Ongoing tuberculosis transmission among second-generation Ethiopian immigrants.

Despite considerable efforts to control tuberculosis (TB) among Ethiopian immigrants in Israel, an outbreak of TB among second-generation Ethiopian immigrants that involved native Israelis occurred between January 2011 and December 2019. The aim of this article is to report on this outbreak and discuss the patient and health system barriers that led to its propagation. Overall, 13 culture-positive TB patients were diagnosed in this outbreak. An additional 36 cases with identical mycobacterium tuberculosis genotypes were identified through cross-checking with the National TB Laboratory Registry. Among the 32 close contacts of the index case, 18 (56.3%) reported for screening and treatment of latent TB infection (LTBI) was recommended for 11 (61.1%) of them. However, none completed treatment and eight eventually developed TB. Of the 385 close contacts identified in this outbreak, 286 (74.3%) underwent contact investigation, 154 (53.8%) were recommended LTBI treatment, but only 26 (16.9%) completed the treatment. Routine contact investigation and treatment practice measures failed to contain the cascade of infection and disease, leading to the spread of the infecting strain of TB. This report highlights the challenges to identify the high-risk group and address barriers to care among such a vulnerable population.

Cost of nurse-managed latent tuberculous infection treatment among hard-to-reach immigrants in Israel.

BACKGROUND: Adherence to treatment of latent tuberculous infection (LTBI), an essential component of tuberculosis (TB) elimination, is generally unsatisfactory. OBJECTIVES: To examine the adherence and costs of nurse-managed, semi-directly observed preventive treatment (semi-DOPT) with twice-weekly isoniazid among hard-to-reach Ethiopian immigrants, and to compare the treatment outcomes of onsite vs. regional TB clinic-based physician's follow-up. METHODS: This was a quasi-experimental retrospective cohort analysis of LTBI treatment among Ethiopian immigrants in reception centres in the Zefat subdistrict of Northern Israel, screened and treated for LTBI during 2005-2011. Two physician follow-up appointments were scheduled for each patient. RESULTS: Of 663 eligible Ethiopian immigrants included in the study, 628 (94.7%) completed treatment. Treatment outcomes were similar among onsite vs. regional TB clinic-based physician follow-up. Non-completion was significantly associated with side effects (P < 0.001). The total costs of treatment were relatively low, but were significantly higher for the TB clinic-based physician follow-up group. CONCLUSION: Nurse-managed semi-DOPT for LTBI treatment with reduced physician follow-up among hard-to-reach Ethiopian immigrants was efficient and safe. Providing on-site physician follow-up proved to be cheaper than standard follow-up at the regional TB clinic. Starting LTBI treatment at an early stage after immigration, and providing treatment and convenient transportation free of charge probably also contributed to the high treatment completion rates.

Tuberculosis Beijing strain outbreak in an Israeli Arab rural community linked to an incarcerated immigrant.

A tuberculosis (TB) outbreak with six definite and four probable cases, caused by a Beijing strain isolate, occurred in an Arab rural community in north Israel. Using epidemiological investigation and strain genotyping, we identified the source case as an incarcerated immigrant. This outbreak illustrates how a systematic breakdown in TB prevention and control measures at multiple levels, within prisons and upon exiting prison, can result in rapid, cross-ethnic transmission of TB to a low-risk population. The close social bonds in this rural community and downsizing of the regional TB clinic staff may also have contributed to the magnitude of this outbreak.

Tuberculosis outbreak among students in a boarding school.

