A follow-up study of gastro-intestinal diseases related to bacteriologically substandard drinking water

In a prospective follow-up study conducted in 52 French alpine villages, one weekly water sample was taken in each village provided with untreated ground water and analyzed as to the presence of four indicator bacteria: total plate count, total coliforms, thermotolerant (fecal) coliforms, and fecal streptococci. Cases of acute gastro-intestinal disease (AGID) occurring among 29,272 inhabitants were reported through physicians, pharmacists, and primary school teachers. A loglinear model identified fecal streptococcus (FS) as the best predictor; the presence of fecal coliforms enhanced the effect of FS. The total bacteria count and the total coliforms had no independent contributions. A threshold analysis suggested that any level of indicator bacteria above zero was associated with an excess of AGID.     

Evaluation of microbial indicators of health risk related to river swimming places

A retrospective follow-up study was conducted among 5,737 tourists in 8 holiday camps, during the 1986 summer, in the Ardèche river basin, in order to study the relationship between the bacteriological water quality and the morbidity that occurred to swimmers. Total morbidity was more frequent among bathers than non-bathers (Risk Ratio = 1.7 [95% confidence interval = 1.4-2.1]); gastro-intestinal illness was the major type of morbidity (RR = 2.8 [1.8-4.4] for "objective gastro-intestinal diseases). After screening for the germs that were best correlated with gastro-intestinal and skin diseases, using simple linear regression, logistic regression models allowed confirmation that fecal streptococci best predicted gastro-intestinal morbidity; it significantly exceeded the risk observed among non-bathers above a concentration of 20 SF/100 ml ("objective" gastro-intestinal morbidity). The relationship with fecal coliforms was less clear. However, they are good indicators of skin diseases risk. These results should help re-evaluation of the current microbiological standards concerning recreational waters.     

Risks Associated with the Microbiological Quality of Bodies of Fresh and Marine Water Used for Recreational Purposes: Summary Estimates Based on Published Epidemiological Studies

The current European standards for microbiological quality of bathing water (i.e., all running or still fresh waters or parts thereof and/or sea water [with the exception of water intended for therapeutic purposes and water used in swimming pools]) were issued in 1976 and are currently undergoing revision. In this article, the authors propose parameters for select microorganism indicators to assist in the establishment of public-health-based objectives for fresh and marine water quality. A type-II meta-analysis of the results of 18 published epidemiological studies was implemented in an attempt to characterize the relationship(s) between concentrations of bacterial indicators and rates of acute gastrointestinal diseases among bathers who had used fresh or marine water for recreational purposes. The authors fit multiple linear-regression models, which allowed for random effects across studies, to derive dose-response curves. Several confounders and effect modifiers were controlled for in the analyses. Risks were then estimated for a hypothetical individual who would bathe 20 times/yr in water that contained a given concentration of microorganisms. For fresh-water-associated highly credible gastrointestinal illnesses, a level of 10 fecal coliforms/100 ml water yielded an attributable risk of 0.2 cases/1,000 person-years; a risk of 2 cases/1,000 person-years was found for fecal streptococci. The corresponding yearly attributable risks were 1 and 13 cases/1,000 person-years, respectively, for 100 bacteria/100 ml fresh water. Risks associated with fecal coliforms were found to be lower in marine water than in fresh water. Irrespective of the type of water examined, total coliforms were related only weakly with acute digestive morbidity. Developers of future bathing-water standards should state the level of risk deemed acceptable for public health. The authors of this study maintain that levels of fecal coliforms and fecal streptococci should be used as criteria for infectious risk management associated with bodies of marine and fresh water used for recreational purposes.     

Risks associated with the microbiological quality of bodies of fresh and marine water used for recreational purposes: summary estimates based on published epidemiological studies

The current European standards for microbiological quality of bathing water (i.e., all running or still fresh waters or parts thereof and/or sea water [with the exception of water intended for therapeutic purposes and water used in swimming pools]) were issued in 1976 and are currently undergoing revision. In this article, the authors propose parameters for select microorganism indicators to assist in the establishment of public-health-based objectives for fresh and marine water quality. A type-II meta-analysis of the results of 18 published epidemiological studies was implemented in an attempt to characterize the relationship(s) between concentrations of bacterial indicators and rates of acute gastrointestinal diseases among bathers who had used fresh or marine water for recreational purposes. The authors fit multiple linear-regression models, which allowed for random effects across studies, to derive dose-response curves. Several confounders and effect modifiers were controlled for in the analyses. Risks were then estimated for a hypothetical individual who would bathe 20 times/yr in water that contained a given concentration of microorganisms. For fresh-water-associated highly credible gastrointestinal illnesses, a level of 10 fecal coliforms/100 ml water yielded an attributable risk of 0.2 cases/1,000 person-years; a risk of 2 cases/1,000 person-years was found for fecal streptococci. The corresponding yearly attributable risks were 1 and 13 cases/1,000 person-years, respectively, for 100 bacteria/100 ml fresh water. Risks associated with fecal coliforms were found to be lower in marine water than in fresh water. Irrespective of the type of water examined, total coliforms were related only weakly with acute digestive morbidity. Developers of future bathing-water standards should state the level of risk deemed acceptable for public health. The authors of this study maintain that levels of fecal coliforms and fecal streptococci should be used as criteria for infectious risk management associated with bodies of marine and fresh water used for recreational purposes.     

