Aviremic organ transplant dengue virus transmission - A case report

Can Wastewater Surveillance Enhance Genomic Tracking of Climate-Driven Pathogens?

Climate change heightens the threat of infectious diseases in Europe, necessitating innovative surveillance methods. Based on 390 scientific papers, for the first time, this review associates climate-related pathogens, data related to their presence in wastewater, and associated available genomic detection methods. This deep analysis reveals a wide range of pathogens that can be tracked through methods such as quantitative and digital PCR, as well as genomic pathogen enrichment in combination with sequencing and metagenomics. Nevertheless, significant gaps remain in the development of methods, particularly for vector-borne pathogens, and in their general harmonization relating to performance criteria. By offering an overview of recent advancements while identifying critical gaps, we advocate for collaborative research and validation to integrate detection techniques into surveillance frameworks. This will enhance public health resilience against emerging infectious diseases driven by climate change.

A Scoping Review of Arthropod-Borne Flavivirus Infections in Solid Organ Transplant Recipients

Arthropod-borne flaviviruses (ABFs), transmitted by mosquitoes or ticks, are increasing due to climate change and globalization. This scoping review examines the epidemiology, clinical characteristics, diagnostics, treatment, and outcomes of ABF infection in solid organ transplant recipients (SOTRs). A database search up to January 25, 2024, focused on ABFs such as West Nile virus (WNV), dengue virus (DENV), Japanese encephalitis virus (JEV), Powassan virus (POWV), yellow fever virus (YFV), and Zika virus (ZIKV), limited to SOTRs. We identified 173 WNV cases from 84 studies, with 28 donor-derived infections (DDIs). Common clinical features included fever (78.5%), altered mental status (65.1%), and weakness or paralysis (45.6%). Treatment involved reducing immunosuppression (IS) in 93 cases, with intravenous immunoglobulin (IVIG), interferon alfa-2b, and ribavirin used in 75 cases. Seven cases involved graft loss or rejection post-infection. WNV infection had a 23.7% mortality rate, with severe neurological complications in 43.9% For DENV infection, 386 cases from 47 studies were identified, including 14 DDI cases. Symptoms included fever (85%), myalgias (56.4%), and headache or retro-orbital pain (34.6%). Severe dengue occurred in 50 cases (13.0%). IVIG was administered in six cases. Reduction in IS was reported in 116 patients. DENV mortality rate was 4.9%. Additionally, 26 cases of less common ABFs such as JEV, POWV, YFV, and ZIKV were described. In summary, ABF infections among SOTRs are associated with higher morbidity and mortality compared to the general population, emphasizing the need for improved preventive strategies, timely diagnosis, and optimized management protocols.

Arbovirus in Solid Organ Transplants: A Narrative Review of the Literature

The incidence of arbovirus infections has increased in recent decades. Other than dengue, chikungunya, and West Nile viruses, the data on arbovirus in solid organ transplant (SOT) are limited to case reports, and infections in renal transplant recipients account for most of the reported cases. Dengue and West Nile infections seem to be more severe with higher mortality in SOT patients than in the general population. Acute kidney injury is more frequent in patients with dengue and chikungunya although persistent arthralgia with the latter is less frequent. There is no clear relationship between arboviral infection and acute cellular rejection. Pre-transplant screening of donors should be implemented during increased arboviral activity but, despite donor screening and negative donor nucleic acid amplification test (NAT), donor derived infection can occur. NAT may be transiently positive. IgM tests lack specificity, and neutralizing antibody assays are more specific but not readily available. Other tests, such as immunohistochemistry, antigen tests, PCR, metagenomic assays, and viral culture, can also be performed. There are a few vaccines available against some arboviruses, but live vaccines should be avoided. Treatment is largely supportive. More data on arboviral infection in SOT are needed to understand its epidemiology and clinical course.

Donor-derived dengue infections - A review of screening protocol and outcomes in an endemic country

BACKGROUND

Donor-derived dengue infections present significant challenges to organ transplantation, particularly in endemic regions like Singapore. Although primarily transmitted by Aedes mosquitoes, dengue can also be transmitted through organ transplantation, occasionally with fatal outcomes. This study aims to evaluate the outcomes and evolution of dengue screening protocols for potential deceased donors in Singapore from 2006 to 2022.

METHODS

Initially, screening was done via dengue immunoglobulin M (IgM), targeting donors with specific clinical criteria (thrombocytopenia, drop in platelet count, prolonged prothrombin time/partial thromboplastin time, and discretion of the transplant team), later transitioning to blood dengue reverse transcription-polymerase chain reaction (RT-PCR) in 2007 with similar criteria, and subsequently universal screening in 2016. In 2021, urine dengue RT-PCR was added following a case of donor-derived dengue infection from an aviremic but viruric donor.

