Seroprevalence of West Nile virus infection in solid organ transplant recipients

A.G. Freifeld, J. Meza, B. Schweitzer, L. Shafer, A.C. Kalil. A.R. Sambol. Seroprevalence of West Nile virus infection in solid organ transplant recipients.
Transpl Infect Dis 2010: 12: 120–126. All rights reserved Background. Of people infected with mosquito‐borne West Nile virus (WNV), <1% develop neuroinvasive disease (NID). Population studies suggest that people older than 65 years may be at higher risk for neurologic symptoms. It has been suggested that solid organ transplant (SOT) recipients are also at higher risk for WNV NID, but definitive serologic and epidemiologic data are lacking. Methods. A serologic screening survey, using a US Food & Drug Administration‐approved enzyme‐linked immunosorbant assay to detect WNV immunoglobulin‐G (IgG) antibody responses in cohorts of SOT recipients and non‐immunocompromised controls, was undertaken at a large Midwestern university organ transplant center in the aftermath of the summer 2003 WNV regional outbreak. Hemagglutination‐inhibition testing was used to confirm WNV IgG‐positive results and differentiate them from positive results caused by Saint Louis encephalitis virus, another flavivirus that is endemic in the Midwestern US. Findings. The rate of WNV IgG‐seropositive responses did not differ between SOT recipients and non‐immunocompromised controls, and were 12% and 10%, respectively. Retrospective chart review showed no documented WNV NID in the seropositive SOT recipients, suggesting an incidence of WNV NID may be as low as 0.7% in this population. Interpretation. Asymptomatic WNV infection is common among immunocompromised SOT patients, occurring as often as it does in non‐immunocompromised controls. Our data indicated that severe WNV NID is less frequent in SOT patients, contrary to what has been suggested in other studies.     

Possible benefit of intravenous immunoglobulin therapy in a lung transplant recipient with West Nile virus encephalitis

Abstract: During the summer of 2000, a countrywide epidemic of West Nile fever (WNF) occurred in Israel, with 417 confirmed cases and 35 deaths. Immunosuppressed patients had a 31% case‐fatality rate, which was significantly higher compared to non‐immunosuppressed patients (13%). We describe a 42‐year‐old male lung‐transplant recipient with serologically confirmed West Nile virus (WNV) encephalitis and deteriorating level of consciousness. He was treated with 0.4 g/kg intravenous immunoglobulin preparation from Israeli donors that contained a high titer of anti‐WNV antibodies (1 : 1600). The patient showed rapid improvement within 24 h and complete disappearance of signs and symptoms within 48 h. This is the second case of an immunosuppressed patient responding to the same preparation of intravenous immunoglobulins. Larger studies are required in order to establish the therapeutic role of immunoglobulins in patients with WNF.     

West Nile virus encephalitis acquired via liver transplantation and clinical response to intravenous immunoglobulin: case report and review of the literature

C. Rhee, E.F. Eaton, W. Concepcion, B.G. Blackburn. West Nile virus encephalitis acquired via liver transplantation and clinical response to intravenous immunoglobulin: case report and review of the literature.
Transpl Infect Dis 2011: 13: 312–317. All rights reserved Abstract: A patient developed West Nile virus (WNV) encephalitis 2 weeks after receiving a liver transplant and recovered fully, following treatment with intravenous immunoglobulin (IVIg). Laboratory testing documented transmission from the organ donor. Clinicians should be suspicious for organ‐transmitted WNV in any post‐transplant patient who develops fever and neurological symptoms. We review previous cases of organ‐transmitted WNV, the use of IVIg for WNV encephalitis, and the issue of organ donor screening.     

Current practices and evaluation of screening solid organ donors for West Nile virus

The first cases of West Nile virus (WNV) transmitted through solid organ transplantation (SOT) were identified in 2002. Subsequently, 5 additional clusters have been reported to public health officials in the United States. Based upon a limited number of known cases, patients who acquire WNV from infected donor organs might be at higher risk for severe neurologic disease and death, compared with patients infected through mosquito bites. In response, some organ procurement organizations (OPOs) have instituted pre‐transplant screening of organ donors for WNV infection. We evaluated the current practices, concerns, and challenges related to screening organ donors for WNV in the United States by reviewing the relevant medical literature and interviewing key stakeholders. Screening organ donors for WNV is not required by national policy. In 2008, 11 (19%) of 58 OPOs performed WNV screening using nucleic acid amplification testing (NAT). These OPOs differ in their screening strategies, NAT performed, and logistical challenges. Concerns of delays in receiving NAT results before transplant and potential false‐positive results leading to organ wasting are limitations to more widespread screening. Furthermore, it is unknown if WNV screening practices decrease SOT‐related morbidity and mortality, or if screening is cost‐effective. Additional data are needed to assess and improve transplant outcomes related to WNV.     

