[Survey of spike-specific immunoglobulin G antibodies at approximately 3 months and 9 months after vaccination against coronavirus disease 2019 (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) in health care workers].

OBJECTIVE: We investigated the antibody titer of spike-specific immunoglobulin G (IgG) antibodies after receiving coronavirus repair uridine ribonucleic acid (RNA) vaccine (BNT162b2, Pfizer) in health care workers. METHODS: At one hospital, health care workers received the vaccination between February and May 2021. A survey using questionnaires and spike-specific IgG antibody tests (Abbott) was conducted in 293 participants who had been vaccinated at least once and consented to this study at the time of medical checkups between April and May 2021. We calculated the antibody titer in each age group and days post-vaccination. We examined whether antibody titers of 4,000 AU/mL or higher (probability of high titer: approximately 95%, Abbott) were associated with adverse reactions after vaccination. In addition (1), the antibody titers at approximately 100 days after the second vaccination in 11 participants were remeasured. Furthermore (2), the antibody titers at approximately 260 days after the second vaccination in 13 participants were remeasured and compared with the initial measurements. RESULTS: Of the participants, 276 were post-2 doses (A), 14 were post-1 dose (B), and 3 discontinued the second vaccination (C) at the time of health checkup. The median antibody titer was 11,045.8 AU/mL (50.7-40,000) in group A, 122.7 AU/mL (2.6-1,127.0) in group B, 27,099.3 AU/mL in one of group C who had recovered from coronavirus disease 2019 (COVID-19), and 574.2 AU/mL (283.3 and 865.1) in the other two of group C. The median antibody titer was the highest in those in their 20s, and there was a significant difference between those under and above 40 years of age. The median titer was the highest in 2 weeks to 1 month after the second vaccination. After the second dose, fatigue (≥ moderate) was associated with antibody titers of 4,000 AU/mL or higher. The antibody titers of 11 and 13 participants at approximately 100 and 260 days after the second vaccination were significantly lower than those at the first measurement, with median values of 2,838.0 AU/mL (832.9-5,698.6) and 512.0 AU/mL (154.0-1,220.0), respectively. CONCLUSIONS: Antibody titers were higher in participants under 40 years of age than those 40 years or older. In addition, the percentage of high antibody titer (≧ 4,000 AU/mL) was higher in those who had severe fatigue after the second vaccination. The peak of antibody titer after the second dose was approximately 1 month, and the titer may decline gradually.

The Diagnosis of Sick House Syndrome: the Contribution of Diagnostic Criteria and Determination of Chemicals in an Indoor Environment.

OBJECTIVE: The study group for sick house syndrome (SHS) in Japan has proposed the classifications, definition and diagnostic criteria for chemical-associated SHS. We compared the physicians' diagnoses to the diagnoses based on the patients' interview sheets including diagnostic criteria only. METHODS: We examined 287 patients with complaints of SHS-like symptoms. We also checked determinations of chemical substances in the patients' homes. RESULTS: A total of 76.0% of the patients were diagnosed as having SHS. Physicians diagnosed 87.6% of those patients as having chemical-associated SHS based on SHS classifications, definition and diagnostic criteria. Based on the patients' interview sheets, 50.3% of the patients who were diagnosed as chemical-associated SHS corresponded to the diagnostic criteria. The 51 of those chemical-associated SHS patients had answered that the chemical substance levels in their homes had been checked, and 20 of those patients answered that at least one of the chemical substance levels was above that set in the guideline by the Japanese Ministry of Health, Labour and Welfare. CONCLUSIONS: Physicians should use all of the classifications, definition and diagnostic criteria. Even if the chemical levels in the home are under the guideline levels, the diagnosis of chemical-associated SHS should not be excluded.

Skin irritation to glass wool or continuous glass filaments as observed by a patch test among human Japanese volunteers.

