Prevalence of Asthma among Young Men Residing in Urban Areas with Different Sources of Air Pollution.

BACKGROUND: Asthma is a common respiratory disease, which is linked to air pollution. However, little is known about the effect of specific air pollution sources on asthma occurrence. OBJECTIVES: To assess individual asthma risk in three urban areas in Israel characterized by different primary sources of air pollution: predominantly traffic-related air pollution (Tel Aviv) or predominantly industrial air pollution (Haifa bay area and Hadera). METHODS: The medical records of 13,875, 16- 19-year-old males, who lived in the affected urban areas prior to their army recruitment and who underwent standard pre-military health examinations during 2012-2014, were examined. Nonparametric tests were applied to compare asthma prevalence, and binary logistic regressions were used to assess the asthma risk attributed to the residential locations of the subjects, controlling for confounders, such as socio-demographic status, body mass index, cognitive abilities, and education. RESULTS: The asthma rate among young males residing in Tel Aviv was 8.76%, compared to 6.96% in the Haifa bay area and 6.09% in Hadera. However, no statistically significant differences in asthma risk among the three urban areas was found in controlled logistic regressions (P > 0.20). This finding indicates that exposure to both industrial- and traffic-related air pollution is associated with asthma prevalence. CONCLUSIONS: Both industrial- and traffic-related air pollution have a negative effect on asthma risk in young males. Studies evaluating the association between asthma risk and specific air pollutants (e.g., sulfur dioxide, particulate matter, and nitrogen dioxide) are needed to ascertain the effects of individual air pollutants on asthma occurrence.

Epidemiologic Surveillance in Israel of Cryptosporidium, a Unique Waterborne Notifiable Pathogen, and Public Health Policy.

BACKGROUND: Cryptosporidium is a major threat to water supplies worldwide. Various biases and obstacles in case identification are recognized. In Israel, Cryptosporidiosis was included among notifiable diseases in 2001 in order to determine the burden of parasite-inflicted morbidity and to justify budgeting a central drinking water filtration plant. OBJECTIVES: To summarize the epidemiologic features of 14 years of Cryptosporidium surveillance and to assess the effects of advanced water purification treatment on the burden of disease. METHODS: From 2001 to 2014, a passive surveillance system was used. Cases were identified based on microscopic detection in stool samples. Confirmed cases were reported electronically to the Israeli Ministry of Health. Overall rates as well as age, gender, ethnicity and specific annual incidence were calculated per 100,000 population in five age groups: 0-4, 5-14, 15-44, 45-64, > 65 years. RESULTS: A total of 522 Cryptosporidium cases were reported in all six public health districts. More cases were detected among Jews and among males, and mainly in young children, with a seasonal peak during summer. The Haifa sub-district reported 69% of the cases. Most were linked to an outbreak from the summer of 2008, which was attributed to recreational swimming pool activity. Cases decreased after installation of a central filtration plant in 2007. CONCLUSIONS: As drinking water in Israel is treated to maximal international standards, the rationale for further inclusion of Cryptosporidium among mandatory notifiable diseases should be reconsidered. Future surveillance efforts should focus on timely detection of outbreaks using molecular high-throughput testing.

Environmental risk factors associated with low birth weight: The case study of the Haifa Bay Area in Israel.

