Sex Differences in the Incidence and Case Fatality Rates From Hemorrhagic Fever With Renal Syndrome in China, 2004-2008

Background. Differences between male and female individuals in response to infectious diseases are an overlooked global health problem. Methods. The relationship between sex and disease outcome was examined in populations of patients with hemorrhagic fever with renal syndrome (HFRS) in mainland China, where most cases of hantavirus exposure occur. HFRS in China is diagnosed on the basis of symptoms and is confirmed with serological testing. The geographical distribution, incidence, and case fatality rates (CFRs) of HFRS in China were estimated and compared by patient sex and age. In a subset of patients with HFRS, clinical manifestations of HFRS were assessed using latent class analysis and compared by sex. Results. There were 80,671 HFRS cases reported during the period 2004-2008, with a majority of HFRS cases (39.2%) occurring among individuals 20-39 years of age. The incidence of HFRS was higher among male patients than among female patients for all individuals.10 years of age. There were 945 deaths (CFR, 1.17%) due to HFRS in China during the period 2004-2008. CFRs were higher among women than among men between the ages of 2039 and >= 50 years of age. There were no sex differences in the geographical distribution of HFRS cases or deaths. Although the prevalence of each clinical marker did not differ by sex, 2 profiles of clinical markers were identified that were related to both severity of disease and sex. Conclusions. These data illustrate a paradox in which the incidence of disease is greater for males, but the severity of disease outcome is worse for females. Several behavioral, societal, and biological factors are hypothesized to be involved.