Organ transplantations and rabies transmission

Spatial Inequality Hides the Burden of Dog Bites and the Risk of Dog-Mediated Human Rabies

Since its reintroduction in 2015, rabies has been established as an enzootic disease among the dog population of Arequipa, Peru. Given the unknown rate of dog bites, the risk of human rabies transmission is concerning. Our objective was to estimate the rate of dog bites in the city and to identify factors associated with seeking health care in a medical facility for wound care and rabies prevention follow-up. To this end, we conducted a door-to-door survey with 4,370 adults in 21 urban and 21 peri-urban communities. We then analyzed associations between seeking health care following dog bites and various socioeconomic factors, stratifying by urban and peri-urban localities. We found a high annual rate of dog bites in peri-urban communities (12.4%), which was 2.6 times higher than that in urban areas (4.8%). Among those who were bitten, the percentage of people who sought medical treatment was almost twice as high in urban areas (39.1%) as in peri-urban areas (21.4%).

Epidemiological scenarios for human rabies exposure notified in Colombia during ten years: A challenge to implement surveillance actions with a differential approach on vulnerable populations

Based on notified cases of human rabies exposure and human deaths by rabies to Colombia public health surveillance system between 2007 and 2016, we conducted a spatiotemporal analysis to identify epidemiological scenarios of high human rabies exposure due to dogs, cats, bats, or farm animals (n = 666,411 cases). The incidence rate of human rabies exposures was analyzed by using geographical information system (spatiotemporal distribution and Cluster and Outlier Analysis (Anselin Local Moran's I)) data for all Colombian cities. The incidence rate of human rabies exposures due to dogs and cats showed an increasing trend, while aggression due bats and farm animals fluctuated throughout the analyzed period. Human deaths by rabies transmitted by cat and bat occurred in the Andean and Orinoquia regions, which had urban and rural scenarios. The urban scenario showed the highest exposure to human rabies due to cats and dogs in cities characterized with high human population density and greater economic development. In contrary, the highest human rabies exposure in the rural scenario was observed due to contact of mucosa or injured skin with the infected saliva of farm animals with the rabies virus, principally among workers in the agroforestry area. The inequality scenario showed some outlier cities with high human rabies exposure due to farm animals principally in the Pacific region (characterized by the highest poverty rates in Colombia), being Afro-descendant and indigenous population the most exposed. The highest exposure due to bats bite was observed among indigenous people residing in cities of the Amazon region as a dispersed population (Amazonian scenario). None of the high exposure scenarios were related to human deaths by rabies due to dogs aggression. The identified scenarios can help develop better surveillance systems with a differential approach to the vulnerable population and strengthening them in areas with rabies viral circulation.

Donor-derived Viral Infections in Liver Transplantation

Donor-derived infections are defined as any infection present in the donor that is transmitted to 1 or more recipients. Donor-derived infections can be categorized into 2 groups: "expected" and "unexpected" infections. Expected transmissions occur when the donor is known to have an infection, such as positive serology for cytomegalovirus, Epstein Barr virus, or hepatitis B core antibody, at the time of donation. Unexpected transmissions occur when a donor has no known infection before donation, but 1 or more transplant recipients develop an infection derived from the common donor. Unexpected infections are estimated to occur in far less than 1% of solid organ transplant recipients. We will review the epidemiology, risk factors, and approaches to prevention and management of donor-derived viral infectious disease transmission in liver transplantation.

Rare and Emerging Viral Infections in the Transplant Population

Viral infections account for a large proportion of emerging infectious diseases, and the agents included in this group consist of recently identified viruses as well as previously identified viruses with an apparent increase in disease incidence. In transplant recipients, this group can include viruses with no recognized pathogenicity in immunocompetent patients and those that result in atypical or more severe disease presentations in the immunocompromised host. In this chapter, we begin by discussing viral diagnostics and techniques used for viral discovery, specifically as they apply to emerging and rare infections in this patient population. Focus then shifts to specific emerging and re-emerging viruses in the transplant population, including human T-cell leukemia virus 1, rabies, lymphocytic choriomeningitis virus, human bocavirus, parvovirus 4, measles, mumps, orf, and dengue. We have also included a brief discussion on emerging viruses and virus families with few or no reported cases in transplant recipients: monkeypox, nipah and hendra, chikungunya and other alphaviruses, hantavirus and the Bunyaviridae, and filoviruses. Finally, concerns regarding infectious disease complications in xenotransplantation and the reporting of rare viral infections are addressed. With the marked increase in the number of solid organ and hematopoietic stem cell transplants performed worldwide, we expect a corresponding rise in the reports of emerging viral infections in transplant hosts, both from known viruses and those yet to be identified.

