Failures of post-exposure rabies prophylaxis

A phase 2b, Randomized, double blinded comparison of the safety and efficacy of the monoclonal antibody mixture SYN023 and human rabies immune globulin in patients exposed to rabies

BACKGROUND

SYN023 is an anti-rabies monoclonal antibody mixture administered as part of post-exposure prophylaxis regimens. The rabies virus neutralizing antibody (RVNA) concentration generally accepted as an adequate immune response to vaccination is ≥ 0.5 IU/mL.

METHODS

Within 54 h of potential rabies exposure, 448 patients in two risk substrata of WHO Category III exposure were randomized to receive either 0.3 mg/kg SYN023 or 0.133 mL/kg human rabies immunoglobulin (HRIG) injected in and around the wound site(s) plus a course of rabies vaccination. Patients were followed for safety and absence of rabies for ≥ 365 days.

RESULTS

GMT RVNA was higher with SYN023 throughout the 2-week post-treatment period. In the primary analysis group (n = 368), 99.4 % of SYN023 recipients versus 4.5 % of HRIG recipients had protective RVNA levels on Day 4. On Day 8, 98.1 % SYN023 versus 12.2 % HRIG recipients were protected. The SYN023:HRIG ratio of geometric mean titer of RVNA (RVNA GMTs) on Day 8 (19.42) exceeded the 10 % superiority margin (P < 0.0001) indicating higher Day 8 RVNA with SYN023. On Day 99, the SYN023:HRIG RVNA GMT ratio (0.66) was below the non-inferiority margin of 20 % (P = 0.9485) suggesting some moderation of vaccine immune response by SYN023 relative to HRIG. The ratio of percent SYN023:HRIG recipients achieving RVNA ≥ 0.5 IU/mL on Day 99 (0.98) met the non-inferiority margin of 20 % (P = 0.013) indicating anti-rabies immune response with SYN023 was non-inferior to HRIG despite this effect. There were no probable/confirmed rabies cases in any patient. Study regimens were well tolerated.

CONCLUSIONS

SYN023 provided higher RVNA than HRIG soon after rabies exposure. By Day 99 post-treatment, GM RVNA with SYN023 was lower than HRIG, however, the percent of SYN023 recipients with a protective response was not inferior at this time point. No rabies cases were reported in the study. The SYN023 safety profile was acceptable.

CLINICALTRIALS

gov ID: NCT03961555.

Safety and immunogenicity of three dose levels of an investigational, highly purified Vero cell rabies vaccine: A randomized, controlled, observer-blinded, Phase II study with a simulated post-exposure regimen in healthy adults

A serum-free, highly purified rabies vaccine produced in Vero cells is under development. The initial formulation, PVRV-NG, was evaluated in five Phase II studies and subsequently reformulated (PVRV-NG2). This multicenter, observer-blinded Phase II study investigated the safety and immune response of three different doses (antigen content) of PVRV-NG2 versus a licensed human diploid cell rabies vaccine (HDCV; Imovax rabies®). Healthy adults (N = 320) were randomized to receive PVRV-NG2 (low, medium, or high dose), PVRV-NG, or HDCV (2:2:2:1:1 ratio), according to a five-dose Essen simulated post-exposure regimen (Days [D] 0, 3, 7, 14, and 28). All participants received human rabies immunoglobulin intramuscularly on D0. Immunogenicity was assessed at D0, 14, 28, 42, and 6 months after the final injection using the rapid fluorescent focus inhibition test. Seroconversion rates were calculated as the percentage of participants achieving rabies virus neutralizing antibody titers ≥0.5 IU/mL. All analyses were descriptive. At each timepoint, geometric mean titers (GMTs) increased with antigen content (measured using an enzyme-linked immunosorbent assay). High-dose PVRV-NG2 GMTs were the highest at all timepoints, medium-dose PVRV-NG2 GMTs were similar to those with HDCV, and low-dose PVRV-NG2 GMTs were similar to PVRV-NG. The safety profile of PVRV-NG2 was comparable to PVRV-NG; however, fewer injection site reactions were reported with PVRV-NG2 or PVRV-NG (range 36.7-47.5%) than with HDCV (61.5%). This study demonstrated a dose-effect of antigen content at all timepoints. As post-exposure prophylaxis, the safety and immunogenicity profiles of the high-dose PVRV-NG2 group compared favorably with HDCV. Clinicaltrials.gov number: NCT03145766.