Tuberculosis (TB) outbreaks present a public health challenge. Six cases of active TB emerged in a boarding school in Israel during 1 yr. An epidemiological outbreak investigation was performed, followed by implementation of control measures. The investigation included interviews, tuberculin skin test (TST) and chest radiographs of the students. Close contact (n = 155) was defined as being in the same class or dormitory with a patient. Remote contact (n = 246) was defined as being in the school. An epidemiological association was detected among five of the cases and a distinct pattern was found in molecular analysis. TST was performed in 398 (99.2%) students. Repeated (two-step) TST was applied to the close contacts. The degree of contact, country of origin and previous bacille Calmette-Guérin vaccination were significantly associated with TST reactions. Preventive directly observed therapy was completed by 157 (91.3%) students. During 5 yrs follow-up, no additional cases emerged. While investigating a tuberculosis outbreak, the definition of degree of contact is a significant predictor for detecting positive tuberculin test. Immigration from an endemic country, as well as previous bacille Calmette-Guérin vaccination have a major effect on tuberculin skin-test results. The directly observed therapy approach was found to be successful in preventing further morbidity.

Compulsory detention of recalcitrant tuberculosis patients in the context of a new tuberculosis control programme in Israel.

OBJECTIVE: To analyse the use of compulsory detention in the context of a new national tuberculosis (TB) control programme launched in 1997. METHODS: A retrospective review was made of the use of compulsory detention in the management of infectious TB before and after the initiation of a new TB control programme, using data from the central TB registry in the Ministry of Health and the charts of each patient. RESULTS: Between 1994 and 2001, 13 recalcitrant patients out of 3056 (0.43%) cases of pulmonary TB were brought to trial. Eleven patients were detained. All were either hospitalized under a court order and, when failing to comply with the order, hospitalized in prison, or referred directly to a prison hospital. Twelve of 13 (92%) patients were new immigrants. After the new programme was launched, proportionately fewer patients were brought to trial [6/943 (0.64%) in 1994-1996 compared with 7/2113 (0.33%) in 1997-2001]. CONCLUSION: The reduction in the number of individuals detained could be viewed as an improvement in TB control due to the new TB control programme. It remains to be shown whether these individuals, most of whom had drug-resistant strains of TB, posed a sufficient threat to public health to justify detention.

Screening and management of tuberculosis in immigrants: the challenge beyond professional competence.

SETTING: Right of entry may sometimes be denied to immigrants because of the threat of tuberculosis. During 1990-2000 some 1050000 immigrants, mostly from countries highly endemic for TB, arrived in Israel, a low prevalence country. Nevertheless, TB rates in Israel have remained low. OBJECTIVE: To emphasise the challenge beyond technical competence for TB control for immigrants from the perspective of Israel's National Tuberculosis Programme (NTP). MATERIALS AND METHODS: We defined criteria for an NTP geared to immigration, and analysed our implementation of the European Task Force recommendations on international migration and TB control. We interviewed immigrants and health care workers to identify barriers to diagnosis, prevention and treatment of TB among immigrants. We used classical epidemiology to evaluate the impact of immigration on TB rates in the host population. RESULTS: Until now there has been no evidence of significant spread of TB from immigrants to the host population. Successful outcome of treatment has been noted in over 75%, although a sub-population of immigrant substance abusers is proving more difficult to treat. CONCLUSIONS: The risk of TB for the host country is very low and it seems possible to enhance TB control in immigrants with measures designed to address their cultural needs.

The new National Tuberculosis Control Programme in Israel, a country of high immigration.

SETTING: Israel has implemented a new tuberculosis (TB) control programme in response to the rise in the incidence of tuberculosis due to immigration in the last decade. It complies with World Health Organization guidelines, and also includes specific measures addressing the needs of immigrants. We describe the new programme and compare the outcome of treatment prior and after its realisation. METHODS: Each component of the new strategy was scrutinised, aspects that did not function well were identified and how we contended with these issues is described. Analysis of outcome of treatment was according to WHO/IUATLD definitions. RESULTS: Better and clearer organisation of TB treatment in all its aspects, including cultural sensitivity, has been obtained. Compliance improved from less than 27% for successful outcome before the new programme to more than 75% after. In addition to the improvement in completion rates, the universal use of directly observed treatment has ensured enhanced adherence. CONCLUSION: Using legislative, administrative and budgetary measures, as well as clinical guidelines published by the Ministry of Health, the TB infrastructure in Israel has been successfully reorganised. The decision to do so was not only clinically and organisationally justifiable, it is also economically viable.

Epidemiological analysis of tuberculosis treatment outcome as a tool for changing TB control policy in Israel.

BACKGROUND: Sensing an inadequacy of tuberculosis control due to an influx of TB associated with immigration, we analyzed TB treatment outcome in Israel by population groups. OBJECTIVES: To provide an epidemiological basis necessary for any new national TB control policy, and to bring it to the attention of the medical profession in Israel and abroad since its results led to a change in Israel's TB control policy. METHODS: We reviewed all TB cases notified during the period 1990 to September 1992. "New cases" (820 cases, 93.5%) and "re-treatment cases" (57 cases, 6.5%) were analyzed according to three mutually exclusive groups: "successful outcome," "death," and "potentially unsatisfactory outcome" (according to WHO/IUATLD definitions). RESULTS: Of 820 "new cases," 26.6% had a "satisfactory outcome," 68.5% had a "potentially unsatisfactory outcome" and 4.9% died; compared to 47.4%, 45.6% and 7% among 57 "re-treatment cases," respectively. Using logistic regression analysis, outcome was associated with the district health office (P < 0.0001), the TB "experience" of the notifying clinic (P < 0.0001), and the form of TB (P = 0.02). No significant relationships were obtained for population groups, gender and age, interval between arrival in Israel and TB notification, and bacteriological results. CONCLUSIONS: Non-supervised TB treatment resulted in poor outcomes regardless of population groups. Better outcomes occurred in the larger TB clinics. Therefore, in addition to measures such as adequate drug supplies, reorganization of TB laboratories and training of TB personnel, we recommend the "directly observed treatment short-course" for all cases as well as reducing the number of treatment centers thereby increasing their case load.

Routine two-step skin testing for tuberculosis in the staff of a geriatric hospital in Israel: booster and conversion rates.

The objective of this study was to determine the prevalence of positive skin tests amongst the staff of a 200 bed geriatric hospital in Haifa, Israel. By comparing the findings with those of a study performed five years previously, we hoped to ascertain the number of conversions which had occurred in the period studied. This was undertaken in order to assess a new policy from the Israel Ministry of Health regarding skin testing for health care workers. We also hoped to decide upon the frequency of skin testing required and to compare data from recent immigrants from countries with a high prevalence of TB. In 1997, we performed two-step skin testing (TSST) on 318 health care workers. We ascertained the number of positive reactions on the first and second testing and calculated the number of subjects who showed significant boosting. We also compared the results to those obtained in a study in 1992 and calculated the rate of conversion. We used multivariate analysis to examine the effects of age, gender, country of origin, years in Israel, previous BCG vaccination, previous exposure to contagious TB, work site and area of residence in the city, on the response to TSST. Between 1990 and 1996, 655 000 immigrants from the former USSR arrived; 'recent immigration' was defined from that date onward. The final number of positive reactions out of 282 subjects, who were either positive or negative on step 1 and presented for step 2, was 171 (60%). Booster effect was not significantly associated with any of the variables examined. The size of reaction in TSST was related to country of origin and recent immigration. The 83 recent immigrants from the former USSR had more frequent (61%) and larger reactions (mean (sd): 9.0 (6.46) mm) than the 114 native-born Israelis with 39% positive reactions (6.2 (5.89) P= 0.009). Comparison with 1992 revealed 26 (31%) of previous negatives as positive. Conversion was associated with age. All conversions save one were in individuals younger than 50 years (P= 0.07). In conclusion, TSST, performed to enable detection of recent infection after exposure to contagious TB, was relevant for 40% of health care workers (HCWs). Second step testing contributed an additional 23% positive reactions. New immigrants had larger initial reactions. Conversion occurred mostly in younger workers and could be either due to unrecognized TB in the hospital or to exposure in the community.

Pulmonary oedema induced by strenuous swimming: a field study.