Rabies virus transmission via solid organs or tissue allotransplantation

BACKGROUND

Rabies, for which the mortality rate is almost 100%, is a zoonotic viral disease that can be transmitted via solid organs or tissue allotransplantation. Dozens of deaths from rabies via solid organs or tissues allotransplantation (ROTA) have been documented during the last decades. In 2015 and 2016, two cases of rabies virus transmission via solid organs or tissue allotransplantation were reported in China, which further underscore the risk and importance of this special type of rabies for organ transplant recipients.

MAIN TEXT

From 1978 to 2017, at least 13 cases of ROTA, causing dozens of deaths, have been reported worldwide, whether in the high-risk or low-risk countries of rabies. The reported incubation period of ROTA ranges from 11 days to more than 17 months, while the historical incubation period of rabies is generally considered to range from ~ 1 week to several years. The pathogenesis of ROTA is not clear, but the use of post-exposure prophylaxis (PEP) can play a protective role in the transplant recipients. We also summarize reports about ROTA in China, combined with the actual situation regarding work on rabies surveillance and elimination, and suggest countermeasures for the prevention and control of ROTA in the future.

CONCLUSIONS

Understanding the significance of ROTA, screening the suspected organs, assessing the risk and protecting the related population will be effective way to prevent and control further occurrence of ROTA.

The first report evaluating the post-exposure rabies prophylaxis in children exposed to animals in the Lublin Province (Eastern Poland) in 2010-2016 - a retrospective study

INTRODUCTION

Rabies continues to be one of the most important viral diseases and remains a significant threat to public health across the globe. The World Health Organization (WHO) has determined that most rabies cases occur in children. Dog bites on humans are a major public-health problem. Poland has not achieved rabies free status yet. Post-exposure prophylaxis (PEP) in humans can effectively prevent death after exposure to a potentially infected animal.

THE AIM

The main objective of this study was to estimate the frequency of PEP among children exposed to animals, who had attended consultations at the Department of Infectious Diseases for Children in the Jan Boży Hospital in Lublin.

PATIENTS AND METHODS

We retrospectively analyzed the medical records from the period of 2010-2016 of all pediatric patients (0-17 years of age) who had been exposed to animals and attended consultations at the Department of Infectious Diseases for Children in the Jan Boży Hospital in Lublin.

RESULTS

During the studied period, 519 children who had been exposed to animals attended consultations, and a prophylactic procedure consisting of active immunization was applied to 32.8%. The male children accounted for 55.3%. The mean age was 9.2 years. The biggest group of children (406) had been exposed to dogs, 62 children to cats, and 15 to rats. Most children had upper-limbs injuries. During the studied period, i.e. 2010-2016, there were 1713 confirmed cases of rabid animals in Poland, and 60 cases were recorded in the Lublin Province. We did not observe any cases of rabies in our exposed and vaccinated patients.

CONCLUSIONS

The number of rabid animals in the Lublin Province had decreased to low levels, but the expected decrease in the number of PEP's administered did not occur. Since all children were vaccinated in accordance with the recommendations, the possible reason for vaccination's being administered in the quantities greater than the number of rabid animals recorded in the Lublin Province are bites by animals unavailable for veterinary observations and also the lack of more frequent reports regarding the current epizootic situation of rabies. The use of rabies immunoglobulin (RIG) in children in the Lublin Province is at a very low level, i.e. at 0.58%. The yearly numbers of exposed pediatric patients were at similar levels, which indicates that education programs should be introduce to reduce the number of animal bites in children.

