Rabies virus transmission via solid organs or tissue allotransplantation

Testing of tissue specimens obtained from SARS-CoV-2 nasopharyngeal swab-positive donors

Risk for transmission of SARS-CoV-2 through allogeneic human tissue transplantation is unknown. To further evaluate the risk of virus transmission, tissues were obtained from deceased donors who had tested positive for SARS-CoV-2 RNA via nasopharyngeal swab. This study evaluated an array of human tissues recovered for transplantation, including bone, tendon, skin, fascia lata, vascular tissues, and heart valves. Tissue samples and plasma or serum samples, if available, were tested for viral RNA (vRNA) using a real time PCR system for the presence of virus RNA. All samples were tested in quadruplicate for both subgenomic (sgRNA) and genomic (gRNA) RNA encoding the SARS-CoV-2 nucleocapsid gene. Amplification of a cellular housekeeping gene served as the positive control for every sample. A total of 47 tissue samples from 17 donors were tested for SARS-CoV-2 RNA. Four donors had plasma or serum available for paired testing. SARS-CoV-2 RNA was not detected from any tissue or plasma/serum sample tested. Based on these findings, risk of transmission through the transplantation of tissue types studied from SARS-CoV-2 infected donors is likely to be low.

Recent updates on laboratory diagnosis of rabies

Rabies is a lethal viral disease transmitted through the bite of rabid animals. India has a high burden of rabies, contributing to a significant proportion of the global deaths. However, under-reporting of the disease is prevalent due to lack of laboratory confirmation. Laboratory diagnosis of rabies plays a crucial role in differentiating the disease from clinical mimics, initiation of appropriate care, implementing infection control measures and informing disease surveillance. This review provides an overview of the recent advancements in laboratory diagnosis of rabies, aimed at updating physicians involved in diagnosis and management of rabies cases in India.

Tracking lethal threat: in-depth review of rabies

An infectious disease known as rabies (family Rhabdoviridae, genus Lyssavirus) causes severe damage to mammals' central nervous systems (CNS). This illness has been around for a very long time. The majority of human cases of rabies take place in underdeveloped regions of Africa and Asia. Following viral transmission, the Rhabdovirus enters the peripheral nervous system and proceeds to the CNS, where it targets the encephalon and produces encephalomyelitis. Postbite prophylaxis requires laboratory confirmation of rabies in both people and animals. All warm-blooded animals can transmit the Lyssavirus infection, while the virus can also develop in the cells of cold-blooded animals. In the 21st century, more than 3 billion people are in danger of contracting the rabies virus in more than 100 different nations, resulting in an annual death toll of 50,000-59,000. There are three important elements in handling rabies disease in post exposure prophylaxis (PEP), namely wound care, administration of anti-rabies serum, and anti-rabies vaccine. Social costs include death, lost productivity as a result of early death, illness as a result of vaccination side effects, and the psychological toll that exposure to these deadly diseases has on people. Humans are most frequently exposed to canine rabies, especially youngsters and the poor, and there are few resources available to treat or prevent exposure, making prevention of human rabies challenging.

Single-domain antibodies applied as antiviral immunotherapeutics

Viral infections have been the cause of high mortality rates throughout different periods in history. Over the last two decades, outbreaks caused by zoonotic diseases and transmitted by arboviruses have had a significant impact on human health. The emergence of viral infections in different parts of the world encourages the search for new inputs to fight pathologies of viral origin. Antibodies represent the predominant class of new drugs developed in recent years and approved for the treatment of various human diseases, including cancer, autoimmune and infectious diseases. A promising group of antibodies are single-domain antibodies derived from camelid heavy chain immunoglobulins, or VHHs, are biomolecules with nanometric dimensions and unique pharmaceutical and biophysical properties that can be used in the diagnosis and immunotherapy of viral infections. For viral neutralization to occur, VHHs can act in different stages of the viral cycle, including the actual inhibition of infection, to hindering viral replication or assembly. This review article addresses advances involving the use of VHHs in therapeutic propositions aimed to battle different viruses that affect human health.