The purpose of the study was to document the incidence and recurrence rate of pulmonary oedema induced by strenuous swimming (SIPO), and to study the changes in relevant physiological parameters. Thirty-five young men were repeatedly examined over a 2-month period after a swimming time trial in the open sea. A tentative diagnosis of SIPO was made when the swimmer reported shortness of breath accompanied by cough. Twenty-nine events of SIPO were diagnosed in 21 individuals (60% incidence). Oxygen saturation was significantly reduced in SIPO. Mean forced vital capacity (FVC) and FEV(1) were significantly lower in the severe SIPO group. Also, mean FVC and mid-expiratory flows (FEF(25-75%)) obtained 12 months earlier during screening for the programme were lower in individuals who later had SIPO. The ratios of post-swim FVC and FEV(1) values to the corresponding selection examination values were lower in the severe SIPO group. Thus volumes decreased in the SIPO group, besides being lower at the start. Shortness of breath and coughing following strenuous swimming were related to hypoxaemia and reduction in lung volumes, suggesting pulmonary oedema. SIPO was a common and often recurrent phenomenon. Lower initial lung volumes and flows might predict future susceptibility to SIPO.

Traveller's coccidioidomycosis: case report of pulmonary infection diagnosed in Israel.

A 60-year-old temporary Israeli resident travelled to Arizona, developed an influenzalike infection, and returned with a space-occupying lesion in the lung. Since the patient was a heavy smoker, lung cancer was suspected and he was operated on. A granuloma was reported on frozen sections, and Coccidioides immitis was revealed on stained preparations and by microbiological investigation. Coccidioidomycosis is unusual in Israel; therefore, it is important to be aware of this mycosis in patients who have a history of recent visits to areas of endemicity in North America, Central America, and South America.

The work-rate-dependent effect of carbon monoxide on ventilatory control during exercise.

The effect of low levels of carbon monoxide (CO) was studied during exercise in order to determine the work-rate dependent effect of CO breathing on exercise ventilation (VE). Ten normal subjects (aged 32.8 +/- 7.1 years) were studied during air breathing and air with added CO to bring carboxyhemoglobin (COHb) to approximately 11% and 20%. During the incremental exercise test, VE was not affected by CO breathing at work rates below the lactic acidosis threshold (LAT), defined as the O2 uptake above which CO2 is excreted by the lungs consequent to buffering of metabolic acid (not hyperventilation) (Beaver et al. (1986) J. Appl. Physiol. 60: 2020-2027). However, VE was increased above the LAT as work rate and COHb saturation were increased. At the end of constant work rate exercise, the increase in VE caused by increased COHb was positively correlated (r = 0.83, P less than 0.0001) with the increase in venous lactate sampled 2 min into recovery. This was complemented by a decrease in end-tidal PCO2 versus lactate (r = 0.76, P less than 0.0001). We conclude that the increase in exercise VE resulting from COHb levels up to 20%, is restricted to work rates above the LAT, and is proportionately higher, the greater the lactic acidosis.

Evidence that diffusion limitation determines oxygen uptake kinetics during exercise in humans.

To determine the role of arterial O2 content on the mechanism of muscle O2 utilization, we studied the effect of 2, 11, and 20% carboxyhemoglobin (COHb) on O2 uptake (VO2), and CO2 output (VCO2) kinetics in response to 6 min of constant moderate- and heavy-intensity cycle exercise in 10 subjects. Increased COHb did not affect resting heart rate, VO2 or VCO2. Also, the COHb did not affect the asymptotic VO2 in response to exercise. However, VO2 and VCO2 kinetics were affected differently. The time constant (TC) of VO2 significantly increased with increased COHb for both moderate and heavy work intensities. VO2 TC was positively correlated with blood lactate. In contrast, VCO2 TC was negatively correlated with increased COHb for the moderate but unchanged for the heavy work intensity. The gas exchange ratio reflected a smaller increase in CO2 stores and faster VCO2 kinetics relative to VO2 with increased COHb. These changes can be explained by compensatory cardiac output (heart rate) increase in response to reduced arterial O2 content. The selective slowing of VO2 kinetics, with decreased blood O2 content and increased cardiac output, suggests that O2 is diffusion limited at the levels of exercise studied.

