Association between -221 X/Y polymorphism of mannose-binding lectin (MBL) gene and susceptibility to HTLV-1 infection among people from an endemic region in the Northeast of Iran

BackgroundThe role of (MBL) gene single nucleotide polymorphisms (SNPs) has been well documented in susceptibility to several infectious diseases. This study aimed to investigate the association between two MBL promoter variants, -550 H/L and -221 X/Y, and susceptibility to HTLV-1 infection.MethodsA total of 153 subjects infected with HTLV-1 and 169 healthy controls were recruited. SSP-PCR method was applied to genotype -550 H/L and -221 X/Y polymorphisms. Associations between genotypes or alleles and susceptibility to HTLV-1 infection were analyzed by Pearson's Chi-Square. p ≤ .05 was considered statistically significant.ResultsStatistical analysis revealed significant differences between the two groups in the -221 position (χ2 = 19.709; p = .000). The MBL YX genotype was significantly associated with increased susceptibility to HTLV-1 (OR = 2.73, %95 CI = 1.74–4.30). Combined genotype of the two loci showed that the HYHX genotype (OR = 2.20, 95% CI = 1.95–2.48) and LYLX (OR = 1.97, 95% CI = 1.13–3.45) were associated with an increased risk of HTLV-1 infection.ConclusionOur results represent the importance of -221 X > Y variants in acquisition of HTLV-1 as this is the case for several other viral and bacterial infections.     

Antecedentes familiares de primer grado como factor de riesgo en el cáncer colorrectal

ObjectiveTo evaluate the association between first-degree family history and colorectal cancer (CRC).MethodWe analyzed data from 2857 controls and 1360 CRC cases, collected in the MCC-Spain project. The adjusted odds ratio (OR) and 95% confidence interval (95% CI) of association with the family history of CRC was estimated by non-conditional logistic regression.ResultsFirst-degree relatives doubled the risk of CRC (OR: 2.19; 95% CI: 1.80–2.66), increasing in those with two or more (OR: 4.22; 95% CI: 2.29–7.78) and in those whose relatives were diagnosed before 50 years (OR: 3.24; 95% CI: 1.52–6.91). Regarding the association of the family history with the location, no significant differences were observed between colon and rectum, but there were in the relation of these with the age of diagnosis, having more relatives those diagnosed before 50 years (OR: 4.79; 95% CI: 2.65–8.65).ConclusionsFirst-degree relatives of CRC increase the chances of developing this tumor, they also increase when the relative is diagnosed at an early age. Therefore, it must be a target population on which to carry out prevention measures.     

自然抗性相关巨噬细胞蛋白1基因多态性与肺结核易感性的研究

目的　探讨自然抗性相关巨噬细胞蛋白 1基因 (NRAMP1)多态性与中国汉族人群肺结核发病的关系。方法　采用以医院为基础的病例对照研究设计 ,用聚合酶链反应 限制性片段长度多态性分析 (PCR RFLP)法检测NRAMP1基因中INT4、D5 4 3N及 3′UTR 3个多态性位点的基因型 ,并对结核病相关危险因素进行问卷调查 ,应用SPSS软件进行单因素和多因素非条件logistic回归分析。2 0 0 1年 4月至 2 0 0 2年 6月选择 110例肺结核病例 ,平均年龄为 (2 8± 13)岁 ;对照组为 180名健康体检者 ,平均年龄为 (2 7± 9)岁。对NRAMP1基因各多态性位点进行单因素分析。结果　病例组D5 4 3NG/A及 3′UTRTGTG +/del基因型频率显著高于对照组 ,OR值 (95 %CI)分别为 2 2 2 (1 0 3～ 4 78)和 1 93(1 14～ 3 2 6 )。病例组和对照INT4各基因型频率比较差异无显著性。多因素分析调整暴露史和疫苗接种史 2个因素后 ,D5 4 3NG/A及 3′UTRTGTG +/del基因型仍与结核病显著相关 ,调整OR值 (95 %CI)分别为 3 0 4 (1 12～ 8 2 7)和 2 36 (1 2 0～ 4 6 4 ) ,而病例和对照组INT4位点多态性比较差异未见显著性。结论　NRAMP1基因D5 4 3N及 3′UTR位点多态性可能是汉族人群肺结核的易感因素。     

