No MRSA in general practice

MRSA is mainly a hospital infection. The resistant bacterium has, so far, not been found in a random selection of patients in Dutch general practice. Researchers of NIVEL and the University Medical Centre in Maastricht recently published their findings in Clinical Microbiology and Infection.

Nearly a quarter of the Dutch population is carrying the bacterium Staphylococcus aureus, the antibiotic susceptible variant of the notorious hospital bacterium (meticillin resistant Staphylococcus aureus). The bacterium lives in the nose and, usually, the host suffers no illness effects. The bacterium can, however, cause a deadly infection in strongly weakened patients. A study by NIVEL and the University Medical Centre in Maastricht of 2,700 randomly swabbed patients shows that two thirds of the staphylococcus strains in GP practice are resistant to penicillin and amoxicillin. “These antibiotics are therefore hardly useful anymore for infections caused by Staphylococcus aureus”, says NIVEL-researcher Gé Donker. “That is why GPs do not use these any more for such infections.” However, most S. aureus-strains are still susceptible for other antibiotics. The researchers found no MRSA at all in the GP practices.

Hospital bacterium
In Dutch hospitals, MRSA even emerges more often. Between 2002 and 2006 the number of MRSA-cases doubled. The origin of MRSA is, therefore, not the ‘open population’ but hospitals and well-known risk groups, such as patients treated in hospitals abroad, patients with recurring skin infections, farmers who keep pigs or veal calves and family members of these risk groups. Gé Donker: “The fact that we do not find MRSA in GP practices shows that the outbreaks of MRSA in hospitals have not spread outside the hospitals. This is good news, but it does not mean that it could never change. GPs should continue to limit antibiotic prescriptions in order to prevent resistance.”

Nose swab
The study was done in 17 general practices participating in the “CMR (continuous morbidity registration) Sentinel Practice Network of The Netherlands” of NIVEL, and 10 additional general practices. The GPs took nose swabs of 2,691 patients without symptoms of infection. The nose swabs were examined in the bacteriological laboratory of the University Medical Centre in Maastricht for S. aureus and the susceptibility to several antibiotics.