Use of fluoroquinones to treat multidrug-resistant tuberculosis in children has led to the emergence of pneumococci in children that is also resistant to this class of drugs. These are the conclusions of authors of an article published in a forthcoming edition of The Lancet.
Dr Anne von Gottberg, National Institute for Communicable Diseases, Gauteng, South Africa, and colleagues assessed 21,521 cases of invasive pneumococcal disease (including severe pneumonia and meningitis) between 2000 and 2006, and screened 19,404 isolates (90% of cases) for ofloxacin (a fluoroquinone) resistance. The minimum inhibitory concentrations (MIC) for all isolates were measured, and levofloxacin resistance was defined as an MIC of 4mg/l or more. Nose and throat pneumococcal carriage was assessed in 65 children in two tuberculosis hospitals where invasive pneumococcal disease caused by levofloxacin-resistant Streptococcus pneumoniae had been detected.
The researchers found 12 cases of invasive pneumococcal disease that were identified as levofloxacin-resistant, all in children aged under 15 years. The outcome was known for 11 of these 12 patients; five of them died. Invasive pneumococcal disease caused by levofloxacin-resistant S pneumoniae was associated with a history of TB treatment – eight out of nine (89%) children with non-susceptible isolates had a history of treatment for TB versus 396 (18%) of 2202 children with susceptible isolates. Among hospitalised children with nose and throat pneumococcal carriage, almost 100% of these bacteria were levofloxacin resistant.
The authors conclude: “Our data suggest that the use of fluoroquinones to treat multidrug-resistant tuberculosis in children has led to the emergence of invasive pneumococcal diseases caused by levofloxacin-non-susceptible S pneumoniae and its nosocomial spread among children.”