American Journal of Infection Control 42 (2014) 246-8
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
journal homepage: www.ajicjournal.org
Major article
Lessons learned from earthquake-related tuberculosis exposures in a community shelter, Japan, 2011 Hajime Kanamori MD, PhD, MPH a, b, *, Ryo Kimura PHN c, David J. Weber MD, MPH d, Bine Uchiyama MD, PhD b, Yoichi Hirakata MD, PhD b, Noboru Aso MD, PhD b, Koji Kiryu MD c, Mitsuo Kaku MD, PhD a a
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan Department of Respiratory Medicine, Miyagi Cardiovascular and Respiratory Center, Kurihara, Japan Miyagi Prefectural Government Kesennuma Public Health Center, Kesennuma, Japan d Department of Medicine, University of North Carolina, Chapel Hill, NC b c
Key Words: Interferon-g release assay Contact investigation Natural disaster
Background: Refugees and displaced populations after natural disasters have been vulnerable to tuberculosis. We report an active pulmonary tuberculosis case at a shelter and the subsequent contact investigation and review lessons learned from the 2011 Great East Japan Earthquake. Methods: The contact investigation was conducted to identify latent tuberculosis infection among a total of 95 contact persons, including 78 evacuees at the shelter, who were exposed to the index tuberculosis patient. The association between exposure time of contacts to a patient with active tuberculosis and results of interferon-g release assay (IGRA) was also examined. Results: IGRA was positive in 9 (12.3%) of 73 evacuees at the shelter. Contacts who were exposed to active tuberculosis for more than 25 days were significantly more likely to be IGRA positive, compared with contacts exposed for less than 20 days. All of the 4 evacuees with latent tuberculosis infection who initiated treatment completed the regimen successfully. Conclusion: When a disaster strikes and many people are living in shelters, it is essential for health care personnel to first suspect tuberculosis and implement prevention and control in collaboration with referral hospitals and public health centers. Copyright Ó 2014 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
The Japanese national surveillance system has reported the occurrence of infectious diseases such as tetanus and legionellosis and outbreaks such as influenza and norovirus gastroenteritis following the 2011 Great East Japan Earthquake and subsequent tsunami.1 Refugees and displaced populations after natural disasters have been vulnerable to tuberculosis (TB).2,3 We experienced and described TB cases and contact investigations after the Japan Earthquake that were associated with evacuees at a shelter, an infected disaster volunteer, and among health care personnel providing care to patients in hospital rooms without the ability to provide negative pressure.4-6 We report here another case of active pulmonary TB at a shelter and the subsequent contact investigation
* Address correspondence to Hajime Kanamori, MD, PhD, MPH, Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. E-mail address: [email protected] (H. Kanamori). Conflicts of interest: None to report.
after the Japan earthquake. We also review lessons learned from TB contact investigations after the Japan earthquake. METHODS The index case was a 77-year-old man with liver dysfunction who was referred and admitted to our hospital in the middle of June after the Great East Japan Earthquake on March 11, 2011. He stayed at a shelter with his family and other evacuees from March 11 to April 10 (1 month) because his house had been destroyed by the tsunami prior to returning to his home. The patient reported cough, sputum production, and appetite loss from the end of March. He had anorexia, weight loss, and pollakiuria from April and visited a urologic clinic. He also reported fever from the end of May for which he saw a general practitioner who referred him to a general hospital for detailed evaluation. He had a previous history of a gastric ulcer and prostatic hypertrophy, but no history of tuberculosis infection or immunologic abnormalities. This study
0196-6553/$36.00 - Copyright Ó 2014 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajic.2013.10.004
H. Kanamori et al. / American Journal of Infection Control 42 (2014) 246-8 Table 1 Results of interferon-g release assay and tuberculin skin test in contact investigation for the index case by age IGRA (n)
Table 2 Association between exposure time of contacts to the index case and results of interferon-g release assay
TST (n)
IGRA (n)
Age, y Contacts tested Negative Positive Contacts tested Negative Positive 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99 Total
0 4 5 8 8 17 17 16 9 1 85
0 4 5 8 8 16 16 11 6 1 75
247
0 0 0 0 0 1 1 5 3 0 10
8 1 0 0 0 0 0 0 0 0 9
0 1 0 0 0 0 0 0 0 0 1
8 0 0 0 0 0 0 0 0 0 8
IGRA, interferon-g release assay; TST, tuberculin skin test. NOTE. IGRA results were evaluated according to the Japanese guideline for using the QuantiFERON-TB Gold In-Tube.8
RESULTS Eight (88.9%) of the 9 child contacts tested were TST positive, although they had received bacille Calmette-Guérin (BCG) vaccination. Ten (11.8%) of the 85 adult contacts tested were IGRA positive (Table 1). Eight (18.6%) of the 43 contacts who were exposed to
Positive
All
36 35 71
1 8 9
37 43 80
Exposure time 20 days Exposure time 25 days All
IGRA, interferon-g release assay. NOTE. IGRA-positive rate in exposure time 25 days versus 20 days (8/43 vs 1/37, respectively, P ¼ .0077, Fisher test).
