Israel Medical Association Journal

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.

Objective: 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. 

 

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.

Objective: 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.

Background: Several studies have identified associations between low vitamin D concentrations and risk of upper respiratory infections (URI). T lymphocytes have a major anti-viral role, are affected by vitamin D metabolism, and may mediate the link between vitamin D and URIs. Competitive swimmers have a relatively high rate of URIs, alongside a high prevalence of low vitamin D concentration. 

Objectives: To examine the associations linking T cell receptor excision circles (TREC, markers of thymus activity), circulating 25(OH)D concentrations and the effect of vitamin D supplementation, and URI symptoms in young competitive swimmers.

Methods: We tested 82 adolescent swimmers for serum 25(OH)D and TREC concentrations and found that 55 had vitamin D insufficiency. Randomized supplementation of either vitamin D3 or placebo was given for 12 winter weeks. URI symptoms were recorded weekly. The associations between TREC copy numbers, vitamin D and URI burden were examined.

Results: TREC concentrations decreased with the participants’ age (r = -0.346, P = 0.003), with no significant between-gender difference. TREC concentrations did not materially differ among subjects with normal, insufficient or deficient vitamin D status, and were not affected by vitamin D supplementation. No significant correlations were found between TREC levels or their changes during the study period, and mean URI severity or duration. 

Conclusions: Thymus activity, represented by higher TREC levels, was not related to vitamin D concentrations or status, and was not affected by vitamin D supplementation in adolescent swimmers. TREC concentrations were not associated with URI severity or duration in this population.

 

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[1] should 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 influenza vaccine 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 a significant association only between influenza vaccination coverage and the presence of chronic illness and influenza vaccination in the past.

Conclusions: Influenza vaccination coverage among Nazareth Hospital health care workers was low. They did not view themselves as different to the general population with regard to vaccination. An intervention program was launched after the study period, aimed at increasing the knowledge on the efficacy and safety of the vaccine, stressing the importance of vaccinating HCWs, and administering the vaccine at the workplace. The program raised the vaccination coverage to 50%.