Effectiveness of Paxlovid, an Oral Antiviral Drug, Against the Omicron BA.5 Variant in Korea: Severe Progression and Death Between July and November 2022

Background@#Paxlovid is an oral antiviral drug that received emergency use authorization in South Korea for the treatment of patients with mild-to-moderate coronavirus disease 2019 (COVID-19) on January 14, 2022. Since the onset of the severe acute respiratory syndrome coronavirus 2 pandemic, the virus has continued to evolve. The emergence of new variants has raised concerns about possible reductions in the effectiveness of vaccines and drugs. The effectiveness of Paxlovid in patients infected with the omicron variant and subvariants has not yet been determined. This study assessed the effectiveness of Paxlovid at reducing the risk of severe/critical illness or death and death in patients with mild-to-moderate COVID-19 caused by omicron subvariant BA.5. @*Methods@#In this nationwide retrospective cohort study, data on 8,902,726 patients were collected from four sources (the Drug Utilization Review database, COVID-19 Patient Information Management System, confirmed patient information, and basic epidemiological investigation data) between July 1 and November 30, 2022. Multivariable logistic regression analysis was conducted, with adjustment for age, sex, severe acute respiratory syndrome coronavirus 2 immunity (vaccination), and comorbidities. @*Results@#A total of 1,936,925 patients with COVID-19 were included in the analysis, including 420,996 patients treated with Paxlovid, and 1,515,959 patients not treated with Paxlovid. Paxlovid treatment in patients aged ≥ 60 years of age was associated with significantly reduced risk of severe/critical illness or death (46.0%), and death rate (32.5%), and its effectiveness was high, regardless of vaccination status. @*Conclusion@#Paxlovid is effective at reducing the risk of death due to COVID-19 in patients with omicron BA.5 infection, especially in older patients, regardless of vaccination status. This suggests that older patients with COVID-19-related symptoms should be administered Paxlovid, regardless of their vaccination status, to reduce severity and risk of death.

A Healthcare-Associated Outbreak of HCV Genotype 2a at a Clinic in Seoul

Objectives@#An epidemiological investigation was conducted into a hepatitis C virus (HCV) outbreak at an outpatients clinic in Seoul (2011-2012). The aim of the study was to analyze the scale of infection, identify the source of infection, and route of transmission to prevent hepatitis C transmission in the future. @*Methods@#A retrospective study of the outpatients and health care workers (n = 7,285) in the target outpatient clinic during 2011-2012 was conducted. The history of the study population infection with hepatitis C, electronic medical records, field visits, and health care worker interviews were examined for the period between March 1>st , 2006 and March 25th , 2016. The blood samples were collected and tested for anti-HCV antibodies, HCV RNA and HCV gene in 2016. @*Results@#The rate of anti-HCV positive results was 4.4% in the study population. The risk factors associated with an anti-HCV positive result were ≥ 10 clinic visits, and receiving an invasive procedure including a nerve block and a block of the peripheral branch of the spinal nerve (p < 0.05). There were 112 HCV RNA positive cases out of 320 anti-HCV positive test result cases, amongst which 100 cases had the dominant HCV genotype 2a which formed either 1 cluster (n = 56) or 2 clusters (n = 25). This result indicated exposure to a high-association infection source. @*Conclusion@#Anti-HCV antibodies and genotypic analysis showed an epidemiological association between the outbreak of HCV and invasive procedures performed (2011-2012) at an outpatients clinic in Seoul.

Factors Influencing Maternal Depression in Low-Income Families with Young Children

PURPOSE: This study aimed to investigate the factors influencing maternal depression in low-income families with young children. METHODS: The study consisted of 376 mothers in low-income families from participants enrolled in the population-based study of 2011 PSKC by Korea Institute of Child Care and Education. The factors including depression, self-esteem, parenting stress, marital conflict, father involvement in child rearing, social support, and family life event were assessed with questionnaires. Data analysis was conducted by description analysis, partial correlation, and hierarchical regression using SPSS 22.0 program. RESULTS: The results showed that 10.6% of mothers were in severe depressive group in this study. Also the result revealed that marital conflict was the strongest predictor of maternal depression. CONCLUSION: The results suggest that mothers with young children in low-income families especially had difficulty with depression due to family related factors. Implications included the need to support mothers and develop intervention programs focusing on family relationships in order to improve and sustain mental health.

Effect of Breastfeeding Duration on Cognitive Development in Infants: 3-Year Follow-up Study

We investigated the association between breastfeeding and cognitive development in infants during their first 3 years. The present study was a part of the Mothers' and Children's Environmental Health (MOCEH) study, which was a multi-center birth cohort project in Korea that began in 2006. A total of 697 infants were tested at age 12, 24, and 36 months using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II). The use and duration of breastfeeding and formula feeding were measured. The relationship between breastfeeding and the mental development index (MDI) score was analyzed by multiple linear regression analysis. The results indicated a positive correlation between breastfeeding duration and MDI score. After adjusting for covariates, infants who were breastfed for ≥ 9 months had significantly better cognitive development than those who had not been breastfed. These results suggest that the longer duration of breastfeeding improves cognitive development in infants.

