Seroepidemiology of leptospirosis in southern Vietnamese children

OBJECTIVE: To estimate the seroprevalence of human leptospirosis in southern Vietnam. METHODS: All pupils (n=961) of two primary schools in two communes in southern Vietnam were screened for the presence of serum Leptospira immunoglobulin (Ig)G. Leptospira IgM was tested in 92 randomly selected samples. IgM and IgG were tested with a commercially available enzyme-linked immunosorbent assay (ELISA). RESULTS: Leptospira IgG was found in 123 (12.8%, 95% CI: 10.8-15.1) children with a male:female ratio of 1.5:1. At the age of 7 years the prevalence was 11%. Log-linear binary regression of the IgG seroprevalence by age showed a mean seroconversion rate of 1.5% (95% CI: 1.23-1.75) per year. Five (5.4%, 95% CI: 2.3-12.1) samples were definitely positive for IgM. Presence of serum Leptospira IgG antibodies was significantly associated with swimming in rivers (RR: 1.745, 95% CI: 1.117-2.724) and wading through water (RR 1.793, 95% CI: 1.181-2.722). CONCLUSION: Our data emphasize the importance of leptospirosis among children in Vietnam, despite the absence of severe disease, and stress the need for adequate and cheap diagnostics.     

Incidence of primary dengue virus infections in Southern Vietnamese children and reactivity against other flaviviruses

Objective To study the incidence of asymptomatic primary dengue infections among children and reactivity against other flaviviruses. Methods A total of 216 children, who had no dengue‐specific IgG antibodies during a serosurvey in 2003 were re‐examined 23 months later to determine if seroconversion had occurred. Dengue‐specific IgG was demonstrated with enzyme‐linked immunosorbent assay (ELISA) and reactivity patterns against other flaviviruses were assessed by using immunofluorescence assay (IFA). Results Sixty‐six children had seroconverted for dengue virus‐specific IgG; the true annual incidence of primary dengue was thus 17.3% (95% CI: 13.8–21.4). Japanese Encephalitis virus (JEV)‐specific IgG antibodies were detected by IFA among three (4.6%) samples that showed seroconversion in the dengue ELISA, because of cross‐reactivity. Conclusion Our findings highlight the high incidence of dengue among Vietnamese children; JEV infections are rare. The true annual incidence of dengue can be estimated with a single cross‐sectional seroprevalence survey.     

重症登革热临床特征、预警指征及危险因素的研究进展

登革热是由登革病毒感染引起的急性传染性疾病,重症登革热是登革热的一种严重类型,临床特征主要为严重出血、血浆渗漏及器官损伤。重症登革热发病机制非常复杂,高龄、心血管疾病、中风、糖尿病、慢性呼吸道疾病及肾病均是其高危因素。因目前登革热尚无特效治疗药物,早期识别是降低病死率的关键。故本研究对重症登革热临床特征、预警指征及危险因素进行综合分析,以期为重症登革热的预防、早期诊断及临床治疗提供参考依据。     

Risk factors for the incidence of dengue virus infection in preschool children

Objective To estimate the seroincidence of dengue in children living in Salvador, Bahia, Brazil and to evaluate the factors associated. Methods A prospective serological survey was carried out in a sample of children 0–3 years of age. A multilevel logistic model was used to identify the determinants of seroincidence. Results The seroprevalence of dengue was 26.6% in the 625 children evaluated. A second survey detected an incidence of 33.2%. Multilevel logistic regression showed a statistically significant association between the seroincidence of dengue and age and the premises index. Conclusion In Salvador, the dengue virus is in active circulation during early childhood; consequently, children have heterotypic antibodies and run a high risk of developing dengue haemorrhagic fever, because the sequence and intensity of the three dengue virus serotypes currently circulating in this city are very similar to those that were circulating in Rio de Janeiro, Brazil, in 2008. Therefore, the authors strongly recommend that the health authorities in cities with a similar epidemiological scenario be aware of this risk and implement improvements in health care, particularly targeting the paediatric age groups. In addition, information should be provided to the population and actions should be implemented to combat this vector.     