Advances in rabies prophylaxis and treatment with emphasis on immunoresponse mechanisms

Rabies is a vaccine-preventable fatal disease in man and most mammals. Although rabies is recorded in 150 territories and is responsible for at least 60,000 human deaths every year worldwide, it is a neglected tropical problem. Most of the rabies free countries are considered to be fragile free as the disease may re-emerge easily through wild mammals. For the performance of effective rabies eradication programs, a complex set of strategies and activities is required. At the time, a joint project of WHO-OIE-FAO which was announced in 2015, plans to control animal-human-ecosystems rabies interface. For effective rabies control, prophylactic policies must be applied. These include various educational outreaches for farmers and people living in endemic areas, enforced legislation for responsible dog ownership, control programs for the free-ranging stray dog and cat populations, field large-scale vaccination campaigns, and the development of new vaccine delivery strategies for both humans and animals. The present work presents the advances in the development of new safe, effective and economic vaccines for domestic dogs, and oral vaccines for the control of the disease in wild animals. It presents also some therapeutic protocols used for the treatment of patients.

Rabies Virus Transmission in Solid Organ Transplantation, China, 2015-2016

We report rabies virus transmission among solid organ transplantation recipients in Changsha, China, in 2016. Two recipients were confirmed to have rabies and died. Our findings suggest that more attention should be paid to the possibility of rabies virus transmission through organ transplantation for clinical and public health reasons.

Rabies - epidemiology, pathogenesis, public health concerns and advances in diagnosis and control: a comprehensive review

Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus Lyssavirus and family Rhabdoviridae. It affects all warm-blooded animals and the disease is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. Over 60,000 peoples die every year due to rabies, while approximately 15 million people receive rabies post-exposure prophylaxis (PEP) annually. Bite of rabid animals and saliva of infected host are mainly responsible for transmission and wildlife like raccoons, skunks, bats and foxes are main reservoirs for rabies. The incubation period is highly variable from 2 weeks to 6 years (avg. 2-3 months). Though severe neurologic signs and fatal outcome, neuropathological lesions are relatively mild. Rabies virus exploits various mechanisms to evade the host immune responses. Being a major zoonosis, precise and rapid diagnosis is important for early treatment and effective prevention and control measures. Traditional rapid Seller's staining and histopathological methods are still in use for diagnosis of rabies. Direct immunofluoroscent test (dFAT) is gold standard test and most commonly recommended for diagnosis of rabies in fresh brain tissues of dogs by both OIE and WHO. Mouse inoculation test (MIT) and polymerase chain reaction (PCR) are superior and used for routine diagnosis. Vaccination with live attenuated or inactivated viruses, DNA and recombinant vaccines can be done in endemic areas. This review describes in detail about epidemiology, transmission, pathogenesis, advances in diagnosis, vaccination and therapeutic approaches along with appropriate prevention and control strategies.

Rabies Acquired Through Kidney Transplantation in a Child: A Case Report

Rabies is usually transmitted to humans through bites of infected animals; however, it can rarely be transmitted through deceased donor organs or tissues when not suspected. Here, we report a case of rabies transmission in a child. The child was a 5-year-old girl who was admitted to the pediatric intensive care unit with encephalitis of unexplained cause 3.5 months after she received a kidney transplant from a deceased donor. The laboratory and imaging studies did not reveal any explanation for her rapidly declining clinical and neurologic condition, which ended with death 4 days after admission. Death of another recipient from the same donor led to an investigation that revealed rabies as the cause. Both corneas were explanted from other recipients to prevent further death. Polymerase chain reaction sequence analysis of the corneas was consistent with a rabies virus from the same donor's state of residence. Rabies transmission, although rare, should be suspected when a donor comes from or has visited endemic countries. Donors with unclear causes of death should be rejected.

Probable Rabies Virus Transmission through Organ Transplantation, China, 2015

During July 2015, physicians at a hospital in Beijing, China, diagnosed rabies in 2 patients who had each received a kidney from a common organ donor who had died from acute progressive encephalitis of unknown cause. The patients had rabies incubation periods of 42 and 48 days. Altered mental status developed in both patients and progressively worsened to deep coma within 80 days after transplantation; both patients died. Two other transplant recipients received corneas but remained well after receiving timely rabies prophylaxis. An effective regulatory system for testing donors should be implemented to decrease the occurrence of donor-derived infectious diseases. In addition, health education should be improved to enhance public awareness of transplant-associated infectious diseases. Transplant recipients and other persons with exposure to organs or tissues from donors with rabies must be provided consistent health monitoring and follow-up, including rabies postexposure prophylaxis; any remaining organs and tissues must be quarantined and not transplanted.