Cancer incidence among physicians occupationally exposed to ionizing radiation in Finland

OBJECTIVES: Occupational radiation exposure was estimated, and the cancer incidence among physicians working with radiation was compared to that of unexposed physicians. METHODS: A cohort of 1312 physicians was identified from the Finnish occupational radiation exposure registry. Radiation exposure data were obtained from 1970 to 2001 on the basis of individual dosimeters. Never-monitored Finnish physicians (N=15 821) were used as a reference group, identified from census data of Statistics Finland. Incident cancer cases were identified by record linkage with the Finnish Cancer Registry. RESULTS: The cumulative radiation dose exceeded the recording level (0.3-3.0 mSv during a 3-month period for 1029 radiation-exposed physicians (59.8%). Six percent of the radiologists had received a cumulative dose of 50 mSv or more. Altogether there were 41 cancers observed among the radiation-exposed physicians and 998 cases found in the never-monitored group. Standardized incidence ratios (SIR) for all cancers were comparable with those of the general population among physicians monitored for radiation [SIR 1.0, 95% confidence interval (95% CI) 0.7-1.4] and other physicians (SIR 1.0, 95% CI 1.0-1.1). For specific cancer sites, a slightly elevated risk of female breast cancer was found among monitored physicians when compared with other physicians (rate ratio 1.7, 95% CI 1.0-3.1). No obvious dose-response relationship was found for the overall cancer incidence. CONCLUSIONS: According to the results from a nationwide cohort, occupational exposure to medical radiation is not a strong risk factor for cancer among physicians. Possible excess risk could not be reliably demonstrated even after the follow-up of a nationwide cohort for up to 30 years.     

Drinking Water Quality and the Geospatial Distribution of Notified Gastro-Intestinal Infections

Introduction

Even brief episodes of fecal contamination of drinking water can lead directly to illness in the consumers. In water-borne outbreaks, the connection between poor microbial water quality and disease can be quickly identified. The impact of non-compliant drinking water samples due to E. coli taken for regular monitoring on the incidence of notified acute gastrointestinal infections has not yet been studied.

Methods

The objective of this study was to analyse the geographical distribution of notified acute gastrointestinal infections (AGI) in Slovenia in 2010, with hotspot identification. The second aim of the study was to correlate the fecal contamination of water supply system on the settlement level with the distribution of notified AGI cases. Spatial analysis using geo-information technology and other methods were used.

Results

Hot spots with the highest proportion of notified AGI cases were mainly identified in areas with small supply zones. The risk for getting AGI was drinking water contaminated with E. coli from supply zones with 50–1000 users: RR was 1.25 and significantly greater than one (p-value less than 0.001).

Conclusion

This study showed the correlation between the frequency of notified AGI cases and non-compliant results in drinking water monitoring.     

Tuberculosis in healthcare workers at a general hospital in Mexico.

OBJECTIVE: To determine the incidence rate of tuberculosis (TB) disease among healthcare workers (HCWs) at a general hospital. DESIGN: Retrospective analysis of TB cases among HCWs over the course of 5 years. SETTING: A 140-bed general hospital in Tijuana, Mexico. PARTICIPANTS: All hospital employees who developed TB during the 5-year period. RESULTS: From 1 January 1999 through 31 December 2003, 18 TB cases were diagnosed among the hospital personnel. During that period, the mean (+/- standard deviation) annual work force of the hospital was 819+/-21.7 employees. The TB incidence rate was 439.56 cases per 100,000 employees; this rate was 10.98 times higher than the rate for the general population of the city. The TB incidence rate for physicians was 860.21 cases per 100,000 employees, that for nurses was 365.85 cases per 100,000 employees, and that for physicians in training was 1,846.15 cases per 100,000 employees. Physicians in training had a higher risk of acquiring TB than did either physicians (relative risk, 2.14 [95% confidence interval, 1.34-35.66) or nurses (relative risk, 5.04 [95% confidence interval, 3.16-83.33). Three of the HCWs with TB disease were infected with a drug-resistant strain of Mycobacterium tuberculosis, and one of the infecting strains was multidrug resistant. Asymptomatic TB infection among HCWs was not addressed during this study. CONCLUSIONS: The TB incidence rate among the HCWs at the hospital is extremely high, compared with that in the general population. The implementation of infection control measures is an urgent priority, to reduce this occupational hazard.     