Table 3 Review of earthquake-related tuberculosis exposures and contact investigations, Japan, 2011 Source description Age Gender
was approved by the Ethics Committee of Miyagi Cardiovascular and Respiratory Center, Kurihara, Japan. A chest radiograph revealed extensive infiltrative shadows in both lungs. Acid fast bacilli (AFB) were observed by sputum smear and was graded Gaffky 9 (grade 3þ on the World Health Organization scale). Mycobacterium tuberculosis complex was detected by polymerase chain reaction. As a result of his detailed examination, he was diagnosed as pulmonary TB and transferred to the TB ward where he was placed in a negative-pressure single room. The patient was treated with a 3-drug regimen of isoniazid, rifampin, and ethambutol. Pyrazinamide was not used because of liver dysfunction. Sputum culture yielded M tuberculosis, and antimycobacterial susceptibility testing revealed that the strain was susceptible to isoniazid, rifampicin, ethambutol, streptomycin, and ethionamide. He improved and was discharged in August after sputum smears were repeatedly negative for AFB. He continued to receive directly observed treatment at an outpatient clinic but died of congestive heart failure in September. Gathering contacts’ information was challenging in the shelter after the earthquake. A contact investigation was conducted to identify latent tuberculosis infection (LTBI) among a total of 95 contact persons who were exposed to this TB patient, including 78 evacuees at the shelter, 9 family members, 4 health care providers, 2 shelter volunteers, and 2 carpenters. Although exposed children aged under 5 years were assigned high priority for investigation, there is lack of evidence about the performance of interferon-g release assay (IGRA) in children.7 In this investigation, LTBI in 9 contacts (an infant and children 10 years of age) was determined by tuberculin skin test (TST), and LTBI in 85 contacts (children aged > 10 years and adults) was done by the whole-blood IGRA using QuantiFERON-TB Gold In-Tube (QFT-3G) (Cellestis; Chadstone, Victoria, Australia) from June to September 2011 (2-5 months after the last possible exposure). IGRA results were evaluated according to the Japanese guideline.8 The association between exposure time of contacts to a patient with active tuberculosis and results of IGRA was also examined for 80 of the 85 contacts tested with IGRA. TST or IGRA was not available for one contact because he was a patient with a terminal disease (ie, cholangiocarcinoma).
Negative
Type
70s Male Evacuee 80s Female Evacuee 30s Female Volunteer
Sputum No. of No. of IGRA No. of IGRA smear contacts tested positive (%) Reference 3þ 1þ 1þ
95 62 72
85 57 59
10 (11.8) 9 (15.8) 6 (10.2)
This study 4 5
IGRA, interferon-g release assay.
active TB for more than 25 days were IGRA positive, whereas only 1 (2.7%) of the 37 contacts who were exposed to active TB for less than 20 days were IGRA positive (P ¼ .0077, Fisher test, 2-tailed; Table 2). For TST- or IGRA-positive contacts, medical examination and chest radiography were performed, but there were no findings characteristic of pulmonary TB. After physicians explained risks and benefits to contacts, the prophylactic treatment of LTBI was instituted for 4 contacts (4 evacuees), and the others received follow-up chest radiography. Children contacts who were weakly TST positive received follow-up chest radiography because they had a BCG vaccination. All of the 4 contacts with LTBI who initiated treatment completed the regimen successfully. As of January 2013, there have been no active TB cases observed among contacts. Table 3 reviews earthquake-related TB exposures and contact investigations.