Evaluating the benefit of serology during potential Australian bat lyssavirus and rabies post-exposure prophylaxis

Post-exposure prophylaxis (PEP) for potential lyssavirus exposures consists of wound management, rabies vaccination and may include rabies immunoglobulin (RIG). Rabies serology is sometimes indicated if there is risk of PEP failure.

OBJECTIVES

Evaluate the benefit of serology by indication.

METHODS

Chart review of potential lyssavirus exposures managed at a Public Health Unit (June 2015 - December 2022) where serology was requested was conducted. The proportion of non-therapeutic titres was compared by sex, age, Indigenous status, serology indication, and whether RIG was given.

RESULTS

46 notifications with serology were included. Males (5/19) and people over 40 (3/16) were more likely to demonstrate a non-therapeutic response. 2/3 of cases where vaccine doses were not given in the deltoid were non-therapeutic. The rate of non-therapeutic titres was similar for RIG given into the ipsilateral arm (2/11) and given excess RIG for weight (1/4). Although this small sample was inconclusive in isolation, it was also noted that all cases who did not receive RIG had therapeutic serology, whereas 6/35 of those receiving RIG had non-therapeutic serology.

CONCLUSIONS

This study supports broader literature questioning the utility of systemic RIG administration as likely limited and potentially detrimental considering the increased risk of immune interference.

IMPLICATIONS FOR PUBLIC HEALTH

Highlights a need to review Australian national guidelines to align with World Health Organization advice recommending local RIG administration only.

Rabies postexposure prophylaxis: What the U.S. emergency medicine provider needs to know

Approximately 55,000 patients per year in the United States are exposed to potentially rabid animals and receive rabies postexposure prophylaxis (PEP) and these patients commonly present to the emergency department (ED) for wound care and PEP. Despite the number of rabies exposures seen in EDs each year, there appears to be a knowledge gap among health care providers with regard to prescribing and administering rabies PEP. The following review aims to bridge that knowledge gap by discussing the importance of obtaining a comprehensive exposure history to determine the category of the encounter, the type of animal, and the location of the bite and of consulting outside expert resources to determine whether the rabies PEP series is indicated. In addition, this article will discuss dosing, administration, and schedule of the rabies vaccine and human rabies immune globulin to ensure patients are fully protected from developing rabies. Lastly, this article discusses the potential cost associated with rabies PEP and provides information on managing this barrier.

Fatal Human Rabies Infection With Suspected Host-Mediated Failure of Post-Exposure Prophylaxis Following a Recognized Zoonotic Exposure-Minnesota, 2021

BACKGROUND

No human rabies post-exposure prophylaxis (PEP) failure has been documented in the United States using modern cell culture-based vaccines. In January 2021, an 84-year-old male died from rabies 6 months after being bitten by a rabid bat despite receiving timely rabies PEP. We investigated the cause of breakthrough infection.

METHODS

We reviewed medical records, laboratory results, and autopsy findings and performed whole-genome sequencing (WGS) to compare patient and bat virus sequences. Storage, administration, and integrity of PEP biologics administered to the patient were assessed; samples from leftover rabies immunoglobulin were evaluated for potency. We conducted risk assessments for persons potentially exposed to the bat and for close patient contacts.

RESULTS

Rabies virus antibodies present in serum and cerebrospinal fluid were nonneutralizing. Antemortem blood testing revealed that the patient had unrecognized monoclonal gammopathy of unknown significance. Autopsy findings showed rabies meningoencephalitis and metastatic prostatic adenocarcinoma. Rabies virus sequences from the patient and the offending bat were identical by WGS. No deviations were identified in potency, quality control, administration, or storage of administered PEP. Of 332 persons assessed for potential rabies exposure to the case patient, 3 (0.9%) warranted PEP.

