OBJECTIVESTo manage evidence-based diseases, it is important to identify the characteristics of patients in each country.METHODSThe Korea HIV/AIDS Cohort Study seeks to identify the epidemiological characteristics of 1,442 Korean individuals with human immunodeficiency virus (HIV) infection (12% of Korean individuals with HIV infection in 2017) who visited 21 university hospitals nationwide. The descriptive statistics were presented using the Korea HIV/AIDS cohort data (2006-2016).RESULTSMen accounted for 93.3% of the total number of respondents, and approximately 55.8% of respondents reported having an acute infection symptom. According to the transmission route, infection caused by sexual contact accounted for 94.4%, of which 60.4% were caused by sexual contact with the same sex or both males and females. Participants repeatedly answered the survey to decrease depression and anxiety scores. Of the total participants, 89.1% received antiretroviral therapy (ART). In the initial ART, 95.3% of patients were treated based on the recommendation. The median CD4 T-cell count at the time of diagnosis was 229.5 and improved to 331 after the initial ART. Of the patients, 16.6% and 9.4% had tuberculosis and syphilis, respectively, and 26.7% had pneumocystis pneumonia. In the medical history, sexually transmitted infectious diseases showed the highest prevalence, followed by endocrine diseases. The main reasons for termination were loss to follow-up (29.9%) and withdrawal of consent (18.7%).CONCLUSIONSEarly diagnosis and ART should be performed at an appropriate time to prevent the development of new infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly, causing in COVID-19 being declared a global pandemic by the World Health Organization. The key variants include alpha, beta, gamma, and delta; these exhibit high viral transmission, pathogenicity, and immune evasion mechanisms. The delta variant, first confirmed in India, was detected in the majority of COVID-19 patients at the recent wave in the Republic of Korea. Here, the features of the delta variant were compared to the earlier waves, with focus on increased transmissibility. The viral load, from the initial days of infection to 14 days later, was compared based on epidemiological data collected at the time of confirmed diagnosis. The increased viral load observed in the delta variant-led infections influences the scale of the wave, owing to the increased rate of transmission. Infections caused by the delta variant increases the risk of hospitalization within 14 days after symptom onset, and the high viral load correlates with COVID-19 associated morbidity and mortality. Therefore, the future studies should compare the trend of disease severity caused by the high viral load of delta variant with previous waves and analyze the vaccine effects in light of the delta variant of fourth wave.

Although the number of newly diagnosed cases of HiV is decreasing worldwide, those in Korea have been steadily on the rise, especially among adolescents (ages 10-19 years) and young adults (ages 20-29 years). To identify the characteristics in the new diagnosis among these age groups, we analyzed HIV testing sizes and HIV prevalence under the national HIV surveillance system in Korea in the last six years. We collected data of HIV tests conducted at Blood Banks (BB), Public Health Centers (PHCs), and Military Manpower Administration (MMA) nationwide every year from 2010 to 2015, except for anonymous tests. HIV prevalence, calculated as the number of new HIV-diagnosed cases per 10,000 test-takers per year, was analyzed according to sex, age, institution, and reason for HIV testing. Data were analyzed using logistic regression. In the three testing institutes, there were new cases of HIV with 50% and 75% of cases diagnosed in young adults and adolescents, respectively. The total size of HIV tests at the three sites was approximately 3.5 million tests per year; 80% of these were conducted in BBs, 10% in PHCs, and 10% in MMA. HIV prevalence, according to age, increased across all age groups for the six years, especially prevalent in young adults doubled during that period (1.01 per 10,000 testtakers in 2010, 2.45 in 2015). HIV prevalence among the "suspected" young male adults who visited PHCs for tests, was highest during the six years, increasing 6.5 times in the last two years (315.79 per 10,000 test-takers in 2014, 335.55 in 2015) compared to before 2014. We identified the characteristics of growing HiV infection in Korea as the increase of HiV prevalence among the suspected of young male adults at PHCs. Further, we propose that HIV prevalence in MMA can be used as an essential index for national HIV surveillance of adolescent boys in Korea. HIV infection, known to the public since the early 1980s, has been rapidly spreading worldwide through sexual contact, vertical transmission, blood transfusions, and needle sharing for injection drug use (IDU). The HIV epidemic has different transmission routes and the speed of spreading across countries 1. Globally, for more than 35 years, approximately 78 million individuals have been infected with HIV, with 35 million HIV-related deaths, and 37 million people are currently living with HIV 2. The first HIV-infection in Korea was identified in 1985, and over the next 30 years or so, approximately 15,000 individuals were identified as HIV-infected. It was reported that more than 99% of individuals diagnosed with HIV in Korea were infected via sexual contact, while transmission through blood transfusion, vertical transmission, and needle sharing for IDU was infrequent 3. Soon after the discovery of HIV in Korea, the country initiated a prevention program focused on HIV transmission reduction by regularly performing HIV screening tests on high-risk groups for sexually transmitted infections (STI) and extending it to other groups 4-6. Hospitals or clinics and public health centr...

