Penicillin susceptibility of pneumococcal isolates causing acute otitis media in children: seasonal variation

Temporal trends in ambulatory antibiotic prescription rates in South Carolina: Impact of age, gender, and resident location

OBJECTIVE

To examine the temporal trends in ambulatory antibiotic prescription fill rates and to determine the influences of age, gender, and location.

DESIGN

Population-based cohort study.

SETTING

Ambulatory setting in South Carolina.

PATIENTS

Patients ≤64 years of age from January 2012 to December 2017.

METHODS

Aggregated pharmacy claims data for oral antibiotic prescriptions were utilized to estimate community antibiotic prescription rates. Poisson regression or Student t tests were used to examine overall temporal trend in antibiotic prescription rates, seasonal variation, and the trends across age group, gender, and rural versus urban location.

RESULTS

Overall antibiotic prescription rates decrease from 1,127 to 897 per 1,000 person years (P < .001). The decrease was more noticeable in persons aged <18 years (26%) and 18-39 years (20%) than in those aged 40-64 years (5%; P < .001 for all). Prescription rates were higher among females than males in all age groups, although this finding was the most pronounced in group aged 18-39 years (1,232 vs 585 per 1,000 person years; P < .0001). Annualized antibiotic prescription rates were higher during the winter months (December-March) than the rest of the year (1,145 vs 885 per 1,000 person years; P < .0001), and rates were higher in rural areas than in urban areas (1,032 vs 941 per 1,000 person years; P < .0001).

CONCLUSIONS

The decline in ambulatory antibiotic prescription rates is encouraging. Ongoing ambulatory antibiotic stewardship efforts across South Carolina should focus on older adults, rural areas, and during the winter season when antibiotic prescriptions peak.

Seasonality of antimicrobial resistance rates in respiratory bacteria: A systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance (AMR) rates may display seasonal variation. However, it is not clear whether this seasonality is influenced by the seasonal variation of infectious diseases, geographical region or differences in antibiotic prescription patterns. Therefore, we assessed the seasonality of AMR rates in respiratory bacteria.

METHODS

Seven electronic databases (Embase.com, Medline Ovid, Cochrane CENTRAL, Web of Science, Core Collection, Biosis Ovid, and Google Scholar), were searched for relevant studies from inception to Jun 25th, 2019. Studies describing resistance rates of Streptococcus pneumoniae and Haemophilus influenzae were included in this review. By using random-effects meta-analysis, pooled odd ratios of seasonal AMR rates were calculated using winter as the reference group. Pooled odd ratios were obtained by antibiotic class and geographical region.

RESULTS

We included 13 studies, of which 7 were meta-analyzed. Few studies were done in H. influenzae, thus this was not quantitively analyzed. AMR rates of S. pneumoniae to penicillins were lower in other seasons than in winter with pooled OR = 0.71; 95% CI = 0.65-0.77; I2 = 0.0%, and to all antibiotics with pooled OR = 0.68; 95% CI = 0.60-0.76; I2 = 14.4%. Irrespective of geographical region, the seasonality of AMR rates in S. pneumoniae remained the same.

CONCLUSION

The seasonality of AMR rates could result from the seasonality of infectious diseases and its accompanied antibiotic use.

Antibiotics for the allergist: part 1

OBJECTIVE

To review antibiotic use and selection for disorders commonly seen in allergy practice.

DATA SOURCES

MEDLINE searches were performed cross-referencing the keywords antibiotic, antimicrobial, management, and treatment with multiple disorders commonly seen in allergy practice. References of the chosen articles were also examined.

STUDY SELECTION

Articles were selected based on their relevance to the subject matter.

RESULTS

A large body of research is available that is relevant to both conventional and novel uses of antibiotics. The use of antibiotics is in question for some disorders, whereas novel approaches to therapy with macrolide antibiotics are areas of active investigation. Meanwhile, patterns of microbial resistance continue to evolve.

CONCLUSION

For decades, antibiotics have been traditional first-line treatments for many disorders. Recently, this paradigm appears to be shifting as periods of observation come into favor and nonbacterial causes of inflammation are under greater scrutiny. Nonetheless, appropriate antibiotic selection often remains a key element in the treatment of these disorders. Knowledge of the relevant microbiology is an inherent requirement in selecting antibiotic therapies and necessitates awareness of current trends in bacterial resistance.

Comparison of study designs for acute otitis media trials

BACKGROUND

A framework for evaluating the efficacy of antibiotics in development as well as those currently approved for acute otitis media (AOM) is needed.

OBJECTIVE

Review strengths and limitations of various antibiotic trial designs and their outcome measures.

