epidemiological characteristics
Recently Published Documents

ObjectiveThe purpose of this study is to analyze the positive rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid testing (NAT), cases of and deaths due to SARS-CoV-2, and the epidemiological characteristics of SARS-CoV-2 to identify high-risk populations.MethodsA retrospective study in Jiulongpo district of Chongqing was conducted by performing continuous observations of the frequency of SARS-CoV-2 NAT, analyzing the data of close contacts of patients and asymptomatic carriers, and collecting epidemiological data. Data were collected from January 20, 2020, when the first case of SARS-CoV-2 infection was reported, to March 26, 2020. Descriptive statistical analysis and Cochrane–Mantel–Haenszel analysis were used to compare the positive detection rates and positive diagnostic rates of different exposure groups.ResultsA total of 7,118 people received 10,377 SARS-CoV-2 nucleic acid tests in one district, and the SARS-CoV-2 positive rates were 0.40% (18/4446) and 0.15% (4/2672) in people receiving one and ≥ two nucleic acid tests (p = 0.06), respectively. Those with suspected cases (12.35%) and close contacts (8%) had higher positive rates than people tested at fever clinics (0.39%) (p < 0.001). The median latency (range) of cases was 5 (2, 9) days, and the median time from diagnosis to recovery was 22 (14, 25) days. One recovered patient received a positive test result at 28 days after recovery when she attempted to donate blood. Six clustered cases, including one patient who died, indicated persistent human-to-human transmission. One patient who was diagnosed after death was found to have infected 13 close contacts. People working in catering and other public service departments (36.36%) and people who are unemployed and retirees (45.45%) have an increased risk of infection compared with technical staff (9.09%) and farmers (9.09%).ConclusionThe total positive rate was low in the tested population, and more effective detection ranges should be defined to improve precise and differentiated epidemic control strategies. Moreover, in asymptomatic carriers, SARS-CoV-2 tests were positive after recovery, and patients with suspected SARS-CoV-2 infection who die may pose serious potential transmission threats.

BACKGROUND: COVID-19 disease can affect women at any stage of pregnancy, and newborns could become infected with SARS-CoV-2 through vertical or horizontal transmission. Little is known about SARS-CoV-2 infection in neonates born to mothers with COVID-19. Experts emphasize the importance of ensuring the safety of newborns without compromising the benefits of early contact with the mother. The aim of the study was to investigate the epidemiological characteristics of newborns born to mothers infected with SARS-CoV-2. METHODS: Observational, prospective cohort study was conducted in the intensive care unit of the perinatal center (Georgia). Information was collected by reviewing and personal observations of medical histories of newborns born to mothers infected with SARS-CoV-2. RESULTS: The study included 38 newborns with suspected (n = 16; 42.1%) and confirmed (n = 22; 57.9%) COVID-19 infection cases, treated in the neonatal intensive care unit. The study did not reveal the risk of vertical transmission of SARS-CoV-2 infection and confirmed a fairly large rate of horizontal transmission of infection (n = 25; 66%). Skin-to-skin mother care was performed in 68.7% of newborns, 26.3% received exclusive maternal or donated breast milk during hospital stay. CONCLUSION: Prevention of horizontal transmission of infection in newborns should be a priority. It is recommended skin-to-skin mother care and maternal or donated breast milk during hospital stay, taking into account the health of the mother and the newborn, following the rules of hygiene and use of the mask by the infected mother.

Background: Animal bite is a serious and dangerous threat to human health. The highest prevalence rate of animal bite in Iran is in Golestan, Ardabil and, then Khorasan. The present study examined the epidemiological characteristics and the trend of animal bites during 2014-2018. Results: In this study, out of 3784 cases bitten by animals, 2821 happened by a sudden attack. Most reports of the animal bite were from dogs. Also, the trend of animal bite during 2014-2018 was increasing and the charts showed that the trend will continue to increase the next year. Conclusion: Due to the increasing trend of animal bites, it is necessary to take basic measures such as training endangered groups, forming a committee to eliminate stray dogs, and strengthening the care system and immunization program.