BACKGROUND: Low birth weight (LBW) is known to be associated with infant mortality and postnatal health complications. Previous studies revealed strong relationships between LBW rate and several socio-demographic factors, including ethnicity, maternal age, and family income. However, studies of association between LBW rate and environmental risk factors remain infrequent. STUDY METHODS: We retrieved a geo-referenced data set, containing 7216 individual records of children born in 2015 in the Haifa Bay Area in Israel. Using this dataset, we analysed factors affecting LBW prevalence by applying two alternative techniques: analysis of LBW rates in small census area (SCAs) and more recently developed double kernel density (DKD) relative risk (RR) estimates. RESULTS: In the SCA models, LBW rate was found to be associated with proximity to petrochemical industries (B=-0.26, 95%CI=-0.30, -0.22), road density (B=0.05, 95%CI=0.02, 0.08), distance to the seashore (B=0.17, 95%CI=0.14, 0.22), PM2.5 (B=0.06, 95%CI=0.04, 0.09) and NOx (B=0.10, 95%CI=0.06, 0.13) exposure estimates. Although similar factors emerged in the DKD models as well, in most cases, the effects of these factors in the latter models were found to be stronger: proximity to petrochemical industries (B=-0.48, 95%CI= -0.51, -0.30), road density (B=0.05, 95%CI=0.02, 0.08), distance to the seashore (B=0.24, 95%CI=0.21, 0.27), PM2.5 (B=0.08, 95%CI=0.05, 0.10) and NOx (B=0.20, 95%CI=0.17, 0.23) exposure estimates. In addition, elevation above the sea level was found to be statistically significant in spatial dependence models estimated for both DKD and SCA rates (P < 0.01). CONCLUSION: The analysis revealed an excess LBW rate in residential areas located close to petrochemical industries and a protective effect of seashore proximity and elevation above the sea level on the LBW rate. We attribute the latter finding to the moderating effect of elevated seashore locations on outdoor temperatures during the hot summer season.

Application of the double kernel density approach to the analysis of cancer incidence in a major metropolitan area.

RATIONALE: Although cancer is a main cause of human morbidity worldwide, relatively small numbers of new cancer cases are recorded annually in single urban areas. This makes the association between cancer morbidity and environmental risk factors, such as ambient air pollution, difficult to detect using traditional methods of analysis based on age standardized rates and zonal estimates. STUDY GOAL: The present study investigates the association between air pollution and cancer morbidity in the Greater Haifa Metropolitan Area in Israel by comparing two analytical techniques: the traditional zonal approach and more recently developed Double Kernel Density (DKD) tools. While the first approach uses age adjusted Standardized Incidence Ratios (SIRs) for small census areas, the second approach estimates the areal density of cancer cases, normalized by the areal density of background population in which cancer events occurred. Both analyses control for several potential confounders, including air pollution, proximities to main industrial facilities and socio-demographic attributes. RESULTS: Air pollution variables and distances to industrial facilities emerged as statistically significant predictors of lung and NHL cancer morbidity in the DKD-based models (p<0.05) but not in the models based on SIRs estimates (p>0.2). CONCLUSION: DKD models appear to be a more sensitive tool for assessing potential environmental risks than traditional SIR-based models, because DKD estimates do not depend on a priory geographic delineations of statistical zones and produce a smooth and continuous disease 'risk surface' covering the entire study area. We suggest using the DKD method in similar studies of the effect of ambient air pollution on chronic morbidity, especially in cases in which the number of statistical areas available for aggregation and comparison is small and recorded morbidity events are relatively rare.

Environmental rather than genetic factors determine the variation in the age of the infancy to childhood transition: a twins study.

OBJECTIVE: Using a twins study, we sought to assess the contribution of genetic against environmental factor as they affect the age at transition from infancy to childhood (ICT). STUDY DESIGN: The subjects were 56 pairs of monozygotic twins, 106 pairs of dizygotic twins, and 106 pairs of regular siblings (SBs), for a total of 536 children. Their ICT was determined, and a variance component analysis was implemented to estimate components of the familial variance, with simultaneous adjustment for potential covariates. RESULTS: We found substantial contribution of the common environment shared by all types of SBs that explained 27.7% of the total variance in ICT, whereas the common twin environment explained 9.2% of the variance, gestational age 3.5%, and birth weight 1.8%. In addition, 8.7% was attributable to sex difference, but we found no detectable contribution of genetic factors to inter-individual variation in ICT age. CONCLUSIONS: Developmental plasticity impacts much of human growth. Here we show that of the ∼50% of the variance provided to adult height by the ICT, 42.2% is attributable to adaptive cues represented by shared twin and SB environment, with no detectable genetic involvement.