CONCLUSIONS

This is the first reported failure of rabies PEP in the Western Hemisphere using a cell culture-based vaccine. Host-mediated primary vaccine failure attributed to previously unrecognized impaired immunity is the most likely explanation for this breakthrough infection. Clinicians should consider measuring rabies neutralizing antibody titers after completion of PEP if there is any suspicion for immunocompromise.

Comparative Neutralization Activity of Commercial Rabies Immunoglobulin against Diverse Lyssaviruses

Novel lyssaviruses, the causative agents of rabies, continue to be described mostly due to increased surveillance in bat hosts. Biologicals for the prevention of rabies in humans have, however, remained largely unchanged for decades. This study aimed to determine if commercial rabies immunoglobulin (RIG) could neutralize diverse lyssaviruses. Two commercial preparations, of human or equine origin, were evaluated against a panel consisting of 13 lyssavirus species. Reduced neutralization was observed for the majority of lyssaviruses compared to rabies virus and was more evident for lyssaviruses outside of phylogroup I. Neutralization of more diverse lyssaviruses only occurred at very high doses, except for Ikoma lyssavirus, which could not be neutralized by the RIG evaluated in this study. The use of RIG is a crucial component of rabies post-exposure prophylaxis and the data generated here indicate that RIG, in its current form, will not protect against all lyssaviruses. In addition, higher doses of RIG may be required for neutralization as the genetic distance from vaccine strains increases. Given the limitations of current RIG preparations, alternative passive immunization options should be investigated.

The final stages of dog rabies elimination from Japan

Rabies is a lethal zoonotic disease mainly transmitted to humans by dog bites. The purpose of this study was to assess the efficacy of rabies control policies in Japan, which resulted in the elimination of the disease from the country in 1957. Using historical records from the Kanto region (Chiba, Kanagawa, Saitama and Tokyo Prefectures) between 1947 and 1956 where the final canine cases were recorded, we undertook a descriptive epidemiological study, applying spatio-temporal scan statistics using SaTScan and estimating the effective reproduction number (R_t ) for the clusters and each prefecture using the growth rates. There were 1,567 dog rabies and 161 human rabies cases recorded during this period. Vaccination coverage in registered dogs was over 70% after 1951, with much lower coverage in free-roaming and unregistered dogs. Eight clusters of dog rabies cases were identified: the first appeared in 1947 in Tokyo and was linked to three further clusters in peripheral prefectures between 1947 and 1951. Three more clusters occurred in Tokyo again between 1952 and 1954, and the last cluster was in Tokyo and Kanagawa between 1955 and 1956. R_t in the first cluster was 1.68, and R_t values in the others ranged between 1.18 and 1.86, with an exception of 4.05 in the smallest cluster in Tokyo in 1952 (10 cases). The moving average of R_t coincided with the clusters. As dog vaccination and dog management progressed, and the number of dog rabies cases declined, the moving average of R_t declined to below 1. Delays in the implementation of dog management policies in Kanagawa may have prolonged this last outbreak. These results demonstrate the effectiveness of coordinated control policy involving dog vaccination and management of free-roaming dog populations for rabies elimination.

Delays in initiating rabies post-exposure prophylaxis among dog bite victims in Wakiso and Kampala districts, Uganda

Background   Although rabies in dog bite patients is preventable through timely initiation of post-exposure prophylaxis (PEP), a number of barriers to achieving PEP exist. This study investigated the delays to initiation of PEP among dog bite patients in the emergency departments of two PEP centers in Uganda. Methods A cross-sectional study was conducted among dog-bite patients that presented to two selected rabies PEP centers. A semi-structured questionnaire was used to collect data. Delay to receive PEP was defined as reporting for PEP beyond 24 hours after the bite event. Generalized linear models were used to calculate prevalence ratios and the 95% confidence intervals as a measure of association between delay and patient factors. Results Out of 376 participants, just over half (53.5%) were males. The majority of participants (54.0%) were 15 years or older and 28.5% had no formal education. Just over three-quarters (77.9%) had category II dog bite wounds. Nearly 40% delayed to receive PEP, and median (inter quartile range) lag time between bite event and seeking medical care of 18 (41) hours. Compared to education level of secondary or above, patients with no formal education (adj. PR=4.06, 95% CI: 2.69 -  6.10) or primary education (adj.PR=2.15, 95% CI: 1.37 -  3.35), belonging to the lowest socio-economic tertile as compared to the highest (adj.PR=1.58, 95% CI: 1.10 - 2.28), knowing the owner of the biting dog (adj.PR=1.30, 95% CI: 1.02 - 1.65) and having category II wounds (adj.PR=2.31, 95% CI: 1.43 - 3.71) were all associated with delayed presentation for PEP. Conclusions and recommendations Delays to receive PEP are common and are associated with poor level of education or low socio-economic status, knowledge of who the dog owner is and less severity of bite wounds. Seeking care irrespective of wound severity or knowledge of dog owner should be promoted.