Risk factors and clinical features associated with severe dengue infection in adults and children during the 2001 epidemic in Chonburi, Thailand

OBJECTIVES: Dengue haemorrhagic fever (DHF) is an important cause of morbidity in South-east Asia and used to occur almost exclusively in young children. In recent years, there has been a progressive shift in age-distribution towards older children and adults. We investigated an outbreak in 2001 in both children and adults, in an endemic area of Thailand. METHODS: Retrospective study of 347 patients with serologically confirmed dengue infection admitted to Chonburi Hospital during an epidemic in 2001. RESULTS: A total of 128 (37%) patients had dengue fever (DF) and 219 (63%) had DHF. Patients with DHF were significantly older than patients with DF (11 years vs. 8 years). Clinical bleeding was noted in 124 individuals, both with DF (n = 24) and DHF (n = 100), and significantly more frequently in adults. Twenty-nine (13.2%) of all DHF cases were caused by primary infection. Secondary dengue infection was associated significantly with the development of DHF in children, OR (95% CI) = 3.63 (1.94-6.82), P < 0.0001, but not in adults, OR (95% CI) = 0.6 (0.02-6.04), P = 1. Unusual clinical manifestations were observed in 23 patients: three presented with encephalopathy and 20 with highly elevated liver-enzymes. In the latter group, four patients were icteric and nine had gastrointestinal bleeding. CONCLUSION: These results indicate that DHF in South-east Asia is common in both children and adults. In dengue-endemic countries, dengue should be considered as a differential diagnosis in patients with clinical gastrointestinal bleeding in association with increased liver enzymes.     

Seroprevalence and risk factors for dengue infection in socio-economically distinct areas of Recife, Brazil

Brazil currently accounts for the majority of dengue cases reported in the Americas, with co-circulation of DENV 1-3. Striking variation in the epidemiological pattern of infection within cities has been observed. Therefore, investigation of dengue transmission in small areas is important to formulate control strategies. A population-based household survey was performed in three diverse socio-economic and environmental areas of Recife, a large urban center of Brazil, between 2005 and 2006. Dengue serostatus and individual- and household-level risk factors for infection were collected in residents aged between 5 and 64 years. A total of 2833 individuals were examined, and their residences were geo-referenced. Anti-dengue IgG antibodies were measured using commercial ELISA. The dengue seroprevalence and the force of infection were estimated in each area. Individual and household variables associated with seropositivity were assessed by multilevel models for each area. A spatial analysis was conducted to identify risk gradients of dengue seropositivity using Generalized Additive Models (GAM). The dengue seroprevalence was 91.1%, 87.4% 74.3%, respectively, in the deprived, intermediate and high socio-economic areas, inversely related to their socio-economic status. In the deprived area, 59% of children had already been exposed to dengue virus by the age of 5 years and the estimated force of infection was three times higher than that in the privileged area. The risk of infection increased with age in the three areas. Not commuting away from the area was a risk factor for seropositivity in the deprived area (OR = 2.26; 95% CI: 1.18-4.30). Number of persons per room was a risk factor for seropositivity in the intermediate (OR = 3.00; 95% CI: 3.21-7.37) and privileged areas (OR = 1.81; 95% CI: 1.07-3.04). Living in a house, as opposed to an apartment, was a risk factor for seropositivity in the privileged area (OR = 3.62; 95% CI: 2.43-5.41). The main difference between the privileged and other areas could be attributed to the much larger proportion of apartment dwellers. Intensive vector control, surveillance and community education should be considered in deprived urban areas where a high proportion of children are infected by an early age.     

