RESUMEN
<p><b>OBJECTIVE</b>To investigate the relationship between the infection rate of Mycoplasma pneumoniae (MP) and age, sex and season.</p><p><b>METHODS</b>Passive agglutination assay was used to detect Mycoplasma pneumoniae antibodies (MP-Ab) in the serum of patients with respiratory tract infection, and MP-Ab test results in 2010 were analyzed.</p><p><b>RESULTS</b>The positive rates of 5 year test results were 30.10%; among the results, the positive rates of male and female patients were respectively 30.74% and 36.12%, the difference was statistically significant (P < 0.05); And every age group were significantly different (P < 0.001), among each group, the positive rate of 3-14 years old patients was the highest; the season was no significant difference in incidence rates; the patients of positive titer > 1:640 accounted for 10.18% of the patients.</p><p><b>CONCLUSION</b>MP infection is increasing year by year, children aged 3 to 14 has become the high-risk groups. Women are more susceptible to MP than the men and the chances of infection are throughout the year, but the most of the patients have a good prognosis.</p>