西尼罗病毒感染免疫应答反应研究进展

西尼罗病毒病是由西尼罗病毒引起的一种人兽共患传染病,给人类和动物健康带来重大危害。虽现已有疫苗处在研究阶段,但仍没有人用疫苗获批上市。通过感染动物模型,有关西尼罗病毒免疫反应的研究已经开展。本文对固有免疫和获得性免疫在抵抗西尼罗病毒感染中的作用进行综述,为进一步研究西尼罗病毒激发免疫应答反应的机制和新型疫苗研制提供依据。     

Unusual presentation of chromoblastomycosis due to Cladophialophora carrionii in a renal and pancreas transplant recipient patient successfully treated with posaconazole and surgical excision

C. Dupont, T.A. Duong, S. Mallet, M.F. Mamzer‐Bruneel, E. Thervet, M.E. Bougnoux, B. Dupont. Unusual presentation of chromoblastomycosis due to Cladophialophora carrionii in a renal and pancreas transplant recipient patient successfully treated with posaconazole and surgical excision.
Transpl Infect Dis 2010: 12: 180–183. All rights reserved Abstract: Chromoblastomycosis is a chronic, tropical and subtropical, subcutaneous mycosis caused by inoculation of dematiaceous molds. This disease is uncommonly reported in patients who have undergone solid organ transplantation. We describe a case of chromoblastomycosis caused by Cladophialophora carrionii that occurred 7 years after transplantation in a 58‐year‐old male renal and pancreatic transplant recipient. Diagnosis was based on histopathology and isolation of multiple colonies of the dematiaceous mold in pure culture. Identification was achieved by sequencing of the internal transcribed spacer regions of the rRNA. The patient was successfully treated with posaconazole and surgical excision of a residual lesion.     

西尼罗病毒的研究进展

西尼罗病毒（West Nile Virus,WNV）属黄病毒科,为正单链RNA病毒,主要由蚊虫叮咬传播。近几年,随着WNV感染的流行,除蚊虫叮咬以外的传播途径如输血等日益受到重视,WNV感染的实验室诊断不断取得进展,相关疫苗的研制也在进行之中。本文就WNV的分子生物学、流行病学、感染与免疫、实验室诊断及疫苗的研究进展作一综述。     

BK virus encephalitis with thrombotic microangiopathy in an allogeneic hematopoietic stem cell transplant recipient

R. Lopes da Silva, I. Ferreira, G. Teixeira, D. Cordeiro, M. Mafra, I. Costa, J.M. Bravo Marques, M. Abecasis. BK virus encephalitis with thrombotic microangiopathy in an allogeneic hematopoietic stem cell transplant recipient.
Transpl Infect Dis 2011: 13: 161–167. All rights reserved Abstract: BK virus (BKV) infection occurs most often in immunocompromised hosts, in the setting of renal or bone marrow transplantation. Hemorrhagic cystitis is the commonest manifestation but in recent years infections in other organ systems have been reported. We report an unusual case of biopsy‐proven BKV encephalitis in a hematopoietic stem cell transplant patient who subsequently developed thrombotic microangiopathy. As far as we know, this is the first report of such an association in a transplant patient.     

West Nile virus: immunity and pathogenesis

West Nile virus (WNV) is a neurotropic, arthropod-borne flavivirus that is maintained in an enzootic cycle between mosquitoes and birds, but can also infect and cause disease in horses and humans. WNV is endemic in parts of Africa, Europe, the Middle East, and Asia, and since 1999 has spread to North America, Mexico, South America, and the Caribbean. WNV infects the central nervous system (CNS) and can cause severe disease in a small minority of infected humans, mostly immunocompromised or the elderly. This review discusses some of the mechanisms by which the immune system can limit dissemination of WNV infection and elaborates on the mechanisms involved in pathogenesis. Reasons for susceptibility to WNV-associated neuroinvasive disease in less than 1% of cases remain unexplained, but one favored hypothesis is that the involvement of the CNS is associated with a weak immune response allowing robust WNV replication in the periphery and spread of the virus to the CNS.     