DISCUSSION The tsunami just after the Japan earthquake claimed many lives in a moment, and survivors were often obliged to reside in shelters.9 General physicians had an important role in medical care for evacuees with chronic conditions. Older TB patients often visit general physicians with an atypical presentation of TB, including lower prevalence of fever, sweating, hemoptysis, cavitary disease, lower levels of serum albumin and blood leukocytes, higher prevalence of dyspnea, and concomitant conditions such as cardiovascular disorders, chronic obstructive pulmonary disease, diabetes, and malignancies.10 The older TB patient in this case had atypical presentation, and the physician at initial medical examination did not suspect TB, which may have delayed the time to TB diagnosis and resulted in TB spread in the shelter. It would be difficult for untrained shelter staff to screen older persons for the presence of TB, especially if they present with atypical symptoms. To maintain physicians’ competence in prevention, diagnosis, and treatment of TB, continuous medical education and training should focus on general physicians rather than pulmonologist or infectious diseases physicians. It is essential for health care personnel supporting shelters to first suspect TB in persons with consistent symptoms and accelerate rapid diagnosis and treatment of TB in collaboration with referral hospitals where AFB testing and chest radiography are available. Patients with known or suspected TB should be
248
H. Kanamori et al. / American Journal of Infection Control 42 (2014) 246-8
transferred to a medical facility as soon as possible because isolation and respiratory protection for airborne spread diseases such as TB is impossible to implement in a shelter.11 Planning for infection prevention and control in shelters and training shelter staff as well as health care personnel are necessary so that we take measures against infectious disease transmission in unforeseeable disasters. In this investigation, IGRA was positive (indicating LTBI) in 10 (11.8%) of the 85 contacts tested, especially in 9 (12.3%) of 73 evacuees at the shelter. A previous Japanese study revealed that the QFT-G-positive rate was 7.1% for those aged 40 to 69 years.12 IGRA would be more useful than TST in TB contact tracing in Japan and other countries that provide BCG vaccination program. However, IGRA cannot differentiate recent TB infection with remote infection, and, therefore, LTBI diagnosis in the elderly contacts remains challenging in Japan, which is still one of the TB middle-burden countries. For young children, TST is problematic because Japan still has an active BCG vaccination program. Mori et al revealed the wide gap between QFT-G-positive rate and predicted prevalence of TB infection by age group, especially among the elderly population, which suggests waning of specific interferon-g response with time after TB infection.12 In the previous case at a different shelter,4 TB contact investigation was conducted just after the Japan earthquake, and it was more difficult to obtain contacts’ information for the following reasons: (1) many evacuees had moved to secondary shelters or relatives’ homes; (2) many public health nurses spent their effort and time for disaster support; and (3) a manager of the shelter was anxious about harmful rumors. However, in this case, we could obtain more data on contact persons and exposure time to the TB patient. Prompt screening could have identified this TB case earlier and allowed appropriate isolation, which may have resulted in lower contacts, exposure times, and IGRA-positive rate. Contacts who were exposed to active TB for more than 25 days were significantly more likely to be IGRA positive compared with contacts exposed for less than 20 days. According to an article by Kenyon et al, airline passengers who were seated for more than 8 hours in the same or adjoining row were more likely to be infected than other passengers.13 Using a decision tree to predict positive TSTs, Gerald et al suggested that contacts to an active TB case be investigated for TST if the total exposure time was larger than 120 hours per month.14 On the other hand, Golub et al reported that TB can be transmitted through casual contact (eg, 3 times with no more than 15 minutes each time during the infectious period).15 Furthermore, in this case, the shelter had poor ventilation and was approximately 180 m2 with 80 evacuees who stayed there, whereas the shelter size in the previous case was 60 m2, and 50 evacuees stayed.4 According to the univariate analysis, minimum ventilation (eg, closed windows and doors or window/fan exhaust) and minimum size (eg, a vehicle, a car, or a bedroom) were associated with TST-positive results.16 Although impaired health care services and access after a natural disaster can lead to poor treatment adherence, all (4/4, 100%) patients in our case completed successfully the regimen for their LTBI as did the patients in the previous case (8/8, 100%). Our results may be partially attributed to health care personnel’s efforts and “kizuna”
