Risk Factors For Positive Test Research Articles

Spatio-temporal distribution and agroecological factors associated with canine leptospirosis in Great Britain

Leptospirosis is an important global zoonotic disease that affects a wide range of mammalian species. Canine leptospirosis outbreaks have been reported after metereological events such as flooding (eg. in Brazil and the United States of America) suggesting an environmental association, but there has been no such study in Great Britain (GB). The distribution of cases across GB is also unreported. Objectives of this study were to: (1) assess the spatio-temporal variation of leptospirosis test submissions (2) explore associations between agroecological risk factors and distribution of different canine leptospirosis serogroups in GB, and (3) generate probability of presence maps for the different serogroups. Data analysed comprised laboratory submissions (n = 3986) to IDEXX laboratories between 1st January 2009 and 31st December 2018 for PCR or MAT leptospirosis testing. Spatial and seasonal scan statistics were used to investigate spatial and temporal clustering of positive tests, logistic regression was used to identify significant agroecological risk factors for positive tests, and the Maxent algorithm was used to model the environmental niche of four serogroups. There was an increased risk of a positive test result in the West Midlands of England (relative risk = 2.16) and between October and January (relative risk = 1.54). Logistic regression identified season and region to be significantly associated with a positive diagnosis,with higher odds of a positive test in Autumn (OR = 1.86 95 %CI 1.29−2.69) and Winter (OR = 1.51, 95 %CI 1.02−2.23) and in the East (OR = 2.20, 95 %CI = 1.31−3.71) and West Midlands (OR = 2.32, 95 %CI 1.45−3.71). The increased test-positive proportion in Autumn together with the increased odds of a positive diagnosis in Autumn suggests there may be a seasonal pattern to the canine leptospirosis in GB. The most important variable associated with higher leptospirosis presence in all ecological niche models was higher average annual temperature. The importance and retention of other variables differed between serogroups. Overall, a higher probability of leptospirosis presence was predicted in southern England and a low probability in Scotland and northern England. Although leptospirosis vaccine usage provides protection against the majority of serogroups identified here, one is not represented in the currently licensed vaccine formulations and therefore leptospirosis should remain a differential diagnosis in vaccinated dogs demonstrating consistent clinical signs of the disease.

"Yubi-wakka" (Finger-Ring) Test: A Tool to Detect Prefrailty in Elderly Populations, a Pilot Study.

BackgroundPreventing frailty of elderly is an urgent issue in Japan. The “Yubi-wakka” (finger-ring) test was developed and validated as a predictor of sarcopenia, disability and even mortality. To clarify the prevalence of “frailty” defined by this test and the relationship between other indexes cross-sectionally and prospectively, we conducted this study.MethodsFive thousand four hundred and five subjects who were 65 to 74 years old participated in this study. In a sitting position, the subjects surrounded their calf using their own finger-ring, and whether the calf was larger, just fit, or smaller than the finger-ring was determined. We analyzed these “Yubi-wakka” (finger-ring) test results and other clinical indexes. We used Student’s t-tests and the Chi-squared tests to compare the data between the groups, and logistic regression tests to adjust for multiple variables.ResultsIn total, 38.8% of the subjects’ calves were judged as being “larger”, 45.6% as “just fit” and 15.6% as “smaller”, which was the positive test result. The positive rate differed among medical facilities without any known different characteristics. The comparison between the “larger” and “smaller” groups revealed that body weight, red blood cell count, serum lipids, uric acid and liver enzymes were significantly different between the groups. Metabolic syndrome was more common in the “larger” group. In multiple analysis, low body mass index was an independent risk factor in both sexes. Positive urinary glucose, higher aspartate aminotransferase, systolic blood pressure and low alanine transaminase were risk factors for positive test results for males. Smoking, high hemoglobin and old age were risk factors for positive test results in females.ConclusionsThe test was simple and feasible enough for the primary care setting, without the requirement of any devices. However, the positive rate varied among the clinics. The subjects’ age was limited to under 75 years, and the test possibly detected individuals without metabolic syndrome and fatty liver. We are also planning to increase the subjects’ age range and collect data prospectively.

Interferon-Gamma Release Assay-Based Screening for Pediatric Latent Tuberculosis Infection in an Urban Primary Care Network

To assess outcomes from a QuantiFERON-tuberculosis (TB) Gold (QFT)-based screening for pediatric latent TB infection (LTBI) in the Denver Health Community Health System (CHS), an urban primary-care network in the US. We retrospectively analyzed all QFTs (n = 6685) performed on children aged 2-18 years between January 5, 2011, and August 18, 2014. Risk factors for positive testing in the CHS population were identified by logistic regression, and further assessed using a case-control comparison. Results from CHS were compared with higher-TB-risk populations (refugee and TB clinics) in our health system. Positive QFT occurred in 79 of 3745 (2.1%) CHS patients. Positive rates increased with age (0.3% in age 2-5 years to 4.9% in age 13-18 years). Indeterminate results were uncommon (0.8%) including in children <5 (1.3%). Risk factors for positive tests in the CHS population included non-Medicaid insured/uninsured and non-English/Spanish preferred language. In the case-control analysis, birth/travel to/residence in a TB-endemic country was the only identified risk factor for positive testing (OR 5.2 [95% CI 1.04-25.5]). Rates of positive testing were lower in the CHS population than the refugee/TB clinic populations, including among children age 2-5. QFT-based LTBI screening was successfully introduced in our pediatric primary-care health system, and supported our programmatic goals of identifying LTBI cases while limiting unnecessary LTBI treatment courses. Increasing positive rates with age, and higher rates in the refugee/TB populations compared with CHS, add indirect evidence of adequate test sensitivity, even among young children, for whom data on interferon-gamma release assay performance are limited.