METHODS

A review of 157 published trials involving 36,710 subjects for the treatment of AOM.

RESULTS

AOM trials have three designs: (1) clinical, clinical diagnosis and assessment of outcomes; (2) single tympanocentesis, microbiologic diagnosis (by middle ear fluid culture) and clinical assessment of outcomes; and (3) double tympanocentesis, microbiologic diagnosis and microbiologic outcome assessment. Identifiable strengths and limitations of each design are reviewed. Case definitions for entry of children in trials of AOM vary widely. The lack of stringent diagnostic criteria in a clinical design allows for inclusion of a significant proportion of children with a non-bacterial etiology (i.e., viral AOM or otitis media with effusion). Tympanocentesis increases diagnostic accuracy at study entry; however, the procedure is confounding because of its potentially therapeutic benefit and the procedure is not performed in a uniform manner. A second tympanocentesis allows a high sensitivity to detect microbiologic eradication, but it does not correlate with clinical outcomes in half of the cases. The timing of outcome assessment also varies widely among trials.

CONCLUSIONS

Improved clinical diagnosis criteria for AOM are needed to enhance specificity; emphasis on a bulging tympanic membrane has the best evidence base. Tympanocentesis within study designs has merits. At study entry it assures diagnostic accuracy but may alter outcomes and it is useful to document microbiologic outcomes but lacks specificity for clinical outcomes. For all designs, test of cure assessment 2-7 days after completion of therapy seems most appropriate.

Seasonal distribution of otitis media pathogens among Costa Rican children

BACKGROUND

Otitis media is an important cause of pediatric consultation, and knowledge of yearly pathogen distribution might improve antimicrobial selection.

OBJECTIVES

To determine the seasonal pathogen and antimicrobial resistance distribution among Costa Rican children with otitis media.

METHODS

Between 1999 and 2004, 952 children with otitis media, aged 3-144 months who participated in various clinical trials, were analyzed. Data obtained from this period were compared against historical data collected between 1992 and 1997.

RESULTS

Five hundred sixteen (52%) children had a baseline middle ear fluid pathogen isolated. The most common pathogens were Streptococcus pneumoniae 252 (49%), Haemophilus influenzae 190 (37%), S. pyogenes 38 (7%), and Moraxella catarrhalis 36 (7%). The overall proportion of H. influenzae (24-37%; P = 0.01) and the production of beta-lactamase producing H. influenzae (2.6-7%; P = 0.02) increased from 1992-1997 to 1999-2004. There was a nonstatistically significant trend for a higher frequency of S. pneumoniae and H. influenzae isolates detected during the rainy season than during the dry season: S. pneumoniae 58% versus 42% but not significant (P = 0.1) and H. influenzae 68% versus 32% (P = 0.06), respectively. During the rainy season, penicillin-nonsusceptible S. pneumoniae was identified more frequently (38.5%) than during the dry season (18%) (P = 0.003; odds ratio: 2.94; 95% confidence interval: 1.4-6.45). Penicillin-nonsusceptible S. pneumoniae decreased from 46.5% (1999-2001) to 16% (2002-2003) and this was associated with a significant decline of a circulating 19F penicillin-resistant S. pneumoniae serotype (from 89% to 26%), respectively.

CONCLUSIONS

S. pneumoniae and H. influenzae are the 2 most common pathogens producing otitis media in Costa Rican children. An increase in the number of H. influenzae and M. catarrhalis was observed in recent years. Penicillin-nonsusceptible S. pneumoniae isolates were more commonly observed during the rainy season, in which increased morbidity with respiratory pathogens is observed.

Enterococcal colonization of infants in a neonatal intensive care unit: associated predictors, risk factors and seasonal patterns

Background

During and shortly after birth, newborn infants are colonized with enterococci. This study analyzes predictors for early enterococcal colonization of infants in a neonatal intensive care unit and describes risk factors associated with multidrugresistant enterococci colonization and its seasonal patterns.

Methods

Over a 12-month period, we performed a prospective epidemiological study in 274 infants admitted to a neonatal intensive care unit. On the first day of life, we compared infants with enterococcal isolates detected in meconium or body cultures to those without. We then tested the association of enterococcal colonization with peripartal predictors/risk factors by using bivariate and multivariate statistical methods.