Fatal nonocclusive mesenteric ischaemia: population-based incidence and risk factors

Objectives. To estimate the incidence and extension of visceral organ infarction, and to evaluate potential causes, in patients with autopsy‐verified nonocclusive mesenteric ischaemia (NOMI) and transmural intestinal infarction. Setting. In Malmö, Sweden, the autopsy rate between 1970 and 1982 was 87%, creating possibilities for a population‐based study. Design. Amongst 23 446 clinical autopsies, 997 cases were coded for intestinal ischaemia in a database. In addition, 7569 forensic autopsy protocols were analysed. In a nested case–control study within the clinical autopsy cohort, four NOMI‐free controls, matched for gender, age at death and year of death, were identified for each fatal NOMI case to evaluate risk factors. Results. The overall incidence of autopsy‐verified fatal NOMI was 2.0/100 000 person‐years, increasing with age up to 40/100 000 person‐years in octogenarians. Patients with stenosis of the superior mesenteric artery (SMA; n = 25) were older (P = 0.002) than those without (n = 37), and had more often a concomitant stenosis of the coeliac trunk (P < 0.001). Synchronous infarction in the liver, spleen or kidney occurred in one‐fifth of all patients. Fatal cardiac failure [OR 2.9 (1.7–5.2)], history of atrial fibrillation [OR 2.2 (1.2–4.0)] and recent surgery [OR 3.4 (1.6–6.9)] were risk factors for fatal NOMI. Conclusions. Fatal heart failure was the leading cause of intestinal hypoperfusion, although stenosis of the SMA and coeliac trunk, atrial fibrillation and recent surgery contributed significantly. Collaboration across specialties seems to be of utmost importance to improve the prognosis.     

New-onset and idiopathic thrombotic thrombocytopenic purpura: incidence, diagnostic validity, and potential risk factors

OBJECTIVE: The aim of this study was to determine the incidence rate for new-onset and idiopathic thrombotic thrombocytopenic purpura (TTP) among adults 20-64 years old, the validity of diagnostic criteria, and potential risk factors for TTP. METHODS: This retrospective observational study analyzed automated administrative data from 11 geographically dispersed U.S. health plans. Cases of TTP were identified based on the presence of an inpatient hospital claim for TTP (ICD-9-CM 446.6) between 1/1/97 and 12/31/01 and confirmed by medical record review. Pharmacy and medical claims were used to evaluate outpatient drug exposure and comorbidities preceding hospitalization for TTP. Cases and the base population were screened so as to result in an incidence rate for idiopathic TTP. RESULTS: We confirmed new-onset and idiopathic TTP in 9 of 15 presumptive cases for an incidence density of 1.4 per million person-years (95% CI: 0.6-2.6). The rate increased to 1.8 per million person-years after projection and age-standardization. The highest incidence rate of TTP was found in patients 50-64 years old (2.8 per million person-years; 95% CI: 0.8-7.1). These 9 patients had no apparent risk factors for TTP based on claims and medical record data. CONCLUSIONS: In a general U.S. population, the incidence rate of confirmed new-onset and idiopathic TTP was lower than previously reported, but appears to be on the rise. Our findings suggest that administrative claims data are useful for identifying outpatient drug exposures and comorbidities potentially associated with TTP.     

Aplastic anemia in Brazil: incidence and risk factors

This study is the first large-scale epidemiological investigation of acquired aplastic anemia (AAA) in South America. The objective was to estimate the incidence and to identify risk factors for AAA in Brazil. A national case-control study was conducted to investigate the risk factors for the disease. One hundred twenty-five cases and 129 controls were included. Multiple logistic regression was used in the estimation of odds ratios (OR) to control confounding. The size of Brazil made it unfeasible to estimate the incidence of AAA in the whole country, and we limited the calculation to the state of Parana. The annual incidence of AAA in Parana was 2.4 cases/10(6) inhabitants. There was no positive association between chloramphenicol use and AAA (OR 0.4; 95% CI: 0.1-2.9). The OR of AAA associated with household pesticides that include organophosphates in their composition was 2.7 (1.0-8.4). The OR for the usage of unspecified thinner and/or acetone for at least 7 days was 3.0 (1.2-7.3). Cases of AAA in Brazil seem to be associated with some factors traditionally related to this disease, such as certain solvents and the incidence is similar to what has been reported from Europe.     