Changes in seroprevalence of hepatitis B surface antigen and epidemiologic characteristics in the Republic of Korea, 1998-2013 / 한국역학회지

OBJECTIVES: This study investigated changes in hepatitis B seroprevalence from 1998 to 2013, and to identify differences in epidemiologic characteristics between hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative people. METHODS: HBsAg seropositive rates were compared by year, sex, and age using the blood test data from the periods I to VI (1998-2013) of the Korea National Health and Nutrition Examination Survey. Interviews and self-administered surveys were conducted to collect data on health behavior, quality of life, comorbidities, and health care utilization. RESULTS: HBsAg seropositive rates in the Republic of Korea decreased from 4.6% in 1998 to 2.9% in 2008, and then remained the same for the next five years. While seropositive rates by age were the highest at 35 to 39 years of age in 1998, it peaked at 50 to 54 years of age in 2013. HBsAg-positive people showed high values from two liver function tests, including glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase, and the prevalence rates of liver cirrhosis and liver cancer were also significantly high. Indices for health behavior and quality of life showed no significant differences between HBsAg-positive and HBsAg-negative people. CONCLUSIONS: While HBsAg seropositive rates tended to decline after 1998, there have been no significant changes over the most recent five years. We should focus on treatment of existing hepatitis B patients along with immunization programmes to prevent new hepatitis B infections. In addition, it may be necessary to encourage HBsAg-positive people to follow healthier life-styles in order to prevent further progression of hepatitis B to liver cirrhosis and liver cancer.

Regional Distribution of Hepatitis C Virus Infection in the Republic of Korea, 2007-2011

BACKGROUND/AIMS: In Korea, hepatitis C is included as an infectious disease in a sentinel surveillance system. Recently, a large variation in hepatitis C incidence between different regions in Korea has been noticed. The current study verified the nationwide distribution of hepatitis C infection for effective prevention and management. METHODS: We counted the number of hepatitis C patients who visited a hospital per county using the National Health Insurance database from 2007 to 2011. The age-adjusted prevalence ratio was used, and the age adjustment method was used as an indirect standardization method. Disease mapping and spatial analysis were conducted using a geographic information system. RESULTS: The annual prevalence of diagnosed hepatitis C was approximately 0.12% to 0.13% in Korea. The age-adjusted prevalence ratios in Busan, Jeonnam, and Gyeongnam were high (1.75, 1.4, and 1.3, respectively). The three regions in the southern coastal area of the Korean Peninsula were identified as a high-prevalence cluster (Moran's index, 0.3636). CONCLUSIONS: The present study showed that hepatitis C infection has very large regional variation, and there are several high-risk areas. Preventive measures focusing on these areas should be applied to block the transmission of hepatitis C and reduce the disease burden.

Meta-Analysis of the Relationship between CXCR4 Expression and Metastasis in Prostate Cancer

PURPOSE: Experimental studies have suggested that the stromal-derived factor-1 (SDF-1)/CXCR4 axis is associated with tumor aggressiveness and metastasis in several malignancies. We performed a meta-analysis to elucidate the relationship between CXCR4 expression and the clinicopathological features of prostate cancer. MATERIALS AND METHODS: Data were collected from studies comparing Gleason score, T stage, and the presence of metastasis with CXCR4 levels in human prostate cancer samples. The studies were pooled, and the odds ratio (OR) of CXCR4 expression for clinical and pathological variables was calculated. RESULTS: Five articles were eligible for the current meta-analysis. We found no relationship between CXCR4 expression and Gleason score ( or =7). The forest plot using the fixed-effects model indicated an OR of 1.585 (95% confidence interval [CI]: 0.793~3.171; p=0.193). Further, CXCR4 expression was not associated with the T stage ( or =T3), and the relevant meta-analysis showed OR=1.803 (95% CI: 0.756~4.297, p=0.183). However, increased CXCR4 expression was strongly associated with metastatic disease with a fixed-effects pooled OR of 7.459 (95% CI: 2.665~20.878, p<0.001). CONCLUSIONS: Our meta-analysis showed that the higher CXCR4 protein expression in prostate cancer specimens is significantly associated with the presence of metastatic disease. This supports previous experimental data supporting the role played by the SDF-1/CXCR4 axis in metastasis.

Impact of Surgical Varicocele Repair on Pregnancy Rate in Subfertile Men With Clinical Varicocele and Impaired Semen Quality: A Meta-Analysis of Randomized Clinical Trials

PURPOSE: To elucidate the impact of surgical varicocele repair on the pregnancy rate through new meta-analyses of randomized clinical trials that compared surgical varicocele repair and observation. MATERIALS AND METHODS: The PubMed and Embase online databases were searched for studies released before December 2012. References were manually reviewed, and two researchers independently extracted the data. To assess the quality of the studies, the Cochrane risk of bias as a quality assessment tool for randomized controlled trials was applied. RESULTS: Seven randomized clinical trials were included in our meta-analyses, all of which compared pregnancy outcomes between surgical varicocele repair and control. There were differences in enrollment criteria among the studies. Four studies included patients with clinical varicocele, but three studies enrolled patients with subclinical varicocele. Meanwhile, four trials enrolled patients with impaired semen quality only, but the other three trials did not. In a meta-analysis of all seven trials, a forest plot using the random-effects model showed an odds ratio (OR) of 1.90 (95% confidence interval [CI], 0.77 to 4.66; p=0.1621). However, for subanalysis of three studies that included patients with clinical varicocele and abnormal semen parameters, the fixed-effects pooled OR was significant (OR, 4.15; 95% CI, 2.31 to 7.45; p<0.001), favoring varicocelectomy. CONCLUSIONS: Varicocelectomy for male subfertility is proven effective in men with clinical varicocele and impaired semen quality. Therefore, surgical repair should be offered as the first-line treatment of clinical varicocele in subfertile men.