Prediction of Shigellosis outcomes in Israel using machine learning classifiers.

Shigellosis causes significant morbidity and mortality in developing and developed countries, mostly among infants and young children. The World Health Organization estimates that more than one million people die from Shigellosis every year. In order to evaluate trends in Shigellosis in Israel in the years 2002-2015, we analysed national notifiable disease reporting data. Shigella sonnei was the most commonly identified Shigella species in Israel. Hospitalisation rates due to Shigella flexenri were higher in comparison with other Shigella species. Shigella morbidity was higher among infants and young children (age 0-5 years old). Incidence of Shigella species differed among various ethnic groups, with significantly high rates of S. flexenri among Muslims, in comparison with Jews, Druze and Christians. In order to improve the current Shigellosis clinical diagnosis, we developed machine learning algorithms to predict the Shigella species and whether a patient will be hospitalised or not, based on available demographic and clinical data. The algorithms' performances yielded an accuracy of 93.2% (Shigella species) and 94.9% (hospitalisation) and may consequently improve the diagnosis and treatment of the disease.

Association between ambient air pollution and proliferation of umbilical cord blood cells.

It has been established as a common knowledge that ambient air pollution (AAP) has an adverse effect on human health. The pathophysiological mechanism of this impact is likely to be related to the oxidative stress. In the current study we estimate the association between AAP and cell proliferation (CP) of umbilical cord blood cells, representing maternal organism most proximal to the fetal body. Blood samples were tested for proliferation in 292 enrolled Arab-Bedouin women at delivery (July 2012-March 2013). The estimates of AAP were defined by a hybrid satellite based model predicting both PM2.5 (particles<2.5µm in diameter) and PM10 (particles<10µm in diameter) as well as monitoring stations for gaseous air pollutants. Risk estimates of pollution exposure were adjusted to medical history, household risk factors and meteorological factors on the day of delivery or one week prior. Ambient ozone (O3) levels on 1, 2, 3and 4 days prior to delivery were associated with lower CP (Prevalence ratio (PR)=0.92, 0.92, 0.93, 0.93, respectively). Increase in inter-quartile range (IOR) of PM2.5 one day before delivery was associated with 9% increase in CP levels (PR=1.09). The positive direction in association was changed to negative association with CP for PM2.5 levels measured at more distant time periods (PR=0.90 and 0.93 for lags 5 and 6 days, respectively). Investigation of PM10 levels indicated a similar pattern (PR=1.05 for pollution values recorded one day before delivery and 0.93 and 0.95 for lags of 5 and 6 days, respectively). Carbon monoxide (CO) levels were associated with lower CP on the day of delivery and 1day prior (PR=0.92 and PR=0.94). To conclude, the levels of cell proliferation of umbilical cord blood cells appear to be associated with the AAP. More studies are needed to support our findings.

Reduction of blood culture contamination rate by an educational intervention.

The efficacy of an educational intervention to prevent blood culture contamination (BCC) in internal medicine was studied in two medical wards in a busy tertiary-care hospital in which blood cultures were obtained by physicians rather than dedicated phlebotomists. Baseline BCC rates were 5.7% and 7.1% in intervention and control wards, respectively (p 0.6), compared with 1.95% and 6.7%, respectively, post-intervention (p < 0.001). Following multivariate analysis, only an absence of intervention was an independent variable associated with BCC. Thus simple educational intervention reduced BCC in internal medicine and was considered to be cost-effective.

Seroepidemiology and molecular epidemiology of Kaposi's sarcoma-associated herpesvirus among Jewish population groups in Israel.

BACKGROUND: The incidence of classic Kaposi's sarcoma among Jews in Israel is among the highest in the developed world. Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8) is causally linked to Kaposi's sarcoma. Very little is known about the prevalence of KSHV in the Middle East or about the modes of transmission in Mediterranean countries. METHODS: From 1992 through 1995, sera were obtained from 1648 adults who had tested positive for hepatitis B virus (HBV) surface antigen 20 years earlier at blood donations; sera were also obtained from 2403 of their family members. All sera were tested for anti-KSHV antibodies with the use of an indirect immunofluorescence assay. To analyze the effects of various factors on the risk of KSHV infection for both the HBV-positive cohort and their families, logistic regression for cluster data and generalized estimating equations were used. All statistical tests were two-sided. RESULTS: Among family members, the seroprevalence of antibodies against KSHV was 9.9% (95% confidence interval [CI] = 8.7% to 11.1%); among the former blood donors who had tested positive for hepatitis B, it was 22% (95% CI = 19.9% to 24.1%). Overall, the best predictor of KSHV status was the place of birth. The most important risk factors found for both husband and wife to test KSHV positive were their own places of birth and their spouse's seropositivity. For a child to test positive, the most important risk factor was maternal seropositivity. CONCLUSIONS: The crude prevalence rate of KSHV among the Jewish population in Israel is 9.9%. Important routes of KSHV transmission in the families studied are spouse to spouse and mother to child. The presence of KSHV in Jews in Israel of all ethnic origins and their high incidence of reported Kaposi's sarcoma suggest that KSHV was introduced into the Jewish population prior to the major Diaspora.