Falls incidence, risk factors, and consequences in Chinese older people: a systematic review

Falls incidence in Chinese older people has been reported to be approximately half that of Caucasian populations. It is possible that the falls risk factor profile may differ significantly between Caucasian and Chinese populations, and a better understanding of this reported difference in incidence and associated risk factors may influence potential approaches to future intervention. A systematic literature review was conducted using the EMBase, Medline, Chinese Electronic Periodical Services, and WanFangdata databases to collate and evaluate the studies that have addressed the incidence and risk factors for falls in Chinese older people. Twenty-one studies conducted in China, Hong Kong, Macao, Singapore, and Taiwan met the inclusion criteria. Fall rates ranged between 14.7% and 34% per annum (median 18%). In the four prospective studies, injuries were reported by 60% to 75% of those reporting falls, with fractures constituting 6% to 8% of all injuries. One hundred thirty-two variables were identified as fall risk factors, with commonly reported factors being female sex, older age, use of multiple medications, gait instability, fear of falling, and decline in activities of daily living. The findings reveal a consistently lower incidence of self-reported falls in Chinese older people than in Caucasian older people, although the types and prevalence of risk factors were not dissimilar from those found in studies of Caucasian older people. A greater understanding of the health, behavioral, and lifestyle factors that influence fall rates in Chinese populations is required for elucidating fall prevention strategies in Chinese and non-Chinese older people.     

Incidence and risk factors of probable dengue virus infection among Dutch travellers to Asia

We studied the incidence of dengue virus (DEN) infections in a cohort of Dutch short-term travellers to endemic areas in Asia during 1991-92. Sera were collected before and after travel. All post-travel sera were tested for DEN immunoglobulin M (IgM) [IgM capture (MAC)-enzyme-linked immunosorbent assay (ELISA)] and IgG (indirect ELISA). Probable DEN infection was defined as IgM seroconversion or a fourfold rise in IgG ratio in the absence of cross-reaction with antibody to Japanese encephalitis virus (JEV). Infections were considered clinically apparent in case of febrile illness (> 24 H) with headache, myalgia, arthralgia or rash. Probable DEN infection was found in 13 of 447 travellers (incidence rate 30/1000 person-months, 95% CI 17.4-51.6). One infection was considered secondary; no haemorrhagic fever occurred. The clinical-to-subclinical infection rate was 1 : 3.3. The risk of infection showed marked seasonal variation. DEN infections are frequent in travellers to endemic areas in Asia; most remain subclinical.     

The incidence and risk factors of contralateral knee arthroplasty after primary unilateral unicompartmental knee arthroplasty

Unicompartmental knee arthroplasty (UKA) is one of the commonly used surgical methods for unicompartmental osteoarthritis in recent years. Although the prognosis of the operated knee has been widely studied, there are relatively little data on the natural history of the contralateral knee after unilateral replacement. The aim of this study was to explore the incidence and risk factors of consequential knee arthroplasty in patients with bilateral knee osteoarthritis (KOA) after receiving primary unilateral UKA, so as to provide a theoretical basis for making a more comprehensive treatment strategy for patients with KOA.We conducted a retrospective study and enrolled patients with bilateral KOA received unilateral UKA from June 2015 to December 2019 in the third department of joint orthopedics, the third hospital of Hebei Medical University. The patients were divided into replacement group and non-replacement group according to whether the contralateral knee joint received knee arthroplasty. Information about treatment of contralateral knee joint was collected from medical records to determine the incidence. Univariate analysis and multivariate logistic regression analysis were performed to identify the independent risk factors.A total of 502 patients were enrolled in this study. The incidence of contralateral knee arthroplasty was 38.64%. In the univariate analysis, vertical angle of mechanical axis, knee joint''s internal and external joint space, Kellgren–Lawrence (K-L) classification, femoral tibial angle were the significant risk factors for contralateral knee arthroplasty. In the multivariate model, only vertical angle of mechanical axis ≥3.03° (odds ratio [OR] 4.36, 95% confidence interval [CI], 2.47–9.11), K-L classification grades 3 and 4 (OR 2.46,3.72; 95%CI, 1.31–4.25, 1.98–6.87), and femoral tibial angle ≥187.32° (OR 6.32, 95%, 2.23–18.87) remained associated with the occurrence of knee arthroplasty.About a quarter of patients with bilateral KOA received unilateral UKA will receive contralateral knee arthroplasty. Higher K-L classification, femoral tibial angle, and mechanical axis vertical angle are identified risk factors.     