Glass wool and continuous glass filaments have been used in industry. We examined the irritability of those among Japanese. A patch test was performed on 43 volunteers for the followings: glass wool for non-residential use with and without a urea-modified phenolic resin binder, that for residential use with and without the binder, and continuous glass filaments with diameters of 4, 7, 9, and 13 µm. Materials were applied to an upper arm of each volunteer for 24 h. The skin was observed at 1 and 24 h after the removal. At 1 h after removal, slight erythema was observed on the skin of a woman after the exposure to glass wool for residential use without the binder. Erythema was observed on the skin of another woman at 1 h after a 24-h exposure to glass wool for non-residential use without the binder. There were no reactions at 24 h after the removal. The low reactions in the patch test suggested that the irritability caused by glass wool, irrespective of a resin component, could be induced mechanically, and that the irritability caused by continuous glass filaments with resin could be slight and either mechanical or chemical.

The degree of workers' use of annual health checkup results among Japanese workers.

In Japan, the Industrial Safety and Health Law obliges all workers to undergo annual health checkups in their workplaces. At the plant for this study, workers who have one or more abnormal findings pointed out in their annual health checkups are summoned by occupational health staff and subsequently attend health consultations conducted by occupational health nurses each year. We investigated what kinds of health consultations have improved the workers' use of the results of their annual health checkups by an anonymous self-administered questionnaire survey. In addition, we discussed the associations with the multidimensional health locus of control (MHLC) and the degree of the workers' use of these results. A total of 837 questionnaires were analyzed. The average age of the respondents was 47.9 yr (range: 19-68 yr). The main results suggest that it is necessary for occupational health staff to give workers practical advice to improve their lifestyle habits and convey to them the effectiveness of preventive health behaviors. Workers with high scores in the belief in the "internal health locus of control (IHLC)" and low scores in the "chance health locus of control (CHLC)" use the results of their health checkups to help them manage their own health.

A pilot study testing the dimensions of safety climate among Japanese nurses.

To investigate the dimensions of safety climate among Japanese nurses, an anonymous self-administered questionnaire survey was conducted. The subjects involved in the survey included 293 full-time nurses (registered nurses and licensed practical nurses) working in a public hospital, excluding directors of nursing. A total of 221 of the 293 nurses answered the questionnaires. Among 221 questionnaires, the questionnaires, which had missing values in the question items used in this study, were excluded from the analyses. Consequently, a total of 201 questionnaires were analyzed. The average age of the subjects was 34.7 yr. As a result of exploratory factor analysis, 5 factors were extracted as follows: intellectual development regarding medical safety among nurses, accumulated fatigue, nursing conditions, supervisors' attitudes, and communication with physicians. All the values of Cronback's coefficient alpha among these 5 factors were between 0.804 and 0.892. As a result of the confirmatory factor analysis of the 5 factors, the value of the GFI (Goodness of Fit Index) was 0.868. The value of the CFI (Comparative Fit Index) was 0.943. The value of the RMSEA (Root Mean Square Error of Approximation) was 0.062. The results of this study will contribute to the investigation of the dimensions of a nurses' safety climate scale in the future. The associations between the dimensions of the safety climate and the motivation to work toward improving patients' safety among Japanese nurses will need to be examined, as will those between the dimensions of the safety climate and actual clinical mistakes.

Factors associated with workers' perceived helpfulness of and need for health consultations given by an occupational physician at a Japanese manufacturing plant.

OBJECTIVE: The aim of this study was to clarify measures for improving the functionality of health consultations by occupational physicians, by examining factors associated with workers' perceived helpfulness of, and need for, these consultations. METHODS: An anonymous self-administered questionnaire survey was conducted at a Japanese manufacturing plant. RESULTS: Multiple regression analyses showed that workers' perceived helpfulness of, and need for, health consultations given by an occupational physician was held in common and significantly associated with the occupational physician's dedication and complete protection of privacy. CONCLUSIONS: For health consultations given by occupational physicians to be effective, it is necessary to help employees realize the physicians' outstanding dedication and to convey to the workers the absolute assurance of their privacy protection.