Donor-derived infection--the challenge for transplant safety

Unusual clinical syndromes or clusters of infections in recipients of organs from the same donor suggest donor-derived infection as a possible source of transmission

The incidence of transmission of unexpected infection by organ allografts is low, but precise data are lacking

Screening of donors for common pathogens involves both epidemiologic history and microbiological assays, and is highly effective for preventing the transmission of HIV and hepatitis B and C viruses

Donor screening for uncommon pathogens must be guided by knowledge of changes in the local epidemiology of infection

The key element in the detection of donor-derived infection is suspicion on the part of the clinicians caring for organ recipients

Application of newer microbiological techniques will increase the speed of donor screening and enhance transplant safety

Each year, over 70,000 organs are transplanted worldwide. The degree of risk of transmission of infection from transplanted organs to the recipient is largely unknown and is difficult to assess for specific organs. Here, Jay A. Fishman and Paolo A. Grossi describe the major risk factors for organ donor-derived transmission of infection and discuss opportunities to reduce the incidence of such events.

Organ transplantation, including of the heart, lung, kidney, liver, pancreas, and small bowel, is considered the therapy of choice for end-stage organ failure. Each year, over 70,000 organs are implanted worldwide. One donor may provide multiple organs, as well as corneas and other tissues, for multiple recipients. The degree of risk for transmission of infection carried with grafts, notably of viruses, is largely unknown and, for a specific organ, difficult to assess. The approach to microbiological screening of organ donors varies with national and regional regulations and with the availability and performance of microbiological assays used for potential donors. Transmission of both expected or common, and unexpected infections has been observed in organ transplants, generally recognized after development of clusters of infections among recipients of organs from a common donor. Other than for unusual or catastrophic events, few data exist that define the incidence and manifestations of donor-derived infections or the ideal assays to use in screening to prevent such transmissions. Absolute prevention of the transmission of donor-derived infections in organ transplantation is not possible. However, improvements in screening technologies will enhance the safety of transplantation in the future.

Rabies in Europe: what are the risks?

Rabies remains a serious endemic disease in animal populations in many European countries. Oral vaccination by use of rabies vaccine baits has proved to be durably efficient for controlling and eliminating terrestrial rabies. However, the recurrence of rabies in some countries highlights the fragility of rabies-free country status and the need for continuous surveillance. In Eastern and Southern countries, the rabies control programmes for foxes should be accompanied by stray dog management measures in view of the high populations of strays in certain areas. Alerts of rabies in pets imported from enzootic countries are regularly reported in Europe, threatening the rabies-free status of terrestrial animals. New variants of rabies virus have been recently discovered in autochthonous bats, implying research studies to assess the efficacy of the current vaccines against those strains and the possible crossing of the species barrier in terrestrial mammals. The incidence of the disease in humans is very low, with cases contracted in Europe or in enzootic countries. Sustainable strategies of vaccination programmes in animals and improvement of public awareness, particularly for travelers, regarding rabies risks and legislation for pet movements would render accessible the elimination of rabies in Europe.

A large-scale, rapid public health response to rabies in an organ recipient and the previously undiagnosed organ donor

This article describes and contrasts the public health response to two human rabies cases: one organ recipient diagnosed within days of symptom onset and the transplant donor who was diagnosed 18 months post-symptom onset. In response to an organ-transplant-related rabies case diagnosed in 2013, organ donor and recipient investigations were conducted by multiple public health agencies. Persons with potential exposure to infectious patient materials were assessed for rabies virus exposure. An exposure investigation was conducted to determine the source of the organ donor's infection. Over 100 persons from more than 20 agencies spent over 2700 h conducting contact investigations in healthcare, military and community settings. The 564 persons assessed include 417 healthcare workers [5.8% recommended for post-exposure prophylaxis (PEP)], 96 community contacts (15.6% recommended for PEP), 30 autopsy personnel (50% recommended for PEP), and 21 other persons (4.8% recommended for PEP). Donor contacts represented 188 assessed with 20.2% recommended for PEP, compared with 5.6% of 306 recipient contacts recommended for PEP. Human rabies cases result in substantial use of public health and medical resources, especially when diagnosis is delayed. Although rare, clinicians should consider rabies in cases of encephalitis of unexplained aetiology, particularly for cases that may result in organ donation.