Evidence that the metabolic acidosis threshold is the anaerobic threshold.

We evaluated maximal O2 uptake (VO2max), the metabolic acidosis threshold determined by the V-slope analysis [plot of CO2 output (VCO2) as a function of oxygen uptake (VO2)], the ratio of increase in VO2 to work rate increment (delta VO2/delta WR), the upper slope (S2) of the V-slope analysis, and the VO2 for work below and above the metabolic acidosis threshold to determine whether the changes in O2 transport caused by increased carboxyhemoglobin (HbCO) affected these parameters and variables. Ten normal subjects (aged 32.8 +/- 7.1 yr) performed symptom-limited incremental exercise tests in a ramp pattern on a cycle ergometer while breathing air and air with added carbon monoxide to cause HbCO to be approximately 11% and 20%. VO2max decreased by 11.6 and 19.3%, the metabolic acidosis threshold decreased by 11.9 and 19.6%, delta VO2/delta WR decreased by 8.9 and 14.0%, and S2 increased by 13.6 and 21.8% when HbCO was increased to 11 and 20%, respectively. Most importantly, VO2 was unchanged related to work rate below the metabolic acidosis threshold during the tests with increased HbCO but was reduced at the work rates above the metabolic acidosis threshold. These findings are consistent with the concept that the metabolic acidosis threshold is synonymous with an anaerobic threshold, i.e., the latter demarcating the VO2 above which the contracting muscles are not adequately supplied with O2 but below which they are.

Evidence supporting the existence of an exercise anaerobic threshold.

In this paper, we provided evidence to support the concept that work above the anaerobic threshold, measured by the V-slope method, is, in fact, performed partially anaerobically. In contrast, work performed below the anaerobic threshold is totally aerobic (Figure 2, 4 and 5). The VO2 at the transition from aerobic to partial anaerobic metabolism must depend on cardiovascular performance since it regulates the capillary PO2 level needed for O2 diffusion transport into the mitochondria (Figure 1). At high work rates, the capillary PO2 needed for the oxygen requirement might not be met by the cardiovascular oxygen supply. This would result in the oxygen consumed being less than the oxygen required by the working tissue (Figure 2), with the oxygen equivalent difference necessarily coming from anaerobic metabolism. The consequences are increased lactate formation and metabolic acidosis, and the physiological and biochemical disturbances which result from the latter.

Intra-arterial and cuff blood pressure responses during incremental cycle ergometry.

Brachial intra-arterial blood pressure [systolic (AS) and diastolic (AD)] and cuff blood pressure [systolic (CS) and fourth- and fifth-phase diastolic (CD)] were simultaneously measured by a single observer in 13 middle-aged men during 1-min incremental cycle exercise. On the average, the mean AS exceeded the mean CS by 10 to 11 mm Hg, while the mean AD exceeded the average fourth and fifth CD by 5 and 13 mm Hg, respectively. During incremental exercise, AS, CS, AD, and fourth-phase CD increased, while fifth-phase CD decreased. We also measured intra-arterial blood pressure in nine young adult men smokers during 1-min incremental cycle exercise. In both groups, the average intra-arterial blood pressures increased in a relatively linear fashion from rest to maximal exercise: AS change = 74 +/- 5 mm Hg (SE) and AD change = 28 +/- 3 mm Hg for young men; AS change = 59 +/- 5 mm Hg and AD change = 12 +/- 3 mm Hg for middle-aged men. In this population of middle-aged smokers, intra-arterial mean blood pressure during exercise approximated diastolic plus 2/5 pulse pressure for intra-arterial measures or diastolic plus 1/2 pulse pressure for cuff measures rather than the traditional formula of diastolic plus 1/3 pulse pressure.