BackgroundLimited data on the incidence and clinical characteristics of adult pertussis infections are available in Korea.MethodsThirty-one hospitals and the Korean Centers for Disease Control and Prevention collaborated to investigate the incidence and clinical characteristics of pertussis infections among adults with a bothersome cough in non-outbreak, ordinary outpatient settings. Nasopharyngeal aspirates or nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and culture tests.ResultsThe study enrolled 934 patients between September 2009 and April 2011. Five patients were diagnosed as confirmed cases, satisfying both clinical and laboratory criteria (five positive PCR and one concurrent positive culture). Among 607 patients with cough duration of at least 2 weeks, 504 satisfied the clinical criteria of the US Centers for Disease Control and Prevention (i.e., probable case). The clinical pertussis cases (i.e., both probable and confirmed cases) had a wide age distribution (45.7±15.5 years) and cough duration (median, 30 days; interquartile range, 18.0~50.0 days). In addition, sputum, rhinorrhea, and myalgia were less common and dyspnea was more common in the clinical cases, compared to the others (p=0.037, p=0.006, p=0.005, and p=0.030, respectively).ConclusionThe positive rate of pertussis infection may be low in non-outbreak, ordinary clinical settings if a PCR-based method is used. However, further prospective, well-designed, multicenter studies are needed.

Reliable water quality monitoring data, identifying potential pollution sources, and quantifying the corresponding potential pollution source apportionment are essential for future water resource management and pollution control. Here, we collected water quality data from seven monitoring sites to identify spatiotemporal changes in surface water in the Imjin River Watershed (IRW), South Korea, distinguish potential pollution sources, and quantify the source apportionment from 2018–2020. An analysis was performed based on multivariate statistical techniques (MST) and the absolute principal component score-multiple linear regression (APCS-MLR) model. Statistically significant groups were created based on spatiotemporally similar physicochemical water quality characteristics and anthropogenic activities: low-pollution (LP) and high-pollution (HP) regions, and dry season (DS) and wet season (WS). There were statistically significant mean differences in water quality parameters between spatial clusters, rather than between temporal clusters. We identified four and three potential factors that could explain 80.75% and 71.99% in the LP and HP regions, respectively. Identification and quantitative evaluation of potential pollution sources using MST and the APCS-MLR model for the IRW may be useful for policymakers to improve the water quality of target watersheds and establish future management policies.

No abstract

Objectives: This study aimed to evaluate the antibacterial activity of phytoncide on oral biofilm. Methods: Antibacterial activity of phytoncide was examined on the bacteria Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, Porphyromonas gingivalis, and oral biofilm. After mixing the phytoncide, S. mutans, A. actinomycetemcomitans, E. faecalis, and P. gingivalis with a culture alone turbid and mixed, and they were then incubated at 37°C under anaerobic conditions and cultured. Following incubation, a microplate reader was used to measure the absorbance and observe the amount of bacteria. In addition, non-polarized saliva containing bacteria was grown for 72 h under anaerobic conditions for the determination of biofilm biomass and bacterial numbers. Various concentrations of phytoncide were added to the saliva biofilm. Statistical significance tests were conducted using the Mann-Whitney test and SPSS 24.0. Results: S. mutans, A. actinomycetemcomitans, E. faecalis, P. gingivalis, and antibacterial effects were shown as phytoncide concentrations increased in oral biofilm. Observing the growth of bacteria using phase difference microscopes showed that the number of bacteria decreases as the phytoncide concentration increased. Also, the formation of biofilm in the saliva decreased compared to the control group. Conclusions: Based on the experimental results of phytoncide on oral biofilms causing oral cavity formation in the saliva decreased compared to that in the control group. Phytoncide showed antibiosis against oral biofilms when it remained inside the mouth for above certain concentrations. Accordingly, using phytoncide as a clinical method for preventing oral disease is deemed to be effective.