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The role of antibiotics, immunizations, and adenoviruses in pertussis
Abstract:
Sixty-five patients with pertussis were identified by a clinical criterion, and Bordetella pertussis was isolated from 75% of these patients or their symptomatic household contacts. Negative nasopharyngeal cultures were usually associated with either a history of antibiotic therapy with erythromycin or tetracycline (two of three patients), two or more diphtheria and tetanus toxoids with pertussis (DTP) vaccines (six of eight patients), or both (two of three patients). Erythromycin therapy resulted in the elimination of B. pertussis from the nasopharynx in 2 to 7 days (mean, 3.6 days) compared with 7 to 17 or more days (mean, greater than 12 days) in patients treated with no antibiotics, but had no effect on the duration or severity of illness as judged by length of hospitalization. Adenoviruses were recovered from five of 44 patients cultured. Four of these isolates were from throat swabs obtained early in the illness and the remaining isolate was from one of 33 repeated viral cultures obtained two to three weeks later; B. pertussis was also isolated from these five patients. Paired serum samples were obtained from only two of these patients. Neither demonstrated a fourfold rise in adenoviral complement-fixing antibodies. Therefore, in these patients, adenoviral isolation may have been secondary to reactivation of a latent viral infection by infection with B. pertussis.
Insights
Erythromycin effectively eliminates Bordetella pertussis from the nasopharynx, but does not shorten illness duration. Vaccination and prior antibiotic use can lead to negative pertussis cultures.
Area of Science:
- Pediatrics
- Infectious Diseases
- Microbiology
Background:
- Pertussis, caused by Bordetella pertussis, remains a significant public health concern.
- Understanding factors influencing B. pertussis detection and treatment outcomes is crucial for disease control.
Purpose of the Study:
- To investigate the clinical criteria for pertussis diagnosis.
- To evaluate the impact of antibiotic therapy and vaccination on B. pertussis culture results.
- To explore the association between B. pertussis and adenovirus co-infections.
Main Methods:
- Clinical identification of 65 pertussis patients.
- Bordetella pertussis isolation via nasopharyngeal cultures.
- Analysis of factors affecting culture negativity, including antibiotic history (erythromycin, tetracycline) and diphtheria and tetanus toxoids with pertussis (DTP) vaccination status.
- Viral cultures for adenovirus detection.
- Assessment of erythromycin's effect on B. pertussis clearance and illness severity.
Main Results:
- Bordetella pertussis was isolated from 75% of clinically diagnosed pertussis patients.
- Negative nasopharyngeal cultures were associated with prior erythromycin/tetracycline therapy or multiple DTP vaccine doses.
- Erythromycin therapy significantly reduced B. pertussis clearance time (mean 3.6 days) compared to no antibiotics (mean >12 days) but did not affect hospitalization duration.
- Adenoviruses were detected in five patients also infected with B. pertussis; evidence for a significant rise in adenovirus antibodies was lacking, suggesting possible secondary infection or reactivation.
Conclusions:
- Erythromycin is effective in eradicating B. pertussis from the nasopharynx but does not alter clinical disease severity or duration.
- Prior antibiotic treatment and DTP vaccination can lead to false-negative B. pertussis cultures.
- The co-occurrence of adenovirus in B. pertussis patients may indicate secondary infection or reactivation of latent adenovirus, potentially triggered by B. pertussis infection.