(the idea of bonds and connections) among people in the affected area. Acknowledgment The authors thank the health care personnel who were involved in this investigation for their contribution and Satoko Tadano, Miyagi Prefectural Government Shiogama Public Health Center, for her insightful comments and suggestions. References 1. National Institute of Infectious Diseases. Infectious disease outbreaks related to the March 11 Great East Japan Earthquake in 2011 and infection control measures taken. Infectious agents surveillance report (IASR) 2011; 32: P. S1, Supplement. Available from: http://idsc.nih.go.jp/iasr/32/32s/me32s1.html. Accessed May 6, 2013. 2. World Health Organization. Tuberculosis care and control in refugee and displaced populations. An interagency field manual. 2nd ed. Geneva, Switzerland: WHO; 2007. Available from: http://whqlibdoc.who.int/publications/2007/ 9789241595421_eng.pdf. Accessed May 7, 2013. 3. Oeltmann JE, Varma JK, Ortega L, Liu Y, O’Rourke T, Cano M, et al. Multidrugresistant tuberculosis outbreak among US-bound Hmong refugees, Thailand, 2005. Emerg Infect Dis 2008;14:1715-21. 4. Kanamori H, Aso N, Tadano S, Saito M, Saito H, Uchiyama B, et al. Tuberculosis exposure among evacuees at a shelter after earthquake, Japan, 2011. Emerg Infect Dis 2013;19:799-801. 5. Kanamori H, Uchiyama B, Hirakata Y, Chiba T, Okuda M, Kaku M. Lessons learned from a tuberculosis contact investigation associated with a disaster volunteer after the 2011 Great East Japan Earthquake. Am J Respir Crit Care Med 2013;187:1278-9. 6. Kanamori H, Aso N, Weber DJ, Koide M, Sasaki Y, Tokuda K, et al. Latent tuberculosis infection in nurses exposed to tuberculous patients cared for in rooms without negative pressure after the 2011 Great East Japan Earthquake. Infect Control Hosp Epidemiol 2012;33:204-6. 7. Mazurek GH, Jereb J, Vernon A, LoBue P, Goldberg S, Castro K. IGRA Expert Committee; Centers for Disease Control and Prevention (CDC). Updated guidelines for using interferon g release assays to detect Mycobacterium tuberculosis infection, United States, 2010. MMWR Recomm Rep 2010;59:1-25. 8. Preventive Committee of the Japanese Society for Tuberculosis. Guidelines for using the QuantiFERON-TB Gold In-Tube (in Japanese). Kekkaku 2011;86: 839-44. 9. Kanamori H, Kunishima H, Tokuda K, Kaku M. Infection control campaign at evacuation centers in Miyagi prefecture after the Great East Japan Earthquake. Infect Control Hosp Epidemiol 2011;32:824-6. 10. Pérez-Guzmán C, Vargas MH, Torres-Cruz A, Villarreal-Velarde H. Does aging modify pulmonary tuberculosis? A meta-analytical review. Chest 1999;116: 961-7. 11. Association for Professionals in Infection Control and Epidemiology (APIC) Emergency Preparedness Committee. Infection prevention and control for shelters during disasters, 2007/2008. Available from: http://www.apic.org/ Resource_/TinyMceFileManager/Practice_Guidance/Emergency_Preparedness/ Shelters_Disasters.pdf. Accessed May 7, 2013. 12. Mori T, Harada N, Higuchi K, Sekiya Y, Uchimura K, Shimao T. Waning of the specific interferon-g response after years of tuberculosis infection. Int J Tuberc Lung Dis 2007;11:1021-5. 13. Kenyon TA, Valway SE, Ihle WW, Onorato IM, Castro KG. Transmission of multidrug-resistant Mycobacterium tuberculosis during a long airplane flight. N Engl J Med 1996;334:933-8. 14. Gerald LB, Tang S, Bruce F, Redden D, Kimerling ME, Brook N, et al. A decision tree for tuberculosis contact investigation. Am J Respir Crit Care Med 2002;166: 1122-7. 15. Golub JE, Cronin WA, Obasanjo OO, Coggin W, Moore K, Pope DS, et al. Transmission of Mycobacterium tuberculosis through casual contact with an infectious case. Arch Intern Med 2001;161:2254-8. 16. Bailey WC, Gerald LB, Kimerling ME, Redden D, Brook N, Bruce F, et al. Predictive model to identify positive tuberculosis skin test results during contact investigations. JAMA 2002;287:996-1002.