South to North Migration Patterns of Tuberculosis Patients Diagnosed in the Mexican Border with Texas

The Mexican state of Tamaulipas serves as a migration waypoint into the US. Here, we determined the contribution of immigrants to TB burden in Tamaulipas. TB surveillance data from Tamaulipas (2006–2013) was used to conduct a cross-sectional characterization of TB immigrants (born outside Tamaulipas) and identify their association with TB treatment outcomes. Immigrants comprised 30.8% of TB patients, with?>?99% originating from internal Mexican migration. Most migration was from South to North, with cities adjacent to the US border as destinations. Immigrants had higher odds of risk factors for TB [older age (≥?65 year old, OR 2.4, 95% CI 2.1, 2.8), low education (OR 1.3, 95% CI 1.2, 1.4), diabetes (OR 1.2, 95% CI 1.1, 1.4)], or abandoning treatment (adjusted OR 1.2, 95% CI 1.0, 1.5). There is a need to identify strategies to prevent TB more effectively in Tamaulipas, a Mexican migration waypoint.

     

Characteristics of tuberculosis patients with positive sputum smear in Catalonia, Spain

BACKGROUND: Patients with positive sputum smears are those with the capacity to spread infection. The objective of this study was to describe the incidence of tuberculosis in Catalonia (an autonomous community in the northeast of Spain which includes Barcelona) and to determine risk factors associated to patients with positive sputum smear test. METHODS: New cases of tuberculosis detected by active surveillance between May 1996 and April 1997 were studied. The study was analysed as a coincident cases and controls study. The rate of incidence was calculated per 100,000 persons-year. The association of the dependent variable--case of tuberculosis with positive sputum smear--with the remainder of independent variables was determined by odds ratio (OR) with a 95% confidence interval (CI). RESULTS: A total of 2508 cases of tuberculosis were detected. The rate of incidence was 41.4 per 100,000 persons-year. Of these 19.4% (487/2508) were coinfected with HIV and 35.6% (893/2508) presented a positive sputum smear, which implies a rate of 14.7 per 100,000 persons-year. In an adjusted multivariate analysis, cases with positive smears were positively associated with the 15-24 (OR=1.9; 95% CI: 1.4-2.4), 25-34 (OR=2.1; 95% CI: 1.7-2.7) and 35-44 years (OR=1.7; 95% CI: 1.3-2.2) age compared with persons 45 years old and above; with males (OR=1.8; 95% CI: 1.5-2.2) and consumers of alcohol (OR=2.1; 95% CI: 1.7-2.7) and negatively with those under 15 years of age (OR=0.1; 95% CI: 0.1-0.2) and coinfection with HIV (OR=0.5; 95% CI: 0.3-0.7). CONCLUSIONS: Measures to control tuberculosis transmission (prompt diagnosis, study of contacts and directly observed treatments) should be reinforced for male adults with excessive consumption of alcohol.     

Familial aggregation of ischemic stroke in young women: the Stroke Prevention in Young Women Study

BACKGROUND AND PURPOSE: Stroke occurs infrequently in young adults. While a familial basis for older onset stroke is well established, the extent of familial clustering in young-onset stroke is unknown. To address this issue, we compared the frequency of stroke in relatives of stroke cases to that in relatives of controls across different ages and by stroke subtype. METHODS: Through a population-based case-control study of stroke, we identified 487 women aged 15-49 years with ischemic stroke and 615 women without stroke matched by age and geographic region. Family history of stroke was collected for 5,749 relatives (parents and siblings) of case and control probands by standardized interview. RESULTS: Strokes were reported in 149 relatives of case patients and 119 relatives of controls. Siblings of stroke case patients had more than four times the risk of stroke compared to siblings of controls (OR, 4.17; 95% CI, 1.9-8.8) and mothers of stroke case patients had twice the risk of stroke compared to mothers of control subjects (OR, 2.02; 95% CI, 1.4-3.0). The association between stroke in probands and family history of stroke was strongest among women aged 15-24 years (OR, 2.5; 95% CI, 0.4-15.1), and diminished with increasing proband age (OR, 1.6; 95% CI, 0.8-3.3 among women 25-34 years and OR, 1.5; 95% CI, 1.1-1.9 among women 35-49 years; P<0.0001 for trend). CONCLUSIONS: We conclude that young-onset stroke aggregates in families and that the magnitude of aggregation increases with decreasing proband age.     