Review of human rabies prophylaxis and treatment

Rabies is a devastating encephalitis caused by RNA viruses that use mammals as reservoirs. In the United States, most naturally acquired human cases have come from bats. The use of appropriate preexposure and postexposure prophylaxis can be nearly 100% effective. If prophylaxis is not used, or is implemented incorrectly, the patient may develop clinical rabies, which is almost universally fatal. All health care practitioners should be familiar with the appropriate evaluation of patients presenting with a possible rabies exposure and ensure that expeditious and appropriate prophylaxis is provided to help prevent the development of this lethal disease.

Involvement of extraneural tissues and upregulation of inducible nitric oxide synthase after experimental infection with rabies virus in BALB/c mice and LEW/SsN rats

Rabies virus can cause fatal encephalomyelitis, but the involvement of extraneural organs has not been well characterized. In this study, we investigated the histopathological changes and the distribution of viral antigens in extraneural organs after pathogenic rabies virus infection in mouse and rat models. In histopathological examination, classical viral encephalitis and rabies-specific Negri body were observed in the brain. In addition to the central nervous system (CNS), inflammatory responses were found in other organs, such as the heart, kidney, liver, and lung. Similarly, immunohistochemical staining and reverse transcription-polymerase chain reaction revealed the presence of rabies virus in the CNS and extraneural tissues. Moreover, macrophages, especially in the lung and heart, were involved in the infection. Transcriptional analyses of the expression of inducible nitric oxide synthase (iNOS) demonstrated that rabies virus potentiated the gene expression of iNOS in the brain, lung, and heart. The immunoreactive iNOS-positive macrophages were detected adjacent to the infection. These results suggest that macrophages are involved in the extraneural infection and the expression of iNOS in macrophages contributes to the formation of tissue inflammation. Our study indicates the involvement of extraneural organs following rabies virus infection, which may aggravate the progression of this deadly disease.

Infectivity of rabies virus-exposed macrophages

Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays.

Rabies: relevance, prevention, and management in travel medicine

Rabies is a zoonotic viral disease, transmitted only in mammals. Terrestrial rabies, predominantly transmitted by dogs, is the most important rabies cycle threatening humans. The causative neurotropic virus is a negative-stranded RNA virus of the family Rhabdoviridae, genus Lyssavirus. This genus contains several rabies-related viruses. All variants are known or suspected to cause rabieslike diseases. Transmission occurs by the virus entering through the skin or the mucosa after bites, scratches, or preexisting injuries contaminated by the saliva of an infected mammal. Only 51 human rabies cases that have not been transmitted by animal bites are described.

Outcomes of transplantation using organs from a donor infected with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae

Transmission of pathogens from donor to recipient is a potential complication of organ transplantation. Herein, we describe the clinical course and outcomes of 4 transplant recipients who received tissues from a donor with multi-organ infection with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae. Recipient 1 underwent simultaneous liver and kidney transplantation for alpha-1 antitrypsin deficiency and alcohol-related cirrhosis, and acute tubular necrosis, respectively. Soon after transplantation, he developed an infected hematoma and peritonitis due to KPC-producing K. pneumoniae despite receiving tigecycline prophylaxis. He was treated with a prolonged course of tigecycline, amikacin, and meropenem, in conjunction with surgical evacuation and percutaneous drainage of the infected fluid collections. Recipient 2 underwent living-donor liver transplantation for cholangiocarcinoma and primary sclerosing cholangitis using vein graft from the donor infected with KPC-producing K. pneumoniae. Culture of the preservation fluid containing the vein graft was positive for KPC-producing K. pneumoniae. The patient received preemptive amikacin and tigecycline, and he did not develop any infection (as evidenced by negative surveillance blood cultures). The isolates from the donor and Recipients 1 and 2 were indistinguishable by pulsed-field gel electrophoresis. Recipients 3 and 4 underwent kidney and heart transplantation, respectively; both patients received perioperative tigecycline prophylaxis and did not develop infections due to KPC-producing K. pneumoniae. All transplant recipients had good short-term outcomes. These cases highlight the importance of inter-institutional communication and collaboration to ensure the successful management of recipients of organs from donors infected with multidrug-resistant organisms.

