[Multivariate model to predict Streptococcus pyogenes tonsillitis].
OBJECTIVE
to develop a multivariate model to predict the Streptococcus pyogenes isolation in patients with acute tonsillitis.


METHODS
cross-sectional analytic study on patients with acute tonsillitis without a recent history of antimicrobial consumption. We evaluated 14 signs and 18 symptoms. A pharyngeal culture was realized on 5% sheep blood agar. Group A streptococci was identified by standard methods.


METHODS
sensitivity, specificity, predictive values, chi2, Fisher's exact test, crude and adjusted odds ratio (OR) with 95% CI using dichotomical logistic regression with direct method and Hosmer and Lemeshow-goodness-fit test.


RESULTS
there were 213 participants, 37% were males; a mean age of 14.9 years. We isolated Streptococcus pyogenes in 15%, and 84 % of them had received antimicrobials. We identified signs and symptoms associated with Streptococcus pyogenes isolation: painful swallowing (OR=4.45, 95% CI = 1.13-17.53); tonsils with exudates (OR=3.20, 95% CI = 1.22-8.43); smelly breath (OR=2.78, 95% CI = 1.09-7.10); painful neck nodes (OR=2.70, 95% CI = 1.05-6.96). The presence of nasal symptoms was a protective factor (OR=0.25, 95% CI = 0.09-0.71).


CONCLUSIONS
the prevalence of Streptococcus pyogenes tonsillitis was similar to other reports. We found signs and symptoms associated to Streptococcus pyogenes isolation that allowed us to elaborate a decision algorithm.
Villaseñor-Sierra
Alberto
A
Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco. avillase@prodigy.net.mx
Caballero-Hoyos
José Ramiro
JR
Jáuregui-Lomelí
Juan José
JJ
Flores-Sánchez
Jesús
J
Martínez-Sandoval
Francisco
F
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology*; D013297:Streptococcus pyogenes; D014069:Tonsillitis / Q000175:diagnosis* / Q000382:microbiology*; D055815:Young Adult