Survival of amoebae on building materials.

UNLABELLED: Moisture damage and concurrent microbial growth in buildings are associated with adverse health effects among the occupants. However, the causal agents for the symptoms are unclear although microbes are assumed to play a major role. Fungi and bacteria are not the only microbes inhabiting moist building materials; it was recently revealed that amoebae are also present. As amoebae have the potential to harbor many pathogens and to modulate the characteristics of growing microbes, a better appreciation of the growth and survival of amoebae in moisture damage conditions will add to the understanding of their effects on health outcomes. In this study, we investigated the ability of amoebae to survive on six building materials. Furthermore, both aged and unused materials were tested. Amoebae survived on gypsum board and mineral wool for the whole 2 months experiment even without additional sustenance. When sustenance (heat-killed bacteria) was available, aged pine wood and birch wood also allowed their survival. In contrast, amoebae were quickly killed on fresh pine wood and they did not survive on concrete or linoleum. In conclusion, our data show that amoebae can persist on several common building materials once these materials become wet. PRACTICAL IMPLICATIONS: Amoebae are able to survive on many building materials should the materials become wet. Amoebae have the potential to increase growth, cytotoxicity, and pathogenicity of other microbes present in moisture damages, and they may carry potentially pathogenic bacteria as endosymbionts and thus introduce them into the indoor air. Therefore, amoebae may have a prominent role in the microbial exposures occurring in moisture-damaged buildings. The presence of amoebae could be usefully included in reporting the microbial damage of material samples.

A method to compare exposed populations in seroepidemiology.

In seroepidemiology when a single sample is taken from exposed and non-exposed subjects, the results of serological tests are usually reduced to a dichotomy: normal (low or no antibodies) or elevated (high or antibodies found). The choice of the cutoff point between these values has been based on various vaguely defined methods and the results depend, at least partly, on the method chosen. An alternative method is introduced here which is not based on the absolute value of a serological test but on the rank order of the values of the test. In this ordered series the risk ratio (RR) and the upper and lower confidence limits (CL) are plotted for each exposed subject as the cutoff value is moved from the highest value to the lowest one. The method is applicable in quantitative immunoassays. If a priori defined RR and confidence limit or limits are reached at any point of the plot, the data support the original hypothesis. The advantage of this alternative method is that no single cutoff value is needed.

A cluster of inflammatory rheumatic diseases in a moisture-damaged office.

OBJECTIVE: To describe a cluster of inflammatory rheumatic diseases in an office workplace that suggests the presence of an environmental trigger. METHODS: There had been an indoor air problem in the workplace since the early 1990s. Large areas of the outer walls of the building were found to be moisture-damaged and contaminated by microbial growth. Case histories of the personnel were studied, and their working areas were related to the areas with highest microbial contamination. The incidence of inflammatory rheumatic diseases was compared with the statistics of the same geographic area. RESULTS: Ten patients with inflammatory rheumatic diseases (3 rheumatoid arthritis, 4 ankylosing spondylitis, 2 Sjögren's syndrome, and one of psoriatic arthritis) entitled to specially reimbursed medication were diagnosed in 1987-2000 (seven cases in 1995-1998). The incidence density ratio computed for the period 1987-2000 was 6.8 (95% confidence interval 3.6-13.0) for all office personnel and 13.2 (6.0-29.0) for those working close to the wall sustaining the worst damage. CONCLUSION: The accumulation of chronic inflammatory rheumatic diseases in a single workplace suggests that some environmental exposure in this damp office had triggered the diseases.

Antibodies against Yersinia among farmers and slaughterhouse workers.