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
journal homepage: www.ajicjournal.org
Major article
Lessons learned from earthquake-related tuberculosis exposures in a community shelter, Japan, 2011 Hajime Kanamori MD, PhD, MPH a, b, *, Ryo Kimura PHN c, David J. Weber MD, MPH d, Bine Uchiyama MD, PhD b, Yoichi Hirakata MD, PhD b, Noboru Aso MD, PhD b, Koji Kiryu MD c, Mitsuo Kaku MD, PhD a a
Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan Department of Respiratory Medicine, Miyagi Cardiovascular and Respiratory Center, Kurihara, Japan Miyagi Prefectural Government Kesennuma Public Health Center, Kesennuma, Japan d Department of Medicine, University of North Carolina, Chapel Hill, NC b c
Key Words: Interferon-g release assay Contact investigation Natural disaster
Background: Refugees and displaced populations after natural disasters have been vulnerable to tuberculosis. We report an active pulmonary tuberculosis case at a shelter and the subsequent contact investigation and review lessons learned from the 2011 Great East Japan Earthquake. Methods: The contact investigation was conducted to identify latent tuberculosis infection among a total of 95 contact persons, including 78 evacuees at the shelter, who were exposed to the index tuberculosis patient. The association between exposure time of contacts to a patient with active tuberculosis and results of interferon-g release assay (IGRA) was also examined. Results: IGRA was positive in 9 (12.3%) of 73 evacuees at the shelter. Contacts who were exposed to active tuberculosis for more than 25 days were significantly more likely to be IGRA positive, compared with contacts exposed for less than 20 days. All of the 4 evacuees with latent tuberculosis infection who initiated treatment completed the regimen successfully. Conclusion: When a disaster strikes and many people are living in shelters, it is essential for health care personnel to first suspect tuberculosis and implement prevention and control in collaboration with referral hospitals and public health centers. Copyright Ó 2014 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
The Japanese national surveillance system has reported the occurrence of infectious diseases such as tetanus and legionellosis and outbreaks such as influenza and norovirus gastroenteritis following the 2011 Great East Japan Earthquake and subsequent tsunami.1 Refugees and displaced populations after natural disasters have been vulnerable to tuberculosis (TB).2,3 We experienced and described TB cases and contact investigations after the Japan Earthquake that were associated with evacuees at a shelter, an infected disaster volunteer, and among health care personnel providing care to patients in hospital rooms without the ability to provide negative pressure.4-6 We report here another case of active pulmonary TB at a shelter and the subsequent contact investigation
* Address correspondence to Hajime Kanamori, MD, PhD, MPH, Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. E-mail address: [email protected] (H. Kanamori). Conflicts of interest: None to report.
after the Japan earthquake. We also review lessons learned from TB contact investigations after the Japan earthquake. METHODS The index case was a 77-year-old man with liver dysfunction who was referred and admitted to our hospital in the middle of June after the Great East Japan Earthquake on March 11, 2011. He stayed at a shelter with his family and other evacuees from March 11 to April 10 (1 month) because his house had been destroyed by the tsunami prior to returning to his home. The patient reported cough, sputum production, and appetite loss from the end of March. He had anorexia, weight loss, and pollakiuria from April and visited a urologic clinic. He also reported fever from the end of May for which he saw a general practitioner who referred him to a general hospital for detailed evaluation. He had a previous history of a gastric ulcer and prostatic hypertrophy, but no history of tuberculosis infection or immunologic abnormalities. This study
0196-6553/$36.00 - Copyright Ó 2014 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajic.2013.10.004
H. Kanamori et al. / American Journal of Infection Control 42 (2014) 246-8 Table 1 Results of interferon-g release assay and tuberculin skin test in contact investigation for the index case by age IGRA (n)
Table 2 Association between exposure time of contacts to the index case and results of interferon-g release assay
TST (n)
IGRA (n)
Age, y Contacts tested Negative Positive Contacts tested Negative Positive 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99 Total
0 4 5 8 8 17 17 16 9 1 85
0 4 5 8 8 16 16 11 6 1 75
247
0 0 0 0 0 1 1 5 3 0 10
8 1 0 0 0 0 0 0 0 0 9
0 1 0 0 0 0 0 0 0 0 1
8 0 0 0 0 0 0 0 0 0 8
IGRA, interferon-g release assay; TST, tuberculin skin test. NOTE. IGRA results were evaluated according to the Japanese guideline for using the QuantiFERON-TB Gold In-Tube.8
RESULTS Eight (88.9%) of the 9 child contacts tested were TST positive, although they had received bacille Calmette-Guérin (BCG) vaccination. Ten (11.8%) of the 85 adult contacts tested were IGRA positive (Table 1). Eight (18.6%) of the 43 contacts who were exposed to
Positive
All
36 35 71
1 8 9
37 43 80
Exposure time 20 days Exposure time 25 days All
IGRA, interferon-g release assay. NOTE. IGRA-positive rate in exposure time 25 days versus 20 days (8/43 vs 1/37, respectively, P ¼ .0077, Fisher test).
