Background: We aimed to analyze the epidemiology, clinical characteristics, and outcomes of malaria caused by Plasmodium vivax among military members of the Republic of Korea (ROK). Methods: We reviewed the medical records of patients diagnosed with P. vivax malaria in 16 military hospitals in the ROK between 2012–2021, excluding other types of malaria, as well as imported cases and those treated in civilian hospitals. Results: In total, 653 patients were treated for P. vivax malaria. Their mean age was 22.0 ± 3.8 years, and their mean body weight was 73.4 ± 10.8 kg. Hospitalization occurred in 92.0% (n = 601) of the cases, with 4.4% (n = 29) recurring. The mean administered dose was 20.7 ± 3.4 mg/kg for the chloroquine (CQ) base and 3.5 ± 1.2 mg/kg for the primaquine (PQ) base.Between 2012–2016 and 2017–2021, the mean patient body weight increased (72.9 ± 11.1 vs.74.3 ± 10.3 kg, P = 0.044). Correspondingly, the total administered doses of CQ (1,476.0 ± 144.0 vs. 1,515.1 ± 155.1 mg, P = 0.010) and PQ (242.6 ± 79.7 vs. 265.7 ± 92.3 mg, P < 0.001) were increased. However, there was no difference in the weight-based dosage of CQ (20.7 ± 3.6 vs. 20.7 ± 3.2 mg/kg, P = 0.580) or PQ (3.33 ± 1.1 vs. 3.64 ± 1.3 mg/kg, P = 0.256), nor in the percentage of patients who received sub-recommended doses. Among the 27 patients who experienced recurrence and had available initial treatment data, the proportion of those prescribed PQ (24 [88.9%] vs. 623 [99.5%], P = 0.001) and the mean PQ dose (2.75 ± 0.7 vs.3.50 ± 1.2 mg/kg, P = 0.003) were significantly lower in the recurrence group. Conclusion Over time, as the body weight of patients with P. vivax malaria in the ROK military has increased, the administered dosages of CQ and PQ have correspondingly risen.However, these dosages often remain suboptimal when compared to the body weightbased recommendations by the World Health Organization. Of particular concern is the continued administration of antimalarial drugs at suboptimal doses, which may contribute to an elevated risk of recurrence. Further education may therefore be beneficial to ensuring appropriate dosing for more effective malaria treatment.

Background: Renal replacement therapy (RRT) is an important treatment option for sepsisassociated acute kidney injury (AKI); however, the optimal timing for its initiation remains controversial. Herein, we investigated the clinical outcomes of early continuous kidney replacement therapy (CKRT), defined as CKRT initiation within 6 hours of sepsis-associated AKI onset, which was earlier than the initiation time defined in previous studies. Methods: We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. This study included patients aged ≥ 18 years who met the sepsis diagnostic criteria and received CKRT because of stage 2 or 3 AKI. Early and late CKRTs were defined as CKRT initiation within 6 hours and after 6 hours of the development of sepsisassociated AKI, respectively. Results: Of the 33,236 patients diagnosed with sepsis, 553 underwent CKRT for sepsisassociated AKI. After excluding cases of early mortality and patients with a dialysis history, 45 and 334 patients were included in the early and late CKRT groups, respectively. After propensity score matching, the 28-day mortality rate was significantly lower in the early CKRT group than in the late CKRT group (26.7% vs. 43.9%, P = 0.035). The early CKRT group also had a significantly greater number of days free of mechanical ventilation (median, 19; interquartile range [IQR], 3–25) and vasopressor administration (median, 21; IQR, 5–26) than the late CKRT group did (median, 10.5; IQR, 0–23; P = 0.037 and median, 13.5;IQR, 0–25; P = 0.028, respectively). The Kaplan–Meier curve also showed that early CKRT initiation was associated with an improved 28-day mortality rate (log-rank test, P = 0.040).In contrast, there was no significant difference in the 28-day mortality between patients who started CKRT within 12 hours and those who did not (log-rank test, P = 0.237). Conclusion Early CKRT initiation improved the survival of patients with sepsis-associated AKI. Initiation of CKRT should be considered as early as possible after sepsis-associated AKI onset, preferably within 6 hours.