Parental occupational exposure to pesticides and childhood germ-cell tumors

In a recently completed US case-control study (Children's Oncology Group, 1993-2001) with 253 cases and 394 controls, the authors investigated the association between parental occupational exposure to pesticides and risk of childhood germ-cell tumors. Information on occupational pesticide exposure was collected using job-specific module questionnaires and assessed by an experienced industrial hygienist. Odds ratios for childhood germ-cell tumors associated with maternal exposures before pregnancy, during pregnancy, and after the birth of the index child were 1.0 (95% confidence interval (CI): 0.8, 1.4), 1.1 (95% CI: 0.7, 1.6), and 1.3 (95% CI: 0.9, 1.8), respectively. Paternal exposures before pregnancy, during pregnancy, and after the birth of the index child were not related to germ-cell tumors (odds ratios (ORs) were 0.9 (95% CI: 0.7, 1.2), 0.8 (95% CI: 0.5, 1.2), and 0.8 (95% CI: 0.5, 1.3), respectively). When both parents had ever been occupationally exposed to pesticides before the index pregnancy, the odds ratio was 0.8 (95% CI: 0.4, 1.3). Subgroup analyses showed a positive association between maternal exposure to herbicides during the postnatal period and risk of germ-cell tumors in girls (OR = 2.3, 95% CI: 1.0, 5.2) and an inverse association between paternal exposure to pesticides during the index pregnancy and germ-cell tumors in boys (OR = 0.2, 95% CI: 0.1, 1.0). This study did not provide strong evidence supporting a relation between parental pesticide exposure in the workplace and risk of germ-cell tumors among offspring.     

Dwellings, crowding, and tuberculosis in Montreal

The association of tuberculosis (TB) with poverty has long been recognized, yet it may reflect not only characteristics of poor individuals, but also housing and neighborhood features which promote airborne spread. We sought to determine whether dwelling and building features, residential density and crowding are independently associated with TB occurrence in a low-incidence setting. We used residential addresses to geocode active TB cases reported in Montreal in 1996-2000. These "case dwellings" were linked to the municipal dwelling geodatabase from 2000, and to Canadian census data from 1996. We compared them with randomly selected Montreal dwellings ("controls," in a 1:10 ratio), using the same data sources. From multivariate logistic regression, the 595 case dwellings were more likely than the 5950 control dwellings to be in buildings >5 stories tall (adjusted odds ratios [OR] 1.6; 95% CI: 1.0-2.5), constructed since 1970 (adjusted OR 2.5; 1.8-3.6), in the lowest quartile for resale valuation (adjusted OR 1.3; 1.0-1.6), and on blocks where lot coverage exceeded the median value (adjusted OR 1.3; 1.0-1.6). Case dwellings were also more often found in census tracts with more persons per room, and a higher proportion of inhabitants who had arrived in Canada within the last 5 years. We conclude that dwelling and building features-notably dwellings in taller and new buildings, with lower resale value, and dwellings on blocks with high residential density-as well as crowding, were associated with TB occurrence, after adjustment for sociodemographic factors.     

Multidrug-resistant tuberculosis in Belarus: the size of the problem and associated risk factors

Objective

To assess the problem of multidrug-resistant tuberculosis (MDR-TB) throughout Belarus and investigate the associated risk factors.

Methods

In a nationwide survey in 2010–2011, 1420 tuberculosis (TB) patients were screened and 934 new and 410 previously treated cases of TB were found to meet the inclusion criteria. Isolates of Mycobacterium tuberculosis from each eligible patient were tested for susceptibility to anti-TB drugs. Sociobehavioural information was gathered in interviews based on a structured questionnaire.

