Association between Pollen Risk Indexes, Air Pollutants, and Allergic Diseases in Korea.

OBJECTIVES: This study, different from the past researches, has been conducted in all age groups to understand the association between air pollutants, pollen risk indexes, and outpatients with allergic rhinitis (AR), asthma, and atopic dermatitis (AD). METHODS: Data on air pollutants, pollen risk indexes, and outpatients with each disease were collected from 2003 through 2011 to verify the association between them. All data are time-series materials that have been observed by time (day) and region, and are in a nonlinear shape. In particular, the total number of outpatients per day is a count data that had a Poisson distribution as the response variable. SAS 9.3 was used to make a statistical model, generalized additive model, with lag effects for the analysis. RESULTS: For allergic diseases during spring (April-May) and fall (September-October), a significant association was shown between the variables of air pollutants, pollens, and the number of outpatients. Especially, the estimates of NO2 [AR (43.00967 ± 0.11284), asthma (52.01837 ± 0.06452), AD (52.01837 ± 0.06452), p < 0.001] in spring and SO2 [AR (43.00967 ± 0.11284), asthma (52.01837 ± 0.06452), AD (52.01837 ± 0.06452), p < 0.001] in fall were highly significant and showed a positive association with all diseases. CONCLUSION: Domestically and even internationally, various studies on the allergic diseases are being conducted. However, not many studies related to similar studies. In the need of creating grounds to back up these efforts, additional studies on allergic diseases, as well as researches utilizing pollen data, air pollution data, and claims data provided by the Health Insurance Corporation that has no problem in the representativeness of the data that have close relationships to the allergic disease will be needed.

A 9-year Trend in the Prevalence of Allergic Disease Based on National Health Insurance Data.

OBJECTIVES: To investigate trends in the prevalence of allergic disease over a 9-year period. METHODS: Using National Health Insurance Service (NHIS) data, the annual number of patients with allergic disease was obtained for each regional subdivisions (small cities, counties, and districts) from 2003 to 2011. Annual populations for each sub-region were obtained and used to calculate the standardized prevalence. To compare prevalence within the study period, data was standardized spatially and temporally. For standardization, demographic data was used to obtain the registered population and demographic structure for 2010, which was used to perform direct standardization of previous years. In addition, a geographic information system (GIS) was used to visualize prevalence for individual sub-regions, and allergic diseases were categorized into five groups according to prevalence. RESULTS: The nationwide outpatient prevalence of allergic rhinitis increased approximately 2.3-fold, from 1.27% in 2003 to 2.97% in 2013, while inpatient prevalence also increased approximately 2.4-fold,. The outpatient prevalence of asthma increased 1.2-fold, and inpatient prevalence increased 1.3-fold. The outpatient prevalence of atopic dermatitis decreased approximately 12%, and inpatient prevalence decreased 5%. CONCLUSIONS: There was a large difference between prevalence estimated from actual treatment data and prevalence based on patients' self-reported data, particularly for allergic rhinitis. Prevalence must continually be calculated and trends should be analyzed for the efficient management of allergic diseases. To this end, prevalence studies using NHIS claims data may be useful.

MERS epidemiological investigation to detect potential mode of transmission in the 178th MERS confirmed case in Pyeongtaek, Korea.

Most cases of Middle East Respiratory Syndrome (MERS) infection in Korea (outbreak: May 11-July 4, 2015) occurred in hospital settings, with uncertain transmission modes in some cases. We performed an in-depth investigation epidemiological survey on the 178th case to determine the precise mode of transmission. A 29- year-old man living in Pyeongtaek presented on June 16 with a febrile sensation, chills, and myalgia. Upon confirmatory diagnosis on June 23, he was treated in an isolation room and discharged on July 2 after cure. An epidemiological investigation of all possible infection routes indicated two likely modes of transmission: exposure to MERS in Pyeongtaek St. Mary's Hospital during a visit to his hospitalized father (May 18-29), and infection through frequent contact with his father between the latter's referral to Pyeongtaek Good Samaritan Bagae Hospital for treatment without confirmatory diagnosis until his death (May 29-June 6). Although lack of clear proof or evidence to the contrary does not allow a definitive conclusion, all other possibilities could be excluded by epidemiological inferences. While it is impossible to trace back the modes of transmission of all cases in a large-scale outbreak, case-by-case tracking and isolation of infected individuals and those in close contact with them is important in preventing the spread. Efforts should be made to establish a methodology for rapid tracking of all possible contacts and elimination-based identification of the precise modes of transmission.

Epidemiological investigation of the 119th confirmed Middle East Respiratory Syndrome coronavirus case with an indefinite mode of transmission during the Pyeongtaek outbreak in Korea.

Since the first case was diagnosed on May 20, 2015, there were 186 confirmed cases of Middle East Respiratory Syndrome (MERS) until the end of outbreak in South Korea. Although medical institutions were the most identifiable sources of MERS transmission in South Korea, similar to other countries, in-depth epidemiological investigation was required for some confirmed cases with indefinite contact history or hospital visit records. The subject of epidemiological investigation in the present study was a 35 year-old male patient diagnosed with MERS (#119) who lived in Asan-city and worked in Pyeongtaek-city. Various potential sources of transmission were carefully investigated. While he could have been exposed to MERS through a friend from Saudi Arabia or confirmed MERS cases in his workplace, neighboring areas, and medical institutions, as well as contacts in his home, the chances of transmission were low; however, the potential for transmission through his local community could not be excluded. Practically, it was difficult to determine the modes of transmission for all outbreak cases in communicable disease that occurred in this short period of time. The investigation to identify the mode of transmission in this case was ultimately unsuccessful. However, the various data collected and analyzed to reveal modes of transmission provided detailed information that could not be collected using only interview surveys.