Results

Twenty-three percent of the infants were colonized with enterococci. The three most common enterococcal species were E. faecium (48% of isolates), E. casseliflavus (25%) and E. faecalis (13%). Fifty-seven percent of the enterococci found were resistant to three of five antibiotic classes, but no vancomycin-resistant isolates were observed. During winter/spring months, the number of enterococci and multidrug-resistant enterococci were higher than in summer/fall months (p = 0.002 and p < 0.0001, respectively). With respect to enterococcal colonization on the first day of life, predictors were prematurity (p = 0.043) and low birth weight (p = 0.011). With respect to colonization with multidrug-resistant enterococci, risk factors were prematurity (p = 0.0006), low birth weight (p < 0.0001) and prepartal antibiotic treatment (p = 0.019). Using logistic regression, we determined that gestational age was the only parameter significantly correlated with multidrug-resistant enterococci colonization. No infection with enterococci or multidrugresistant enterococci in the infants was detected. The outcome of infants with and without enterococcal colonization was the same with respect to death, necrotizing enterocolitis, intracerebral hemorrhage and bronchopulmonary dysplasia.

Conclusion

In neonatal intensive care units, an infant's susceptibility to early colonization with enterococci in general, and his or her risk for colonization with multidrug-resistant enterococci in particular, is increased in preterm newborns, especially during the winter/spring months. The prepartal use of antibiotics with no known activity against enterococci appears to increase the risk for colonization with multidrug-resistant enterococci.

Emerging therapies for the treatment and prevention of otitis media

Otitis media is one of the most common disorders occurring in children, and there is growing concern that bacteria are quickly becoming resistant to antimicrobials. As a result, global antibiotic treatment is no longer the standard of care and treatment of otitis media has changed dramatically in the last decade. In addition to new antimicrobials currently in development, the effects of the pneumococcal conjugate vaccine are just beginning to be understood. Furthermore, new surgical techniques are for the first time being tested as alternatives for tympanostomy tubes for recurrent acute otitis media. This review discusses current and emerging otitis media therapeutics, with particular attention to acute otitis media. Topics include antimicrobial use, antimicrobial resistance, effects of vaccination and new surgical techniques.

Milk culture results in a large Norwegian survey--effects of season, parity, days in milk, resistance, and clustering

A nationwide random computerized assignment survey that included 3,538 sets of 4 quarter milk samples from 2,834 dairy cows was conducted during 2000. Every fifth cow from every 50th herd was randomly selected for sampling and culture during each quarter of the year. Milk culture results of pathogens known to be related to mastitis were recorded regardless of whether mastitis had been indicated by any inflammatory measure or not. Farmers were blinded to all test results to minimize any potential interventions that might be prompted by the results. The most prevalent isolate was Staphylococcus aureus, which was identified in 8.2% of the quarter milk samples. More than 15 colony-forming units/0.01 mL of Staph. aureus were found in 4.3% of the quarter milk samples, whereas 3.5% had only 1 to 3 colony-forming units/0.01 mL. Streptococcus dysgalactiae, coagulase-negative staphylococci (CNS), and Streptococcus uberis were isolated from 1.2, 3.3, and 0.4% of quarter milk samples, respectively. No isolates were found in 76.6% of the quarter milk samples tested. Among individual cows, 22.2% had an isolate of Staph. aureus in > or = 1 quarter. Only Strep. dysgalactiae exhibited a higher prevalence with increased parity. Prevalence of Staph. aureus decreased throughout days in milk, but prevalence of Strep. dysgalactiae increased. There was a strong seasonal effect; the highest prevalence of Strep. dysgalactiae and CNS was observed during April and May (late indoor season), and the highest prevalence of Staph. aureus and Strep. uberis was observed during June and July (the outdoor season). A substantial within-cow clustering effect was found for Strep. dysgalactiae, Staph. aureus, and CNS. Additionally, a within-herd effect was found for Strep. uberis, penicillin-resistant Staph. aureus, total Staph. aureus, and CNS. No within-county cluster effect was found. Lastly, both Staph. aureus and CNS exhibited a surprisingly high seasonal effect regarding the prevalence of resistance to penicillin G. Penicillin resistance of Staph. aureus was likely due to higher prevalence of Staph. aureus as a whole, but for CNS, there was also an additional increase caused by a higher proportional rate of penicillin resistance during the late indoor season.

Antimicrobial-resistant bacteria in the community setting

Over the past decade, antimicrobial resistance has emerged as a major public-health crisis. Common bacterial pathogens in the community such as Streptococcus pneumoniae have become progressively more resistant to traditional antibiotics. Salmonella strains are beginning to show resistance to crucial fluoroquinolone drugs. Community outbreaks caused by a resistant form of Staphylococcus aureus, known as community-associated meticillin (formerly methicillin)-resistant Staphylococcus aureus, have caused serious morbidity and even deaths in previously healthy children and adults. To decrease the spread of such antimicrobial-resistant pathogens in the community, a greater understanding of their means of emergence and survival is needed.