infectious diseases
Nontuberculous Mycobacterial Infections
Wound and foreign body infections
Nontuberculous mycobacteria form biofilms; they can survive in water systems in residential, office, and health care facilities. They are difficult to eradicate with common decontamination practices (eg, using chlorine, organomercurials, or alkaline glutaraldehyde). Rapidly growing nontuberculous mycobacteria (Mycobacterium fortuitumcomplex,M. chelonae,M. abscessuscomplex) can cause nosocomial outbreaks of infections, usually due to injection of contaminated solutions, wound contamination with nonsterile water, use of contaminated instruments, or implantation of contaminated devices. These infections may also develop after cosmetic procedures, acupuncture, or tattooing.M. fortuitumcomplex has caused serious infections of penetrating wounds in the eyes and skin (especially feet), in tattoos, and in patients receiving contaminated materials (eg, porcine heart valves, breast implants, bone wax). In the US, outbreaks ofM. abscessusinfection occurred in Georgia (2015) and California (2016). These outbreaks occurred in children when water contaminated withM. abscessusbiofilm was used to irrigate the tooth’s pulp chamber during a root canal; severe infection resulted. Treatment usually requires extensive debridement and removal of the foreign material. Useful drugs include Imipenem 1 g IV every 6 hours Levofloxacin500 mg IV or orally once/day Clarithromycin500 mg orally 2 times a day Trimethoprim/sulfamethoxazole 1 double-strength tablet orally 2 times a day Doxycycline100 to 200 mg orally once/day Cefoxitin2 g IV every 6 to 8 hours Amikacin10 to 15 mg/kg IV once/day Combination therapy with at least 2 drugs that have in vitro activity is recommended. Duration of therapy averages 24 months and may be longer if the infected foreign material remains in the body.Amikacinis usually included for the first 3 to 6 months of therapy. Infections caused byM. abscessusandM. chelonaeare usually resistant to most antibiotics, have proved extremely difficult or impossible to cure, and should be referred to an experienced specialist. 