Effect of In-Utero Antibiotic Exposure on Childhood Outcomes: Methods and Baseline Data of the Fetal Antibiotic EXposure (FAX) Cohort Study.

BACKGROUND: The widespread use of antepartum and intrapartum antibiotics has raised concerns about the possible disruption of the child's gut microbiota and effects on the maturation from the infant to the adult microbiome. The Fetal Antibiotic EXposure (FAX) study provides a cohort to examine the association between in-utero exposure to antibiotics and adverse childhood outcomes including body weight, atopic diseases, and autism spectrum disorders and to investigate the role of other potential factors mitigating or moderating the risk for adverse outcomes. OBJECTIVE: The aim of this paper was to describe the methods, cohort characteristics, and retention of infants included in the study cohort. METHODS: For this retrospective cohort study, we included children born in Kaiser Permanente Southern California (KPSC) hospitals between January 1, 2007, and December 31, 2015, within 22 to 44 completed weeks of gestation with KPSC insurance coverage during the first year of life. Follow-up data collection was performed through electronic medical records. RESULTS: The study cohort was comprised 223,431 children of which 65.7% (146,720/223,431) were exposed to antibiotics in-utero: 19.0% (42,511/223,431) were exposed during the antepartum period, 30.0% (66,896/223,431) during the intrapartum period, and 16.7% (37,313/223,431) exposed during both the antepartum and intrapartum periods. During their first year of life, children had a median of 5 weight and height measurements; the frequency of weight and height measurements declined to a median of 3 in their second year of life and 2 for 3 to 5 years of age. The 5-year retention of children in the health plan was over 80% with the highest retention for Hispanic children. CONCLUSIONS: This cohort of children will provide a unique opportunity to address key questions regarding the long-term sequelae of in-utero exposure to antibiotics using real-world data. The high retention and multiple medical visits over time allow us to model the trajectories of body mass index over time. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12065.

Wheezing in children with pertussis associated with delayed pertussis diagnosis.

BACKGROUND: The classic clinical features of paroxysmal pertussis are often absent in older children and adults and after vaccination. The California pertussis epidemic of 2010 occurred in a highly vaccinated population. METHODS: All pediatric patients (0-18 years) with positive pertussis polymerase chain reaction from July to December 2010 were identified retrospectively from the Kaiser SCAL database. Information extracted by chart review included age at diagnosis, vaccine history, race, cough duration, number of clinic visits before diagnosis, presence of paroxysms, post-tussive emesis or wheezing, treatment for asthma during the course of illness and exposure to confirmed or suspected pertussis cases. RESULTS: Overall 501 pediatric patients (mean age = 8.4 years) with positive pertussis nasopharyngeal polymerase chain reaction were identified. Complete DTaP series and Tdap vaccine had been received by 93% and 38% of eligible patients, respectively. Paroxysms, post-tussive emesis and wheezing on physical examination were present in 34%, 30% and 8% of patients, respectively. Each was associated with a longer duration of symptoms at diagnosis. Wheezing was associated with a delay in diagnosis (60% requiring >1 clinic visit for diagnosis vs. 29% in the overall population, P < 0.0001). Documented exposures were associated with a more timely pertussis diagnosis (after 9.4 days vs. 14.5 days; P < 0.0001). CONCLUSIONS: Wheezing is present on examination of some patients with pertussis in a highly vaccinated pediatric population and appears to delay the diagnosis of pertussis. The presence of wheezing should not be used to exclude this diagnosis in children with chronic cough or other reasons to suspect pertussis.

Increased incidence of sacroiliac joint infection at a children's hospital.

BACKGROUND: Pyogenic sacroiliitis (PSI) is an uncommon type of osteoarticular infection. A study is undertaken to confirm an observed increase in incidence of PSI at our pediatric institution and to evaluate any associations with increasing incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection and other factors. METHODS: All inpatients with osteoarticular infection were identified from the periods of 1992 to 1996 and 2004 to 2007. Patients with surgical site infection, immunologic deficits, decubiti, or other predisposing factors were excluded. Demographic, microbiologic, and clinical factors were analyzed for comparison. RESULTS: Overall 362 cases were included: 205 with osteomyelitis alone and 157 with pyarthrosis, of which 15 were PSI cases. The incidence of PSI increased from the periods of 1992 to 1996 and 2004 to 2007 (0.8 vs. 2.8 cases/y, P=0.03), along with osteomyelitis at pelvic and spinal sites (ie, axial sites; 1.6 vs. 5.0 cases/y; P=0.03), whereas the incidence of osteoarticular infection at other sites remained stable. CA-MRSA was isolated in 1 (6.7%) PSI case. In the second time period, CA-MRSA did not form a higher proportion of S. aureus isolates at sacroiliac or other axial sites (CA-MRSA: 17% of S. aureus in PSI and axial osteomyelitis vs. 45% of S. aureus at nonaxial sites, P=0.08). Patients were older in the second time period (4.5 y vs. 7 y; P<0.0001), and patients with PSI (10.5 y) and axial osteomyelitis (8.5 y) were older than those with osteoarticular infection at other sites (5.3 y; P<0.0001). CONCLUSIONS: The emergence of CA-MRSA does not explain the increasing incidence of PSI. The incidence of PSI and osteomyelitis involving the axial skeleton are increasing, predominantly in older patients. These trends should be prospectively investigated. LEVEL OF EVIDENCE: III, Prognostic Study.