Table 3 Review of earthquake-related tuberculosis exposures and contact investigations, Japan, 2011 Source description Age Gender
was approved by the Ethics Committee of Miyagi Cardiovascular and Respiratory Center, Kurihara, Japan. A chest radiograph revealed extensive infiltrative shadows in both lungs. Acid fast bacilli (AFB) were observed by sputum smear and was graded Gaffky 9 (grade 3þ on the World Health Organization scale). Mycobacterium tuberculosis complex was detected by polymerase chain reaction. As a result of his detailed examination, he was diagnosed as pulmonary TB and transferred to the TB ward where he was placed in a negative-pressure single room. The patient was treated with a 3-drug regimen of isoniazid, rifampin, and ethambutol. Pyrazinamide was not used because of liver dysfunction. Sputum culture yielded M tuberculosis, and antimycobacterial susceptibility testing revealed that the strain was susceptible to isoniazid, rifampicin, ethambutol, streptomycin, and ethionamide. He improved and was discharged in August after sputum smears were repeatedly negative for AFB. He continued to receive directly observed treatment at an outpatient clinic but died of congestive heart failure in September. Gathering contacts’ information was challenging in the shelter after the earthquake. A contact investigation was conducted to identify latent tuberculosis infection (LTBI) among a total of 95 contact persons who were exposed to this TB patient, including 78 evacuees at the shelter, 9 family members, 4 health care providers, 2 shelter volunteers, and 2 carpenters. Although exposed children aged under 5 years were assigned high priority for investigation, there is lack of evidence about the performance of interferon-g release assay (IGRA) in children.7 In this investigation, LTBI in 9 contacts (an infant and children 10 years of age) was determined by tuberculin skin test (TST), and LTBI in 85 contacts (children aged > 10 years and adults) was done by the whole-blood IGRA using QuantiFERON-TB Gold In-Tube (QFT-3G) (Cellestis; Chadstone, Victoria, Australia) from June to September 2011 (2-5 months after the last possible exposure). IGRA results were evaluated according to the Japanese guideline.8 The association between exposure time of contacts to a patient with active tuberculosis and results of IGRA was also examined for 80 of the 85 contacts tested with IGRA. TST or IGRA was not available for one contact because he was a patient with a terminal disease (ie, cholangiocarcinoma).
Negative
Type
70s Male Evacuee 80s Female Evacuee 30s Female Volunteer
Sputum No. of No. of IGRA No. of IGRA smear contacts tested positive (%) Reference 3þ 1þ 1þ
95 62 72
85 57 59
10 (11.8) 9 (15.8) 6 (10.2)
This study 4 5
IGRA, interferon-g release assay.
active TB for more than 25 days were IGRA positive, whereas only 1 (2.7%) of the 37 contacts who were exposed to active TB for less than 20 days were IGRA positive (P ¼ .0077, Fisher test, 2-tailed; Table 2). For TST- or IGRA-positive contacts, medical examination and chest radiography were performed, but there were no findings characteristic of pulmonary TB. After physicians explained risks and benefits to contacts, the prophylactic treatment of LTBI was instituted for 4 contacts (4 evacuees), and the others received follow-up chest radiography. Children contacts who were weakly TST positive received follow-up chest radiography because they had a BCG vaccination. All of the 4 contacts with LTBI who initiated treatment completed the regimen successfully. As of January 2013, there have been no active TB cases observed among contacts. Table 3 reviews earthquake-related TB exposures and contact investigations.