Findings

MDR-TB was found in 32.3% and 75.6% of the new and previously treated patients, respectively, and, 11.9% of the 612 patients found to have MDR-TB had extensively drug-resistant TB (XDR-TB). A history of previous treatment for TB was the strongest independent risk factor for MDR-TB (odds ratio, OR: 6.1; 95% confidence interval, CI: 4.8–7.7). The other independent risk factors were human immunodeficiency virus (HIV) infection (OR: 2.2; 95% CI: 1.4–3.5), age < 35 years (OR: 1.4; 95% CI: 1.0–1.8), history of imprisonment (OR: 1.5; 95% CI: 1.1–2.0), disability sufficient to prevent work (OR: 1.9; 95% CI: 1.2–3.0), alcohol abuse (OR: 1.3; 95% CI: 1.0–1.8) and smoking (OR: 1.5; 95% CI: 1.1–2.0).

Conclusion

MDR-TB is very common among TB patients throughout Belarus. The numerous risk factors identified for MDR-TB and the convergence of the epidemics of MDR-TB and HIV infection call not only for stronger collaboration between TB and HIV control programmes, but also for the implementation of innovative measures to accelerate the detection of TB resistance and improve treatment adherence.     

Case-control study of risk factors for hospitalization caused by pandemic (H1N1) 2009

We conducted a case-control study to identify risk factors for hospitalization from pandemic (H1N1) 2009 virus infection among persons >16 years of age in Sydney, Australia. The study comprised 302 case-patients and 603 controls. In a logistic regression model, after adjusting for age and sex, risk factors for hospitalization were pregnancy (odds ratio [OR] 22.4, 95% confidence interval [CI] 9.2-54.5), immune suppression (OR 5.5, 95% CI 2.8-10.9), pre-existing lung disease (OR 6.6, 95% CI 3.8-11.6), asthma requiring regular preventive medication (OR 4.3, 95% CI 2.7-6.8), heart disease (OR 2.3, 95% CI 1.2-4.1), diabetes (OR 3.8, 95% CI 2.2-6.5), and current smoker (OR 2.0, 95% CI 1.3-3.2) or previously smoked (OR 2.0, 95% CI 1.3-3.0). Although obesity was not independently associated with hospitalization, it was associated with an increased risk of requiring mechanical ventilation. Public health messages should give greater emphasis on the risk for severe disease among pregnant women and smokers.     

NRAMP1基因INT4和3’UTR位点多态性与肺结核易感性的研究

目的 探讨人类自然抵抗相关巨噬细胞蛋白1（NRAMP1）基因INT4和3＇UTR位点多态性与中国北方汉族成人肺结核发病的关系.方法 采用1：1配对的病例对照研究设计,用聚合酶链反应-限制性片段长度多态性分析方法检测NRAMP1基因中INT4和3＇UTR两个多态性位点,对与肺结核相关的危险因素进行问卷调查,进行单因素和多因素条件logistic回归分析,同时对基因型与肺结核病变的性质和程度进行研究.结果 对124对研究对象进行了INT4和3＇UTR两个多态性位点的基因分型,3＇UTR TGTG＋/del基因型病例组频率显著高于对照组,粗OR值（95%CI）为2.923（1.557～5.487）.病例组和对照组INT4各基因型频率比较差异均无统计学意义.对17个环境危险因素进行了单因素分析,在多因素分析中调整卡痕、体重指数、人均居住面积、家族史4个因素后,3＇UTR TGTG＋/del基因型仍与肺结核显著相关,调整OR值（95%CI）为2.955（1.369～6.381）.在INT4不同基因型中,病例组和对照组肺结核病变性质差异具有统计学意义（x2=9.634,P＜0.05）.结论 NRAMP1基因3＇UTR位点多态性可能是中国北方汉族成人肺结核的易感因素,而INT4多态性可能与肺结核的病变性质有关系.     

Family history of reproductive cancers and ovarian cancer risk: an Italian case-control study.

