Prevalence of hantavirus infection in wild Rattus norvegicus and R. rattus populations of Buenos Aires City, Argentina

Objective  To determine the prevalence of infection with hantaviruses in wild Rattus norvegicus and R. rattus populations in areas of Buenos Aires city.
Methods  Norway rats and black rats were trapped from 2003 to 2005 at 10 sites throughout Buenos Aires city. Blood samples for serological analysis were collected by cardiac puncture from all individuals captured and tested by enzyme-linked immunosorbent assay for Seoul hantavirus- and Andes virus-specific IgG antibodies.
Results  Hantavirus seroprevalence was 11.9% in R. norvegicus ( n  = 151), varying between 0% and 26.1% depending on the site. Bigger sexually active males were more likely to be infected with Seoul virus than females or juvenile individuals. No antibody-reactive rodents were detected among 33 R. rattus analysed.
Conclusion  Hantavirus infections are geographically widespread in Buenos Aires city and confirm that they have been enzootic there for at least 20 years.     

Identification of Novel Rodent-Borne Orthohantaviruses in an Endemic Area of Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka

We reported the genetic evidence of circulating hantaviruses from small mammals captured in a chronic kidney disease of unknown etiology (CKDu) hotspot area of Sri Lanka. The high seroprevalence of anti-hantavirus antibodies against Thailand orthohantavirus (THAIV) has been reported among CKDu patients and rodents in Sri Lankan CKDu hotspots. We captured 116 small mammals from CKDu endemic regions in the Polonnaruwa District of Sri Lanka. Seven animals (five out of 11 Mus booduga and two out of 99 Rattus rattus) were PCR-positive for the hantavirus. A rat-borne sequence was grouped with a THAIV-like Anjozorobe virus. In contrast, Mus-borne sequences belonged to the THAIV lineage, suggesting a novel orthohantavirus species according to the phylogenetic analyses and whole-genome comparisons. Our genetic evidence indicates the presence of two THAIV-related viruses circulating in this CKDu endemic area, suggesting a basis for further investigations to identify the infectious virus in patients with CKDu and the CKDu induction mechanism of these viruses.     

Mortality Rate Patterns for Hemorrhagic Fever with Renal Syndrome Caused by Puumala Virus

To investigate nephropathia epidemica in Sweden during 1997–2007, we determined case-fatality rates for 5,282 patients with this disease. Overall, 0.4% died of acute nephropathia epidemica <3 months after diagnosis. Case-fatality rates increased with age. Only women showed an increased case-fatality rate during the first year after diagnosis.     

Seoul Virus Associated with Pet Rats,Scotland, UK, 2019

We describe a case of hemorrhagic fever with renal syndrome caused by Seoul virus in a woman in Scotland, UK. Whole-genome sequencing showed the virus belonged to a lineage characterized by recent international expansion, probably driven by trade in pet rats.     

抗汉坦病毒单链抗体基因向拟南芥遗传转化的初步研究

目的构建抗汉坦病毒mAb1A8scFv的转基因拟南芥植株。方法从含有1A8scFv基因的重组质粒中酶切获得携带Nos终止子的抗体基因片段,将其与CaMV35S启动子相连克隆入载体pCAMBIA2301,构建1A8scFv基因的植物表达载体1A8scFv-pCAMBIA2301。通过农杆菌介导的花粉管法将其转入拟南芥,PCR及Dotblot检测是否获得转基因植株,ELISA和固相酶联斑点实验检测表达产物的生物学活性。结果酶切鉴定结果证明1A8scFv基因被成功克隆入植物表达载体pCAMBIA2301,构建获得1A8scFv-pCAMBIA2301重组质粒。PCR及Dotblot检测证明获得抗汉坦病毒mAb1A8scFv的转基因拟南芥植株。ELISA和固相酶联斑点实验结果证明在转基因拟南芥中成功表达了具有生物学活性的抗汉坦病毒mAb1A8scFv片段。结论成功地将外源基因转入拟南芥中并表达,为进一步研究利用植物表达医用抗体奠定了基础。     