Antibodies to immunoglobulins (Ig) M, G, and A against Yersinia enterocolitica serotypes O:3, O:5, O:8, and O:9 and Yersinia pseudotuberculosis serotypes I and III were analyzed by enzyme immunoassay of the serum samples of 161 slaughterhouse workers, 147 pig farmers, and 114 grain or berry farmers. The crude risk ratios for elevated serum antibody concentrations were calculated with the use of the grain and berry farmers as the reference population. The risk for an elevated Y enterocolitica O:3 Ig G concentration was 3.0 (95% confidence interval (95% CI) 1.3-7.1) for the pig farmers and 1.8 (95% CI 0.7-4.4) for the slaughterhouse workers and the respective risks for elevated Y enterocolitica O:9 Ig G were 2.4 (95% CI 1.1-5.5) and 1.7 (95% CI 0.7-4.0). Since these two serotypes are commonly associated with swine, the increased number of subjects with elevated antibody levels could be causally related to occupational contact with this animal.

A fatal case of hard-metal disease.

OBJECTIVES: The purpose of this report is to present a case of hard-metal disease in which the symptoms and findings were minimal early in the disease, but further exposure rapidly led to a fatal outcome. HISTORY: A 22-year-old nonsmoking white male, employed for over four years in hard-metal tool grinding, started experiencing a dry cough and shortness of breath during exercise. Preliminary investigations did not reveal any cause for these symptoms, and the patient continued to work. Several months later he developed clinically apparent alveolitis with recurrent pneumothorax. Pulmonary infiltrates in chest radiographs did not disappear during corticosteroid treatment. Soon it was evident that the patient had irreversible pulmonary failure, and a bilateral lung transplantation was performed. No signs of rejection were seen in the resected lungs. The patient died of pneumonia five months later, but no signs of hard-metal disease were found in the transplanted lung. CONCLUSIONS: This fatal case of hard-metal lung disease demonstrates that symptoms and findings in pulmonary function tests or chest radiographs may be minimal or misleading in the early stages of the disease. Cobalt-exposed workers with inexplicable respiratory symptoms should be closely monitored and the exposure should be suspended.

Joint symptoms and diseases associated with moisture damage in a health center.

Rheumatic diseases do not usually cluster in time and space. It has been proposed that environmental exposures may initiate autoimmune responses. We describe a cluster of rheumatic diseases among a group of health center employees who began to complain of symptoms typically related to moldy houses, including mucocutaneous symptoms, nausea and fatigue, within a year of moving into a new building. Dampness was found in the insulation space of the concrete floor below ground level. Microbes indicating mold damage and actinobacteria were found in the flooring material and in the outer wall insulation. The case histories of the personnel involved were examined. All 34 subjects working at the health center had at least some rheumatic complaints. Two fell ill with a typical rheumatoid factor (RF)-positive rheumatoid arthritis (RA), and 10 had arthritis that did not conform to any definite arthritic syndrome (three met the classification criteria for RA). Prior to moving into the problem building one subject had suffered reactive arthritis, which had then recurred. Another employee had undiagnosed ankylosing spondylitis and later developed psoriatic arthritis, and another developed undifferentiated vasculitis. A total of 16 subjects developed joint pains, 11 of these after beginning work at the health center. Three subjects developed Raynaud's symptom. Fourteen cases had elevated levels of circulating immune complexes in 1998, 17 in 1999, but there were only three cases in 2001, when the health center had been closed for 18 months. The high incidence of joint problems among these employees suggests a common triggering factor for most of the cases. As some of the symptoms had tended to subside while the health center was closed, the underlying causes are probably related to the building itself and possibly to the abnormal microbial growth in its structures.

Of microbes and men.

UNLABELLED: Moisture accumulation in building structures, the microbial ecology of water-damaged sites and human exposure to biological contaminants are complex phenomena and may result in various types of indoor air pollution and adverse health outcomes. Commonly reported are building-related irritation symptoms, respiratory infections and non-specific symptoms and occasionally neurological impairment. Various diseases have been associated with mold exposure, e.g. an increased risk of asthma development and exacerbation as well as clusters of hypersensitivity pneumonitis, pulmonary hemorrhage in infants and rheumatic diseases. The causal agents of these illnesses, still poorly understood, may be linked to the complex interactions between bacteria and fungi with environmental growth substrates and other microorganisms which lead to a wide diversity of exposures. Fungi and bacteria growing on building materials may produce toxic secondary metabolites, and the material appears to be a key determinant of metabolite production. Modern building technology has provided new ecological niches for microbes which readily exploit faults in moisture control. To better describe microbial exposures in buildings, current method development focuses on chemical markers of biomass and assays for specific genetic sequences. PRACTICAL IMPLICATIONS: Dampness and moisture phenomena in buildings, resulting microbial and chemical exposures and individual human responses are complex phenomena. While the causative links between exposing agents and health responses are still not well understood, the essential issue is to prevent the problems with good design, construction and maintenance.

Work-related symptoms and Salmonella antibodies among wastewater treatment plant workers.

Wastewater treatment plant workers are exposed to microbes, including Salmonella, but the prevalence of antibodies against Salmonella species or serovars in their serum samples has not been studied. Antibodies against Salmonella Infantis and lipopolysaccharide antigen common to S. Enteritidis and S. Typhimurium in immunoglobulin classes IgA, IgM and IgG were measured from 79 serum samples of wastewater treatment plant workers and from 79 blood donor samples. Faecal samples for Salmonella and Campylobacter were studied. Gastrointestinal, dermal and other symptoms were compared between 81 wastewater treatment plant workers and 89 food-processing workers. The blood donors had more antibodies against all of the tested antigens expect for S. Infantis in IgM and IgA classes, even though the wastewater treatment plant workers had more gastrointestinal symptoms than the controls. No Salmonella or Campylobacter were found in any faecal samples. Salmonella is not a probable cause of symptoms among wastewater treatment plant workers.

Contact with pigs and cats associated with high prevalence of Toxoplasma antibodies among farmers.

Antibodies to Toxoplasma were measured by enzyme linked immunosorbent assay (ELISA) in sera from 159 abattoir workers, 142 pig farmers, and 106 grain or berry farmers. Farmers occupationally exposed to pigs had antibodies in 53 (37%) cases, abattoir workers in 40 (25%) cases, and farmers not exposed to pigs in 24 (23%) cases. In each group antibodies were more prevalent among those who had a cat or cats in the household. Controlling for age and cat contacts changed the prevalences less than one percent. The results indicate that pig farmers might have an occupational risk of toxoplasmosis. As the prevalence of antibodies among abattoir workers was about the same as among the referent farmers, it seems unlikely that infection from Toxoplasma could be acquired by mere handling of raw meat.

Possible confounders of the relationship between occupational swine contact and Yersinia enterocolitica 0:3 and 0:9 antibodies.

Increased risk of high Yersinia enterocolitica 0:3 and 0:9 antibody content has been previously reported in occupations with swine contact. In this study several possible confounders of this elevated risk among pig farmers and abattoir workers were considered. Only in three instances the standardized risk ratio was decreased close to unity, namely after the standardization of Y. enterocolitica 0:3 IgG antibody positivity for age among abattoir workers, after the standardization of Y. enterocolitica 0:9 IgG antibody positivity for farm butchering among pig farmers and for smoking among abattoir workers. As the decrease did not apply for both pig farmers and abattoir workers and for both 0:3 and 0:9 serotypes considered, it seems reasonable to assume that the three decreases represent products of multiple testing inherent in this kind of search of confounders rather than any true effects. In view of the present knowledge on the determinants of yersinia antibodies in populations, the crude risk ratios for elevated yersinia antibodies can be held to be reasonably unconfounded.

Fungal spores as such do not cause nasal inflammation in mold exposure.

The increased frequency of respiratory symptoms and diseases among sawmill workers has been linked to occupational exposure to airborne contaminants, especially to different fungi. Similar adverse health effects, together with elevated levels of inflammatory mediators in the nasal lavage (NAL) fluid, have been detected in people working in mold-damaged buildings. However, the indoor fungal spore concentrations in moldy houses are much lower than those in sawmills. To study the effect of fungal spores as such on the inflammatory markers in the NAL fluid, we conducted a similar study in sawmill workers who had an intense exposure to fungal spores. NAL was performed in 11 sawmill workers both during high occupational microbial exposure and during their vacation. Concentrations of nitric oxide (NO), tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-4, IL-5, and IL-6 in NAL fluid were analyzed, and occupational exposure to inhalable dust, fungal spores, endotoxins and terpenes was confirmed by personal monitoring during the day of sampling. In addition, health data were collected with a questionnaire. Personal exposures to fungal spores varied from 2 x 10(5) spores/m(3) to 1.5 x 10(6) spores/m(3) (mean 7 x 10(5) spores/m(3)). Concentrations of inhalable dust, endotoxins, and terpenes were relatively low. There were no differences between work and vacation in the concentrations of NO and proinflammatory cytokines in NAL fluid or in the reporting of symptoms, and the levels were lower than in workers at a moldy school building. However, the concentration of TNFalpha in the NAL fluid was positively correlated with the concentration of terpenes in the working environment (r =.768; p =.006). These results show that microbial exposure as such does not invariably result in inflammatory changes detectable with the NAL method. We suggest that the type of microbial flora or microbial products in the occupational environment determines the proinflammatory potency of microbial exposure.

Inflammatory mediators in nasal lavage, induced sputum and serum of employees with rheumatic and respiratory disorders.

Exposure to microbes present in mould-damaged buildings has been linked to increased frequency of various inflammatory diseases. The current study examined differences in inflammatory mediators in nasal lavage (NAL), induced sputum (IS) and serum of occupants with rheumatic or respiratory disorders and their controls, all working in the same moisture-damaged building. Exhaled nitric oxide (NO) measurements, lung function tests, skin-prick tests and health data collection by questionnaire were performed. Concentrations of NO, interleukin (IL)-1, IL-4, IL-6 and tumour necrosis factor-alpha in NAL, IS and serum (excluding NO and IL-1) of the subjects were measured during an occupational exposure period and the vacation period without such exposure. The concentrations of IL-4 in NAL fluid were significantly higher among all occupants during the working period (geometric mean 8.5 microg x mL(-1), range 0-206.5 microg x mL(-1)), as compared to that during vacation (0.4 microng x mL(-1) range 0-3.7 pg x mL(-1)) (p = 0.008). Absence from the work environment also significantly diminished reporting of symptoms. IL-4 levels in the serum of case subjects were significantly higher than in controls. Moreover, employees with respiratory symptoms had markedly higher exhaled NO values than their controls (p = 0.028). In summary, these data suggest that mediators in nasal lavage samples reflect the occupational exposure to moulds, whereas possible indicators of existing disorders are detectable in serum.

The treatment of acute transient cough: a placebo-controlled comparison of dextromethorphan and dextromethorphan-beta 2-sympathomimetic combination.

The efficacy of an antitussive-beta 2-sympathomimetic combination (dextromethorphan-salbutamol) was compared with that of a plain antitussive (dextromethorphan) and a placebo in a double-blind trial in 108 out-patients with cough associated with acute respiratory infection. The dextromethorphan-salbutamol combination was superior to dextromethorphan or placebo in the suppression of cough at night, although a spontaneous improvement occurred in all treatment groups during the 4-day treatment period. No statistically significant differences between the treatments were shown in the symptom scores for the cough frequency and severity during the day, sputum quantity or ease of expectoration. A significant improvement in cough during the day was observed in all treatment groups. The results suggest that the use of antitussives is usually unnecessary; the only indication might be symptomatic relief, especially at night. An antitussive combined with a beta 2-sympathomimetic might be the most effective treatment in this type of cough.

An outbreak of respiratory diseases among workers at a water-damaged building--a case report.