Transplant-associated and blood transfusion-associated tropical and parasitic infections

Blood transfusion and transplantation may represent efficient mechanisms of spreading infectious agents to naive populations. In the developed countries, as a consequence of globalization, several factors such as international commerce, tourism, and immigration have acted as important features for the emergence or reemergence of infectious diseases previously referred to as tropical. This article reviews the relevant bacterial, protozoan and viral infections that are more frequently associated with blood transfusion and/or solid organ or marrow transplantation and may affect susceptible populations worldwide.

[Rabies transmission through organ transplantation]

Classic rabies is a progressive and lethal infectious disease of animals, which may be transmitted to humans. Inter-human infections are extremely rare. The present case describes transmittal of rabies virus by lung transplantation from an infected donor. Histologically, a lymphocytic encephalomyelitis with neuronal cytoplasmic inclusion bodies was found. Immunohistochemically, rabies virus antigen was detected in the central, autonomous and peripheral nervous system. By means of electron microscopy, virions were demonstrated in the brain. A central task of health care in transplantations is the detection of uncommon infectious agents and the prevention of their transmittal.

Rabies in Asia: the classical zoonosis

Rabies remains a constant threat to humans throughout much of Asia. The dog is the main reservoir and vector with wildlife playing a very minor role. No Asian country or region has been declared rabies free by WHO in over two decades and there is evidence of canine rabies spread to new regions during the past 10 years. We now have the knowledge and technology to control canine rabies. The main barrier in managing this costly endemic is lack of motivation by authorities to address this issue along with regional inability of public health and livestock (agriculture) officials to tackle this issue in cooperation and coordination. Rabies is one of the first recognized zoonoses and a model for a true "One Health" management goal where human; veterinary, and government officials must work together in harmony to defeat this disease.

Tissue donation and virus safety: more nucleic acid amplification testing is needed

In tissue and organ transplantation, it is of great importance to avoid the transmission of blood-borne viruses to the recipient. While serologic testing for anti-human immunodeficiency virus (HIV)-1 and -2, anti-hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), and Treponema pallidum infection is mandatory, there is until now in most countries no explicit demand for nucleic acid amplification testing (NAT) to detect HIV, hepatitis B virus (HBV), and HCV infection. After a review of reports in the literature on viral transmission events, tissue-specific issues, and manufacturing and inactivation procedures, we evaluated the significance of HIV, HCV, and HBV detection using NAT  in  donors of various types of tissues and compared our results with the experiences of blood banking organizations. There is a significant risk of HIV, HCV, and HBV transmission by musculoskeletal tissues because of their high blood content and the high donor-recipient ratio. If no effective virus inactivation procedure for musculoskeletal tissue is applied, donors should be screened using NAT  for  HIV, HCV, and HBV. Serologically screened cardiovascular tissue carries a very low risk of HIV, HCV, or HBV transmission. Nevertheless, because effective virus inactivation is impossible (retention of tissue morphology) and the donor-recipient ratio may be as high as 1:10, we concluded that NAT  should be performed for HIV, HCV, and HBV as an additional safety measure. Although cornea allografts carry the lowest risk of transmitting HIV, HCV, and HBV  owing to corneal physiology, morphology, and the epidemiology of corneal diseases, NAT  for  HCV should still be performed. If the NAT  screening of a donor for HIV, HCV, and HBV is negative, quarantine storage of the donor tissue seems dispensable. In view of numerous synergistic effects with transfusion medicine, it would be advantageous for tissue banks to cooperate with blood bank laboratories in performing virological tests.