Background: We aimed to analyze the epidemiology, clinical characteristics, and outcomes of malaria caused by Plasmodium vivax among military members of the Republic of Korea (ROK). Methods: We reviewed the medical records of patients diagnosed with P. vivax malaria in 16 military hospitals in the ROK between 2012–2021, excluding other types of malaria, as well as imported cases and those treated in civilian hospitals. Results: In total, 653 patients were treated for P. vivax malaria. Their mean age was 22.0 ± 3.8 years, and their mean body weight was 73.4 ± 10.8 kg. Hospitalization occurred in 92.0% (n = 601) of the cases, with 4.4% (n = 29) recurring. The mean administered dose was 20.7 ± 3.4 mg/kg for the chloroquine (CQ) base and 3.5 ± 1.2 mg/kg for the primaquine (PQ) base.Between 2012–2016 and 2017–2021, the mean patient body weight increased (72.9 ± 11.1 vs.74.3 ± 10.3 kg, P = 0.044). Correspondingly, the total administered doses of CQ (1,476.0 ± 144.0 vs. 1,515.1 ± 155.1 mg, P = 0.010) and PQ (242.6 ± 79.7 vs. 265.7 ± 92.3 mg, P < 0.001) were increased. However, there was no difference in the weight-based dosage of CQ (20.7 ± 3.6 vs. 20.7 ± 3.2 mg/kg, P = 0.580) or PQ (3.33 ± 1.1 vs. 3.64 ± 1.3 mg/kg, P = 0.256), nor in the percentage of patients who received sub-recommended doses. Among the 27 patients who experienced recurrence and had available initial treatment data, the proportion of those prescribed PQ (24 [88.9%] vs. 623 [99.5%], P = 0.001) and the mean PQ dose (2.75 ± 0.7 vs.3.50 ± 1.2 mg/kg, P = 0.003) were significantly lower in the recurrence group. Conclusion Over time, as the body weight of patients with P. vivax malaria in the ROK military has increased, the administered dosages of CQ and PQ have correspondingly risen.However, these dosages often remain suboptimal when compared to the body weightbased recommendations by the World Health Organization. Of particular concern is the continued administration of antimalarial drugs at suboptimal doses, which may contribute to an elevated risk of recurrence. Further education may therefore be beneficial to ensuring appropriate dosing for more effective malaria treatment.

Background: Renal replacement therapy (RRT) is an important treatment option for sepsisassociated acute kidney injury (AKI); however, the optimal timing for its initiation remains controversial. Herein, we investigated the clinical outcomes of early continuous kidney replacement therapy (CKRT), defined as CKRT initiation within 6 hours of sepsis-associated AKI onset, which was earlier than the initiation time defined in previous studies. Methods: We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. This study included patients aged ≥ 18 years who met the sepsis diagnostic criteria and received CKRT because of stage 2 or 3 AKI. Early and late CKRTs were defined as CKRT initiation within 6 hours and after 6 hours of the development of sepsisassociated AKI, respectively. Results: Of the 33,236 patients diagnosed with sepsis, 553 underwent CKRT for sepsisassociated AKI. After excluding cases of early mortality and patients with a dialysis history, 45 and 334 patients were included in the early and late CKRT groups, respectively. After propensity score matching, the 28-day mortality rate was significantly lower in the early CKRT group than in the late CKRT group (26.7% vs. 43.9%, P = 0.035). The early CKRT group also had a significantly greater number of days free of mechanical ventilation (median, 19; interquartile range [IQR], 3–25) and vasopressor administration (median, 21; IQR, 5–26) than the late CKRT group did (median, 10.5; IQR, 0–23; P = 0.037 and median, 13.5;IQR, 0–25; P = 0.028, respectively). The Kaplan–Meier curve also showed that early CKRT initiation was associated with an improved 28-day mortality rate (log-rank test, P = 0.040).In contrast, there was no significant difference in the 28-day mortality between patients who started CKRT within 12 hours and those who did not (log-rank test, P = 0.237). Conclusion Early CKRT initiation improved the survival of patients with sepsis-associated AKI. Initiation of CKRT should be considered as early as possible after sepsis-associated AKI onset, preferably within 6 hours.