Variables correlated with elderly referral from nursing homes to general hospitals.

BACKGROUND: Referring patients from nursing homes to general hospitals exposes them to nosocomial diseases, and may result in the development of a broad spectrum of physical, mental and social damages. Therefore, minimizing the referring of nursing home patients to hospitals is an important factor for keeping the elderly healthy and minimizing health expenditures. In this study we examined the variables related to the referral rates from nursing homes to general hospitals and the relationship between the referral and the mortality rates among the elderly who live in nursing homes in the Haifa Sub-district. METHODS: Thirty-two nursing homes were included in a cross-sectional study. All medical directors and head nurses were interviewed using a structured questionnaire between November 2006 and October 2007. Statistical analysis, including the ANOVA and the nonparametric Spearman tests, were employed to determine the factors that influence referral rates and the correlation between referral rates and mortality rates. RESULTS: The referral rate ranged between 18 and 222 per 100 financed elderly in a single year. In the multivariate analysis, the absence of a physician from the nursing home at the time of the referral to general hospitals was the only significant variable related to referral rates. No significant relationships were found between referral rates and mortality rates. CONCLUSIONS: Absence of a significant relationship between referral rates and mortality rates may indicate that high referral rates do not necessarily protect the elderly from death. Therefore, any recommendations issued by the Ministry of Health (MOH) should emphasize in-house treatment rather than hospitalization. Clear instructions on referral from nursing homes to general hospitals need to be constructed by the MOH. The MOH should increase the presence of physicians in the nursing homes, especially, when the need to refer a patient arises. Further quantitative and epidemiologic studies should be conducted in order to, more fully and reliably, create guidelines for policy recommendations.

Contribution of nitrogen oxide and sulfur dioxide exposure from power plant emissions on respiratory symptom and disease prevalence.

This study investigates the association between exposure to ambient NOx and SO2 originating from power plant emissions and prevalence of obstructive pulmonary disease and related symptoms. The Orot Rabin coal-fired power plant is the largest power generating facility in the Eastern Mediterranean. Two novel methods assessing exposure to power plant-specific emissions were estimated for 2244 participants who completed the European Community Respiratory Health Survey. The "source approach" modeled emissions traced back to the power plant while the "event approach" identified peak exposures from power plant plume events. Respiratory symptoms, but not prevalence of asthma and COPD, were associated with estimates of power plant NOx emissions. The "source approach" yielded a better estimate of exposure to power plant emissions and showed a stronger dose-response relationship with outcomes. Calculating the portion of ambient pollution attributed to power plants emissions can be useful for air quality management purposes and targeted abatement programs.

Residential proximity to petroleum storage tanks and associated cancer risks: Double Kernel Density approach vs. zonal estimates.

BACKGROUND AND AIMS: The relationship between exposure to petroleum products and cancer is well-established in occupational studies carried out among employees of transportation and oil-producing industries. However, question remains whether living near petroleum storage facilities may represent a cancer risk. In the present study, we examined cancer incidence rates associated with residential proximity to the Kiryat Haim industrial zone in Northern Israel, using different analytical techniques and adjusting for several potential confounders, such as road proximity, population density, smoking rates and socio-demographic attributes. METHODS: Both traditional zonal approaches and more recently developed Double Kernel Density (DKD) tools were used to estimate relative risks of lung and NHL cancers attributed to residential proximity to the petroleum storage site. RESULTS: Zonal approaches based on comparing ASRs across small census areas (SCAs) did not detect any significant association between residential proximity to the industrial zone and the two types of cancers under study (P>0.2). In contrast, the DKD approach revealed that the relative density of both lung and NHL cancers declined in line with distances from the industrial zone, especially among the elderly (Lung: t>-12.0; P<0.01; NHL: t>-9.0; P<0.01), adjusted for proximity to main roads, population density, smoking rate, average income, and several other potential confounders. CONCLUSIONS: Living near petroleum storage sites may represent significant cancer risk which cannot always be detected by traditional zonal approaches commonly used in epidemiological studies, especially if the number of census areas available for the analysis is small.