We describe a military hospital building with severe, repeated and enduring water and mold damage, and the symptoms and diseases found among 14 persons who were employed at the building. The exposure of the employees was evaluated by measuring the serum immunoglobulin G (IgG)-antibodies against eight spieces of mold and yeast common in Finnish water and mold damaged buildings and by sampling airborne viable microbes within the hospital. The most abundant spieces was Sporobolomyces salmonicolor. All but one of the employees reported some building-related symptoms, the most common being a cough which was reported by nine subjects. Four new cases of asthma, confirmed by S. salmonicolor inhalation provocation tests, one of whom was also found to have alveolitis, were found among the hospital personnel. In addition, seven other workers with newly diagnosed rhinitis reacted positively in nasal S. salmonicolor provocation tests. Skin prick tests by Sporobolomyces were negative among all 14 workers. Exposure of the workers to mold and yeast in the indoor air caused an outbreak of occupational diseases, including asthma, rhinitis and alveolitis. The diseases were not immunoglobulin E (IgE)-mediated but might have been borne by some other, as yet unexplained, mechanism.

Self-reported health, illness, and self-care among finnish physicians: a national survey.

BACKGROUND: Physicians' health problems have been discussed mainly in relation to substance abuse and psychiatric disorders. In this study, the prevalence of common chronic diseases and their treatment were determined. OBJECTIVE: To find differences in self-reported health status, amount of sick leave, and the use of health services among physicians according to sex and specialty. Data were also compared with those of the total employed population. DESIGN AND SETTING: Cross-sectional postal questionnaire survey in Finland. PARTICIPANTS AND METHODS: A random sample of licensed physicians younger than 66 years (n = 4477) was randomly selected from the register of the Finnish Medical Association. A total of 3313 physicians (74%) responded. MAIN OUTCOME MEASURES: Perceived health, prevalence of diseases, self-treatment of diseases, amount of sick leave, and medical consultations. RESULTS: Female physicians assessed their health as being better than other female employees and had used health services and had been on sick leave more often than their male colleagues. Male physicians assessed their health as being equal to that of other men. Both female and male physicians had fewer sick leave than other employees. However, physicians-especially men-reported many common chronic illnesses as often or more often than other employees. Physicians had consulted other medical professionals less often than other employees, and they primarily self-treated their illnesses. Of the specialties, psychiatrists had used health services and had been on sick leave more often than other physicians. CONCLUSION: This study indicates that the usual form of care of physicians' diseases is self-treatment and "working through" illnesses. Arch Fam Med. 2000;9:1079-1085

Treatment of respiratory tract infections with erythromycin acistrate and two formulations of erythromycin base.

Erythromycin acistrate (EA)--a new ester of erythromycin--was compared with erythromycin base as enterocoated pellets in capsules (EB enterocapsules) and enterocoated tablets of erythromycin base (EB enterotablets) in the treatment of respiratory tract infections. The present double-blind, multicentre study, conducted in eight occupational health centres, included 474 patients; 236 treated with EA, 117 with EB enterocapsules and 121 with EB enterotablets. The diagnoses included tonsillitis, sinusitis, otitis media, bronchitis and pneumonia. The patients were examined on admission and at the end of the treatment. The dosage of EA was 400 mg tid and that of the two erythromycin base preparations 500 mg tid. The treatment was given for seven to 14 days. In the EA-group, 97% of patients were clinically cured by the end of the treatment, while the cure rates for EB enterocapsules and EB enterotablets were 95% and 94%, respectively. Gastrointestinal side effects were reported by 36% of the patients on EA, 54% on EB enterocapsules and 50% on EB enterotablets. Discontinuations due to adverse effects occurred in 8% in the EA, in 21% in the EB enterocapsule and in 12% in the EB enterotablet groups. All three preparations were thus equally effective, but EA caused statistically significantly less gastrointestinal side effects overall (P less than 0.01), especially nausea (P less than 0.01) and abdominal pain (P less than 0.05), than the two formulations containing erythromycin base. Also discontinuations due to side effects occurred statistically significantly less frequently in the EA-group.