Subacute immune response to primary EBV infection leading to post‐transplant lymphoproliferative disease in a renal transplant patient

A 23‐year‐old man sero‐negative for Epstein–Barr virus (EBV) developed recurrent sore throats 3 and 6 months after a renal transplant from an EBV sero‐positive donor. Tonsillar biopsy at 9 months post‐transplant showed post‐transplant lymphoproliferative disease (PTLD) caused by EBV. Following reduction of immunosuppressive treatment, he developed further signs and symptoms, and serological evidence of infectious mononucleosis followed by resolution of lymphadenopathy. This case emphasizes the difficulty in interpreting EBV serology in immunosuppressed patients and the importance of pre‐transplant EBV serology.     

西尼罗病毒RT-PCR检测方法的建立及其初步应用

目的　建立西尼罗病毒 (WestNilevirus ,WNV)RT PCR检测方法 ,为WNV感染的诊断和流行病学调查奠定基础。方法　选择Vero E6细胞进行WNV培养 ,通过乳鼠脑内接种病毒培养液获得WNV感染脑组织。在病毒基因组E区和C区设计 3对引物 ,以WNV培养液 ,建立并优化病毒核酸RT PCR分析方法。然后 ,以此对感染蚊虫模拟标本和乳鼠脑组织进行检测。PCR产物测序后 ,用Blast进行同源性分析。结果　用RT PCR在WNV培养液中扩增出与预期大小一致的核苷酸片段 ,并通过改变循环数 ,模板稀释倍数等参数对该方法进行了优化 ;将建立的方法用于检测感染蚊虫模拟标本和感染乳鼠脑组织 ,均检测出WNV目的基因片段 ,且扩增效果与病毒培养液无明显差异 ;套式PCR能显著提高检测的敏感性 ( 10 8-10 9倍 )。结论　本研究建立的WNVRT PCR检测方法具有较高的敏感性 ,可用于WNV感染的流行病学调查研究     

Large Human Outbreak of West Nile Virus Infection in North-Eastern Italy in 2012

Human cases of West Nile virus (WNV) disease have been reported in Italy since 2008. So far, most cases have been identified in north-eastern Italy, where, in 2012, the largest outbreak of WNV infection ever recorded in Italy occurred. Most cases of the 2012 outbreak were identified in the Veneto region, where a special surveillance plan for West Nile fever was in place. In this outbreak, 25 cases of West Nile neuroinvasive disease and 17 cases of fever were confirmed. In addition, 14 WNV RNA-positive blood donors were identified by screening of blood and organ donations and two cases of asymptomatic infection were diagnosed by active surveillance of subjects at risk of WNV exposure. Two cases of death due to WNND were reported. Molecular testing demonstrated the presence of WNV lineage 1 in all WNV RNA-positive patients and, in 15 cases, infection by the novel Livenza strain was ascertained. Surveillance in other Italian regions notified one case of neuroinvasive disease in the south of Italy and two cases in Sardinia. Integrated surveillance for WNV infection remains a public health priority in Italy and vector control activities have been strengthened in areas of WNV circulation.     

West Nile Virus Antibody Prevalence in Horses in Ukraine

West Nile virus (WNV) is a mosquito-borne virus of global importance. Over the last two decades, it has been responsible for significant numbers of cases of illness in humans and animals in many parts of the world. In Ukraine, WNV infections in humans and birds were first reported more than 25 years ago, yet the current epidemiological status is quite unclear. In this study, serum samples from over 300 equines were collected and screened in order to detect current WNV activity in Ukraine with the goal to estimate the risk of infection for humans and horses. Sera were tested by enzyme-linked immunosorbent assay (ELISA) and virus neutralization assay (NT) to detect WNV-specific antibodies. The results clearly revealed that WNV circulates in most of the regions from which samples were obtained, shown by a WNV seroprevalence rate of 13.5% of examined horses. This is the first topical report indicating the presence of WNV infections in horses in Ukraine, and the results of this study provide evidence of a widespread WNV circulation in this country.     

West Nile virus meningitis in a chronic immunosuppressed patient with rheumatoid arthritis

The clinical presentation of West Nile virus (WNV) can be severe in immunosuppressed patients. A 65-year-old with steroid-dependent rheumatoid arthritis on infliximab and methotrexate presented with meningitis and profound muscular weakness. Serum WNV IgM and IgG antibody were positive. WNV should be included in the differential diagnosis of neurological symptoms in peak months.     

Subacute cytomegalovirus appendicitis in a renal transplant recipient

Cytomegalovirus (CMV) infections in transplant patients is a well‐known disease. We describe the first case, to our knowledge, documenting CMV appendicitis in a renal transplant patient, and its clinical presentation, diagnosis, and treatment.