Reduction In Annual Incidence Research Articles

Epidemiology of Scabies in Korea (2010~2021): An Updated Report

Background: Scabies is a neglected disease that significantly affects the daily lives of patients and their cohabitants. Objective: To investigate the current epidemiological data regarding scabies in Korea. Methods: This was a nationwide population-based observational study using data from the National Health Insurance claims database (reference period: 2010~2021). The primary outcome measure was the annual incidence of scabies. Subgroup analyses were performed disaggregated by sex, age, and region of residence. Results: A total of 517,296 scabies cases were identified, with a male-to-female ratio of 0.83. The annual age-standardized incidence rates steadily decreased from 2010 (97.6 per 100,000 person-years [PY]) to 2021 (43.4 per 100,000 PY), with an average annual percent change of -5.0%. A steep decrease was observed in 2015 (-12.9%), 2020 (-12.7%), and 2021 (-22.8%). An aging trend in patients with scabies was observed, with patients aged ≥50 years accounting for 36.5% and 63.8% of patients in 2010 and 2021, respectively. The ≥80 years age group showed the highest age-specific incidence rate. Although all age groups showed a reduction in annual incidence, the extent of the reduction was relatively greater in patients aged <50 years. The number of patients with scabies was the highest in Gyeonggi, Seoul, and Busan, while the regional incidence rates were highest in Gwangju, Jeonbuk, Jeonnam, Daejeon, and Jeju. Conclusion: During the last 12 years, there has been a gradual decrease in the overall prevalence of scabies. However, the incidence remains relatively higher among the elderly population.

Evaluation of TB elimination strategies in Canadian Inuit populations: Nunavut as a case study.

Tuberculosis (TB) continues to disproportionately affect Inuit populations in Canada with some communities having over 300 times higher rate of active TB than Canadian-born, non-Indigenous people. Inuit Tuberculosis Elimination Framework has set the goal of reducing active TB incidence by at least 50% by 2025, aiming to eliminate it by 2030. Whether these goals are achievable with available resources and treatment regimens currently in practice has not been evaluated. We developed an agent-based model of TB transmission to evaluate timelines and milestones attainable in Nunavut, Canada by including case findings, contact-tracing and testing, treatment of latent TB infection (LTBI), and the government investment on housing infrastructure to reduce the average household size. The model was calibrated to ten years of TB incidence data, and simulated for 20 years to project program outcomes. We found that, under a range of plausible scenarios with tracing and testing of 25%–100% of frequent contacts of detected active cases, the goal of 50% reduction in annual incidence by 2025 is not achievable. If active TB cases are identified rapidly within one week of becoming symptomatic, then the annual incidence would reduce below 100 per 100,000 population, with 50% reduction being met between 2025 and 2030. Eliminating TB from Inuit populations would require high rates of contact-tracing and would extend beyond 2030. The findings indicate that time-to-identification of active TB is a critical factor determining program effectiveness, suggesting that investment in resources for rapid case detection is fundamental to controlling TB.

Gender differences in the incidence of systemic lupus erythematosus in Norway: a population-based cohort study

<h2>Abstract</h2><h3>Background</h3> Norway is one of the few countries worldwide where societal factors facilitate complete population-based cohorts on rare diseases. We aimed to estimate gender differences in the annual incidence of systemic lupus erythematosus in South-East Norway (population 2·9 million). <h3>Methods</h3> This population-based cohort study was done using databases from 12 public hospitals in South-East Norway. We identified participants on the basis of a diagnosis with systemic lupus erythematosus (ICD-10 code M32), chart reviews, and recorded demographic and clinical parameters. Participants with clinical systemic lupus erythematosus who met the 1997 American College of Rheumatology (ACR) classification criteria were included. We looked for secular trends by dividing the cohort into two decades (1999–2007 and 2008–2017) and stratified by age and gender. We defined gender in accordance with the Norwegian social security number, which defines individuals as female or male. Time trend analysis was estimated using the χ² test. <h3>Findings</h3> Between Jan 1, 1999, and Dec 31, 2017, records for 3490 individuals were extracted. 1558 (44·6%) of 3490 had a systemic lupus erythematosus diagnosis in their medical record. The 1997 ACR criteria were met by 1300 (83·4%) of 1558 people, and 673 (51·8%) of those 1300 were diagnosed between 1999–2017. The median age of participants was 38 years (IQR 25–49). The peak incidence rate was 4·3 per 100 000 women aged 20–29 years and 0·6 per 100 000 men aged 40–69 years. The average incidence rate of systemic lupus erythematosus in children and adolescents (defined as disease onset at age 15 years or younger) was stable at 0·3 for during 1999–2007 and 0·4 during 2008–2017. The average incidence rate for adult-onset systemic lupus erythematosus (defined as disease onset at age 16 years or older) in 1999–2017 was 1·6 per 100 000 people (2·7 per 100 000 women and 0·5 per 100 000 men). The incidence rate for 1999–2007 was 3·0 per 100 000 women and 0·6 per 100 000 men. The incidence rate in 2008–2017 was 2·4 per 100 000 women and 0·4 per 100 000 men. Women aged 50–59 years had a significant reduction in annual incidence from 3·0 per 100 000 during 1999–2007 to 1·3 per 100 000 during 2008–2017 (p=0·0007). The overall incidence rate for adults, children, and adolescents showed a significant decline during 1999–2017 from 1·85 to 1·13 per 100 000 (p=0·0036). The decline for women was from 3·08 to 2·13 per 100 000 (p=0·033) and for men was from 0·58 to 0·14 per 100 000 (p=0·033). Women aged 50–59 years also showed a significant decline in annual incidence during 1999–2017 from 3·39 to 1·07 per 100 000 women aged 50–59 years (p=0·0031). <h3>Interpretation</h3> We found decreasing incidence of systemic lupus erythematosus during 1999–2017, which was most pronounced in women aged 50–59 years. This finding might be due to the reduction of hormone replacement therapy in this timeframe. <h3>Funding</h3> The Norwegian Women's Public Health Association, The DAM Foundation, Vivi Irene Hansens Foundation, and the Norwegian Rheumatism Association.

