Seroepidemiological investigation on hantavirus prevalence in rodent population at international ports in Taiwan, 2007-2009

Yin-Hsin Lee1, Shu-Fen Chang2, His-Chieh Wang2, Jui-Wei Hsieh3, Min-Cheng Lin4, Shin-Yan Yang5

2012 Vol.28 NO.10

Correspondence Author： Shu-Fen Chang

Abstract：

A total of 1,572 rodents consisted of six species in four genera, two families, and two orders have been captured at international ports in Taiwan for the investigation of rodent population and hantavirus seropositive rate during January 2007-December 2009. The majority of the captured rodents were the species of Rattus norvegicus (54.77%). The percentage for other species in descending order was 18.64% for Suncus murinus, 15.90% for Rattus losea, 7.95% for Bandicota indica, 2.61% for Rattus tanezumi, and 0.13% for Apodemus agrarius. The species of Bandicota indica was caught only at Taoyuan airport and was the dominant species of the areas, Rattus losea was commonly found at Taipei seaport, Kinmen areas, and Taoyuan airport, but the dominant species at other international ports were Rattus norvegicus and Suncus murinus. By rodent species, the positive rate for hantavirus antibody was highest (19.05%) in R. norvegicus, followed by R. losea (4.40%), R. tanezumi (2.44%), and S. murinus (2.39%). The overall average positive rate for hantavirus antibody was 11.64% for the time period between 2007 and 2009, which is approximately equal to that detected in 2005 (11.03％) and in 2006 (11.43%). This indicates that a certain percentage of rodents at international ports in Taiwan has been infected with hantavirus and should not be neglected. The average seropositive rate for hantavirus antibody in rodents captured at international ports during November 2004-December 2009 was 11.56% (4.11% - 25.99%) except four ports detected 0.00%, including Taipei seaport, Songshan airport, Taoyuan airport, and Hualian seaport. The seropositive rate at other international ports in descending order was Keelung (25.99％), Suao (23.17％), Kaohsiung seaport (21.95％), Penghu (21.43％), Taichung (14.81％), Kaohsiung airport (12.90％), Matsu (8.47％), Kinmen (5.84％), Mailiao (4.11％). The dominant species include B. indica, R. norvegicus, and R. losea at Taoyuan airport; R. losea, S. murinus, and R. norvegicus at Kinmen arreas; R. norvegicus, R. tanezumi, and S. murinus at Hualian seaport; R. norvegicus at Suao seaport; and R. norvegicus and S. murinus at the rest of the international ports. We suggest that rodent control activities and relevant public health measures should focus on the species specifically presenting in individual port areas. Although the hantavirus seropositive rate in rodent population slightly increased in 2008 but slightly decreased in 2009 during 2007-2009, the rate was still maintained at a certain level. Human might acquire hantavirus infection when in contact with excreta or secretions from infected rodents. Therefore, the threats of hantavirus infection should not be neglected. Furthermore, the competent authorities at international ports should strengthen environmental health in port areas and decrease density of rodent population so that the chance of contact between rodent and human could be reduced and the occurrence of human infection could be eliminated.