Angiostrongylus vasorum infection in dogs: Presentation and risk factors

Infection with the nematode Angiostrongylus vasorum is an emerging cause of canine disease in Europe and part of North America, yet published data on its epidemiology in endemic areas are lacking. This study tested faecal samples from 897 dogs attending veterinary practices in the southern part of Great Britain, a long standing endemic focus. Among 790 dogs presenting with respiratory or other signs broadly suggestive of angiostrongylosis, 16% tested positive on a single Baermann's examination, compared with 2% of healthy dogs in the same catchment areas. Risk factors for positive tests included age (higher risk in younger dogs), season (more cases earlier in the calendar year), and worming history (lower risk if given milbemycin oxime in the past 12 weeks). Sex, neutering status and breed were not significant in terms of risk of testing positive. The most common clinical signs in infected dogs were respiratory, along with non-specific signs such as lethargy and exercise intolerance, while bleeding, neurological and gastrointestinal signs were also recorded. Around half the dogs sampled that showed signs of extra-pulmonary disease also had respiratory signs. Direct faecal smears and Baermann's tests read after one hour detected 56% and 83% of diagnosed cases respectively. The data confirm that A. vasorum is commonly associated with disease in endemic areas, which manifests with a broad range of signs at primary care level. Information on risk factors is useful in diagnosis and control, and forms a basis for further epidemiological investigation.

Tuberculin Skin Testing of Hospitalized Patients

We sought to define the prevalence of tuberculin skin test (TST) positivity in a group of newly hospitalized patients, to identify risk factors for positive tests, and to examine the impact of testing on infection control practices.Unblinded cohort study over 5 days in July 1992.A 1,000-bed university-affiliated hospital.All patients admitted (excluding obstetric patients and newborns) were interviewed. Patients without a history of tuberculosis (TB) or a positive TST were offered a TST with Candida and tetanus controls.Of 346 patients offered the test, 21 (6%) had a prior history of TB or a positive TST, and 36 (10%) declined to participate; 279 of the remaining 289 completed the study. Anergy was demonstrated in 94 (33.7%) of 279 patients. New positive TSTs were identified in 19 (10.3%) of 185 nonanergic patients. Of the 19 TST-positive patients, 6 (32%) had infiltrates on chest radiographs and were evaluated for active TB. One patient was treated empirically for active TB, and five received isoniazid prophylaxis. Risk factors for a new positive TST included age (odds ratio [OR], 1.56 per decade of life; P = .021), African American race (OR, 4.81; P = .008), alcohol abuse (OR, 5.53; P = .005), and peptic ulcer disease (OR, 4.53; P = .017). Risk factors for anergy included admission to a surgical service (OR, 2.1; P = .006), current use of steroids (OR, 2.65; P = .005), and human immunodeficiency virus (HIV) infection (OR, undefined; P = .034).Despite a high rate of anergy, routine tuberculin skin testing identified a substantial number of patients with TB infection who might otherwise have gone unrecognized.

Tuberculin skin testing of hospitalized patients.

We sought to define the prevalence of tuberculin skin test (TST) positivity in a group of newly hospitalized patients, to identify risk factors for positive tests, and to examine the impact of testing on infection control practices. Unblinded cohort study over 5 days in July 1992. A 1,000-bed university-affiliated hospital. All patients admitted (excluding obstetric patients and newborns) were interviewed. Patients without a history of tuberculosis (TB) or a positive TST were offered a TST with Candida and tetanus controls. Of 346 patients offered the test, 21 (6%) had a prior history of TB or a positive TST, and 36 (10%) declined to participate; 279 of the remaining 289 completed the study. Anergy was demonstrated in 94 (33.7%) of 279 patients. New positive TSTs were identified in 19 (10.3%) of 185 nonanergic patients. Of the 19 TST-positive patients, 6 (32%) had infiltrates on chest radiographs and were evaluated for active TB. One patient was treated empirically for active TB, and five received isoniazid prophylaxis. Risk factors for a new positive TST included age (odds ratio [OR], 1.56 per decade of life; P = .021), African American race (OR, 4.81; P = .008), alcohol abuse (OR, 5.53; P = .005), and peptic ulcer disease (OR, 4.53; P = .017). Risk factors for anergy included admission to a surgical service (OR, 2.1; P = .006), current use of steroids (OR, 2.65; P = .005), and human immunodeficiency virus (HIV) infection (OR, undefined; P = .034). Despite a high rate of anergy, routine tuberculin skin testing identified a substantial number of patients with TB infection who might otherwise have gone unrecognized.