绵羊新孢子虫病和弓形虫病血清流行病学调查及风险因素分析

目的 调查河南、江苏和浙江省绵羊的新孢子虫病和弓形虫病的感染状况并进行风险因素分析,为绵羊寄生虫病防控和羊肉肉品安全监测提供基础依据。方法 采用间接免疫荧光(IFAT)和改良凝集实验法(MAT)分别检测绵羊血清中的新孢子虫和弓形虫的抗体。统计分析风险因素的OR值及P值。结果 绵羊新孢子虫的感染率为11.88%(62/522),弓形虫抗体的阳性率为17.81%(93/522)。地域和流产史是绵羊感染弓形虫的风险因素(P<0.05),但与新孢子虫的感染不相关(P>0.05);年龄和性别均与这两种原虫的感染不相关(P>0.05)。结论 河南、江苏和浙江省绵羊新孢子虫病和弓形虫病的阳性率均较高,羊肉肉品安全现状堪忧。该地域绵羊的新孢子虫病流行情况首次报道。     

老年髋部骨折术前深静脉血栓发生率及危险因素分析

目的研究老年髋部骨折术前深静脉血栓(DVT)的发生率及其危险因素,从而促进DVT的预防。方法回顾性分析解放军总医院2008年3月至2012年10月收治的老年髋部骨折患者386例,根据术前双下肢静脉彩超结果分为DVT组和非DVT组,分析糖尿病、肿瘤、心血管病、呼吸疾病、肝病、肾病、风湿病及痴呆等危险因素。结果术前34例(8.8%)确诊为DVT,其中股静脉2例(5.88%),胭静脉4例(11.76%),胫后静脉l例(2.94%),单侧小腿肌间静脉20例(58.82%),双侧小腿肌间静脉5例(14.71%),腓静脉2例(5.88%)。术前因肺动脉栓塞死亡3例。BMI≥30.0 kg/m~2、风湿病史、合并≥3种内科疾病为术前DVT发生的独立危险因素(P0.05)。结论老年髋部骨折术前DVT发生率高,BMI≥30.0 kg/m~2、风湿病史及合并≥3种内科疾病的患者入院后应评估血栓风险,积极预防,以减少DVT的发生。     

Prevalence and risk factors for hepatitis C infection in rural north Vietnam

Background In Vietnam, the prevalence of hepatitis C virus (HCV) infection among injecting drug users and patients with liver disease is known to be high, yet the magnitude of HCV in the general population, particularly in rural areas, has not been clearly estimated. A community-based study was used to determine the prevalence of HCV infection in a rural population of north Vietnam and explore risk factors associated with HCV acquisition. Method A community-based viral hepatitis seroprevalence study using a multistage sampling method to recruit participants was undertaken. The study population size (n = 837) had been determined on the basis of estimated hepatitis B virus (HBV) prevalence. Information on demography and potential risk factors were obtained using face-to-face interviews, and all selected participants were tested for anti-HCV antibody. Results HCV prevalence in the study population was 1.0% (95% CI: 0.4%–1.9%). Hospital admission (adjusted odds ratio [AOR]: 7.19; 95% CI: 1.59–32.53; P = .01) and having tattoos (AOR: 13.37: 95% CI: 1.86–96.15; P = .01) were independent predictors of HCV infection, and farmers were less likely to have HCV infection than those in other occupations (AOR: 0.19; 95% CI: 0.04–0.84; P = .02). Conclusion The prevalence of HCV infection is low in the general rural population in northern Vietnam. An association between HCV infection and hospital admission and tattoos indicate a need to improve the standards of infection control in healthcare and other settings in this region. This project was funded by the Ministry of Health of Vietnam.