High prevalence of childhood asthma in Northern Israel is linked to air pollution by particulate matter: evidence from GIS analysis and Bayesian Model Averaging.

The medical records of 3922 school children residing in the Greater Haifa Metropolitan Area in Northern Israel were analyzed. Individual exposure to ambient air pollution (SO(2) and PM(10)) for each child was estimated using Geographic Information Systems tools. Factors affecting childhood asthma risk were then investigated using logistic regression and the more recently developed Bayesian Model Averaging (BMA) tools. The analysis reveals that childhood asthma in the study area appears to be significantly associated with particulate matter of less than 10 µm in aerodynamic diameter (PM(10)) (Odds Ratio (OR) = .11; P<0.001). However, no significant association with asthma prevalence was found for SO(2) (P >0.2), when PM(10) and SO(2) were introduced into the models simultaneously. When considering a change in PM(10) between the least and the most polluted parts of the study area (9.4 µg/m(3)), the corresponding OR, calculated using the BMA analysis, is 2.58 (with 95% posterior probability limits of OR ranging from 1.52 to 4.41), controlled for gender, age, proximity to main roads, the town of a child's residence, and family's socio-economic status. Thus, it is concluded that exposure to airborne particular matter, even at relatively low concentrations (40-50 µg/m(3)), generally below international air pollution standards (55-70 µg/m(3)), appears to be a considerable risk factor for childhood asthma in urban areas. This should be a cause of concern for public health authorities and environmental decision-makers.

Influenza vaccination coverage determinants among employees of the Nazareth Hospital in Israel.

BACKGROUND: Health care workers bear the risk of both contracting influenza from patients and transmitting it to them. Although influenza vaccine is the most effective and safest public health measure against influenza and its complications, and despite recommendations that HCWs be vaccinated, influenza vaccination coverage among them remains low. OBJECTIVES: To characterize influenza vaccination coverage and its determinants among employees in an Arab hospital in Israel. METHODS: An anonymous self-administered questionnaire was distributed among employees involved in patient care in the winter of 2004-2005 at Nazareth Hospital in Israel. The questionnaire included items related to health demographic characteristics, health behaviors and attitudes, knowledge and attitude concerning influenza vaccination, and whether the respondent had received the flu shot during the previous winter or any other winter. RESULTS: The overall rate of questionnaire return was 66%; 256 employees participated in the study. The immunization coverage rate was 16.4%, similar to that reported for other hospitals in Israel. Logistic regression analysis demonstrated that influenza vaccination coverage was significantly and solely associated with the presence of chronic illness and influenza vaccination. CONCLUSIONS: Influenza vaccination coverage among Nazareth Hospital health care workers was low. They did not view themselves as different from the general population with regard to vaccination. Three years after the study, an intervention program was launched with the aim of increasing knowledge on the efficacy and safety of the vaccine; it stressed the importance of vaccinating HCWs and administering the vaccine at the workplace. The program led to a 50% increase in vaccination coverage.

Spatial analysis of air pollution and cancer incidence rates in Haifa Bay, Israel.