The relation between family history of ovarian, breast, and endometrial cancer and risk of epithelial ovarian carcinoma was analyzed within the framework of a case-control study conducted from 1983 to 1989. The study included 755 cases of ovarian cancer and 2,023 controls in hospital for a spectrum of acute nongynecologic, hormonal, or neoplastic conditions in the Greater Milan area, Italy. Eighteen cases (2%) and 24 controls (1%) reported a history of ovarian cancer in a first-degree relative: The corresponding multivariate adjusted odds ratio (OR) was 1.9 (95% confidence interval (CI) 1.1-3.6). The risk of ovarian cancer was elevated in women reporting a family history of breast cancer (OR = 1.6, 95% CI 1.1-2.3), but no significant association emerged with a family history of endometrial cancer (OR = 1.3, 95% CI 0.8-1.7). When the data were stratified by family history of breast cancer, a family history of ovarian cancer was over 10 times more frequent in both cases and controls who reported a family history of breast cancer than in cases and controls reporting no family history of breast cancer. The estimated odds ratio for ovarian cancer associated with a family history of the disease was 2.3 (95% CI 1.1-4.5) in women not reporting a family history of breast cancer, but no association emerged in the subgroup of women reporting a family history of breast cancer. These results confirm that a family history of ovarian cancer increases the risk of the disease, but the percentage of ovarian cancer cases explained by a family history of the disease is small: Less than 1% of observed cases in this study could be attributed to this "family risk factor."     

A survey of latent tuberculosis infection among laboratory healthcare workers in New York City.

OBJECTIVE: To determine the prevalence of positive tuberculin skin tests (TSTs), incidence of TST conversion, risk factors for positive TSTs, and history of active TB among HCWs in microbiology laboratories in New York City. DESIGN: Two-year survey from May 1999 to June 2001. SETTING: Nineteen microbiology laboratories. RESULTS: During the first year, interviews were conducted with 345 laboratory HCWs (mean, 18 HCWs per site; range, 2 to 51) to assess the prevalence of positive TSTs, but 3 (1%) could not recall their result and were excluded from further analyses. The mean age of the remaining 342 HCWs was 48 years; 68% (n = 233) were female, 54% (n = 183) received bacille Calmette-Guerin (BCG) vaccination, and 71% (n = 244) were foreign born. The prevalence of a positive TST was 57% (n = 196), but only 20% (n = 39) of the HCWs received isoniazid. The incidence of TST conversion in the second year of the study was 1% (1 of 108). Multivariate analysis identified age (odds ratio [OR] per year, 1.05; 95% confidence interval [CI95], 1.02-1.08), foreign birth (OR, 3.80; CI95, 1.98-7.28), BCG immunization (OR, 4.89; CI95, 2.72-8.80), and employment in a mycobacteriology laboratory (OR, 2.14; CI95, 1.25-3.68) as risk factors for a positive TST. Only one HCW had been treated for active TB. CONCLUSIONS: The prevalence of positive TSTs was high among laboratory HCWs, but the TST conversion rate was low. Higher rates of treatment for latent TB infection are desirable.     

Tuberculosis in Bissau: incidence and risk factors in an urban community in sub-Saharan Africa

BACKGROUND: Despite the long history of tuberculosis (TB) research, population-based studies from developing countries are rare. METHODS: In a prospective community study in Bissau, the capital of Guinea-Bissau, we assessed the impact of demographic, socioeconomic and cultural risk factors on active TB. A surveillance system in four districts of the capital identified 247 adult (>or=15 years) cases of intrathoracic TB between May 1996 and June 1998. Risk factors were evaluated comparing cases with the 25,189 adults living in the area in May 1997. RESULTS: The incidence of intrathoracic TB in the adult population was 471 per 100 000 person-years. Significant risk factors in a multivariate analysis were increasing age (P < 0.0001), male sex (odds ratio [OR] = 2.58, 95% CI: 1.85, 3.60), ethnic group other than the largest group (Pepel) (OR = 1.64, 95% CI: 1.20, 2.22), adult crowding (OR = 1.68, 95% CI: 1.18, 2.39 for >2 adults in household), and poor quality of housing (OR = 1.66, 95% CI: 1.24, 2.22). Household type was important; adults living alone or with adults of their own sex only, had a higher risk of developing TB than households with husband and wife present, the adjusted OR being 1.76 (95% CI: 1.11, 2.78) for male households and 3.80 (95% CI: 1.69, 8.56) for female households. In a multivariate analysis excluding household type, child crowding was a protective factor, the OR being 0.68 (95% CI: 0.51, 0.90) for households with >2 children per household. CONCLUSIONS: Bissau has a very high incidence of intrathoracic TB. Human immunodeficiency virus (HIV), increasing age, male sex, ethnicity, adult crowding, family structure, and poor housing conditions were independent risk factors for TB. Apart from HIV prevention, TB control programmes need to emphasize risk factors such as socioeconomic inequality, ethnic differences, crowding, and gender.     