Background: Malaria elimination strategies in the Republic of Korea (ROK) have decreased malaria incidence but face challenges due to delayed case detection and response. To improve this, machine learning models for predicting malaria, focusing on high-risk areas, have been developed. Methods: The study targeted the northern region of ROK, near the demilitarized zone, using a 1-km grid to identify areas for prediction. Grid cells without residential buildings were excluded, leaving 8,425 cells. The prediction was based on whether at least one malaria case was reported in each grid cell per month, using spatial data of patient locations. Four algorithms were used: gradient boosted (GBM), generalized linear (GLM), extreme gradient boosted (XGB), and ensemble models, incorporating environmental, sociodemographic, and meteorological data as predictors. The models were trained with data from May to October (2019–2021) and tested with data from May to October 2022. Model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). Results: The AUROC of the prediction models performed excellently (GBM = 0.9243, GLM = 0.9060, XGB = 0.9180, and ensemble model = 0.9301). Previous malaria risk, population size, and meteorological factors influenced the model most in GBM and XGB. Conclusion Machine-learning models with properly preprocessed malaria case data can provide reliable predictions. Additional predictors, such as mosquito density, should be included in future studies to improve the performance of models.

Background: Patients with hematologic malignancies exhibit persistent severe acute respiratory syndrome coronavirus 2 positivity over long periods after coronavirus disease 2019 (COVID-19) diagnosis. However, the frequency of, risk factors for, and prognosis of prolonged COVID-19 in immunocompromised patients remain unclear. Therefore, we investigated the long-term outcomes of COVID-19 in lymphoma patients and identified the associated factors and impact of prolonged COVID-19 on mortality. Methods: A multicenter retrospective cohort study of 583 lymphoma patients was conducted in 3 tertiary hospitals in South Korea. Patients receiving lymphoma treatment who were quarantined after obtaining a diagnosis of COVID-19 by polymerase chain reaction (PCR) or antigen test from August 2021 to September 2022 were examined. Results: Overall, 115 patients (19.7%) were diagnosed with COVID-19. Among 77 patients with clinical data, 24 had prolonged COVID-19. Patients in the prolonged COVID-19 group showed higher rates of receiving rituximab maintenance therapy following bendamustine and rituximab (BR) treatment for follicular lymphoma. This group did not show significant differences in clinical presentation within 30 days of COVID-19 diagnosis; however, it showed higher rates of re-admission due to COVID-19 pneumonia compared with the non-prolonged COVID-19 group. BR treatment followed by rituximab maintenance therapy is one of the risk factors for persistent PCR positivity, delayed or persistent pneumonia, and COVID-19 related admission after quarantine period. Prolonged COVID-19 was an independent risk factor for 1-year mortality. Conclusion Prolonged COVID-19 was more frequent in lymphoma patients who received BR treatment followed by rituximab maintenance therapy and associated with unfavorable longterm outcomes and higher 1-year mortality.

With advancements in antiretroviral therapy (ART), the average lifespan of people with human immunodeficiency virus (HIV) is increasing, as is the number of older adults with HIV. Accordingly, the number of patients with HIV who undergo surgery or require critical care for various reasons is increasing. Since the prognosis of people with HIV depends on the continuous and effective maintenance of ART, there is a need to consider effectively maintaining ART in people with HIV in these conditions. This case involved a 55-year-old patient with well-controlled HIV who received ART and presented to the emergency room with acute abdominal pain. He was diagnosed with extensive bowel infarction and panperitonitis and received critical care in the intensive care unit, including mechanical ventilation and continuous renal replacement therapy. The patient was administered enteral nutrition via a nasogastric tube. The patient subsequently underwent extensive small bowel resection and developed short bowel syndrome. The patient maintained ART during that period. A literature review related to the use of ART under these conditions is included in this study. This case was discussed at the [Exploring Difficult Cases in HIV Clinics] of the Korean Society for AIDS Conference held in 2023.

