Changes in the Incidence of Acute Hematogenous Osteomyelitis from Unidentified Pathogens

Overview

This study examined the temporal association between COVID-19-related nonpharmaceutical interventions (NPIs) and the incidence of unidentified-pathogen acute hematogenous osteomyelitis (UP-AHO) in children aged 1 to <5 years in France. UP-AHO incidence decreased significantly after NPI implementation in March 2020 and increased after school reopening in September 2020, alongside major changes in seasonal viral circulation.

Background

Acute hematogenous osteomyelitis (AHO) accounts for approximately 40% of osteoarticular infections in children younger than 5 years. Its epidemiology is difficult to establish because blood cultures are positive in only approximately 20%-30% of cases. Kingella kingae is considered to be involved in 50%-80% of AHO cases in young children in several countries and is probably the leading pathogen in UP-AHO. Viral infections may disrupt the oropharyngeal mucosal barrier and facilitate K. kingae translocation into the bloodstream.

Data Highlights

• The study included 5,619 children hospitalized with UP-AHO from January 2015 through August 2023; the median age was 2 years.

• UP-AHO incidence decreased 57.6% immediately after NPI implementation in March 2020.

• Incidence increased 101.0% immediately after school reopening in September 2020.

• Human rhinovirus accounted for an estimated 21.3% of UP-AHO incidence, and varicella-zoster virus accounted for 9.8%.

Key Findings

• AHO accounts for approximately 40% of osteoarticular infections in children younger than 5 years.

• Blood cultures are positive in only approximately 20%-30% of AHO cases.

• In France, Israel, and Switzerland, K. kingae is considered to be involved in 50%-80% of AHO cases in young children and is probably the leading pathogen in UP-AHO.

• UP-AHO incidence decreased significantly following NPI implementation and rebounded significantly after school reopening.

• Temporal associations were strongest for human rhinovirus and, to a lesser extent, varicella-zoster virus, particularly among children aged 1 to <3 years.

Clinical Implications

The findings support a temporal relationship between seasonal viral circulation and UP-AHO in young children, particularly in a setting where K. kingae is considered a leading cause. The authors suggest that changes in human rhinovirus and varicella-zoster virus circulation may help explain shifts in UP-AHO incidence, while emphasizing that experimental studies are needed to clarify the underlying molecular interactions.

Conclusion

UP-AHO incidence in children aged 1 to <5 years decreased significantly after COVID-19-related NPIs were implemented and increased after schools reopened. These changes were temporally associated with human rhinovirus and varicella-zoster virus circulation, providing additional support for a relationship between seasonal viruses and UP-AHO, which is caused principally by K. kingae in young children in this setting.

Related Resources & Content

1. Woods CR, Bradley JS, Chatterjee A, et al. Journal of the Pediatric Infectious Diseases Society. 2021 — Clinical Practice Guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 Guideline on Diagnosis and Management of Acute Hematogenous Osteomyelitis in Pediatrics.

2. Basmaci R, Bidet P, Bonacorsi S. Microorganisms. 2022 — Kingella kingae and Viral Infections.

3. Droz N, Enouf V, Bidet P, et al. Journal of Pediatrics. 2018 — Temporal Association Between Rhinovirus Activity and Kingella kingae Osteoarticular Infections.

4. Basmaci R, Bonacorsi S, Ilharreborde B, et al. Future Microbiology. 2015 — High Respiratory Virus Oropharyngeal Carriage Rate During Kingella kingae Osteoarticular Infections in Children.

5. Angoulvant F, Ouldali N, Yang DD, et al. Clinical Infectious Diseases. 2021 — Coronavirus Disease 2019 Pandemic: Impact Caused by School Closure and National Lockdown on Pediatric Visits and Admissions for Viral and Nonviral Infections—A Time Series Analysis.

6. Rybak A, Levy C, Angoulvant F, et al. JAMA Network Open. 2022 — Association of Nonpharmaceutical Interventions During the COVID-19 Pandemic With Invasive Pneumococcal Disease, Pneumococcal Carriage, and Respiratory Viral Infections Among Children in France.

7. Lorrot M, Gillet Y, Basmaci R, et al. Infectious Diseases Now. 2023 — Antibiotic Therapy for Osteoarticular Infections in 2023: Proposals From the Pediatric Infectious Pathology Group (GPIP).