Survey of the degree of examinees' satisfaction with instructions on how to read results of general health checkups at a workplace.

To clarify measures for making clearer instructions on how to read the results of general health checkups in a workplace by surveying the views of workers on these instructions, an anonymous self-administered questionnaire survey was conducted at a Japanese manufacturing plant. The responses of 984 male workers were analyzed. The average age of the subjects was 32.1 yr (range, 19-60 yr). Regarding the instructions, 4.1% of the subjects answered "definitely sufficient," 58.9% "somewhat sufficient," 28.0% "neither sufficient nor insufficient," 8.1% "somewhat insufficient" and 0.8% "definitely insufficient." Multiple regression analysis showed that the degree of examinees' satisfaction significantly correlated with the health condition (standard partial regression coefficient =0.189, p<0.001), knowledge of health management (standard partial regression coefficient =0.095, p=0.014), and fear of lifestyle-related diseases (standard partial regression coefficient =0.095, p=0.009). The adjusted R square value of the multiple regression analysis was 0.064. It is necessary to provide more detailed information to those with poor health. Because the instructions contain many difficult medical terms, health professionals must give instructions that are easy to understand. Those feeling fear of lifestyle-related diseases may already know how to read checkup results. It is necessary to promote awareness of lifestyle-related diseases targeting people unfamiliar with such diseases.

Classification of patients complaining of sick house syndrome and/or multiple chemical sensitivity.

Sick house syndrome (SHS) is a Japanese concept derived from sick building syndrome (SBS), however SHS includes a broader scope of sickness than does SBS. Symptoms of SHS/SBS disappear after leaving the sick house/building, while symptoms of multiple chemical sensitivity (MCS) are elicited by the chance of chemical exposure after leaving the sick house/building. To establish the concept of SHS, we propose to introduce a new classification for SHS. A total of 214 patients complaining of SHS and/or MCS were independently classified using a new classification by clinical ecologists who are experienced physicians with expert knowledge of clinical ecology and general physicians according to disease pathogenesis from clinical records. The classification is as follows: type 1 (symptoms of chemical intoxication), type 2 (symptoms developed possibly due to chemical exposure), type 3 (symptoms developed not because of chemical exposure but rather because of psychological or mental factors), and type 4 (symptoms developed due to allergies or other diseases). The agreements on the classification made by clinical ecologists and general physicians reached 77.1% (Cohen's kappa=0.631), suggesting that this new classification was both apt and accurate. Relations between SHS and allergy/MCS were also studied. The cases classified as SHS type 4 more frequently had allergic past histories than did other types. The proportion of possible MCS cases was higher in the chemical induced SHS group (types 1 and 2) than in other types among male patients. For the universal use in clinical practice, it is necessary to prepare helpful diagnostic criteria of this SHS classification based on pathogenesis and carry our study forward all over the country.

The association of needlestick injury with depressive symptoms among first-year medical residents in Japan.

Depressive symptoms among medical residents are common. The objective of this study was to determine the association of depressive symptoms with needlestick injury among first-year medical residents (so-called "intern"). We conducted a prospective cohort study among 107 medical residents in 14 training hospitals. The baseline survey was conducted in August 2005 and the follow-up survey was conducted in March 2006. Depressive symptoms were based on the Center for Epidemiological Study of Depression. Factors associated with depressive symptoms were examined using logistic regression analysis. For medical residents without depressive symptoms at the baseline survey, needlestick injury events were associated with depressive symptoms at the follow-up survey (corrected odds ratio [cOR]=2.98; 95% confidence interval [CI], 1.16-3.70). Because it was not possible to determine when the medical residents developed depressive symptoms, it is not possible to definitely determine causality between needlestick injury and depressive symptoms, although these findings are suggestive. Therefore, it would seem prudent to suggest the provision of mental health services to medical residents sustaining a needlestick injury since this may be helpful in identifying and treating depression.