Objectives: Subclinical tuberculosis (TB) represents a substantial proportion of individuals with TB disease, although limited evidence is available to understand the epidemiological characteristics of these cases. We aimed to explore the prevalence of subclinical patients with TB and identify the underlying association between the subclinical TB cases in the study setting and the Beijing genotype.Methods: A retrospective study was conducted among patients with incident TB at the Fifth People’s Hospital of Suzhou between January and December 2018. A total of 380 patients with TB were included in our analysis.Results: Of the 380 patients, 81.8% were active TB cases, whereas the other 18.2% were subclinical TB cases. Compared with patients aged 65 years and older, the risk of having subclinical TB is higher among younger patients. The use of smear, culture, and Xpert identified 3, 16, and 13 subclinical TB cases, respectively. When using a combination of positive culture and Xpert results, the sensitivity improved to 33.3%. In addition, the neutrophil-to-lymphocyte ratio was significantly elevated in the active TB group compared with that in the subclinical TB group. We also observed that the proportion of the Beijing genotype in the subclinical TB group was significantly lower than that in the active TB group.Conclusion: To conclude, our data demonstrate that approximately one-fifth of patients with TB were subclinical in Suzhou. Mycobacterium tuberculosis could be detected by the existing microbiologic diagnostics in one-third of patients with subclinical TB. The patients with subclinical TB are more prone to having low neutrophil-to-lymphocyte ratio values than those with active TB. Additionally, non-Beijing genotype strains are associated with subclinical TB.

Abstract Background Chronic lymphocytic leukemia (CLL) is the most prevalent subtype of leukemia in Western countries, causing a substantial health burden on patients and society. Comprehensive evaluation of the epidemiological characteristics of CLL is warranted, especially in the current context of global population aging. The main objective of this study is evaluating the disease burden of CLL at global, regional, and national levels from 1990 to 2019. As secondary objectives, we studied the influence of demographic factors and performed risk factor analysis. We hope this study could provide evidence for the evaluation of the effectiveness of previous prevention strategies and the formulation of future global health policies. Results Based on data of CLL between 1990 to 2019 from the Global Burden of Disease (GBD) study 2019, we depicted the age, gender, and regional structure of the CLL burden population and described the impact of social development on the disease burden of CLL. The distribution and changing trends of attributable risk factors were also investigated. The global burden of CLL has increased dramatically. A high incidence has been achieved in males and elder people. Countries and territories with high social-demographic index (SDI) tended to have higher global burden than low-SDI region. Of risk factors, high body mass index and smoking were the major contributors for CLL-related mortality and disability adjusted life-years (DALYs). Conclusion In summary, the global CLL burden continues to rise over the past 30 years. The relocation of medical resource should be considered on a global scale. Graphical Abstract

Tuberculosis (TB) is a major cause of illness and public health concern, especially in resource-limited countries. This study analyzed the characteristics related to anti-TB drug resistance. Moreover, we examined the evidence-based indications for the treatment of active TB in Angola. This study evaluated the medical records of 176 patients screened for TB from January to September 2016 in Luanda, the capital city of Angola. Approximately 66.5% of the patients were newly diagnosed with active TB. The residence area showed a significant relationship with TB (P = 0.025), whereas age group (P = 0.272), gender (P = 0.853), and HIV status (P = 0.284) did not showed any relationship with TB. Overall, 72.4% of TB patients had resistance to at least one of the anti-TB drugs. The risk of anti-TB drug resistance was higher in males (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 0.42–3.58, P = 0.685] and in TB-HIV coinfected patients [OR: 1.39; (95% CI: 0.26–7.28), P = 0.700], whereas it was lower in patients aged 30 years or older (OR: 0.56; 95% CI: 0.18–1.69) P = 0.303) and in patients living in urbanized areas (OR: 0.74; 95% CI: 0.17–3.25; P = 0.685). Our findings showed that drug-resistant TB is emerging in Angola. Further studies on factors related to anti-TB drug resistance are urgently needed to ascertain the magnitude of the problem and to proffer strategies toward TB control in Angola.

Introduction. The Epstein–Barr virus (EBV) is one of the most common pathogens — it infects 90% of the world’s population. However, specific characteristics of the EBV infection epidemic process remain unidentified. The previous studies focusing on assessment of incidence rates for infectious mononucleosis (IM) tend to ignore the serological status of the population.The aim of the study was to identify epidemiological characteristics and assess the prevalence of serological markers for EBV infection for further epidemic control measures development.Materials and methods. In Moscow, the thorough analysis was performed using the data on IM incidence (Form 2 "Data on Infectious and Parasitic Diseases") and test results for 138,232 people checked for presence of VCA IgG, EBNA IgG, VCA IgM, EA IgG, and EBV DNA in their blood and saliva in 2011–2020.Results. The periodic pattern of IM incidence was discovered, demonstrating the repetitive peaks every 9 to 11 years and a strong direct correlative relationship with detection rates for active EBV infection markers. The intra-annual dynamics of IM incidence is characterized by a seasonal upswing during cold seasons of the year, reaching its peaks in October, November, or February and associated with a marked decrease in the VCA IgG and EBNA IgG seroprevalence. Children within the 1 to 17-year age range are groups at risk for acquiring primary infection, demonstrating significantly lower detection rates for chronic EBV infection (VCA IgG and EBNA IgG) markers and higher rates for VCA IgM and EBV DNA markers in blood compared to adults. The contribution of adult population to the epidemic process is formed through reactivation of chronic infection, which is observed primarily among women.Conclusion. The identified characteristics are essential for comprehensive understanding of the EBV infection epidemic process and can be used for developing preventive and anti-epidemic measures.