Dynamics of Japanese encephalitis virus transmission among pigs in Northwest Bangladesh and the potential impact of pig vaccination.

BackgroundJapanese encephalitis (JE) virus infection can cause severe disease in humans, resulting in death or permanent neurologic deficits among survivors. Studies indicate that the incidence of JE is high in northwestern Bangladesh. Pigs are amplifying hosts for JE virus (JEV) and a potentially important source of virus in the environment. The objectives of this study were to describe the transmission dynamics of JEV among pigs in northwestern Bangladesh and estimate the potential impact of vaccination to reduce incidence among pigs.Methodology/Principal FindingsWe conducted a comprehensive census of pigs in three JE endemic districts and tested a sample of them for evidence of previous JEV infection. We built a compartmental model to describe JEV transmission dynamics in this region and to estimate the potential impact of pig vaccination. We identified 11,364 pigs in the study area. Previous JEV infection was identified in 30% of pigs with no spatial differences in the proportion of pigs that were seropositive across the study area. We estimated that JEV infects 20% of susceptible pigs each year and the basic reproductive number among pigs was 1.2. The model suggest that vaccinating 50% of pigs each year resulted in an estimated 82% reduction in annual incidence in pigs.Conclusions/SignificanceThe widespread distribution of historic JEV infection in pigs suggests they may play an important role in virus transmission in this area. Future studies are required to understand the contribution of pig infections to JE risk in humans and the potential impact of pig vaccination on human disease.

Exemestane for primary prevention of breast cancer in postmenopausal women: NCIC CTG MAP.3—A randomized, placebo-controlled clinical trial.

LBA504 Background: Limited efficacy and serious toxicities have limited uptake of tamoxifen or raloxifene as preventatives of breast cancer. Aromatase inhibitors (AIs) prevent contralateral breast cancers more than tamoxifen in adjuvant trials and have fewer serious side effects. This is the first report of an AI used in primary prevention. Methods: NCIC CTG MAP.3 is a randomized trial designed to detect a 65% reduction in annual incidence of invasive breast cancer (IBC) on exemestane (E) versus placebo (P). Eligible postmenopausal women had ≥ one of the following risk factors: Gail score &gt;1.66%, prior ADH, ALH, LCIS or DCIS with mastectomy, age over 60. Health-related and menopause-specific quality of life (QOL) were assessed by SF-36 and MENQOL questionnaires. Results: From 2004-2010, 4,560 women were randomized: age 62.5 yrs (37-90); Gail Score 2.3 % (0.6-21); BMI 28.0 kg/m2 (15.9-65.4). Risk factors included: age &gt;60 yrs (49%); Gail score &gt;1.66 (40%); and prior ADH, ALH, LCIS or DCIS with mastectomy (11%). At median follow-up of 35 months there were 11 IBCs on E and 32 on P (annual incidence 0.19% vs 0.55%; HR= 0.35, 95% CI 0.18-0.70, p = 0.002); ductal (10E/27P), lobular (1E/5P). Most tumors were ER positive (7E/27P); Her2/neu negative (10E/26P); TNM stage T1 (8E/28P), N0 (7E/22P), M0 (11E/30P). E was superior in all subgroups: by Gail score, age, BMI, prior LCIS and DCIS. The annual incidence rate of IBC or DCIS was 0.35% E and 0.77% P (HR=0.47;95% CI 0.27-0.79; p = 0.004) based on 64 IBCs or DCISs (20E/44P). Clinical bone fractures, osteoporosis, hypercholesterolemia or cardiovascular events were equal in both arms. No clinically meaningful differences in QOL were detected. Conclusions: Exemestane significantly reduced invasive and pre-invasive breast cancers in postmenopausal women at increased risk for breast cancer with no serious toxicities. Exemestane should be considered a new option for primary prevention of breast cancer. Supported by the Canadian Cancer Society; Pfizer Inc. PEG supported in part by Avon Foundation.

Transmission and control of vivax malaria in Afghan refugee settlements in Pakistan

Regular biting collections were conducted in 1993–1994 to investigate seasonal fluctuations in the abundance of anophelines in Afghan refugee villages in north-western Pakistan. Enzyme-linked immunosorbent assays were used to test heads-plus-thoraces for the presence of malaria sporozoites. Anophelines giving positive results for Plasmodium vivax were captured in every month except January. Nine species were positive. Biting rates showed a marked increase in May, after the spring rains, and thus spring transmission of vivax malaria seems certain. However, transmission of vivax malaria reached its peak only after the monsoon in July. To determine the optimal time to control vivax malaria by indoor spraying with residual insecticide, spray campaigns were conducted in either spring or summer in 14 refugee villages. Villages sprayed in July 1994 showed a mean reduction in annual incidence of 62% (95% confidence interval [CI] ±6%) relative to the previous year, whereas villages sprayed in April 1994 showed only a 15% reduction (95% CI±32%). Parasite prevalence surveys conducted in April and October 1994 confirmed the greater efficacy of spray campaigns waged in July. The insecticide malathion proved as effective as the pyrethroid lambdacyhalothrin, even though several species of anopheline were resistant to malathion.