Postexposure prophylaxis for rabies in resource-limited/poor countries

Human rabies is essentially a fatal disease once clinical signs develop. Rabies postexposure prophylaxis (PEP) consists of thorough wound care in combination with administration of rabies immunoglobulin and rabies vaccine. This is highly effective in rabies prevention if carried out diligently. Preexposure rabies prophylaxis simplifies PEP in the event of an exposure by eliminating the need for immunoglobulin. Shortened and more convenient and economical PEP regimens are being developed with promising results. They reduce the cost of PEP as well as travel expenses for the often very poor patients. The intradermal PEP regimen can now reduce the vaccine cost by ~60-70%. Although PEP in humans can prevent death, controlling the canine vector by sustained vaccination remains the mainstay of rabies elimination.

Rabies research in resource-poor countries

Many cost-benefit/effective rabies research projects need to be carried out in less-developed canine-endemic regions. Among these are educational approaches directed at the public and governments. They would address effective primary wound care, availability, and proper use of vaccines and immunoglobulins, better reporting of rabies, final elimination of dangerous nerve tissue-derived vaccines, and the recognition that rabies is still expanding its geographic range. Such efforts could also reduce deaths in victims who had received no or less than adequate postexposure prophylaxis. There is a need for new technology in canine population control and sustainable vaccination. We have virtually no workable plans on how to control bat rabies, particularly that from hematophagous bats. Preexposure vaccination of villagers in vampire rabies-endemic regions may be one temporary solution. Current efforts to reduce further the time required and vaccine dose required for effective postexposure vaccination need to be encouraged. We still have incomplete understanding of the transport channels from inoculation site to rabies virus antibody generating cells. The minimum antigen dose required to achieve a consistently protective and lasting immune response has been established for intramuscular vaccine administration, but is only estimated for intradermal use. Greater knowledge may have clinical benefits, particularly in the application of intradermal reduced dose vaccination methods. Curing human rabies is still an unattained goal that challenges new innovative researchers.

Ante- and post-mortem diagnosis of rabies using nucleic acid-amplification tests

Sensitivity, specificity and short turn-around time nucleic acid-amplification tests (NATs) have been steadily improving. NATs have been employed in the diagnosis of rabies to distinct different strains, as well as to identify new lyssaviruses. NATs have advantages over traditional methods, such as the direct fluorescence antibody test. They can be applied to fluid samples and brain tissue that is substantially decomposed. NATs can be used as an alternative method for confirmation or exclusion of the diagnosis in a suspected rabies patient. Real-time PCR methods are more favored than conventional reverse-transcription PCR methods by several laboratories. Second-round PCR, either nested or heminested, has been used for ante-mortem diagnosis to detect low levels of RNA. This review the details obstacles in making a diagnosis, how to properly utilize NATs (sample preparation, nucleic amplification techniques, amplification targets and primer design); and interprets the results obtained in recent studies.

Recombinant diabody-based immunocapture enzyme-linked immunosorbent assay for quantification of rabies virus glycoprotein

The potency of rabies vaccines, determined using the NIH mouse protection test, can be directly correlated to the amount of rabies virus glycoprotein (RV GP) present in the vaccine. In an effort to develop a simple and sensitive enzyme-linked immunosorbent assay (ELISA) using recombinant diabody for quantification of RV GP, the variable heavy (V(H)) and light chain (V(L)) domains of an RV GP-specific human monoclonal antibody (MAb) secreted by a human x mouse heterohybridoma (human MAb R16E5) was amplified, linked using splicing by overlap extension PCR (SOE PCR), and expressed as a recombinant diabody (D06) in the pET28a bacterial expression system. The diabody D06 was purified by immobilized metal affinity chromatography on a nickel-nitrilotriacetic acid (NTA) agarose column and characterized. The purified diabody was used in combination with a well-characterized RV GP-specific mouse MAb, M5B4, to develop an immunocapture ELISA (IC-ELISA) for the quantification of RV GP in human rabies vaccine preparations. The maximum detection limit of the IC-ELISA using the M5B4-D06 combination was up to 31.25 ng/ml of RV GP. The specificity of the diabody was established by its nonreactivity toward other human viral antigens as determined by ELISA and toward RV GP as determined by immunoblot transfer assay and competitive ELISA with the parent human MAb R16E5 and MAb M5B4. The adjusted r(2) value obtained by the regression through the origin model was 0.902, and the equation for predicted potency values for M5B4-D06-based IC-ELISA and MAb M5B4 IC-ELISA were 0.5651x and 0.8044x, respectively, where x is the estimate of RV GP from the IC-ELISA in micrograms. Analysis of variance (ANOVA) results showed the estimates of the two methods differed significantly (P < 0.001), while the predicted potencies by the two tests did not differ significantly (P > 0.05). The IC-ELISA can be readily adapted to measure the RV GP content in purified antigen, and a vaccine can be formulated based on the estimated GP.