Hantavirus Pulmonary Syndrome,Southern Chile, 1995–2012

Hantavirus is endemic to the Region de Los Lagos in southern Chile; its incidence is 8.5 times higher in the communes of the Andean area than in the rest of the region. We analyzed the epidemiologic aspects of the 103 cases diagnosed by serology and the clinical aspects of 80 hospitalized patients during 1995–2012. Cases in this region clearly predominated during winter, whereas in the rest of the country, they occur mostly during summer. Mild, moderate, and severe disease was observed, and the case-fatality rate was 32%. Shock caused death in 75% of those cases; high respiratory frequency and elevated creatinine plasma level were independent factors associated with death. Early clinical suspicion, especially in rural areas, should prompt urgent transfer to a hospital with an intensive care unit and might help decrease the high case-fatality rate.     

The Association between Hantavirus Infection and Selenium Deficiency in Mainland China

Hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses and transmitted by rodents is a significant public health problem in China, and occurs more frequently in selenium-deficient regions. To study the role of selenium concentration in HFRS incidence we used a multidisciplinary approach combining ecological analysis with preliminary experimental data. The incidence of HFRS in humans was about six times higher in severe selenium-deficient and double in moderate deficient areas compared to non-deficient areas. This association became statistically stronger after correction for other significant environment-related factors (low elevation, few grasslands, or an abundance of forests) and was independent of geographical scale by separate analyses for different climate regions. A case-control study of HFRS patients admitted to the hospital revealed increased activity and plasma levels of selenium binding proteins while selenium supplementation in vitro decreased viral replication in an endothelial cell model after infection with a low multiplicity of infection (MOI). Viral replication with a higher MOI was not affected by selenium supplementation. Our findings indicate that selenium deficiency may contribute to an increased prevalence of hantavirus infections in both humans and rodents. Future studies are needed to further examine the exact mechanism behind this observation before selenium supplementation in deficient areas could be implemented for HFRS prevention.     

汉坦病毒核酸检测试剂参考品的研制

[摘要]　目的　研制汉坦病毒核酸检测试剂参考品并制定其质量评价标准。方法　收集汉坦病毒阳性和阴性临床分离株样本，制备汉坦病毒RNA噬菌体模拟样本，使用宏基因组测序方法和实时荧光定量聚合酶链式反应检测方法进行核酸序列鉴定。选择合适样本组成参考品并使用不同试剂对参考品进行协作标定。根据标定结果确定汉坦病毒核酸检测试剂参考品的质量标准，并评估其稳定性。结果　汉坦病毒核酸检测试剂参考品由20份样本组成，包括阳性参考品5份（PC01～PC05）、阴性参考品11份（NC01～NC11）、精密性参考品2份（R01、R02）以及检出限参考品2份（S01、S05）。其中，检出限参考品1:10梯度稀释后，要求S02、S03为汉坦病毒汉滩型阳性，S06、S07为汉坦病毒汉城型阳性，其余样本不做要求。稳定性评价结果表明，汉坦病毒核酸检测试剂参考品经25 ℃室温放置24 h或反复冻融3次均不影响参考品性能。结论　本研究研制了汉坦病毒核酸检测试剂参考品，并制定了其质量标准，可应用于相关定性检测试剂的质量评价。     

RT－PCR，ELISA和IFA技术应用于汉坦病毒检测的比较

作者报道反转录聚合酶链式反应（ＲＴ－ＰＣＲ），双单克隆抗体（ＭｃＡｂ）夹心法酶联免疫吸附试验（ＳａｎｄｗｉｃｈＥＬＩＳＡ）和间接免疫荧光技术（ＩＦＡ）三种方法对汉坦病毒７６～１１８株细胞培养物中病毒ＲＮＡ及抗原的检测情况，并比较了三种方法的敏感性．结果表明：ＲＴ－ＰＣＲ敏感性最高，种毒后２４ｈ内即可检出病毒ＲＮＡ；其次为夹心法ＥＬＩＳＡ，种毒后４８ｈ可检出冻融细胞上清内的病毒抗原；ＩＦＡ检出感染细胞内病毒抗原的最短时间为７２ｈ．作者对设计引物与提高ＲＴ－ＰＣＲ的敏感性进行了讨论。