DISCUSSION The tsunami just after the Japan earthquake claimed many lives in a moment, and survivors were often obliged to reside in shelters.9 General physicians had an important role in medical care for evacuees with chronic conditions. Older TB patients often visit general physicians with an atypical presentation of TB, including lower prevalence of fever, sweating, hemoptysis, cavitary disease, lower levels of serum albumin and blood leukocytes, higher prevalence of dyspnea, and concomitant conditions such as cardiovascular disorders, chronic obstructive pulmonary disease, diabetes, and malignancies.10 The older TB patient in this case had atypical presentation, and the physician at initial medical examination did not suspect TB, which may have delayed the time to TB diagnosis and resulted in TB spread in the shelter. It would be difficult for untrained shelter staff to screen older persons for the presence of TB, especially if they present with atypical symptoms. To maintain physicians’ competence in prevention, diagnosis, and treatment of TB, continuous medical education and training should focus on general physicians rather than pulmonologist or infectious diseases physicians. It is essential for health care personnel supporting shelters to first suspect TB in persons with consistent symptoms and accelerate rapid diagnosis and treatment of TB in collaboration with referral hospitals where AFB testing and chest radiography are available. Patients with known or suspected TB should be
248
H. Kanamori et al. / American Journal of Infection Control 42 (2014) 246-8
transferred to a medical facility as soon as possible because isolation and respiratory protection for airborne spread diseases such as TB is impossible to implement in a shelter.11 Planning for infection prevention and control in shelters and training shelter staff as well as health care personnel are necessary so that we take measures against infectious disease transmission in unforeseeable disasters. In this investigation, IGRA was positive (indicating LTBI) in 10 (11.8%) of the 85 contacts tested, especially in 9 (12.3%) of 73 evacuees at the shelter. A previous Japanese study revealed that the QFT-G-positive rate was 7.1% for those aged 40 to 69 years.12 IGRA would be more useful than TST in TB contact tracing in Japan and other countries that provide BCG vaccination program. However, IGRA cannot differentiate recent TB infection with remote infection, and, therefore, LTBI diagnosis in the elderly contacts remains challenging in Japan, which is still one of the TB middle-burden countries. For young children, TST is problematic because Japan still has an active BCG vaccination program. Mori et al revealed the wide gap between QFT-G-positive rate and predicted prevalence of TB infection by age group, especially among the elderly population, which suggests waning of specific interferon-g response with time after TB infection.12 In the previous case at a different shelter,4 TB contact investigation was conducted just after the Japan earthquake, and it was more difficult to obtain contacts’ information for the following reasons: (1) many evacuees had moved to secondary shelters or relatives’ homes; (2) many public health nurses spent their effort and time for disaster support; and (3) a manager of the shelter was anxious about harmful rumors. However, in this case, we could obtain more data on contact persons and exposure time to the TB patient. Prompt screening could have identified this TB case earlier and allowed appropriate isolation, which may have resulted in lower contacts, exposure times, and IGRA-positive rate. Contacts who were exposed to active TB for more than 25 days were significantly more likely to be IGRA positive compared with contacts exposed for less than 20 days. According to an article by Kenyon et al, airline passengers who were seated for more than 8 hours in the same or adjoining row were more likely to be infected than other passengers.13 Using a decision tree to predict positive TSTs, Gerald et al suggested that contacts to an active TB case be investigated for TST if the total exposure time was larger than 120 hours per month.14 On the other hand, Golub et al reported that TB can be transmitted through casual contact (eg, 3 times with no more than 15 minutes each time during the infectious period).15 Furthermore, in this case, the shelter had poor ventilation and was approximately 180 m2 with 80 evacuees who stayed there, whereas the shelter size in the previous case was 60 m2, and 50 evacuees stayed.4 According to the univariate analysis, minimum ventilation (eg, closed windows and doors or window/fan exhaust) and minimum size (eg, a vehicle, a car, or a bedroom) were associated with TST-positive results.16 Although impaired health care services and access after a natural disaster can lead to poor treatment adherence, all (4/4, 100%) patients in our case completed successfully the regimen for their LTBI as did the patients in the previous case (8/8, 100%). Our results may be partially attributed to health care personnel’s efforts and “kizuna”