Commentary on the implications of safety and efficacy studies in pediatric patients with administration of human rabies immune globulin (HRIG)?

The FDA strongly encourages rigorous safety and efficacy studies in all age groups for which vaccines and treatments for pervasive and severe diseases are intended. Until recently, there had been no safety and efficacy studies conducted in children for human rabies immune globulins. The publication,” Safety, and efficacy of rabies immunoglobulin in pediatric patients with suspected exposure”, Human Vaccines & Immunotherapeutics, 17:7, 2090–2096, was the first study that prospectively reviewed the use of KEDRAB® 150 IU/ml in 30 pediatric patients ages 0.5–14.9 years old. The results showed that 93.3% achieved RVNA titer >/ = 5 IU/ml, on day 14. Also, no participants reported a serious adverse event (SAE), or an adverse event (AE) leading to study discontinuation, and there were no deaths. The most common treatment emergent adverse events (TEAE) were injection-site pain. Currently there are 3 HRIG products on the US market, KEDRAB®, HyperRab® and Imogam® Rabies HT, but only KEDRAB® has published safety and efficacy data in a pediatric population. While it is common practice to prescribe medications for pediatric patients “off-label” there now exists one product with safety data in children. It is worth considering if this creates a higher medical liability for the prescriber and institution

Clinical, epidemiological, and spatial features of human rabies cases in Metro Manila, the Philippines from 2006 to 2015

Rabies remains a public health problem in the Philippines despite the widespread provision of rabies vaccines and rabies immunoglobulin (RIG) as post-exposure prophylaxis (PEP). Detailed descriptions of recent human rabies cases in the Philippines are scarce. This study aimed to describe the clinical, epidemiological, and spatial features of human rabies cases between January 1, 2006, and December 31, 2015. We conducted a retrospective hospital-based case record review of all patients admitted to one referral hospital in Manila who received a clinical diagnosis of rabies. During the 10-year study period there were 575 patients (average 57.5 cases per year, range 57 to 119) with a final diagnosis of rabies. Most patients were male (n = 404, 70.3%) and aged ≥ 20 years (n = 433, 75.3%). Patients mostly came from the National Capital Region (n = 160, 28.0%) and the adjacent Regions III (n = 197, 34.4%) and IV-A (n = 168, 29.4%). Case mapping and heatmaps showed that human rabies cases were continuously observed in similar areas throughout the study period. Most patients had hydrophobia (n = 444, 95.5%) and/or aerophobia (n = 432, 93.3%). The leading causative animals were dogs (n = 421, 96.3%) and cats (n = 16, 3.7%). Among 437 patients with animal exposure history, only 42 (9.6%) had been administered at least one rabies vaccine. Two patients (0.5%), young children bitten on their face, had received and a full course of rabies vaccine. Human rabies patients were continuously admitted to the hospital, with no notable decline over the study period. The geographical area in which human rabies cases commonly occurred also did not change. Few patients received PEP and there were two suspected cases of PEP failure. The retrospective design of this study was a limitation; thus, prospective studies are required.

