Leptospires, which cause the zoonotic disease leptospirosis, persist in soil and aqueous environments. Several factors, including rainfall, the presence of reservoir animals, and various abiotic and biotic components interact to influence leptospiral survival, persistence, and pathogenicity in the environment. However, how these factors modulate the risk of infection is poorly understood. Here we developed an approach using environmental DNA (eDNA) metabarcoding for detecting the microbiome, vertebrates, and pathogenic Leptospira in aquatic samples. Specifically, we combined 4 sets of primers to generate PCR products for high-throughput sequencing of multiple amplicons through next-generation sequencing. Using our method to analyze the eDNA of leptospirosis-endemic areas in northern Okinawa, Japan, we found that the microbiota in each river shifted over time. Operating taxonomic units corresponding to pathogenic L. alstonii, L. kmetyi, and L. interrogans were detected in association with 12 nonpathogenic bacterial species. In addition, the frequencies of 11 of these species correlated with the amount of rainfall. Furthermore, 10 vertebrate species, including Sus scrofa, Pteropus dasymallus, and Cynops ensicauda, showed high correlation with leptospiral eDNA detection. Our eDNA metabarcoding method is a powerful tool for understanding the environmental phase of Leptospira and predicting human infection risk.

We performed tick surveys in all regions (Kaetsu, Chuetsu, Joetsu, and Sado) of the Niigata prefecture, Japan. A total of 105 field surveys were done from 2016 to 2018 in 41 sites, from north to south, in the prefecture. All 4806 ticks collected were identified and classified by species, sex, and developmental stage. Twelve species were recorded: Dermacentor taiwanensis, Haemaphysalis flava, Haemaphysalis hystricis, Haemaphysalis japonica, Haemaphysalis longicornis, Haemaphysalis megaspinosa, Ixodes ovatus, Ixodes nipponensis, Ixodes persulcatus, Ixodes monospinosus, Ixodes columnae, and Ixodes turdus. The major tick species in Niigata prefecture were H. flava, H. longicornis, and I. ovatus and they comprised 93.4% of all samples. These three species have one generation per year. Climatic and anthropogenic factors may be involved in the substantial change of the endemic species composition from a previous tick survey (1959) in the Niigata prefecture. These factors include increasing temperatures, introduction of new hosts such as the wild boar, highway construction, and a rural exodus facilitating animal migration and reproduction. Tick hosts suitable for the transmission of Japanese spotted fever, Lyme borreliosis, and SFTS occur in Niigata prefecture. Heightened awareness of these three tick-borne diseases is needed for preparation and disease prevention.

Schistosomiasis japonica is an infectious parasitic disease caused by infection with the blood fluke Schistosoma japonicum, which is endemic in China, small pockets of Indonesia, and the Philippines. Of the three countries, the prevalence of infection is the highest in the Philippines, despite decades of mass drug administration (MDA). As a zoonosis with 46 potential mammalian definitive hosts and a snail intermediate host, the control and eventual elimination of S. japonicum requires management of these animal hosts in addition to new interventions for the human hosts, including health education and water, sanitation, and hygiene (WASH) infrastructure. In this review we examine the status and epidemiology of S. japonicum in the Philippines with an overview of the current control program there and what needs to be accomplished in the future to control and eliminate this disease in the country.

Background: The perpetuation of schistosomiasis japonica in the Philippines depends to a major extent on the persistence of its intermediate host Oncomelania hupensis quadrasi, an amphibious snail. While the malacological survey remains the method of choice in determining the contamination of the environment as evidenced by snails infected with schistosome larval stages, an emerging technology known as environmental DNA (eDNA) detection provides an alternative method. Previous reports showed that O. hupensis quadrasi eDNA could be detected in water, but no reports have been made on its detection in soil. Methods: This study, thus focused on the detection of O. hupensis quadrasi eDNA from soil samples collected from two selected schistosomiasis-endemic barangays in Gonzaga, Cagayan Valley using conventional and TaqMan-quantitative (qPCR) PCRs. Results: The results show that qPCR could better detect O. hupensis quadrasi eDNA in soil than the conventional method. In determining the possible distribution range of the snail, basic edaphic factors were measured and correlated with the presence of eDNA. The eDNA detection probability increases as the pH, phosphorous, zinc, copper, and potassium content increases, possibly indicating the conditions in the environment that favor the presence of the snails. A map was generated to show the probable extent of the distribution of the snails away from the body of the freshwater. Conclusion: The information generated from this study could be used to determine snail habitats that could be possible hotspots of transmission and should, therefore, be targeted for snail control or be fenced off from human and animal contact or from the contamination of feces by being a dumping site for domestic wastes.

Japanese spotted fever, a tick-borne disease caused byRickettsia japonica, was firstly described in southwestern Japan. There was a suspicion ofRickettsia japonicainfected ticks reaching the non-endemic Niigata Prefecture after a confirmed case of Japanese spotted fever in July 2014. Therefore, from 2015 to 2017, 38 sites were surveyed and rickettsial pathogens were investigated in ticks from north to south of Niigata Prefecture including Sado island. A total of 3336 ticks were collected and identified revealing ticks of three genera and ten species:Dermacentor taiwanensis,Haemaphysalis flava,Haemaphysalis hystricis,Haemaphysalis longicornis,Haemaphysalis megaspinosa,Ixodes columnae,Ixodes monospinosus,Ixodes nipponensis,Ixodes ovatus,andIxodes persulcatus. Investigation of rickettsial DNA showed no ticks infected byR. japonica. However, three species of spotted fever group rickettsiae (SFGR) were found in ticks,R. asiatica,R. helvetica,andR. monacensis, confirming Niigata Prefecture as a new endemic area to SFGR. These results highlight the need for public awareness of the occurrence of this tick-borne disease, which necessitates the establishment of public health initiatives to mitigate its spread.

To investigate the influence of nutritional status on severe infection complications in patients with rheumatoid arthritis (RA) This retrospective cohort study on 2,108 Japanese patients with RA treated at our hospital in April 2016 evaluated the prognostic nutritional index (PNI) as an index of nutritional status. Patients were classified into the high or low PNI group according to the cutoff PNI value (45.0). Based on propensity score matching analysis, 360 patients in each group were selected for comparing the incidence of serious infection, clinical findings, and PNI scores. The incidence of infection was significantly higher in the low PNI group than in the high PNI group (p < 0.001). The occurrence rate of infectious complication at 104 weeks was significantly higher in the low PNI (<45.0) group than in the high PNI group (p < 0.001), but Cox hazards regression analysis showed that low PNI was not a risk factor of severe infections (hazard ratio 1.080, 95% confidence interval 0.933–1.250, p = 0.300). The incidence of infection was particularly high in elderly patients (≥65 years) with a low PNI, but the incidence in elderly patients with a high PNI was similar to that in nonelderly patients with a high PNI. Patients with RA and malnutrition had a higher incidence of severe infection; thus, evaluating and managing nutritional status is necessary for the appropriate and safe treatment of elderly patients with RA.