Residual microbiological risk after simple chlorine treatment of drinking ground water in small community systems

In order to assess the residual health risk after mere disinfectionof drinking ground water, an epidemiological study was conductedin 24 French villages, among 2,033 schoolchildren aged 7–11years. Thirteen villages which delivered drinking water thatdid not need to be treated because the water naturally met microbiologicalstandards were used as a reference. Eleven other villages wereselected, which were required to disinfect the spring waterbefore distribution because of microbiological contamination.However, after a well-conducted chlorine-only treatment, tapwater also complied with microbiological standards. Acute gastrointestinal(Gl) conditions (diarrhoea and/or vomiting) were recorded dailyduring 8 months using standard questionnaires. The bacteriologicalquality of the water was assessed bi-monthly. The crude incidencerate of diarrhoea was 1.4 times more frequent among childrendrinking treated water than among controls (95% confidence interval:1.30–1.50). This rate ratio was not significantly influencedby the chlorine concentration after treatment. The excess riskwas associated with the occurrence of small epidemics. However,when discarding the epidemic events, the background endemicmorbidity also differed between the 2 groups. This study showsthat after a disinfection-only treatment that produces finishedwater meeting the current bacteriology quality and treatmentefficiency indicators, a low but significant risk of acute Glinfection persists, probably associated with the survival ofsome chlorine-resistant micro-organisms. Effective drinkingwater management should primarily aim at protecting the qualityof natural water. If this does not suffice, this study suggeststhat the treatment of contaminated water should encompass multiplebarriers, not merely disinfection.     

Epidemiological significance of microbiological pollution criteria for river recreational waters

A retrospective follow-up study was conducted during the summer of 1986 in the French Ardèche basin in order to assess the relationship between swimming-related morbidity and the bacteriological quality of the recreational water. 5737 tourists in eight holiday camps were questioned as to the occurrence of illness and their bathing habits during the week preceding the interviews. The rate-ratio contrasting swimmers and non-swimmers for total morbidity is 2.1 (1.8-2.4) = 95% confidence interval); gastrointestinal illness is the major type of morbidity and differs significantly between the two groups (RR = 2.4 (1.9-3.0) for total gastrointestinal cases; RR = 2.3 (1.7-3.2) for 'objective' gastrointestinal cases). Faecal streptococci (FS) are best correlated to gastrointestinal morbidity, using direct linear regression models. Faecal coliforms (FC) are not as good predictors of the risk. The concentration of faecal streptococci above which the 'objective' gastrointestinal morbidity among bathers is significantly greater than among non-bathers is 20 FS/100 ml. Swimmers suffer skin ailments much more frequently than non-swimmers (RR = 3.7 (2.4-5.7]; although the relationship may be artefactual, this type of morbidity is well correlated with the concentration of faecal coliforms, aeromonas and pseudomonas. This study provides epidemiological data on which to base microbiological standards for river recreational waters dependent on what might be considered as an 'acceptable' risk.     

Increased incidence of haematological cancer among physicians in a University Hospital

OBJECTIVES: The oral report of eight cases of cancer over a period of 3 years among physicians working in a French University Hospital led us to conduct a retrospective cohort study to compare the incidence of cancer in these physicians with that of the general population living in the same area. METHOD: The cohort consisted of 940 physicians (72% male, 28% female) who had worked for at least 1 year in this hospital between 1945 and 1994 (a total of 10,693 person-years). The incidence of cancer among physicians was compared with that of the general population using a local cancer registry which has recorded all cancer cases occurring in the Department between 1979 and 1994. Standardised incidence ratio (SIR) was calculated for all causes of cancer and site by site. RESULTS: Although the global incidence of cancer did not differ from that of the general population (SIR=0.97; 95% confidence interval (CI) 0.59-1.5), a significantly increased incidence of haematological malignancy was found among physicians (SIR=5.45; 95% CI 2-11.9). CONCLUSIONS: These findings pointed out the risk of lymphatic and haematopoietic cancer among physicians who started working after 1945 when the first rules pertaining to protection from ionising radiation came into effect. However, limitations of this study such as limited statistical power and lack of individual exposure data should be considered in the interpretation of these findings. Possible aetiological factors responsible for these risks are discussed. Education about general safety protection programmes against carcinogenic risk factors including physical, biological and chemical agents still remains a priority among physicians.     