Rabies remains a public health problem in the Philippines despite improvements in the availability of rabies vaccines and rabies immunoglobulin (RIG) as post-exposure prophylaxis (PEP). The incidence of rabies is highest in Metro Manila and surrounding areas. We reviewed the records of all human rabies patients admitted to the national infectious disease hospital in Manila between 2006 and 2015. This hospital treats most cases in this area. During the 10-year study period, human rabies cases were continuously admitted to the hospital, with no notable decline in numbers by year. Most patients were adult men bitten by domestic dogs. The geographical areas in which cases commonly occurred during the 10-year period also did not change over time. Only 9.6% of patients had received at least one dose of a rabies vaccine as PEP. Although the risk of PEP failure is reported to be almost zero, we identified two suspected cases of PEP failure. The retrospective design of this study was a limitation, and the exact details of PEP were not reliably available. As human rabies death is a significant public health concern, the circumstances of each case should be prospectively investigated. Further research is required to understand how to reduce the number of rabies cases.

Implementation of Clinical Decision Support on Emergency Department Delivery of Human Rabies Immune Globulin

IMPORTANCE

Fatal human rabies infections can be prevented through appropriate rabies postexposure prophylaxis (PEP). Errors in patient selection and administration of human rabies immune globulin in the emergency department (ED) setting were identified in a previous study of rabies PEP administration.

OBJECTIVE

To test the a priori hypothesis that implementation of a rabies PEP bundle in the ED would improve full adherence to 6 human rabies immune globulin quality indicators compared with preimplementation controls.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study was conducted in 15 EDs in a US multihospital health system. Patients who received human rabies immune globulin or rabies vaccine in the ED from January 2015 to June 2018 were included in the preimplementation control group and from December 2019 to November 2020 were included in the postimplementation intervention group. Data were analyzed in January 2021.

EXPOSURE

The PEP bundle was implemented in December 2019 and consisted of electronic health record enhancements, including clinical decision support, ED staff education, and patient education.

MAIN OUTCOMES AND MEASURES

Full adherence to 6 human rabies immune globulin quality indicators: patient selection, dose, timing, infiltration into wounds, administration distant from rabies vaccine site, and administration that avoids the buttock.

RESULTS

The study included 324 patients; 254 patients were in preimplementation group (mean [SD] age, 39 [21] years; 135 [53%] women) and 70 in the postimplementation group (mean [SD] age, 38 [19] years; 33 [47%] women). Most patients presented to EDs embedded in a community hospital (231 patients [71%]). Full adherence increased from 37% in the preimplementation group to 61% postimplementation (absolute increase, 24%; 95% CI, 11% to 37%; P < .001). Adherence improved for quality indicators for infiltration into wounds (137 of 254 patients [54%] to 50 of 70 patients [71%]; P = .009), administration distant from rabies vaccine site (180 of 254 [71%] to 58 of 70 [83%]; P = .04), and administration that avoids the buttock (168 of 254 [66%] to 58 of 70 [83%]; P = .007). No instances of sciatic nerve injury or compartment syndrome were observed.

CONCLUSIONS AND RELEVANCE

In this quality improvement study, implementation of a rabies PEP bundle was associated with improved patient selection and delivery of human rabies immune globulin in EDs across a multihospital health system. Although the bundle included ED staff education and patient discharge education, the observed improvement was likely driven by clinical decision support from the rabies PEP ED order set. Future research should evaluate implementation of this clinical decision support at other health systems.

Time to Revise the WHO Categories for Severe Rabies Virus Exposures–Category IV?

Rabies is a devastating disease and affects millions of people globally, yet it is preventable with appropriate and timely postexposure prophylaxis (PEP). The current WHO exposure categories (Categories I, II, and III) need revision, with a special Category IV for severe exposures. Rare cases of PEP failure have occurred in severe bites to the head and neck. Multiple factors, including route, wound severity, depth, contamination, viral dose, proximity to highly innervated areas and the CNS, and the number of lesions, remain unconsidered. Injuries in areas of high neural density are the most significant considering lyssavirus pathophysiology. Current recommendations do not account for these factors. A Category IV designation would acknowledge the severity and the increased risk of progression. Subsequently, patient management would be optimized with wound care and the appropriate administration of rabies-immune globulin/monoclonal antibodies (RIG/MAbs). All Category IV exposures would be infiltrated with the full dose of intact RIG (i.e., human RIG or MAbs) if the patient was previously unvaccinated. More concentrated RIG/MAb formulations would be preferred. As a world rabies community, we cannot tolerate PEP failures. A fourth WHO categorization will improve the care of these high-risk patients and highlight the global health urgency of this neglected disease.