Background: While Korea maintains a low prevalence of human immunodeficiency virus (HIV), the number of newly diagnosed cases has been steadily rising, reaching approximately 1,000 annually in recent years. The 2022 annual report from the Korea Disease Control and Prevention Agency revealed that women living with HIV (WLWH) constitute 6.4% of the total confirmed people living with the HIV population, totaling 1,219 individuals. Despite this, only a few studies have focused on WLWH in Korea. This study aims to analyze the epidemiological and clinical characteristics of WLWH in Korea. Materials and Methods: We retrospectively collected data by reviewing the medical records of all WLWH who visited 10 urban referral hospitals across Korea between January 2005 and May 2023. Results: A total of 443 WLWH were enrolled in this study. The predominant risk exposure was heterosexual contact, with 235 (53%) participants either married or cohabiting with a male partner at their initial clinic visit. Among the participants, 334 (77.7%) were Korean, 27 (6.1%) were Southeast Asian, and 19 (4.3%) were African. Antiretroviral therapy was initiated by 404 WLWH (91.2%). We observed 118 pregnancies in WLWH following their HIV diagnosis, resulting in 78 live births (66.1%), 18 induced abortions (15.2%), 10 pre-viable fetal losses (8.5%), and four stillbirths (3.4%). Over a cumulative follow-up duration of 3,202.1 years, the incidence rates of breast and cervical cancers were both 2.18 per 1,000 person-years. Additionally, the incidence rates of pelvic inflammatory disease, cervical intraepithelial neoplasm (above grade II), and osteoporosis were 4.67, 11.21, and 13.39 per 1,000 patient-years, respectively. Conclusion This is the first multicenter study to investigate the clinical and epidemiological characteristics of WLWH in Korea. The incidence and prevalence of diseases in women, including breast cancer, cervical cancer, and chronic comorbidities, are high in WLWH in Korea; therefore, further research and efforts are needed to manage these diseases.

With advancements in antiretroviral therapy (ART), the average lifespan of people with human immunodeficiency virus (HIV) is increasing, as is the number of older adults with HIV. Accordingly, the number of patients with HIV who undergo surgery or require critical care for various reasons is increasing. Since the prognosis of people with HIV depends on the continuous and effective maintenance of ART, there is a need to consider effectively maintaining ART in people with HIV in these conditions. This case involved a 55-year-old patient with well-controlled HIV who received ART and presented to the emergency room with acute abdominal pain. He was diagnosed with extensive bowel infarction and panperitonitis and received critical care in the intensive care unit, including mechanical ventilation and continuous renal replacement therapy. The patient was administered enteral nutrition via a nasogastric tube. The patient subsequently underwent extensive small bowel resection and developed short bowel syndrome. The patient maintained ART during that period. A literature review related to the use of ART under these conditions is included in this study. This case was discussed at the [Exploring Difficult Cases in HIV Clinics] of the Korean Society for AIDS Conference held in 2023.

Background: While Korea maintains a low prevalence of human immunodeficiency virus (HIV), the number of newly diagnosed cases has been steadily rising, reaching approximately 1,000 annually in recent years. The 2022 annual report from the Korea Disease Control and Prevention Agency revealed that women living with HIV (WLWH) constitute 6.4% of the total confirmed people living with the HIV population, totaling 1,219 individuals. Despite this, only a few studies have focused on WLWH in Korea. This study aims to analyze the epidemiological and clinical characteristics of WLWH in Korea. Materials and Methods: We retrospectively collected data by reviewing the medical records of all WLWH who visited 10 urban referral hospitals across Korea between January 2005 and May 2023. Results: A total of 443 WLWH were enrolled in this study. The predominant risk exposure was heterosexual contact, with 235 (53%) participants either married or cohabiting with a male partner at their initial clinic visit. Among the participants, 334 (77.7%) were Korean, 27 (6.1%) were Southeast Asian, and 19 (4.3%) were African. Antiretroviral therapy was initiated by 404 WLWH (91.2%). We observed 118 pregnancies in WLWH following their HIV diagnosis, resulting in 78 live births (66.1%), 18 induced abortions (15.2%), 10 pre-viable fetal losses (8.5%), and four stillbirths (3.4%). Over a cumulative follow-up duration of 3,202.1 years, the incidence rates of breast and cervical cancers were both 2.18 per 1,000 person-years. Additionally, the incidence rates of pelvic inflammatory disease, cervical intraepithelial neoplasm (above grade II), and osteoporosis were 4.67, 11.21, and 13.39 per 1,000 patient-years, respectively. Conclusion This is the first multicenter study to investigate the clinical and epidemiological characteristics of WLWH in Korea. The incidence and prevalence of diseases in women, including breast cancer, cervical cancer, and chronic comorbidities, are high in WLWH in Korea; therefore, further research and efforts are needed to manage these diseases.