered to the EFE-P and EHE-P groups, respectively, for six days. After a 4-week washout period, Stage 2 was initiated wherein the subjects were given a study drug different from Stage 1 study drug for six days. Eleven adverse events with a causal relationship to the study drugs (EHE: 8; EFE: 3) were noted; all events were mild in severity. With regard to the incidence of adverse events, EHE and EFE administration, respectively, accounted for 4 cases (out of 12 subjects, similarly below) and 1 case of increased pulse rate (p=0.32) and 3 cases and 1 case of insomnia (p=0.59). Further, there was one case of hot flashes (p=1.00) due to EFE administration and one case of dysuria (p=1.00) due to EHE administration. There were no significant differences in the incidences of adverse events between EHE administration and EFE administration. Therefore, we concluded that EFE is not inferior to EHE in terms of safety.

Effect of single and multiple doses of elobixibat, an ileal bile acid transporter inhibitor, on chronic constipation: A randomized controlled trial.

AIMS: Elobixibat is a minimally absorbed ileal bile acid transporter inhibitor. This study aimed to investigate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of elobixibat in Japanese patients with chronic constipation. METHODS: This study consisted of single-dose and multiple-dose tests with a dose-escalating design. Sixty patients including females and males were randomized into five dose levels of elobixibat (2.5, 5, 10, 15 or 20 mg, n = 10 per level) and corresponding placebo (n = 2 per group). A crossover design was used to examine food effect in single-dose test. Patients received test tablets once daily for 14 days in multiple-dose test. We assessed pharmacokinetic-dose proportionality, levels of serum high- and low-density lipoprotein cholesterol and plasma 7α-hydroxy-4-cholesten-3-one (C4), food effect and sex-specific effect. Adverse events and bowel functions such as bowel movements, stool consistency and straining were also evaluated. RESULTS: Food consumption reduced systemic exposure by around 80% [e.g. least squares mean (ratio of breakfast/no breakfast) maximum plasma concentration: 0.2085 (90% confidence interval, 0.1371-0.3172) at 15 mg] while increased plasma C4 level (P < 0.001). In the multiple-dose test, elobixibat reduced low-density lipoprotein cholesterol and increased C4 whilst unaltering high-density lipoprotein cholesterol level. The increased spontaneous bowel movement frequency was correlated with higher dosage and higher C4 level (R2  = 0.5929 at Week 2). Adverse events were mainly gastrointestinal symptoms, most of which were mild. CONCLUSIONS: Elobixibat should be taken before breakfast. Once-daily administration of elobixibat was found to be safe and tolerated up to 20 mg in female and male patients with chronic constipation.

Combined genogroup I and II norovirus infection at a nursery.

From November 2004 to April 2005, 5 cases of norovirus (NoV) occurred in Sakai City, Japan. These were all diffuse outbreaks due to infections with genogroup II genotype 4 (GII/4) virus strains. Similar outbreaks occurred throughout Japan; hence, GII/4 was assumed to be the prevalent NoV type. However, a NoV outbreak that occurred at a nursery in May 2005, was caused by infections with GI/4 and GII/6 viruses, respectively, from different children. The time course of newly infected patients showed that this nursery outbreak had a two-peak pattern, with the peak numbers of patients occurring on May 19 and May 22. Virological examination and epidemiological research could not determine whether the GI and GII NoV infections occurred at the same time, or whether there was a time difference in their appearance in the nursery. From this outbreak, it is clear that the timing of obtaining samples and obtaining the minimal necessary number of primary samples are essential for accurate epidemiological information to be obtained. In addition, we detected genotypes that were different from the previously prevalent genotypes, which raises the possibility of more frequent NoV infection or a change in the prevalent NoV genotype in this setting. In conclusion, it is difficult to predict outbreaks of NoV; however, through vigilant and early collection and analysis of later samples throughout an outbreak, it is possible to understand the prevalence and perhaps trace the source of NoV infections.

Bacterial superantigen TSST-1 attenuates suppressive efficacy of glucocorticoids and calcineurin inhibitors against blastogenesis of peripheral blood mononuclear cells from patients with antineutrophil cytoplasmic antibody-associated vasculitis and nephrosis.

Successful immunosuppressive therapy is critical for the treatment of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and nephrosis. However, a considerable number of patients have shown clinical resistance to therapy. Bacterial infection might influence the clinical response of patients to immunosuppressive drugs, but few studies have been carried out to investigate the effect of bacterial superantigens on the efficacy of the drugs in these patients. We evaluated the suppressive efficacy of prednisolone, methylprednisolone, cyclosporine, and tacrolimus on the blastogenesis of PBMCs obtained from 12 ANCA-associated vasculitis patients (ANCA patients), eight patients with nephrotic syndrome, and eight healthy subjects. PBMC-stimulation index was calculated from the formula: [3H]thymidine incorporated in the presence of stimulant (dpm)/[3H]thymidine incorporated in the absence of stimulant (dpm). In vitro drug concentrations giving 50% inhibition (IC50s) of PBMC blastogenesis stimulated with concanavalin A (con A) or toxic shock syndrome toxin 1 (TSST-1) derived from Staphylococcus aureus (S. aureus) were calculated. The IC50 values for the four drugs evaluated in TSST-1-stimulated PBMCs were significantly higher than those evaluated in con A-stimulated PBMCs in both ANCA patients and nephrosis patients (p<0.012-0.044). Whereas, the IC50 values for these immunosuppressive drugs, except methylprednisolone, were not significantly different between con A- and TSST-1-stimulated PBMCs in healthy subjects. The stimulation index was not significantly different between the con A- and TSST-1-stimulated PBMCs in either of the subject groups. These observations raise the possibility that TSST-1 induced by S. aureus infection attenuates the clinical efficacy of glucocorticoids and calcineurin inhibitors in ANCA patients and nephrosis patients.