Risk factors for abruptio placentae

The authors studied the relation of sociodemographic, medical, and life-style factors and abruptio placentae in a large cross-sectional data base. The 143 cases of abruption identified in the Delivery Interview Program, conducted in Boston from 1977 to 1980, were compared with 1,257 randomly selected controls. The authors used multiple logistic regression techniques to derive maximum likelihood estimates of the adjusted odds ratios and 95% confidence intervals as measures of the association between exposure factors and abruption. A history of chronic hypertension was associated with a threefold increase in risk (odds ratio (OR) = 3.1, 95% confidence interval (Cl) 1.1-8.4), but pregnancy-induced hypertension was not associated with abruption. Excess risk was associated with advanced maternal age (OR = 2.3, 95% Cl 1.3-3.9), low prepregnancy body mass index (OR = 2.3, 95% Cl 1.3-4.1), a history of prior stillbirth (OR = 3.5, 95% Cl 1.8-7.0), and at least weekly use of marijuana during pregnancy (OR = 2.8, 95% Cl 1.2-6.6). Overall, the association with cigarette smoking during pregnancy was of only borderline significance (OR = 1.5, 95% Cl 1.0-2.2), although there appeared to be a dose-response relation between the number of cigarettes smoked and risk of abruption.     

HLA-DQ基因遗传变异与丙型肝炎病毒感染转归的相关性研究

目的 探讨遗人类白细胞抗原（human leukocyte antigen,HLA）DQ基因多态性与丙型肝炎感染转归的关联。方法 应用TaqMan探针方法检测339例丙型肝炎病毒（hepatitis C virus,HCV）持续感染者,262例HCV自限感染者和942例健康对照者HLA-DQ基因rs2856718和rs7453920位点的基因多态性,比较不同基因型与丙型肝炎病毒感染转归的关系。结果 采用多因素Logistic回归分析,结果显示rs2856718位点杂合基因型AG在感染组中的频率均低于对照组（调整OR=0.73,95%CI:0.56~0.94）;另外,rs7453920 AA基因型可增加个体对HCV的易感性（调整OR=1.75,95%CI:1.01~3.03）。结果显示,与AG单倍型相比,携带AA单倍型的个体可增加丙型肝炎易感性（调整OR=1.67,95%CI:1.11~2.52）。分层分析结果发现,在男性人群中,rs2856718位点的杂合基因型AG在感染组中的频率低于对照组（调整OR=0.68,95%CI:0.51~0.93）;在45~60岁人群中,rs7453920位点突变纯合基因型GG在感染组中的频率高于对照组（调整OR=2.35,95%CI:1.11~4.98）。结论 HLA-DQ基因多态性与丙型肝炎病毒感染转归存在关联。     

Comparison of symptoms and treatment outcomes between actively and passively detected tuberculosis cases: the additional value of active case finding

Passive detection of tuberculosis (TB) cases may lead to delay in treatment which may contribute to increased severity of disease and mortality. Active case finding may be an alternative. In a community survey in Cape Town, South Africa, we actively detected 27 bacteriologically positive TB cases and compared those with 473 passively detected TB cases. Seven of 27 (26%) actively detected TB cases did not start treatment within 2 months and were considered initial defaulters. Those who did start treatment had similar treatment success rates as passively detected TB cases (both 80%) (OR 1.01, CI 0.33-3.09). Passively detected cases reported the presence of the symptoms cough (OR 3.72, 95% CI 1.47-9.39), haemoptysis (OR 3.20, 95% CI 1.03-9.93), night sweats (OR 3.35, 95% CI 1.40-7.99), fever (OR 4.28, 95% CI 1.21-15.14), and weight loss (OR 11.14, 95% CI 4.17-29.74) more often than those detected actively. We conclude that although TB cases detected by a community survey are less symptomatic and are prone to a high initial default rate, active case finding can potentially identify a substantial portion of the existing caseload at an earlier stage of disease, thereby reducing the risk of transmission.     