Rabies postexposure management of travelers presenting to travel health clinics in Auckland and Hamilton, New Zealand

BACKGROUND

Rabies is a fatal disease, and travelers going to endemic areas need to take precautions. Little is known about the rabies postexposure management of travelers from New Zealand.

METHODS

A total of 459 post-travel records from October 1998 until February 2006 at two travel medicine clinics, in Auckland and Hamilton, were examined for those who reported postexposure management to animals while abroad.

RESULTS

Fifty-four patients were included, 48 (88.9%) were New Zealand residents and 52.0% were male. The mean age of exposed travelers was 30.4 years (SD = 15.5). There was an adult to child ratio of 5:1. The highest exposure risk group was those aged 16 to 30 years. South and Southeast Asia were the most prominent geographical regions where exposure occurred, with 45 (83.3%) of subjects being potentially exposed to rabies. Dogs were the commonest animals involved, accounting for two thirds of incidents (36; 66.7%). The commonest sites of animal exposure on the body were the thigh and lower leg (26; 48.1%) and the hand (10; 18.5%). Forty-six (85.2%) of the animal exposures were graded as World Health Organization (WHO) category III. Forty-nine (90.7%) of the travelers had not had preexposure prophylaxis. Once in New Zealand, the correct WHO postexposure prophylaxis regime was applied on 44 of 52 (84.6%) occasions. However, overall, only 25% of the sample received postexposure treatment consistent with WHO guidelines, reflecting inappropriate management abroad.

CONCLUSIONS

Post-travel consultations at two New Zealand travel clinics were analyzed for prophylactic rabies postexposure management. The majority were travelers aged 16 to 30 years, who sustained WHO category III exposures to the lower limb in Asia, predominantly from dogs. Few of these travelers had been immunized prior to travel, and only 25% of them received postexposure prophylaxis consistent with WHO guidelines. Thus, 75% of the study sample remains at theoretical risk of contracting rabies due to inappropriate management overseas.

The first imported case of rabies into Japan in 36 years: a forgotten life-threatening disease

A domestic case of rabies has not been reported in Japan since 1957. The last case of rabies reported in Japan was an imported case from Nepal in 1970. We recently experienced a new case imported from the Philippines, the first case in Japan in 36 years. Although Japanese people are about to forget the dangers of rabies, this case should serve as a warning to those Japanese who are planning a trip abroad.

Rabies: epidemiology, pathogenesis, and prophylaxis

Rabies is a viral zoonosis that causes approximately 50,000 to 100,000 deaths per year worldwide. Most deaths occur in developing countries. Dogs are the major vector, especially in developing countries. The virus is usually transmitted to humans by infected saliva through the bite of a rabid animal; the incubation period averages 30 to 90 d. Hyperexcitability, autonomic dysfunction, hydrophobia, and aerophobia are characteristic of encephalitic rabies, which accounts for 80% of cases. The paralytic form is characterized by flaccid paralysis in the bitten limb, which ascends symmetrically or asymmetrically. Once symptoms develop, the disease is invariably fatal. Animal rabies can be controlled by proper induction of herd immunity, humane removal of stray animals, promotion of responsible pet ownership through education, and enactment of leash laws. Preexposure vaccination with modern cell culture vaccine is recommended for people at high risk of exposure to rabies and for travelers who spend longer than 1 mo in countries where rabies is a constant threat, or who travel in a country where immediate access to appropriate care is limited. Postexposure prophylaxis consists of prompt and thorough wound cleansing and immunization with modern cell culture vaccine, together with administration of rabies immune globulin to those individuals who have not previously received preexposure prophylaxis.