RESULTS

Out of 431 potential deceased donors, 395 (91.6%) underwent dengue screening, with six (1.5%) testing positive for dengue. In 2006, three positive screens were identified: two through dengue IgM and one via blood dengue RT-PCR; subsequent years saw one positive screen each in 2007, 2008, and 2019 via blood dengue RT-PCR. Potential deceased donors with a positive blood dengue screen were rejected as solid organ and tissue donors. Those with negative blood dengue RT-PCR but positive urine dengue RT-PCR would be rejected as kidney donors, but the use of other organs and tissues was at the discretion of the transplantation team.

CONCLUSION

The optimal screening protocol remains uncertain, but our findings suggest that a universal screening strategy utilizing both blood and urine dengue RT-PCR could be considered in dengue-endemic countries.

Risk and benefits of expanded donor screening: A viewpoint from Germany

This review describes the risks and benefits of expanding screening for transmissible pathogens in deceased organ donors. The focus is on the experience and procedure in Germany to make a decision on how to proceed with a possible donor. Three issues are of interest in how screening policies impact the process with the aim of mitigating unexpected transmission risks: (1) Should we add universal or targeted nucleic acid testing to serological tests for common blood-borne viruses (BBVs; HIV, HBV, and HCV)? (2) Which tests should be added for screening in a geographically restricted region beyond testing for these BBVs? (3) Being faced with changes (e.g., climate and population) in the own geographically restricted region, what strategies are needed before implementing new tests, and which considerations apply for proper indication to do this? Testing may only be effective when during donor characterization the appropriate conclusions are drawn from the existing findings and screening tests are initiated. This statement overlaps the need to implement universal screening for a pathogen or targeted screening based on the risk that the donor has acquired the transmissible pathogen or is not as possible to identify by current methods of clinical judgment and/or specific tests.

Dengue virus infection among renal transplant recipients in Singapore: a 15-year, single-centre retrospective review

INTRODUCTION

Dengue is a mosquito-borne viral infection endemic in Singapore. Its impact on renal transplantation is limited to small case series. We aimed to characterise the clinical presentation and outcomes of dengue infection among renal transplant recipients in Singapore.

METHODS

We conducted a 15-year retrospective review of dengue in renal transplant patients treated at Singapore General Hospital between January 2005 and October 2019. The diagnosis of dengue was made if there were a compatible clinical syndrome and a positive dengue diagnostic assay (dengue non-structural 1 antigen, immunoglobulin M or reverse transcriptase-polymerase chain reaction).

RESULTS

Of the 31 patients diagnosed with dengue, 18 (58.1%) were deceased donor recipients. The median age was 52 (interquartile range [IQR] 40-61) years; 16 (51.6%) were females. The median time to diagnosis was 99 (IQR 18-169) months from transplant. The most common clinical symptoms were fever (87.1%), myalgia (41.9%), gastrointestinal symptoms (38.7%) and headache (25.8%). Nineteen (61.3%) patients had dengue without warning signs, nine (29.0%) had dengue with warning signs, three (9.7%) had severe dengue and 30 (96.8%) were hospitalised. Seventeen (54.8%) patients had graft dysfunction, 16 (94.1%) of whom had recovery of graft function. One (3.2%) patient required dialysis and subsequently died. There were two cases of donor-derived infections (DDIs) with favourable outcomes.

CONCLUSION

Our experience with dengue in renal transplant recipients is concordant with published data. Although graft dysfunction is common, it is often transient with favourable outcomes. Outpatient management may be considered for mild infections. Although dengue DDIs are uncommon, more stringent donor screening may be considered in endemic regions.

Insights into dengue immunity from vaccine trials

The quest for an effective dengue vaccine has culminated in two approved vaccines and another that has completed phase 3 clinical trials. However, shortcomings exist in each, suggesting that the knowledge on dengue immunity used to develop these vaccines was incomplete. Vaccine trial findings could refine our understanding of dengue immunity, because these are experimentally derived, placebo-controlled data. Results from these trials suggest that neutralizing antibody titers alone are insufficient to inform protection against symptomatic infection, implicating a role for cellular immunity in protection. These findings have relevance for both future dengue vaccine development and application of current vaccines for maximal public health benefit.

Recent two-year advances in anti-dengue small-molecule inhibitors

Dengue is an acute tropical infectious disease transmitted by mosquitoes, which has posed a major challenge to global public health. Unfortunately, there is a lack of clinically proven dengue-specific drugs for its prevention and treatment. As the pathogenesis of dengue has not been fully elucidated, the development of specific drugs is seriously hindered. This article briefly describes the pathogenesis of dengue fever, the molecular characteristics, and epidemiology of dengue virus, and focuses on the potential small-molecule inhibitors of dengue virus, including on-target and multi-targeted inhibitors, which have been reported in the past two years.