Endemic or regionally limited bacterial and viral infections in haematopoietic stem-cell transplantation recipients: a Worldwide Network for Blood and Marrow Transplantation (WBMT) Review

Literature discussing endemic and regionally limited infections in recipients of haematopoietic stem-cell transplantation (HSCT) outside western Europe and North America is scarce. This Worldwide Network for Blood and Marrow Transplantation (WBMT) article is part one of two papers aiming to provide guidance to transplantation centres around the globe regarding infection prevention and treatment, and considerations for transplantation based on current evidence and expert opinion. These recommendations were initially formulated by a core writing team from the WBMT and subsequently underwent multiple revisions by infectious disease experts and HSCT experts. In this paper, we summarise the data and provide recommendations on several endemic and regionally limited viral and bacterial infections, many of which are listed by WHO as neglected tropical diseases, including Dengue, Zika, yellow fever, chikungunya, rabies, brucellosis, melioidosis, and leptospirosis.

Intravitam Diagnosis of Rabies in Patients with Acute Encephalitis: A Study of Two Cases

Rabies is one of the oldest known zoonotic diseases. Rhabdovirus, an RNA virus belonging to the genus Lyssavirus and family Rhabdoviridae, causes rabies. Rabies diagnosis is challenging as the rabies virus remains confined to neurons after the initial animal bite. It largely remains immune-evasive until the infection reaches the central nervous system. The bottleneck in rabies diagnosis remains the non-availability of technical expertise and failure to collect an appropriate sample. The laboratory confirmation of rabies in both antemortem and postmortem samples is important. The samples were tested for anti-rabies antibodies using quantitative ELISA. In this report, two case studies are presented to demonstrate the suitability of ELISA for the intra vitam diagnosis of rabies using cerebrospinal fluid (CSF) as a diagnostic sample. The interpretation of serology results for both vaccinated and unvaccinated individuals has been discussed in detail, which has helped to confirm the antemortem diagnosis of rabies. In this report, we observed that ELISA can be a viable alternative for anti-rabies antibody detection in CSF and can be used as a viable alternative to more technically challenging tests, such as Rapid Fluorescent Focus Inhibition Test (RFFFIT) and Immunofluorescence Assays (IFA).

A comparative review of serological assays for the detection of rabies virus-specific antibodies

Rabies is a major public health problem with a fatality rate close to 100%, caused by a virus of the Lyssavirus genus, of which rabies virus (RABV) is the prototype. Nonetheless, the complete prevention can be achieved by the induction of neutralizing antibodies by pre- or post-exposure prophylaxis. According to the world health organization (WHO) and World Organization for animal health (OIE), serum titers of rabies virus neutralizing antibodies (RVNA) that are higher or equal to 0.5 international units (IU)/ml indicate adequate immune response after vaccination against rabies. Currently, RFFIT and FAVN are the gold standard tests recommended by both WHO and OIE for detecting and quantitating RVNA in biological samples from individuals or animals previously vaccinated and/or subjects suspected of having been infected by RABV. Although the tests RFFIT and FAVN are efficient, they are time-consuming, labor-intensive manual tests and not cost-effective for routine use. Following the previously mentioned, approaches with alternative methods have been developed to detect RVNA or rabies-specific antibodies in human or animal serum, but with variable success. This work summarizes the advances in the serological assays for the detection of neutralizing antibodies or rabies antibodies and assesses the individual immune status after vaccination against rabies, as well as the mechanisms of RABV neutralization mediated by antibodies. Therefore, the main alternative methods for the determination of RABV or rabies-specific antibodies are exposed, with promising results, besides being easy to execute, of low cost, and representing a possibility of being applied, according to the proposal of each test to the network of Rabies Surveillance Laboratories.

Rabies in Europe: An epidemiological and clinical update

Rabies is a vaccine preventable zoonotic disease with a significant mortality burden worldwide. Several years of vaccination campaigns in wildlife animals have now achieved the control of rabies in Western Europe through a vaccination belt in front of endemic Eastern European countries. Nevertheless, rabies could be imported both by travellers from areas without an active public control of the disease or by animals coming from areas where the virus circulates in wildlife fauna. The knowledge of the current world epidemiology combined with a high index of clinical suspicion are needed to reach a diagnosis of rabies, especially in case of atypical presentation or without a history of animal exposure. The pre-travel counselling to people visiting highly endemic areas is essential to give information on how to reduce exposure to potential sources of infection and to select those subjects who could benefit from pre-travel vaccination. Rabies is almost invariably fatal, but the prompt administration of a vaccine course combined with anti-rabies immunoglobulins significantly reduces the probability to develop life-threatening consequences. In this review, we give a brief epidemiological and clinical update about rabies in Europe.

