Case Study: Pneumococcal Infection Should Be Considered After Influenza Virus Infection

In a case study, investigators found that right sternoclavicular joint septic arthritis should be considered after an influenza virus infection when patients have gradually increasing chest pain.

Investigators followed the case of a 24-year-old female patient who had a 5-day history of fever and right sternoclavicular pain. Importantly, influenza virus infections are commonly paired with a secondary pneumococcal infection, which leads to severe illness and increased mortality.

Sick woman with flu | Image credit: Subbotina Anna - stock.adobe.com

Although sternoclavicular joint septic arthritis is most common for Staphylococcus aureus, it is rare for Streptococcus pneumoniae, so physicians rarely look to diagnose it when pneumococcal is present. S. pneumoniae can manifest as bacterial pneumonia, meningitis, or primary bacteremia, and it can also present as infection in other parts of the body, which is known as unusual invasive pneumococcal disease.

Sternoclavicular joint septic arthritis can be a severe disease, investigators noted, including osteomyelitis, chest wall abscesses, and mediastinitis.

Three weeks before admission to the hospital, the patient in the case study had influenza A and took oseltamivir 75 mg twice daily for 5 days.

During a physical examination, there was no erythema or swelling of the right sternoclavicular joint, but there was pain and tenderness. The physical examination also revealed that her neck was slightly stiff.

Physicians performed laboratory tests, which showed an elevated C-reactive protein level, but there were no autoantibodies against antinuclear or rheumatoid factors in the serum. The patient tested positive for penicillin-susceptible S. pneumoniae.

Additionally, a cerebrospinal fluid examination was performed and there were no abnormal findings; S. pneumoniae was not detected in the fluid.

A computed tomography scan did not show significant findings in the sternoclavicular joint. There were no visible malignancies in the spleen, and it was intact. Further, magnetic resonance imaging (MRI) of the right sternoclavicular joint demonstrated a high signal intensity on the T2-weighted image as well as on the diffusion-weighted image. Physicians did not perform sternoclavicular joint aspirations due to the low amount of fluid in the MRI.

The patient received intravenous antibiotics for 4 weeks, which included 2 g of ceftriaxone daily in the first 2 weeks and 9 g sulbactam/ampicillin daily for the following 2 weeks.

Investigators noted that her clinical condition improved after the antibiotic therapy, in addition to her serum inflammatory marker levels.

Following treatment, the patient was discharged and was changed to oral sultamicillin at 1125 mg per day for 2 weeks. After one month of discharge, the patient’s condition was evaluated, and she remained free of relapse.

Based on these findings, the investigators said it is important to identify a pneumococcal infection after an influenza infection, even when the patient is young with a healthy immune system.

They also noted that the diagnosis should change from an influenza infection if the patient has gradually increasing chest pain after the original diagnosis.

Reference

Yoshimura F, Kubosaki J, Kunitomo K, Tsuji T. Sternoclavicular septic arthritis due to invasive pneumococcal infection after type a influenza virus infection. Cureus. 2023;15(5):e38859. doi:10.7759/cureus.38859