Low prevalence of Chlamydia pneumoniae and Mycoplasma pneumoniae among patients with symptoms of respiratory tract infections inDutch general practices

Acute respiratory disease is one of the most common reasons to consult a ge neral practitioner. A substantial part of these diseases cannot be explaine d by an infection with a virus or a common pathogenic bacterium. To study t his diagnostic deficit, the prevalence of Chlamydia pneumoniae and Mycoplas ma pneumoniae infections was determined in two groups of patients consultin g a general practitioner. DNA of C. pneumoniae and M. pneumoniae was detect ed by a polymerase chain reaction (PCR) in nose/throat swabs from six (1.1% ), and from seven (1.3%) patients, respectively, of 557 patients consulting a general practitioner for complaints suggestive for a virus infection dur ing the 1994/1995 respiratory infections season. Two patients remained C. p neumoniae PCR-positive for at least 4 weeks. All others were negative withi n 3 weeks. Double infections of C. pneumoniae and influenza virus (3/6), an d of M. pneumoniae and respiratory syncytial virus (1/7) or rhinovirus (1/7 ) were diagnosed. During the 1992/1993 season, attempts to isolate C. pneum oniae in cell culture or to detect C. pneumoniae DNA by PCR using throat sw abs were all negative for 80 patients with a sore throat, although serologi cal data suggested a C. pneumoniae infection in 13 (16%) patients. A specim en from another patient of this group was M. pneumoniae PCR-positive and th e corresponding serum specimens showed a persistent high antibody titre. In summary, the prevalence of acute C. pneumoniae and M. pneumoniae infection s was less than 2% in patients consulting a general practitioner.