Mycobacterium kansasii is an acid-fast bacillus (AFB) that is readily recognized based on its characteristic photochromogenicity, which produces a yellow pigment when exposed to light. In 1953, Buhler and Pollack first described the bacterium. Under light microscopy, M kansasii appears relatively long, thick, and cross-barred.
The most common presentation of M kansasii infection is a chronic pulmonary infection that resembles pulmonary tuberculosis. However, it may also infect other organs. M kansasii infection is the second-most-common nontuberculous opportunistic mycobacterial infection associated with AIDS, surpassed only by Mycobacterium avium complex (MAC) infection. The incidence of M kansasii infection increased with the burgeoning of the HIV/AIDS epidemic.
Unlike other nontuberculous mycobacteria (NTM), M kansasii is not readily isolated from environmental sources. However, it has been isolated from a small percentage of specimens obtained from water supplies in areas with high endemicity. Most likely, M kansasii is acquired via either aspiration or local inoculation from the environment. Little evidence exists of person-to-person transmission. Molecular characterization of M kansasii shows that it is a homogeneous group of organisms. Five genotypes, or subtypes, are described. Types I and II are common clinical isolates, while the remaining types (III, IV, V) are recovered from environmental samples only. Type I probably is the most prevalent M kansasii isolate from human sources worldwide.
M kansasii infection of the lung causes a pulmonary disease similar to tuberculosis. Its histopathologic appearance is similar to that of tuberculosis and may include acute suppuration, nonnecrotic tubercles, or caseation. In persons with AIDS or in patients with other forms of immunocompromise, many of its characteristic histologic features may be absent. 
After skin inoculation, M kansasii can cause local disease of the skin and subcutaneous tissue. It may spread from the local site and cause lymphadenitis, infection of a distant organ, or disseminated disease. 
The prevalence of M kansasii, an unusual pathogen in the pre-AIDS era, increased with the HIV pandemic. M kansasii is the second-most-common cause of NTM disease in patients with AIDS. M kansasii infection has typically been described as a disease of urban dwellers and of patients with high incomes and better standards of living. One study of 3 northern California counties found that M kansasii infection was more common in census tracts with a lower income (median income 
M kansasii infection occurs throughout the United States, with the highest incidence in the Midwest and the Southwest. A national laboratory surveillance from 1982-1983 estimated the prevalence of M kansasii infection to be 0.3 case per 100,000 persons. The above study done in northern California estimated an overall incidence of 2.4 cases per 100,000 adults per year in the general population, 115 cases per 100,000 persons with HIV infection per year, and 647 cases per 100,000 persons with AIDS per year.  This was confirmed by another laboratory-based data analysis at San Francisco General Hospital, which showed a decrease in NTM infection from 319 cases in 1993 to 59 in 2001 (P< .001). Mycobacterium avium was found to be the most common isolate in both HIV-positive and HIV-negative patients, followed by M kansasii. 
M kansasii infection has been reported in most areas of the world. The incidence appears to be relatively high in England and Wales and among South African gold miners.  In the United Kingdom, it has been reported as the most common cause of NTM lung infection in patients without HIV infection. 
An increasing incidence of NTM infections, including M kansasii, has been reported in other countries, including Israel, Korea,  Portugal, France, and Japan.
Based on the analysis of identification data received by the NTM-Network European Trials Group (NET) for 20,182 patients in 30 countries across 6 continents in 2008, M kansasii was the sixth most common NTM isolated from pulmonary samples. Mycobacterium avium complex (MAC) was the most common NTM in most countries. 
The likelihood of mortality associated with M kansasii infection depends on various factors, including the presence of comorbid diseases, treatment compliance, rifampicin use, and extent of infection. One US center’s experience, which included 302 patients over more than a 50-year period (1952-1995), showed a mortality rate of 11%, but this included both immunocompromised and nonimmunocompromised patients. 
A retrospective study of South African gold miners treated for M kansasii infection reported mortality rates of 2% in those without HIV infection and 9% in patients with HIV infection. 
Untreated pulmonary M kansasii disease progresses and can lead to death in more than 50% of infected individuals.
M kansasii infection has no reported racial predilection.
M kansasii infection is more common men, with a male-to-female ratio of 3:1.
M kansasii infection is more common in the older population and is rare in children.
The age predilection shifts in conjunction with age predilections of HIV infection.
Untreated M kansasii infection persists in sputum and progresses both clinically and radiographically.