Nitrogen Dioxide pollution and hazardous household environment: what impacts more congenital malformations.

Nitrogen Dioxide (NO2) is a product of fuel combustion originating mainly from industry and transportation. Studies suggest an association between NO2 and congenital malformations (CM). We investigated an independent effect of NO2 on CM by adjusting to individual factors and household environment in 1024 Bedouin-Arab pregnant women in southern Israel. This population is characterised by high rates of CMs, frequent consanguineous marriages, paternal smoking, temporary housing and usage of open fire for heat cooking. Information on household risk factors was collected during an interview. Ambient measurements of 24-h average NO2 and meteorological conditions were obtained from 13 local monitors. Median value of daily NO2 measured in the area was 6.78ppb. CM was diagnosed in 8.0% (82) of offspring. Maternal NO2 exposure during the 1st trimester >8.6ppb was significantly associated with minor CM (RR=2.68, p=0.029). Major CM were independently associated with maternal juvenile diabetes (RR=9.97, p-value=0.002) and heating by open fire (RR=2.00, p-value=0.049), but not NO2 exposure. We found that NO2 emissions had an independent impact only on minor malformations, whereas major malformations depended mostly on the household environment. Antepartum deaths were associated by maternal morbidity.

An uncommon pattern of polyneuropathy induced by lifetime exposures to drift containing organophosphate pesticides.

The natural history of chronic peripheral polyneuropathy following lifetime low-level organophosphate (OP) exposure was investigated. A pilot study (1984-1987) conducted in rural communities in Israel detected subtle reversible in-season changes in nerve conduction patterns of 17 field workers out of 214 residents exposed to seasonal drift containing OP's. We examined 60 individuals (males: 50/60; 83.3%) from the original cohort still residing (more than 40 years) in the same communities. Exposure assessment was based on reports by Israeli institutions and the Bureau of Statistics. Information on personal status, work experience, exposures and symptoms was collected by questionnaires. The nervous system was systematically studied, evaluating cortical upper motor neurons, corticospinal tracts, lower motor neurons and peripheral nerves. Electrophysiological studies included conduction velocities, amplitudes and distal latencies of sensory and motor median, ulnar, tibial and sural nerves; F-waves for proximal nerve functions; thermal and pain thresholds for small thinly-myelinated and non-myelinated fibers; transcranial magnetic stimulation for large fibers. Clinical and electrophysiological features of Carpal Tunnel Syndrome were found in 18% of the subjects, atypically in males only. Fingertips' tingling correlated with both axonal and myelin-dependent parameters (lower wave amplitudes and prolonged latency periods, respectively) in the sensory median nerves bilaterally. OP exposure significantly correlated to prolonged distal latency in the right median sensory nerve (r=0.29; p=0.052; n=45) and lower wave amplitude in the right sural nerve (p=0.031). These findings attest to subtle, predominantly sensory peripheral polyneuropathy following lifetime low-level exposures to drifts containing OP.

Housekeeping health care workers have the highest risk for tuberculin skin test conversion.

BACKGROUND: Not all health care workers (HCWs) are at the same risk for tuberculin skin test (TST) conversion, indicating latent tuberculosis (TB) infection. OBJECTIVE: To identify risk factors for TST conversion among HCWs. METHODS: A retrospective cohort study conducted at a tertiary university medical centre included every HCW who had had a negative two-step TST at work entry and at least one consecutive TST in the period 2005-2009 (mean follow-up period 55 months). Binomic logistic regression analysis was used to identify risk factors for TST conversion. Potential risk factors such as age, health care profession, patient exposure profile, workplace division and history of bacille Calmette-Guérin vaccination were entered in the model. RESULTS: A total of 450 subjects met the inclusion criteria, of whom 93 had TST conversion. The highest annual rates of TST conversion occurred in workers who worked as housekeeping staff (6.9%). Older age, a work environment with high patient turnover and employment in maintenance departments were significant risk factors (adjusted odds ratios 2.05, 5.2 and 8.4 respectively). CONCLUSION: Housekeeping staff, older age workers and health care professionals working in an environment of high patient turnover are at increased risk for latent TB infection.

HBsAg confirmation: an experimental test.

BACKGROUND: The specificity of HBsAg testing is to be confirmed with antibody blocking to avoid false positive results. OBJECTIVE: To test the experimental HrAb HBsAg-blocking activity and to use this new antibody in the verification of repeatedly reactive HBsAg blood serum samples. STUDY DESIGN: HbsAg screening of three quality control panels was followed by a comparative confirmatory test with commercial HuAb and experimental HrAb. The HrAb was used in subsequent HBsAg confirmation trials. RESULTS: A good agreement in the results obtained using the two antibodies was found, independently of the type of HBsAg neutralization step performed (either preincubation or competitive inhibition). Of the 97 repeatedly reactive HBsAg blood serum samples, 79 were 'confirmed positives'. On repeated confirmations by two antibodies, 13/18 'not confirmed' converted to 'confirmed positives', while the same five samples still remained false positive. CONCLUSION: The results suggest that (1) HrAb is as good as HuAb in HBsAg confirmation and (2) HBsAg confirmatory testing is essential in the laboratory examinations of the HBsAg repeatedly reactive samples.