Hantavirus infections in humans and animals, China

Abstract

Hemorrhagic fever with renal syndrome (HFRS) is a serious public health problem in the People's Republic of China. Although 7 sero/genotypes of hantaviruses have been found in rodents, only Hantaan virus (carried by Apodemus agrarius mice) and Seoul virus (carried by Rattus norvegicus rats) reportedly cause disease in humans. During 1950-2007, a total of 1,557,622 cases of HFRS in humans and 46,427 deaths (3%) were reported in China. HFRS has been reported in 29 of 31 provinces in China. After implementation of comprehensive preventive measures, including vaccination, in the past decade in China, incidence of HFRS has dramatically decreased; only 11,248 HFRS cases were reported in 2007. Mortality rates also declined from the highest level of 14.2% in 1969 to ?1% during 1995-2007. However, the numbers of HFRS cases and deaths in China remain the highest in the world.

Figure 1

Annual numbers of hemorrhagic fever with renal syndrome (HFRS) cases (A) and HFRS-caused deaths (B) reported in China, 1950–2007. Incidence rates are cases/100,000 population. Mortality rates are shown at top.

Figure 2

Geographic distribution and annual incidence of hemorrhagic fever with renal syndrome in China in 1986 (A), 1996 (B), and 2006 (C).

Figure 3

Phylogenetic trees of Hantaan virus (HTNV) variants according to the small segment (A) and medium segment (B) coding sequences. PHYLIP program package version 3.65 (http://helix.nih.gov/Applications/phylip.html) was used to construct the phylogenetic trees; the neighbor-joining method was used. Bootstrap values were calculated from 1,000 replicates; only values >50% are shown at the branch nodes. The trees constructed using the maximum-likelihood method (not shown) had similar topology. Scale bars indicate nucleotide substitutions per site. Colors (blue and red) highlight viruses of interest from China. SNV, Sin Nombre virus; DOBV, Dobrava-Belgrade virus; SEOV, Seoul virus; DBSV, Da Bie Shan virus.

Figure 4

Phylogenetic tree of Seoul virus (SEOV) variants according to partial (nt 2001–2301) medium segment sequences (A). Phylogenetic tree of hantaviruses according to complete coding sequences of the medium segment (B). PHYLIP program package version 3.65 (http://helix.nih.gov/Applications/phylip.html) was used to construct the phylogenetic trees; the neighbor-joining method was used. Bootstrap values were calculated from 1,000 replicates; only values >50% are shown at the branch nodes. The trees constructed by using the maximum-likelihood method (not shown) had similar topology. Scale bars indicate nucleotide substitutions per site. Colors (blue and red) highlight viruses of interest from China. SNV, Sin Nombre virus; HTNV, Hantaan virus; PHV, Prospect Hill virus; SEOV, Seoul virus; TULV, Tula virus; MUJV, Muju virus; PUUV, Puumala virus; HOKV, Hokkaido virus; KHAV, Khabarovsk virus; YUJV, Yuanjiang virus; VLAV, Vladivostok virus.