Before rifampin was available, treatment success rates with antimycobacterial drugs were disappointing when compared to tuberculosis. With the advent of rifampin, 4-month sputum conversion rates with rifampin-containing regimens were 100% in 180 patients from 3 studies. Researchers report that long-term relapse rates in patients on these regimens are less than 1%.
Patients with CNS infection have high rates of morbidity and mortality despite appropriate treatment.
Explain the adverse effects of any medications used for treatment, as follows:
Visual problems may occur with administration of ethambutol.
Rifampin reduces the efficacy of oral contraceptives.
Han SH, Kim KM, Chin BS, Choi SH, Lee HS, Kim MS, et al. Disseminated Mycobacterium kansasii infection associated with skin lesions: a case report and comprehensive review of the literature. J Korean Med Sci. 2010 Feb. 25(2):304-8. [Medline]. [Full Text].
Bloch KC, Zwerling L, Pletcher MJ. Incidence and clinical implications of isolation of Mycobacterium kansasii: results of a 5-year, population-based study. Ann Intern Med. 1998 Nov 1. 129(9):698-704. [Medline].
Sheu LC, Tran TM, Jarlsberg LG, Marras TK, Daley CL, Nahid P. Nontuberculous mycobacterial infections at San Francisco General Hospital. Clin Respir J. 2014 May 6. [Medline].
Corbett EL, Churchyard GJ, Hay M. The impact of HIV infection on Mycobacterium kansasii disease in South African gold miners. Am J Respir Crit Care Med. 1999 Jul. 160(1):10-4. [Medline].
Evans AJ, Crisp AJ, Hubbard RB. Pulmonary Mycobacterium kansasii infection: comparison of radiological appearances with pulmonary tuberculosis. Thorax. 1996 Dec. 51(12):1243-7. [Medline].
Hoefsloot W, van Ingen J, Andrejak C, Angeby K, Bauriaud R, Bemer P, et al. The geographic diversity of nontuberculous mycobacteria isolated from pulmonary samples: an NTM-NET collaborative study. Eur Respir J. 2013 Dec. 42(6):1604-13. [Medline].
Maliwan N, Zvetina JR. Clinical features and follow up of 302 patients with Mycobacterium kansasii pulmonary infection: a 50 year experience. Postgrad Med J. 2005. 81:530-33. [Medline].
Marras TK, Morris A, Gonzalez LC. Mortality prediction in pulmonary Mycobacterium kansasii infection and human immunodeficiency virus. Am J Respir Crit Care Med. 2004. 170:793-98. [Medline].
Mitha M, Naicker P, Taljaard J. Cutaneous Mycobacterium kansasii infection in a patient with AIDS post initiation of antiretroviral therapy. J Infect Dev Ctries. 2011 Jul 27. 5(7):553-5. [Medline].
Evans SA, Colville A, Evans AJ. Pulmonary Mycobacterium kansasii infection: comparison of the clinical features, treatment and outcome with pulmonary tuberculosis. Thorax. 1996 Dec. 51(12):1248-52. [Medline].
Witzig RS, Fazal BA, Mera RM. Clinical manifestations and implications of coinfection with Mycobacterium kansasii and human immunodeficiency virus type 1. Clin Infect Dis. 1995 Jul. 21(1):77-85. [Medline].
Gail L. Woods, M.D. et al. Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard. Second Edition. Wayne, PA: Clinical and Laboratory Standards Institute; 2011. M24A2:
Woods GL. Susceptibility testing for mycobacteria. Clin Infect Dis. 2000. 31:1209-1. [Medline].
Smith MB, Molina CP, Schnadig VJ. Pathologic features of Mycobacterium kansasii infection in patients with acquired immunodeficiency syndrome. Arch Pathol Lab Med. 2003. 127:554-60. [Medline].
Griffith DE. Management of disease due to Mycobacterium kansasii. Clin Chest Med. 2002. 23:613-21. [Medline].
Hombach M, Somoskövi A, Hömke R, Ritter C, Böttger EC. Drug susceptibility distributions in slowly growing non-tuberculous mycobacteria using MGIT 960 TB eXiST. Int J Med Microbiol. 2013 Jul. 303(5):270-6. [Medline].
Griffith DE, Aksamit T, Brown-Elliott BA, Catanzaro A, Daley C, Gordin F, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am J Respir Crit Care Med. 2007 Feb 15. 175(4):367-416. [Medline].
Wu TS, Leu HS, Chiu CH, Lee MH, Chiang PC, Wu TL, et al. Clinical manifestations, antibiotic susceptibility and molecular analysis of Mycobacterium kansasii isolates from a university hospital in Taiwan. J Antimicrob Chemother. 2009 Sep. 64(3):511-4. [Medline].