Background: Bloodstream infections are recognized as important nosocomial infections. Escherichia coli (E. coli) is the most prevalent Gram-negative bacillary pathogen causing bloodstream infections (BSIs). This retrospective study investigated drug susceptibility and molecular epidemiology of E. coli isolated from patients with BSI in Shanghai, China.Methods: We collected E. coli isolated from the blood cultures of patients with BSI between January 2016 and December 2019. We randomly selected 20 strains each year to investigate antimicrobial resistance, resistance genes, and molecular epidemiological characteristics. Antimicrobial susceptibility testing was performed by the disk diffusion method. PCR was performed to detect extended-spectrum β-lactamases (ESBLs), carbapenemase genes, and housekeeping genes, and phyloviz was applied to analyze multilocus sequence typing (MLST).Results: Penicillins, first- and second-generation cephalosporins and fluoroquinolones have high resistance rates (>60%). Among the 80 randomly selected strains, 47 (58.8%) produced ESBLs, and one produced carbapenemase. Sequencing of resistance genes identified blaCTX−M−14 (34%, 16/47), blaCTX−M−15 (23.4%, 11/47) and blaCTX−M−27 (14.8%, 7/47) as the most prevalent genotypes of ESBLs. ST131 (14/80) was the most prevalent sequence type (ST), followed by ST1193 (10/80), ST648 (7/80).Conclusions: Our findings suggest that amikacin, carbapenems, and piperacillin-tazobactam have relatively low resistance rates and may be the preferred antibiotic regimens for empiric therapy. ST131 and blaCTX−M−14 are still the main prevalent in Shanghai with a rapid increase in the occurrence of ST1193 is rapidly increasing and more diverse blaCTX genes.

Since the Dabie bandavirus (DBV; former SFTS virus, SFTSV) was identified, the epidemics of severe fever with thrombocytopenic syndrome (SFTS) caused by this virus have occurred in several countries in East Asia. The rapid increase in incidence indicates that this infectious agent has a pandemic potential and poses an imminent global public health threat.The analysis of molecular evolution of SFTS agent that includes its variants isolated in China, Japan and South Korea was performed in this review. The evolution rate of DBV and the estimated dates of existence of the common ancestor were ascertained, and the possibility of reassortation was demonstrated.The evolutionary rates of DBV genome segments were estimated to be 2.28 × 10-4 nucleotides/site/year for S-segment, 2.42 × 10-4 for M-segment, and 1.19 × 10-4 for L-segment. The positions of positive selection were detected in the viral genome.Phylogenetic analyses showed that virus may be divided into two clades, containing six different genotypes. The structures of phylogenetic trees for S-, M- and L-segments showed that all genotypes originate from the common ancestor.Data of sequence analysis suggest that DBV use several mechanisms to maintain the high level of its genetic diversity. Understanding the phylogenetic factors that determine the virus transmission is important for assessing the epidemiological characteristics of the disease and predicting its possible outbreaks.

The assessment of human papillomavirus (HPV) genotype dynamics could support the adoption of more tailored preventive actions against cervical cancer. The aim of the study was to describe the prevalence of HPV infection, HPV genotype distribution, and the epidemiological characteristics of women with ASC-US cytology since the introduction of HPV-DNA testing in Sardinia (Italy), (March 2016–December 2020). Specimens were tested by RT-PCR for 14 high-risk HPV genotypes. A total of 1186 patients were enrolled, with a median (IQR) age of 41 (38–48) years. Of these women, 48.1% were positive for at least one HPV genotype; 311 (26.2%) women were vaccinated with a median (IQR) age of 38 (30/47) years. The percentage of prevalence of HPV-16, -31, -66, -56, and -51 was 36.3%, 18.7%, 11.9%, 11.4% and 10.7%, respectively. The highest prevalence of infection was found in women aged <41 years, and single women. Moreover, women aged >41 years (OR: 0.51, 95% CI: 0.31–0.86; p-value: 0.01), having parity (OR: 0.57, 95% CI: 0.34–0.96, p-value: 0.04), and higher educational level (OR: 0.39, 95% CI: 0.18–0.87; p-value: 0.02) were associated with a lower CIN2+ risk. We did not find a significant difference in terms of prevalence of HPV-16 infection between vaccinated and non-vaccinated (18.3% vs. 17.1%; p-value < 0.001). Our results support the adoption of nonavalent HPV-vaccine to prevent the most prevalent infections caused by HPV-16 and -31 genotypes and underscore the need of surveillance to implement tailored vaccination programs and preventive strategies.