[Nasal carriage of Streptococcus pneumoniae in elderly subjects according to vaccination status].
BACKGROUND
S pneumoniae is the main cause of community-acquired pneumonia in the elderly, group that concentrates 95% of deaths.


OBJECTIVE
To assess the prevalence of nasal carriage of S pneumoniae in institutionalized elderly patients.


METHODS
One hundred eighteen institutionalized subjects aged over 60 years (65 males) were enrolled. Since they were also participating in a controlled protocol related to the immunogenicity of an anti-pneumococcal vaccine, our investigation was also blind and randomized. According to randomization, they received pneumococcal or tetanic vaccine. Nasal swab cultures were taken at the beginning of the trial and two months after vaccination. According to recommended methods, we identified S pneumoniae, the serotypes and their antimicrobial susceptibility.


RESULTS
In the first nasal sample, 16% of subjects were positive for S pneumoniae. The second sample was positive in 12%. Of the 33 isolated serotypes, 9.1% demonstrated intermediate resistance to penicillin and 3.3% were resistant to chloramphenicol.


CONCLUSIONS
The study demonstrated a greater percentage of colonized patients than in the general population. The isolated serotypes are the same that cause invasive diseases in this age group, according to data of the Institute of Public Health of Chile. There were no differences in the percentage of colonization between subjects vaccinated against S pneumoniae and control groups, after two months of follow up. Isolated strains had a low resistance to penicillin. High level resistance was not observed.
Altuzarra H
Rogelio
R
Departamento de Medicina Interna, Facultad de Medicina, Universidad de los Andes, Chile. raltuzarra@uandes.cl
Valenzuela B
M Teresa
MT
Trucco A
Olivia
O
Inostroza S
Jaime
J
Granata S
Paulo
P
Fleiderman V
José
J
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002353:Carrier State / Q000382:microbiology*; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology; D004311:Double-Blind Method; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009305:Nasopharynx / Q000378:metabolism / Q000382:microbiology*; D010403:Penicillin Resistance / Q000187:drug effects; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D016036:Seroepidemiologic Studies; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines