Are we getting closer to the treatment of rabies?

Survival in human rabies but left against medical advice and death followed – Community education is the need of the hour

Human survival after developing rabies is very scary to humanity. We report a case of a 58-year-old woman from Uttar Pradesh (north India), who presented with 5-days of fever and 1-day of altered sensorium associated with agitation, hydrophobia, and bedwetting after 20 days of WHO category 3 bite in the face by a rabid dog. She had taken three doses of anti-rabies vaccinations but not immunoglobulin of postexposure prophylaxis. Laboratory investigation showed a rising titer of virus-neutralizing antibodies in both serum and cerebrospinal fluid (CSF). We treated the patient according to the modified Milwaukee protocol. The patient remained to survive and had a recovery trend during hospital stays of 15 days before relatives took her left against medical advice (LAMA). As we know rabies has approximately 100% mortality rate but by using the aggressive treatment approach (like Milwaukee protocol), the patient may survive. Rabies can be effectively prevented by using adequate postexposure vaccine prophylaxis and rabies immunoglobulin (in category-3) after bite of a rabid animal. Our report along with other published reports should give more motivation to clinicians and education to the public to have an intensive treatment approach and patience, respectively to make rabies survival.

[Сases of human convalescence from rabies and lifetime diagnostics of lyssavirus encephalitis.]

Notwithstanding the availability of effective vaccines, 40 - 60 thousand rabies cases in humans are reported every year. Almost always the disease is fatal because therapeutic treatment of lyssavirus encephalitis has not been developed. Since 1970 the number of reports on rare cases of convalescence including those using experimental treatment protocols has been gradually increasing 20 cases of convalescence, "partial" convalescence or long-term survival of humans (1970-2015) were selected as they were complaint with laboratory criteria of active lyssavirus infection. Children and teenagers were predominant in the analyzed group (85%). The cases were irregularly spread between the continents: Asia - 6 cases, North America - 6 cases, Africa - 2 cases and Europe - 1 case. India and the USA were on the top of the list of countries by the number of described cases. More than 60% humans were infected from dogs, three cases got infection from bats and 2 cases were allegedly associated with an unknown lyssavirus and an unidentified infection source. 70% cases were vaccinated and 10% cases were treated with gamma globulin before the disease onset. Serological tests for detection of antibodies to lyssaviruses in cerebrospinal fluid of infected humans were typically used for diagnostic laboratory verification. Less than 30% IFA and PCR positives were obtained. Lyssaviruses were never detected. Only 4 convalescent patients were treated using experimental protocols. 80% cases demonstrated severe neurological consequences, four (may be more) patients died afterwards within the period from two months to four years. Different perspectives on prospects of Milwaukee protocol use and other therapeutic techniques are given.

[Epizootic characteristics of rabies and rabies assistance in the territory of the Kirov region in the years 2010-2018.]

INTRODUCTION

One of the negative consequences of an increase in the incidence of animal rabies is the increased risk of human infection.

OBJECTIVES

study of the main manifestations of rabies epizootic and the status of anti-rabies care in the Kirov region in 2010-2018.

MATERIAL AND METHODS

Reporting forms of monitoring the situation of rabies FBHI "Center for Hygiene and Epidemiology in the Kirov Region" for 2010-2018 were statistically processed and studied.

RESULTS

Since 2014, increase in the incidence of rabies among animals and expansion of the boundaries of the range have been revealed. Rabies is recorded among foxes (67%), raccoon dogs (up to 40%), domestic and farm animals. Every year in Kirov region over 4 thousand people get injured from animals: dogs (76%) and cats (20%). Damage is often localized on the lower extremities (34%) and was the most dangerous on the head, neck, face, hands (29%). In average of 3,500 victims are sent to immunization.

DISCUSSION

An inverse correlation dependence between preventive oral immunization of wild animals and contacts of people with rabid animals was revealed. A high percentage of refusals from vaccination (up to 31%) is associated with low sanitary literacy of the population.

