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

Acute respiratory disease is one of the most common reasons to consult a general practitioner. A substantial part of these diseases cannot be explained by an infection with a virus or a common pathogenic bacterium. To study this diagnostic deficit, the prevalence of Chlamydia pneumoniae and Mycoplasma pneumoniae infections was determined in two groups of patients consulting a general practitioner. DNA of C. pneumoniae and M. pneumoniae was detected 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 during the 1994/1995 respiratory infections season. Two patients remained C. pneumoniae PCR-positive for at least 4 weeks. All others were negative within 3 weeks. Double infections of C. pneumoniae and influenza virus (3/6), and of M. pneumoniae and respiratory syncytial virus (1/7) or rhinovirus (1/7) were diagnosed. During the 1992/1993 season, attempts to isolate C. pneumoniae in cell culture or to detect C. pneumoniae DNA by PCR using throat swabs were all negative for 80 patients with a sore throat, although serological data suggested a C. pneumoniae infection in 13 (16%) patients. A specimen from another patient of this group was M. pneumoniae PCR-positive and the corresponding serum specimens showed a persistent high antibody titre. In summary, the prevalence of acute C. pneumoniae and M. pneumoniae infections was less than 2% in patients consulting a general practitioner.

Towards a better diagnosis of throat infections (with group A beta-haemolytic streptococcus) in general practice.

BACKGROUND: Sore throat is a common complaint in general practice. However, management strategies are not very clear. A better diagnostic procedure is needed to prevent the overuse of antibiotics. AIM: To assess the diagnostic value of a rapid streptococcal antigen detection test in addition to four clinical features in patients with sore throat, using throat culture and antibody titres as reference tests. METHOD: Four clinical features [fever (history) > or = 38.0 degrees C, lack of cough, tonsillar exudate, and anterior cervical lymphadenopathy] were registered in 558 patients aged 4 to 60 years presenting with sore throat of no more than 14 days' duration. A rapid diagnostic test was performed, as well as a throat culture and antibody titres [fourfold increase in anti-streptolysin-O (ASO) and/or anti-deoxyribonuclease B (anti-DNAase B)] in patients aged 11 years and older. RESULTS: Throat cultures were positive for group A beta-haemolytic streptococcus (GABHS) in 33% of the patients. Rapid tests were positive in 24%. Compared with the throat culture, the sensitivity of the rapid test was 65%, the specificity 96%, the positive predictive value 88%, and the negative predictive value 85%. However, for patients with three or four clinical features, the sensitivity of the rapid test was considerably higher at 75%. Children (< or = 14 years) had a slightly raised specificity and raised positive predictive value and prevalence. With the antibody titres as a reference, the rapid test performed as well as the throat culture with regard to its predictive value. CONCLUSION: For the management of patients with sore throat in general practice, a rapid test may have an additional value, especially in patients with a high chance of having GABHS infection. However, as the sensitivity of the test studied is low, tests with a higher sensitivity are needed.

Do patients with sore throat benefit from penicillin? A randomized double-blind placebo-controlled clinical trial with penicillin V in general practice.

BACKGROUND: The effect of antibiotic therapy in sore throat is questionable and this dilemma has been complicated by the emergence of multiple resistant strains of micro-organisms. AIM: A randomized double-blind placebo-controlled clinical trial was undertaken in patients aged 4-60 years to assess the efficacy of penicillin V on the clinical course and bacteriological response in patients with sore throat in general practice. METHOD: Two hundred and thirty-nine patients presenting with an acute sore throat to 37 general practices in the Netherlands who were clinically suspected of group A beta-haemolytic streptococci (GABHS) were randomized for treatment with penicillin V (n = 121) or placebo (n = 118). Resolution of sore throat, fever and return to daily activities were evaluated by the general practitioner 2 days after the start of treatment and by the patients keeping a diary for 7 days. The result of throat culture after 2 days was evaluated. RESULTS: A difference in resolution of sore throat was present after 2 days in all patients, but was a result of GABHS-positive patients (n = 111; 46%) in favour of those randomized for penicillin V (adjusted odds ratio 5.3; 95% CI 1.9-15.1). An effect in the course of fever was also seen in GABHS-positive patients (adjusted odds ratio 5.3; 95% CI 1.02-27.7). A difference of 1-2 days was seen in clinical recovery. No difference was found in daily activities between the treatment groups. After 2 days, 4% of the penicillin-treated patients harboured GABHS compared with 75% of the placebo group. CONCLUSION: Only GABHS-positive patients benefit from penicillin V in their clinical cure in the first few days. Therefore, rapid testing is necessary. Treatment may be beneficial with regard to the clinical course, but it is not necessary.

Bacterial flora in patients presenting with sore throat in Dutch general practice.

The bacterial growth in patients presenting with a sore throat was assayed and four clinical features were tested in order to reliably differentiate between beta-haemolytic streptococci group A (GABHS) and other micro-organisms. For 2 years, 53 general practitioners (GPs) in The Netherlands took throat swabs from all patients, aged 4-60, presenting with a sore throat lasting 14 days or less. Four clinical features: fever (history), (tonsillary) exudate, anterior cervical lymphadenopathy and absence of cough were registered. In 70% of the 598 patients one or more micro-organisms were cultured from throat specimens. In 48% of the patients beta-haemolytic streptococci were found (32% group A, 7% group C, 4% group G, 5% others). Enterobacteriaceae were cultured in 5%, Candida albicans in 5%, Staphylococcus aureus in 4%, various others in 8% of the patients. In 30% of the patients cultures remained negative. Of the 270 patients with three or four clinical features, 46% (95% Cl, 40-52%) harboured GABHS in their throats, while in 328 patients with less than three features 21% (95% Cl, 16-25%) were GABHS positive. However, this relationship between presence or absence of clinical features and culture result was not found in the youngest age category (4-14 years old). Culture results were not related to sex, smoking habits or the insurance mode of the patient. The clinical relevance of several micro-organisms, other than beta-haemolytic streptococci, remains to be determined. The four mentioned signs and symptoms were helpful in predicting the probability of GABHS in patients aged 15 years and older.(ABSTRACT TRUNCATED AT 250 WORDS)