The Israel National Cancer Registry reported in 2001 that cancer incidence rates in the Haifa area are roughly 20% above the national average. Since Haifa has been the major industrial center in Israel since 1930, concern has been raised that the elevated cancer rates may be associated with historically high air pollution levels. This work tests whether persistent spatial patterns of metrics of chronic exposure to air pollutants are associated with the observed patterns of cancer incidence rates. Risk metrics of chronic exposure to PM(10), emitted both by industry and traffic, and to SO(2), a marker of industrial emissions, was developed. Ward-based maps of standardized incidence rates of three prevalent cancers: Non-Hodgkin's lymphoma, lung cancer and bladder cancer were also produced. Global clustering tests were employed to filter out those cancers that show sufficiently random spatial distribution to have a nil probability of being related to the spatial non-random risk maps. A Bayesian method was employed to assess possible associations between the morbidity and risk patterns, accounting for the ward-based socioeconomic status ranking. Lung cancer in males and bladder cancer in both genders showed non-random spatial patterns. No significant associations between the SO(2)-based risk maps and any of the cancers were found. Lung cancer in males was found to be associated with PM(10), with the relative risk associated with an increase of 1 microg/m(3) of PM(10) being 12%. Special consideration of wards with expected rates <1 improved the results by decreasing the variance of the spatially correlated residual log-relative risk.

Who is affected more by air pollution-sick or healthy? Some evidence from a health survey of schoolchildren living in the vicinity of a coal-fired power plant in Northern Israel.

OBJECTIVE: To evaluate the effects of exposure to air pollution by NO(x) and SO(2) on the development of pulmonary function of children, characterized by different health status. METHODS: A cohort of 1181 schoolchildren from the 2nd to 5th grades, residing near a major coal-fired power plant in the Hadera district of Israel, were subdivided into three health status groups, according to the diagnosis given by a physician at the beginning of the study period in 1996: (a) healthy children; (b) children experiencing chest symptoms, and (c) children with asthma or spastic bronchitis. Pulmonary Function Tests (PFTs) were performed twice (in 1996 and 1999) and analyzed in conjunction with air pollution estimates at the children's places of residence and several potential confounders-height, age, gender, parental education, passive smoking, housing density, length of residence in the study area and proximity to the main road. RESULTS: A significant negative association was found between changes in PFT results and individual exposure estimates to air pollution, controlled for socio-demographic characteristics of children and their living conditions. A sensitivity analysis revealed a decrease in the Forced Expiratory Volume during the First Second (FEV(1)) of about 19.6% for children with chest symptoms, 11.8% for healthy children, and approximately 7.9% for children diagnosed with asthma. Results of a sensitivity test for the Forced Vital Capacity (FVC) were found to be similar. CONCLUSION: Exposure to air pollution appeared to have had the greatest effect on children with chest symptoms. This phenomenon may be explained by the fact that this untreated symptomatic group might experience the most severe insult on their respiratory system as a result of exposure to ambient air pollution, which is reflected by a considerable reduction in their FEV(1) and FVC. Since asthmatic children have lower baseline and slower growth rates, their PFT change may be affected less by exposure to air pollution, reflecting a well known relationship between pulmonary function change and height growth, according to which age-specific height is very similar for preadolescent children, but shifts upward with age during the growth spurt.

Exploratory analysis of potential risk factors of a rare disease: spatial distribution of adrenocortical carcinoma in Israel as a case study.

The underlying assumption of the proposed exploratory approach is that, if the geographic patterns of different diseases are compared, the cases of a 'subject' disease should occur closer to cases of a disease with similar environmental risk factors (etiology) and farther away from cases of a disease with different etiology. In the present study, the performance of proposed approach is investigated by cross-examination of the spatial patterns of three widespread cancers--lung, larynx and colorectal (CRC)--with that of a rare malignant disease--Adrenocortical Carcinoma (ACC). As the analysis indicates, the spatial distribution of ACC is more likely to be related to hereditary factors than to environmental causes, in accordance with current knowledge about this rare disease.

A change in rabies post-exposure treatment guidelines after decision analysis in Israel.