CONCLUSION

The problem of rabies is relevant for the Kirov region. An increase of the proportion of infected domestic and farm animals leads to an increase the risk of human disease. In order to stabilize rabies epizootic, it is necessary to carry out the whole complex of prophylactic measures.

The rabies early death phenomenon: A report of ineffective administration of rabies vaccine during symptomatic disease

It was reported that in some individuals who received postexposure rabies vaccine, clinical features of rabies developed at the shorter time compared to individuals who were exposed, but not received the vaccine, which called “early death” phenomenon. We reported an early death phenomenon in a 67-year-old woman who was bitten by a jackal, although receiving three dose of rabies vaccine. Results show that the immune response to rabies has a dual role, sometimes has a favorable effect on survival but sometimes amplification the disease.

Antiviral therapy for human rabies

Human rabies is virtually always fatal despite numerous attempts at aggressive therapy. Most survivors received one or more doses of rabies vaccine prior to the onset of the disease. The Milwaukee Protocol has proved to be ineffective for rabies and should no longer be used. New approaches are needed and an improved understanding of basic mechanisms responsible for the clinical disease in rabies may prove to be useful for the development of novel therapeutic approaches. Antiviral therapy is thought to be an important component of combination therapy for the management of human rabies, and immunotherapy and neuroprotective therapy should also be strongly considered. There are many important issues for consideration regarding drug delivery to the central nervous system in rabies, which are in part related to the presence of the blood-brain barrier and also the blood-spinal cord barrier. Ribavirin and interferon-α have proved to be disappointing agents for the therapy of rabies. There is insufficient evidence to support the continued use of ketamine or amantadine for the therapy of rabies. Minocycline or corticosteroids should not be used because of concerns about aggravating the disease. A variety of new antiviral agents are under development and evaluation, including favipiravir, RNA interference (for example, small interfering [si]RNAs) and novel targeted approaches, including interference with viral capsid assembly and viral egress.

Current and future approaches to the therapy of human rabies

Human rabies has traditionally been considered a uniformly fatal disease. However, recent decades have seen several instances in which individuals have developed clinical signs of rabies, but survived, usually with permanent neurologic sequelae. Most of these patients had received prophylactic rabies vaccine before the onset of illness. The best outcomes have been seen in patients infected with bat viruses, which appear to be less virulent for humans than strains associated with other rabies vectors. In 2003, an article by rabies experts suggested that survival might be improved through a combination of vaccine, anti-rabies immunoglobulin, antiviral drugs and the anesthetic ketamine, which had shown benefit in an animal model. One year later, a girl in Milwaukee who developed rabies after bat exposure was treated with some of these measures, plus a drug-induced (therapeutic) coma, and survived her illness with mild neurologic sequelae. Although the positive outcome in this case has been attributed to the treatment regimen, it more likely reflects the patient's own brisk immune response, as anti-rabies virus antibodies were detected at the time of hospital admission, even though she had not been vaccinated. This conclusion is supported by the failure of the "Milwaukee Protocol" to prevent death in numerous subsequent cases. Use of this protocol should therefore be discontinued. Future research should focus on the use of animal models to improve understanding of the pathogenesis of rabies and for the development of new therapeutic approaches.

Therapy of human rabies

Preventive therapy for rabies, including wound cleansing and active and passive immunization after a recognized exposure, is highly efficacious. Unfortunately, there is no established therapy that is effective for patients who develop rabies encephalomyelitis. There have been several survivors from rabies and all but one received rabies vaccine prior to the onset of clinical illness. Aggressive approaches to therapy of human rabies may be appropriate in certain situations. There is no scientific rationale for the use of therapeutic coma, and there are many reports of failures using this approach. Therapeutic coma should be abandoned for the therapy of rabies. New approaches such as therapeutic hypothermia should be evaluated, in combination with other therapeutic agents. More basic research is needed on the mechanisms involved in rabies pathogenesis, which will hopefully facilitate the development of new therapeutic approaches in the future for this ancient disease.