In summary, HBoV infection was more prevalent in young children. Patients positive for HBoV alone mainly constituted the high-viral-load group. Most of the HBoV-positive patients with infection caused by other respiratory viruses belonged to the low-viral-load group. These findings suggest that HBoV may be associated with a respiratory infection. Seasonal distribution of active systemic lupus erythematosus and its correlation with meteorological factors OBJECTIVE: To explore the characteristics of seasonal distribution of active systemic lupus erythematosus (SLE) and the influences of meteorological factors including temperature and humidity on active systemic lupus erythematosus. METHODS: The characteristics of seasonal distribution of active SLE and its correlation with meteorological factors were retrospectively analyzed in 640 patients living in the city of Zhanjiang, China and had active SLE between January 1997 and December 2006. RESULTS: In winter, when there are weaker ultraviolet (UV) rays, the ratio of patients with active SLE to total inpatients was 3.89 ‰, which is significantly higher than in other seasons with stronger UV rays, including 2.17 ‰ in spring, 1.87 ‰ in summer and 2.12 ‰ in autumn. The number of patients with active SLE had significant negative correlation with mean temperature and was not significantly related to mean humidity. CONCLUSION: Active SLE has the characteristics of seasonal distribution and is associated with temperature. The mechanism remains to be further studied. Systemic lupus erythematosis (SLE) is a common autoimmune disease. The pathogenesis of SLE and the induced factors of active SLE are not completely clear, but it is generally considered that SLE is caused by both hereditary and environmental factors that ultimately lead to an abnormal immune response. Sunlight and ultraviolet (UV) rays have been considered to be the most important environmental factors in the induction of SLE. 1 Based on this, a high incidence of SLE should occur in summer and autumn when there is stronger sunlight and more intense UV rays. However, in clinical practice, we have found that more patients with SLE visit hospital at the end of autumn and at the end of winter, as well as at the beginning of winter and the beginning of spring, while in the summer and the autumn, less patients with SLE visit hospital. In order to confirm that high incidences of SLE should occur in summer and autumn when sunlight and UV rays are strong, we retrospectively analyzed the characteristics of seasonal distribution of active SLE and its correlation with meteorological factors in 640 patients, who live in the city of Zhanjiang, China and had active SLE between January 1997 and December 2006.