High Prevalence of tuberculosis infection among medical students in Makerere University,Kampala: results of a cross sectional study

Background

Uganda’s Ministry of Health registered a 12% increase in new Tuberculosis (TB) cases between 2001 and 2005. Of these, 20% were from Kampala district and most from Mulago national referral hospital where the largest and the oldest medical school is found. Medical students are likely to have an increased exposure to TB infection due to their training in hospitals compared to other university students. The study compared the prevalence of TB infection and associated factors among undergraduate medical and veterinary students in Makerere University, Uganda.

Methods

This was a cross-sectional study with 232 medical and 250 veterinary undergraduate students. Socio-demographic and past medical history data was collected using questionnaires. A tuberculin skin test was performed on the volar aspect of the left forearm. An induration ≥10 mm in diameter after 48-72 hrs was considered positive. Logistic regression was used to determine association of independent variables with TB infection.

Results

The prevalence of TB infection was higher in medical students (44.8%, 95% C.I= 38.4-51.3%) compared to veterinary students (35.2%, 95% C.I = 29.3-41.1%). The significant predictors of TB infection were: being a medical student (aOR=1.56, 95% CI = 1.05-2.31), male sex (aOR=1.75, 95% CI = 1.17-2.63), history of contact with a confirmed TB case (aOR=1.57, 95% CI = 1.06-2.31) and residing at home (aOR=2.08, 95% CI = 1.20-3.61). Among the medical students, having gone to a day compared to boarding high school (aOR=2.31, 95% CI = 1.06-5.04), involvement in extracurricular clinical exposure (aOR=3.39 95% CI = 1.60-7.16), male sex, residence at home, and history of contact with a TB case predicted TB infection.

Conclusion

Medical students have a higher prevalence of TB infection than veterinary students probably due to increased exposure during training. There is a need to emphasize TB infection control measures in hospitals and the general community.     

The influence of socioeconomic status on stillbirth risk in Sweden

BACKGROUND: Low socioeconomic status (SES) is generally associated with increased risk of stillbirth, but the mechanisms have rarely been investigated. Our aim was to study the association between SES and risk of stillbirth, and to assess whether any differences in risk are mediated by other maternal socio-demographic or anthropometrical characteristics, differences in lifestyle, or attendance at antenatal care. METHODS: Population-based individually-matched case-control study including 702 cases of stillbirth and 702 controls among Swedish primiparous women giving birth 1987-1996. We estimated the risk of stillbirth, and subgroups of stillbirth, for various categories of SES. Odds ratios (OR) with 95% CI, estimated by conditional logistic regression, were used to approximate the relative risk. The estimates were adjusted for maternal age, height, body mass index, cigarette smoking, and when necessary mother's country of birth. RESULTS: Compared with women who were high level white-collar workers, the adjusted risks of stillbirth were as follows: unskilled blue-collar workers, 2.2 (95% CI : 1.3- 3.7), skilled blue-collar workers, 2.4 (95% CI : 1.3-4.1), low level white-collar workers, 1.9 (95% CI : 1.2-3.2), and intermediate level white-collar workers 1.4 (95% CI : 0.9-2.4). These risks were not substantially changed when we further adjusted for attendance at antenatal care, previous reproductive history, or excluded pregnancies with maternal diseases, and pregnancy-related disorders. Low social class was most associated with risks of term antepartum and intrapartum stillbirths. CONCLUSIONS: Low SES increases the risk of stillbirth. The association could not be explained by any of the factors we studied, and the underlying reasons remain unclear.