Failure of indicator bacteria to reflect the occurrence of enteroviruses in marine waters.

The results of several studies conducted along the upper Texas Gulf coast, where a substantial amount of quantitative virological data were collected, are compared to bacteriological indicators and other environmental factors on a statistical basis. Variables common to all these studies were anlayzed by multivariate regression. Although multivariate analysis indicated that the number of viruses detected in water was related to rainfall, salinity, and total coliforms in the water, the amount of variation in the number of viruses accounted for by these factors was not large enough to make them good predictors. Enteroviruses were detected 43 per cent of the time in recreational waters considered acceptable as judged by coliform standards, and 44 per cent of the time when judged by fecal coliform standards. Enteroviruses were detected 35 per cent of the time in waters which met acceptable standards for shellfish-harvesting. Our failure to correlate the occurrence of enteroviruses in marine waters with indicator bacteria, and the frequent occurrence of enteroviruses in water which met current bacteriological standards, indicates that these standards do not reflect the occurrence of enteroviruses, and perhaps other human pathogenic viruses, in marine waters.     

Cancer on the Island of Réunion: results of a survey preliminary to the creation of a tumor registry

Before the organization of a cancer registration in "l'Ile de la Réunion" a retrospective survey about cases notified by public and private physicians was setted in 1981. 1128 cases were notified and 618 were new cases. The estimation of the total incidence of cancer is 1.2 cases by 1000 inhabitants in "l'Ile de la Réunion".     

Health complaints in relation to quality of swimming water in participants of a triathlon]

Participants in a triathlon in Alphen aan den Rijn, the Netherlands, reported gastrointestinal symptoms to the local health authority. A study was performed to establish the number of complaints and the relation with the microbiological water quality at the surface water swimming site, which met current standards. An epidemiological survey was carried out with a questionnaire among 629 participants, with non-participating relatives as controls. Faecal samples of patients and water samples were investigated by conventional methods. 439 participants and 217 controls completed the questionnaire. 140 participants had at least one gastro-intestinal symptom and 28 (6.4%) had highly credible gastroenteritis. Participants had an odds ratio for gastro-enteritis of 14.7 (95% CI: 2.39-604.45). Electron microscopic examination in six of 12 patients showed viruses able to cause such symptoms. Water samples showed considerable faecal pollution at the time of the triathlon (geometric mean counts: thermotolerant coliforms 725/100 ml; faecal streptococci 23/100 ml). The most likely source is the effluent discharge of the nearby waste water treatment plant. A surface water swimming site meeting current standards does not exclude health complaints among tri-athletes.     

Considerable underreporting of malaria in the Netherlands; a capture-recapture analysis

OBJECTIVE: To estimate the completeness of notification of malaria by physicians and laboratories in the Netherlands. METHOD: Capture-recapture analysis was applied to three incomplete, partially overlapping registers of malaria cases in 1995 and 1996: a laboratory survey, the Notification Office and the hospital admission registration. RESULTS: The average response of the 107 laboratories approached was 83.6% over both years. In 1995 and 1996 581 and 535 malaria cases respectively were microscopically diagnosed. In each year physicians officially notified 311 patients. 350 and 330 patients respectively were admitted to hospital. Capture-recapture analysis estimated the total number of new malaria cases at 933 (95% confidence interval: 849-1072) in 1995 and at 774 cases (740-821) in 1996. The estimated completeness of notification in 1995 and 1996 was therefore 33.3% and 40.2% for physicians and 62.3% and 69.1% for the laboratories. CONCLUSION: Laboratory-based notification, introduced in the Infectious Diseases Act, can considerably increase the number of officially reported malaria cases as compared with notification by physicians. However, approximately one-third of the estimated number of cases may still go unreported.     

Hepatitis B and C risk factors in Germany--results of the national surveillance

Collection of risk factor data is part of the national surveillance of hepatitis B and C in Germany. After modifications of risk factor surveillance had been implemented in September 2003, the response rate for data on risk factors increased markedly. For the period between September 2003 and August 2004, information on risk factors (at least one "yes" or "no" answer) was available for 66% (1853) of all notified hepatitis B cases and for 67% (5813) of all notified hepatitis C cases. More than 30% of those hepatitis B cases occurred among risk groups for whom hepatitis B immunisation is recommended by the German Advisory Committee on Immunisation (STIKO). Of the hepatitis C cases with risk factor data, 40% reported previous or continuing injecting drug use (IDU). IDU was predominant among young men (78% among men, aged 15 to 29 years) and can explain the comparatively high incidence observed in young adults, especially among men. The impact of other risk factors (e. g. medical interventions) cannot be quantified without a proper control group. The results of this study demonstrate that--in addition to the hepatitis B immunisation of children and adolescents--vaccination coverage of specific risk groups, as defined by the STIKO, should be increased. Measures to prevent hepatitis C have to focus on intravenous drug users and clearly have to be intensified.     