Background: In South Korea, the epidemiological characteristics of children and adolescents infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have not been reported to date. The purpose of this study was to identify major epidemiological characteristics and transmission patterns of coronavirus disease 2019 (COVID-19) in children and adolescents. Methods: This study was conducted through a system integrated in an epidemiological investigation by the Korea Disease Control and Prevention Agency from January 20, 2020, to June 5, 2021. We analyzed the epidemiological characteristics of 14,967 children and adolescents with COVID-19 according to the age groups and transmission age patterns of 3721 infector-infectee pairs in South Korea. Results: Among the total confirmed COVID-19 cases, 14,967 patients were aged 0-18 years. The most affected age group among children and adolescents were those aged 16-18 years (3589, 24.0%). For all age groups, the infection route through friends and family members (31.9%) was the highest. For the contact age pattern analysis, infection from infectors aged 30-49 years to infectees aged 0-12 years showed a statistically significant relation (p <0.001) compared to that in other age groups. On the other hand, among the infectees aged 13-15 years and 16-18 years were significantly related with adolescents aged 10-19 years (p <0.05). Conclusion: These results suggest that adolescents aged 13-18 years were more infected with COVID-19 than those aged 0-12 years. Furthermore, they are particularly more likely to be infected by friends and family members. Besides, in patients aged 13-18 years, transmission of SARS-CoV-2 was more common from adolescents to adolescents than from adults to adolescents. This research will provide scientific evidence for school policies and vaccine strategies for COVID-19 prevention in children and adolescents.

BackgroundOwing to the continuous increase in the number of new human immunodeficiency virus (HIV) infection in Korea, public health centers (PHCs) have performed anonymous tests since 1989. No study has examined the patterns of anonymous HIV testing performed at PHCs and the characteristics of HIV infection detected in those tests. We aimed to assess the influence of anonymous HIV testing on Korea’s national HIV surveillance.MethodsHIV screening test data from 253 PHCs over a 16-year period were classified into 13 groups based on reason for testing. For anonymous HIV test takers (Anonymous), the HIV positivity per 10,000 tests was calculated, as repetitions could not be distinguished. Those with suspected HIV infection voluntarily underwent HIV testing and revealed their identity (Suspected). HIV prevalence was calculated as the number of HIV-positive persons per 10,000 test takers. Analyses were performed using chi-square and Cochran-Armitage trend test with SAS 9.4.ResultsApproximately 400,000 HIV screening tests were performed at PHCs annually, which remained unchanged in the past 10 years. The proportion of anonymous testing increased from < 3.0% before 2014 to 4.8% in 2014 and 6.1% in 2015. While the number of HIV cases increased, the number of anonymous HIV-positive test results per 10,000 tests decreased from 68.8 in 2010 to 41.8 in 2015. The HIV prevalence among the suspected was approximately 20.0 per 10,000 test takers before 2014, which steeply increased to 71.6 in 2015. Those with suspected HIV were predominantly men, aged 20 years, foreigners, and metropolitan city dwellers in the last 6 years. The high prevalence of persons with suspected HIV resulted in a doubling of HIV prevalence at PHCs between 2014 and 2015.ConclusionsAnonymous and Suspected, which were driven by similar motives, impacted each other. Increase in HIV prevalence among the suspected led to a higher HIV prevalence among all test takers in PHCs and higher proportions of HIV infection nationwide, which could be attributed to the increase in the number of anonymous tests performed in PHCs. HIV positivity among the anonymous and HIV prevalence among the suspected are key indexes of the national HIV surveillance in Korea.