Updates on Rabies virus disease: is evolution toward "Zombie virus" a tangible threat?

Human rabies disease is caused by Rabies Lyssavirus, a virus belonging to Rhabdoviridae family. The more frequent means of contagion is through bites of infected mammals (especially dogs, but also bats, skunks, foxes, raccoons and wolves) which, lacerating the skin, directly inoculate virus-laden saliva into the underlying tissues. Immediately after inoculation, the Rabies virus enters neural axons and migrates along peripheral nerves towards the central nervous system, where it preferentially localizes and injuries neurons of brainstem, thalamus, basal ganglia and spinal cord. After an initial prodromic period, the infection evolves towards two distinct clinical entities, encompassing encephalitic (i.e., “furious”; ~70-80% of cases) and paralytic (i.e., “dumb”; ~20-30% of cases) rabies disease. The former subtype is characterized by fever, hyperactivity, hydrophobia, hypersalivation, deteriorated consciousness, phobic or inspiratory spasms, autonomic stimulation, irritability, up to aggressive behaviours. The current worldwide incidence and mortality of rabies disease are estimated at 0.175×100,000 and 0.153×100,000, respectively. The incidence is higher in Africa and South-East Asia, nearly double in men than in women, with a higher peak in childhood. Mortality remains as high as ~90%. Since patients with encephalitic rabies remind the traditional image of “Zombies”, we need to think out-of-the-box, in that apocalyptic epidemics of mutated Rabies virus may be seen as an imaginable menace for mankind. This would be theoretically possible by either natural or artificial virus engineering, producing viral strains characterized by facilitated human-to-human transmission, faster incubation, enhanced neurotoxicity and predisposition towards developing highly aggressive behaviours. (www.actabiomedica.it)

Update on lyssaviruses and rabies: will past progress play as prologue in the near term towards future elimination?

Rabies is an ancient, much-feared, and neglected infectious disease. Caused by pathogens in the family Rhabdoviridae, genus Lyssavirus, and distributed globally, this viral zoonosis results in tens of thousands of human fatalities and millions of exposures annually. All mammals are believed susceptible, but only certain taxa act as reservoirs. Dependence upon direct routing to, replication within, and passage from the central nervous system serves as a basic viral strategy for perpetuation. By a combination of stealth and subversion, lyssaviruses are quintessential neurotropic agents and cause an acute, progressive encephalitis. No treatment exists, so prevention is the key. Although not a disease considered for eradication, something of a modern rebirth has been occurring within the field as of late with regard to detection, prevention, and management as well as applied research. For example, within the past decade, new lyssaviruses have been characterized; sensitive and specific diagnostics have been optimized; pure, potent, safe, and efficacious human biologics have improved human prophylaxis; regional efforts have controlled canine rabies by mass immunization; wildlife rabies has been controlled by oral rabies vaccination over large geographic areas in Europe and North America; and debate has resumed over the controversial topic of therapy. Based upon such progress to date, there are certain expectations for the next 10 years. These include pathogen discovery, to uncover additional lyssaviruses in the Old World; laboratory-based surveillance enhancement by simplified, rapid testing; anti-viral drug appearance, based upon an improved appreciation of viral pathobiology and host response; and improvements to canine rabies elimination regionally throughout Africa, Asia, and the Americas by application of the best technical, organizational, economic, and socio-political practices. Significantly, anticipated Gavi support will enable improved access of human rabies vaccines in lesser developed countries at a national level, with integrated bite management, dose-sparing regimens, and a 1 week vaccination schedule.

Rabies: Current Preventive Strategies

Desensitization to rabies is a result of successfully eliminating canine rabies in the United States, which occurred in 2007; however, the need for mandatory rabies vaccination in pets remains. Rabies cases are rare in comparison with other vaccine-preventable diseases in companion animals; however, because it is a zoonotic disease with the highest case fatality rate of any infectious disease demands the establishment of strict laws for disease prevention. Preventive strategies include addressing current concerns in consideration of disease surveillance, appropriate vaccination recommendations, and local regulations protecting public health.