Opinions and attitudes on the topic of vaccination of established physicians, pharmacists and their personnel and current vaccination status of these groups

Object of this investigation was to evaluate attitudes and opinions of general practitioners, internal specialists and pharmacists with regard to vaccination. At the same time we investigated the actual vaccination state of these groups and of the medical staff and pharmacy staff. Physicians and pharmacists answered by using a four-page written questionnaire. The vaccination state was evaluated by a single-page questionnaire. Analyses were made by using the statistical program SPSS. The 161 physicians and 188 pharmacists participating in this study generally agree that the risk of infection in practice and pharmacy is not significant. The best vaccine protection in these groups was observed for tetanus. An effective inoculation against this pathogen was documented by 79.4% of physicians and 63.3% of pharmacists. 73.4% of physicians had also a protection against hepatitis B. All other vaccinations were documented as actually protective only in 6-55% of the cases. Physicians and pharmacists agree that their staff should have a vaccination against tetanus, diphtheria and poliomyelitis, followed by hepatitis B and influenza. The vaccination state of medical staff and pharmacy-staff does not attain the demanded standard. It shows levels of 3-70%. Further education in vaccination is more often practised by pharmacists and their staff than by physicians and medical staff. Physicians are more active in advising patients about vaccination than pharmacists and patients rather consult their doctor than a pharmacist to give them vaccination advice. There is still a need for motivation of physicians and pharmacists to be an example for their patients and clients respectively. In addition, more of public information could be helpful.     

太原市中小学教师心理健康状况分析

作者采用精神症状自评量表（SCL－90）对太原市442名中小学教师的心理健康状况进行了调查。结果表明：中小学教师存在一定的心理问题。除“人际敏感”因子外，中小学教师的SCL一90各因子分和阳性项目数均值都显著高于全国常模（P＜0．01）。女教师的“恐怖”因子分显著高于男教师（P＜0．01）。普通学校教师的“人际敏感”、“偏执”、“精神病性”因子分显著高于重点学校（P＜0．05）。不同执教年限教师的“躯体化”、“人际敏感”、“偏执”、“精神病性”因子分阳性项目数均值间也存在着一定的差异。     

Marine waters contaminated with domestic sewage: nonenteric illnesses associated with bather exposure in the United Kingdom.

OBJECTIVES: This study identified possible dose-response relationships among bathers exposed to marine waters contaminated with domestic sewage and subsequent risk of nonenteric illness. METHODS: Four intervention follow-up studies were conducted within the United Kingdom. Healthy volunteers (n = 1273) were randomized into bather and nonbather groups. Intensive water-quality monitoring was used to assign five bacteriological indices of water quality to individual bathers. Illnesses studied were acute febrile respiratory illness, and eye, ear, and skin ailments. RESULTS: Fecal streptococci exposure was predictive of acute febrile respiratory illness, while fecal coliform exposure was predictive of ear ailments. Estimated thresholds of effect occurred at bather exposures above 60 fecal streptococci and 100 fecal coliform per 100 ml of water, respectively. Although no relationship was found between eye ailments and indicator organism exposure, compared with nonbathers, bathers were at higher risk for eye ailments. CONCLUSIONS: Nonenteric illness can be transmitted via recreational contact with marine waters contaminated with sewage. These results argue against the use of a single indicator to establish water quality standards.     

Cancer among meat industry workers

Several studies have found increased risks of cancer among workers in the meat industry, particularly lung and hematologic cancers. Relevant publications were obtained through a computerized literature search with the key words "cancer", "lung cancer", "hematologic neoplasms", "meat products", "abattoirs", and "slaughterhouses", and the evidence available from analyses of routine data, proportionate mortality and incidence studies, and cohort and case-control studies was reviewed. These analyses suggest a significant excess lung cancer risk among meat workers. This risk was associated the most strongly with exposure to animal slaughtering or freshly slaughtered meat or to biological material contained in blood and animal fecal matter, and it was greater than could be attributed to smoking. This finding suggests an etiologic role for biological exposure; however, the specific exposure(s) responsible are unknown, and further research is clearly required. The results of studies of hematologic cancers have been less consistent, but they suggest a small excess risk for leukemia in association with similar exposures.