Brown-Elliott BA, Nash KA, Wallace RJ Jr. Antimicrobial susceptibility testing, drug resistance mechanisms, and therapy of infections with nontuberculous mycobacteria. Clin Microbiol Rev. 2012 Jul. 25(3):545-82. [Medline]. [Full Text].
[Guideline] Haworth CS, Banks J, Capstick T, Fisher AJ, Gorsuch T, Laurenson IF, et al. British Thoracic Society guidelines for the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD). Thorax. 2017 Nov. 72 (Suppl 2):ii1-ii64. [Medline].
American Thoracic Society. Diagnosis and treatment of disease caused by nontuberculous mycobacteria. This official statement of the American Thoracic Society was approved by the Board of Directors, March 1997. Medical Section of the American Lung Association. Am J Respir Crit Care Med. 1997 Aug. 156(2 Pt 2):S1-25. [Medline].
Guna R, Munoz C, Dominguez V. In vitro activity of linezolid, clarithromycin and moxifloxacin against clinical isolates of Mycobacterium kansasii. J Antimicrob Chemother. 2005. 55:950-53. [Medline].
Alcaide F, Benitez MA, Martin R. Epidemiology of Mycobacterium kansasii. Ann Intern Med. 1999 Aug 17. 131(4):310-1. [Medline].
Breathnach A, Levell N, Munro C. Cutaneous Mycobacterium kansasii infection: case report and review. Clin Infect Dis. 1995 Apr. 20(4):812-7. [Medline].
Davidson PT. The diagnosis and management of disease caused by M. avium complex, M. kansasii, and other mycobacteria. Clin Chest Med. 1989 Sep. 10(3):431-43. [Medline].
Fishman JE, Schwartz DS, Sais GJ. Mycobacterium kansasii pulmonary infection in patients with AIDS: spectrum of chest radiographic findings. Radiology. 1997 Jul. 204(1):171-5. [Medline].
O’Brien RJ. The epidemiology of nontuberculous mycobacterial disease. Clin Chest Med. 1989 Sep. 10(3):407-18. [Medline].
Wolinsky E. Mycobacterial diseases other than tuberculosis. Clin Infect Dis. 1992 Jul. 15(1):1-10. [Medline].
Woods GL, Meyers WM. Mycobacterial Diseases. Damjanov I, Linder J, eds. Anderson’s Pathology. St. Louis, Mo: Mosby; 1996. Vol 10: 843-55.
Janak Koirala, MD, MPH, FACP, FIDSA Professor of Medicine and Division Chief, Division of Infectious Diseases, Department of Internal Medicine, Southern Illinois University School of Medicine
Janak Koirala, MD, MPH, FACP, FIDSA is a member of the following medical societies: America Nepal Medical Foundation, American Association for the Advancement of Science, American College of Physicians-American Society of Internal Medicine, American Society for Microbiology, American Society of Tropical Medicine and Hygiene, HIV Medicine Association, Illinois State Medical Society, Infectious Diseases Society of America, International AIDS Society, International Society for Infectious Diseases, International Society of Travel Medicine, Mclean County Medical Society, Nepal Medical Association, Public Responsibility in Medicine and Research, Sangamon County Medical Society
Disclosure: Nothing to disclose.
Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Aaron Glatt, MD Chairman, Department of Medicine, Chief, Division of Infectious Diseases, Hospital Epidemiologist, South Nassau Communities Hospital
Aaron Glatt, MD is a member of the following medical societies: American Association for Physician Leadership, American College of Chest Physicians, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Medical Association, American Society for Microbiology, American Thoracic Society, American Venereal Disease Association, Infectious Diseases Society of America, International AIDS Society, Society for Healthcare Epidemiology of America
Disclosure: Nothing to disclose.
Mark R Wallace, MD, FACP, FIDSA Clinical Professor of Medicine, Florida State University College of Medicine; Clinical Professor of Medicine, University of Central Florida College of Medicine
Mark R Wallace, MD, FACP, FIDSA is a member of the following medical societies: American College of Physicians, American Medical Association, American Society for Microbiology, Infectious Diseases Society of America, International AIDS Society, Florida Infectious Diseases Society
Disclosure: Nothing to disclose.
Klaus-Dieter Lessnau, MD, FCCP Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital
Klaus-Dieter Lessnau, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, Society of Critical Care Medicine
Disclosure: Nothing to disclose.
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