(the idea of bonds and connections) among people in the affected area. Acknowledgment The authors thank the health care personnel who were involved in this investigation for their contribution and Satoko Tadano, Miyagi Prefectural Government Shiogama Public Health Center, for her insightful comments and suggestions. References 1. National Institute of Infectious Diseases. Infectious disease outbreaks related to the March 11 Great East Japan Earthquake in 2011 and infection control measures taken. Infectious agents surveillance report (IASR) 2011; 32: P. S1, Supplement. Available from: http://idsc.nih.go.jp/iasr/32/32s/me32s1.html. Accessed May 6, 2013. 2. World Health Organization. Tuberculosis care and control in refugee and displaced populations. An interagency field manual. 2nd ed. Geneva, Switzerland: WHO; 2007. Available from: http://whqlibdoc.who.int/publications/2007/ 9789241595421_eng.pdf. Accessed May 7, 2013. 3. Oeltmann JE, Varma JK, Ortega L, Liu Y, O’Rourke T, Cano M, et al. Multidrugresistant tuberculosis outbreak among US-bound Hmong refugees, Thailand, 2005. Emerg Infect Dis 2008;14:1715-21. 4. Kanamori H, Aso N, Tadano S, Saito M, Saito H, Uchiyama B, et al. Tuberculosis exposure among evacuees at a shelter after earthquake, Japan, 2011. Emerg Infect Dis 2013;19:799-801. 5. Kanamori H, Uchiyama B, Hirakata Y, Chiba T, Okuda M, Kaku M. Lessons learned from a tuberculosis contact investigation associated with a disaster volunteer after the 2011 Great East Japan Earthquake. Am J Respir Crit Care Med 2013;187:1278-9. 6. Kanamori H, Aso N, Weber DJ, Koide M, Sasaki Y, Tokuda K, et al. Latent tuberculosis infection in nurses exposed to tuberculous patients cared for in rooms without negative pressure after the 2011 Great East Japan Earthquake. Infect Control Hosp Epidemiol 2012;33:204-6. 7. Mazurek GH, Jereb J, Vernon A, LoBue P, Goldberg S, Castro K. IGRA Expert Committee; Centers for Disease Control and Prevention (CDC). Updated guidelines for using interferon g release assays to detect Mycobacterium tuberculosis infection, United States, 2010. MMWR Recomm Rep 2010;59:1-25. 8. Preventive Committee of the Japanese Society for Tuberculosis. Guidelines for using the QuantiFERON-TB Gold In-Tube (in Japanese). Kekkaku 2011;86: 839-44. 9. Kanamori H, Kunishima H, Tokuda K, Kaku M. Infection control campaign at evacuation centers in Miyagi prefecture after the Great East Japan Earthquake. Infect Control Hosp Epidemiol 2011;32:824-6. 10. Pérez-Guzmán C, Vargas MH, Torres-Cruz A, Villarreal-Velarde H. Does aging modify pulmonary tuberculosis? A meta-analytical review. Chest 1999;116: 961-7. 11. Association for Professionals in Infection Control and Epidemiology (APIC) Emergency Preparedness Committee. Infection prevention and control for shelters during disasters, 2007/2008. Available from: http://www.apic.org/ Resource_/TinyMceFileManager/Practice_Guidance/Emergency_Preparedness/ Shelters_Disasters.pdf. Accessed May 7, 2013. 12. Mori T, Harada N, Higuchi K, Sekiya Y, Uchimura K, Shimao T. Waning of the specific interferon-g response after years of tuberculosis infection. Int J Tuberc Lung Dis 2007;11:1021-5. 13. Kenyon TA, Valway SE, Ihle WW, Onorato IM, Castro KG. Transmission of multidrug-resistant Mycobacterium tuberculosis during a long airplane flight. N Engl J Med 1996;334:933-8. 14. Gerald LB, Tang S, Bruce F, Redden D, Kimerling ME, Brook N, et al. A decision tree for tuberculosis contact investigation. Am J Respir Crit Care Med 2002;166: 1122-7. 15. Golub JE, Cronin WA, Obasanjo OO, Coggin W, Moore K, Pope DS, et al. Transmission of Mycobacterium tuberculosis through casual contact with an infectious case. Arch Intern Med 2001;161:2254-8. 16. Bailey WC, Gerald LB, Kimerling ME, Redden D, Brook N, Bruce F, et al. Predictive model to identify positive tuberculosis skin test results during contact investigations. JAMA 2002;287:996-1002.