BACKGROUND: Rabies remains a significant public health problem in Israel. Some 16 000-20 000 persons come yearly to the district health offices after being bitten by animals and 16-18% receive rabies post-exposure treatment. A quality assessment of the rabies post-exposure prophylaxis decisions was never held in Israel before. The purpose of this study was to analyse the decision-making process and to update our rabies prevention guidelines accordingly. METHODS: A retrospective evaluation study of physicians' compliance with rabies post-exposure treatment guidelines in Haifa District Health Office, Ministry of Health, during 1/11/1999 to 31/12/2002. Records of all persons seeking advice (5037) following exposure to animals during the 3 years of the study were examined. Of these 2477 were eligible for the quality audit. The remaining files were analysed for the relative contribution of the different variables considered in the decision-making process. RESULTS: Observed agreement rate and Kappa coefficient were 0.984 and 0.803, respectively. The probability of recommending vaccination was greater when the exposure was from stray dogs as opposed to cats (OR = 48.9; 95% CI 17.9-133.3), if the wound was a bite rather than a scratch (OR = 29.0; 95% CI 19.5-43.2) or in a location defined as rabies enzootic as opposed to rabies free (OR = 7.6; 95% CI 5.8-10.1). CONCLUSIONS: The study demonstrated high compliance with the written guidelines. We weighted the relative importance of the variables determining the decisions. This information was used in formulating the updated guidelines.

Estimating the effect of air pollution from a coal-fired power station on the development of children's pulmonary function.

Using geographical information systems (GIS) tools, the present study analyzed the association between children's lung function development and their long-term exposure to air pollution. The study covered the cohort of 1492 schoolchildren living in the vicinity of a major coal-fired power station in the Hadera sub-district of Israel. In 1996 and 1999, the children underwent subsequent pulmonary function tests (PFT) (forced vital capacity (FVC) and forced expiratory volume during the first second (FEV(1))), and the children's parents completed a detailed questionnaire on their health status and household characteristics. A negative association was found between changes in the results of PFT and the estimated individual levels of air pollution. A sensitivity test revealed a FEV(1) decline from -4.3% for the average pollution level to -10.2% for the high air pollution level. The results of a sensitivity test for FVC were found to be similar. Association with the reported health status was found to be insignificant. As we conclude, air pollution from a coal-fired power station, although not exceeding local pollution standards, had a negative effect on children's lung function development. As argued, previous studies carried out in the region failed to show the above association because they were based on zone approaches that assign average concentration levels of air pollutants to all individuals in each zone, leading to a misclassification bias of individual exposure.

On ecological fallacy, assessment errors stemming from misguided variable selection, and the effect of aggregation on the outcome of epidemiological study.

In social and environmental sciences, ecological fallacy is an incorrect assumption about an individual based on aggregate data for a group. In the present study, the validity of this assumption was tested using both individual estimates of exposure to air pollution and aggregate data for 1,492 schoolchildren living in the in vicinity of a major coal-fired power station in the Hadera region of Israel. In 1996 and 1999, the children underwent subsequent pulmonary function tests (PFT), and their parents completed a detailed questionnaire on their health status and housing conditions. The association between children's PFT results and their exposure to air pollution was investigated in two phases. During the first phase, PFT averages were compared with average levels of air pollution detected in townships, and small census areas in which the children reside. During the second phase, individual pollution estimates were compared with individual PFT results, and pattern detection techniques (Getis-Ord statistic) were used to investigate the spatial data structure. While different levels of areal data aggregation changed the results only marginally, the choice of indices measuring the children's PFT performance had a significant influence on the outcome of the analysis. As argued, differences between individual-level and group-level effects of exposure (i.e., ecological or cross-level bias) are not necessary outcomes of data aggregation, and that seemingly unexpected results may often stem from a misguided selection of variables chosen to measure health effects. The implications of the results of the analysis for epidemiological studies are discussed, and recommendations for public health policy are formulated.

Classic Kaposi sarcoma. Which KSHV-seropositive individuals are at risk?

