Methods: We conducted a retrospective study to identify and evaluate clinical characteristics of SAFV infection in children. We analyzed 5,412 specimens (e.g. nasal discharge, nasopharyngeal excretion, and feces) collected to Niigata Prefectural Institute of Public Health and Environmental Sciences from febrile patients in the Niigata prefecture, Japan, between January 2006 and December 2013. Patients who were co-infected with other viruses were excluded. SAFV was detected by viral isolation or PCR. Genotype of SAFV was identified by partial viral structural protein 1 sequences, and the clinical features of the patients with SAFV infection were evaluated.
We detected 9 SAFV specimens from 9 patients (median age: 5 years, range: 2–16 years; gender: 67% male). Their symptoms at presentation were as follows: fever (>39°C, n = 7), malaise and appetite loss (n = 6), and headache (n = 4). None of the patients experienced nasal discharge or a cough. Seven (78%) patients were diagnosed with pharyngitis and one with meningitis, whereas no obvious source of infection was identified in a 5-years old patient. On physical examination, prominent signs were pharyngeal redness and swelling (n = 8) and cervical lymphadenopathy (n = 3). Blood test in 4 patients revealed that all patients had neutrophil-dominant leukocytosis. SAFV genotype 2 (SAVF2) was detected in 6 cases (67%, pharyngitis (n = 5) and unknown source of infection (n = 1)) and the SAFV genotype 3 in 3 cases (33%, pharyngitis (n = 2) and meningitis (n =1)). SAFV2 infections showed an epidemic pattern for 2 months, with a peak in August 2013. The median duration of the fever was 2 days (range 1–5days), whereas the patient with meningitis remained febrile for 5 days. All patients fully recovered from the SAFV infection without complications.
Conclusion: This study revealed that the potential pathogenicity of SAFV includes pharyngitis and meningitis. Further epidemiological studies are needed to elucidate pathogenicity and clinical characteristics of SAFV in children.
H. Taneichi, None
C. Hirokawa, None
Y. Aizawa, None
A. Saitoh, None