BACKGROUND: Classic Kaposi sarcoma (CKS) is a relatively rare vascular disease primarily affecting human immunodeficiency virus (HIV)-uninfected elderly men. The infection with Kaposi sarcoma-associated herpesvirus (KSHV) is necessary for the establishment of Kaposi sarcoma (KS), although it is not sufficient. Thus, only a small fraction of KSHV-infected individuals develops KS. The cofactors that influence risk of KS among HIV-uninfected individuals are yet to be determined. The objective of the current study was to assess potential risk factors for CKS in the KSHV-infected Jewish population in Israel. METHODS: A case-control study involved 35 CKS cases and 48 matched KSHV-infected controls. Lifestyle and medical history data from case patients and controls were compared by logistic regression analysis. RESULTS: In a multivariate analysis, the authors identified an age-related small increased risk for CKS in subjects originating from Asia and Africa. The risk for CKS increased, although not significantly statistically, in subjects who reported alcohol consumption, diabetes mellitus, herpes simplex, and asthma. No relation was found with cigarette smoking, family size, number of lifetime sexual partners, or sexually transmitted disease. CONCLUSIONS: A borderline increase in CKS risk among elderly subjects originating from Africa or Asia was identified. These results need to be further evaluated by larger studies. The authors believe that genetic and immunologic parameters may alter risk for CKS and, therefore, should also be investigated.

Infection with Kaposi's sarcoma-associated herpesvirus among families of patients with classic Kaposi's sarcoma.

BACKGROUND: Classic Kaposi's sarcoma (CKS) primarily affects elderly Mediterranean or Eastern European men. Incidence rates of CKS in Israel are among the world's highest. In practically all cases, antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV) can be detected. A relatively high seroprevalence rate of KSHV in Israel generally correlates with the incidence of CKS. A sexual mode of virus transmission is recognized among homosexual men, whereas the precise transmission routes in the heterosexual population and those with CKS are still unclear. OBJECTIVE: To better assess the transmission routes of KSHV in Israeli patients with CKS and their first-degree relatives as compared with a control group. DESIGN: Serum was collected from all study participants and tested for KSHV antibodies by means of latent and lytic immunofluorescence assays. An open reading frame 65 (ORF65) Western blot assay was applied as a confirmatory tool. SETTING: Three dermatological departments in Israel. PATIENTS: Sixty-four Jewish patients with CKS, 143 of their first-degree relatives, and 186 hospital-based control subjects. RESULTS: Seropositivity to KSHV was detected in 62 (96.9%) of the patients with CKS, in 56 (39.2%) of their first-degree relatives, and in only 21 (11.3%) of the hospital controls (P<.001). The specific relationship with the index patient (spouse, offspring, or sibling) had no significant effect on the prevalence of serpositivity in the family members. CONCLUSION: Our serologic evidence of familial clustering of KSHV infection suggests a predominantly nonsexual horizontal transmission route of the virus.

Is there an association between shigellosis incidence and socioeconomic status in metropolitan Haifa?

BACKGROUND: Shigellosis incidence rates in Israel have declined continuously over the past 50 years, but they remain 20 times greater than those in the United States. Socioeconomic factors may influence shigellosis morbidity, but this may be difficult to demonstrate in the absence of data for individual patients and when using composite rates for large geographic areas. Use of census tract data for small, relatively homogeneous geographic areas may lessen the effects of the "ecological fallacy." The present study analyzes the effect of socioeconomic status (SES) on shigellosis morbidity in the Haifa metropolitan region. METHODS: The study population consisted of the 7 cities in the Haifa subdistrict that constitute the greater metropolitan region. Cases of shigellosis reported during the years 2000 and 2001 were mapped, and age-standardized rates were calculated for the census tract areas. The incidence rates were then compared with the SES category of the census tract using the Kruskal-Wallis test. RESULTS: No association was found between incidence rates of shigellosis and SES category of the census tract areas in the Haifa metropolitan area for the years 2000 and 2001 (Kruskal-Wallis chi(2)=0.440; P=.803). CONCLUSION: We found no association between shigellosis morbidity and socioeconomic status. This finding is probably real and not the result of reporting bias. Analysis of morbidity using small geographical units such as census tracts is more accurate than analysis using large geographical areas such as cities.