A One Medicine Mission for an Effective Rabies Therapy

Despite the disease's long history, little progress has been made toward a treatment for rabies. The prognosis for patient recovery remains dire. For any prospect of survival, patients require aggressive critical care, which physicians in rabies endemic areas may be reluctant or unable to provide given the cost, clinical expertise required, and uncertain outcome. Systematic clinical research into combination therapies is further hampered by sporadic occurrence of cases. In this Perspective, we examine the case for a One Medicine approach to accelerate development of an effective therapy for rabies through the veterinary care and investigational treatment of naturally infected dogs in appropriate circumstances. We review the pathogenesis of rabies virus in humans and dogs, including recent advances in our understanding of the molecular basis for the severe neurological dysfunction. We propose that four categories of disease process need to be managed in patients: viral propagation, neuronal degeneration, inflammation and systemic compromise. Compassionate critical care and investigational treatment of naturally infected dogs receiving supportive therapy that mimics the human clinical scenario could increase opportunities to study combination therapies that address these processes, and to identify biomarkers for prognosis and therapeutic response. We discuss the safety and ethics of this approach, and introduce the Canine Rabies Treatment Initiative, a non-profit organization with the mission to apply a One Medicine approach to the investigation of diagnostic, prognostic, and therapeutic options for rabies in naturally infected dogs, to accelerate transformation of rabies into a treatable disease for all patients.

Characterization of Emergency Department Rabies Post-Exposure Prophylaxis Procedures with an Infectious Diseases Clinic Referral Process

Purpose: Rabies post-exposure prophylaxis (rPEP) in the emergency department (ED) is associated with high costs, complicated administration protocols, and a time-sensitive vaccination series that often requires ED follow-up visits for subsequent vaccine administration. This study sought to characterize the number of redirected vaccine administrations in those patients referred to ID Clinic, guideline compliance, and opportunities for improvement. Methods: Retrospective chart review of adult and pediatric patients presenting to the ED from 2016 to 2019 and prescribed rabies immunoglobulin. Results: Of the 89 patients included, 66.3% were referred to ID Clinic. Those referred to clinic had significantly fewer average visits to the ED for repeat vaccination (P < .001). Of the 177 vaccinations prescribed for patients referred, 105 were administered in clinic. Overall, having insurance significantly increased the odds of completing the prescribed vaccination series (Odds Ratio (OR) = 4.34, 95% Confidence Interval (CI) = 1.34 to 15.52). Among those patients referred to clinic, having insurance significantly increased the odds of receiving any follow-up doses in clinic (OR = 6.00, 95% CI = 1.48 to 25.98), receiving all of their prescribed follow-up doses in clinic (OR = 10.00, 95% CI = 1.72 to 190.80), and completing the entirety of their vaccination series (OR = 5.89, 95% CI = 1.50 to 26.21). Conclusions: The use of an ID Clinic referral process for rPEP resulted in a significant reduction in the average number of visits to the ED for repeat vaccination, hence avoiding 105 ED visits. Insurance status was a significant factor in both the utilization of the ID Clinic referral system and overall completion of the vaccination series. Future research should explore workflows inclusive of both ED care and outpatient follow-up, care plans for the uninsured, and mechanisms to limit the number of patients that fail to complete the recommended vaccination series.

Delays in initiating rabies post-exposure prophylaxis among dog bite victims in Wakiso and Kampala districts, Uganda

Background: Although rabies in dog bite patients is preventable through timely initiation of post-exposure prophylaxis (PEP), a number of barriers to achieving PEP exist. This study investigated the delays to initiation of PEP among dog bite patients in the emergency departments of two PEP centers in Uganda. Methods: A cross-sectional study was conducted among dog-bite patients that presented to two selected rabies PEP centers. A semi-structured questionnaire was used to collect data. Delay to receive PEP was defined as reporting for PEP beyond 24 hours after the bite event. Generalized linear models were used to calculate prevalence ratios and the 95% confidence intervals as a measure of association between delay and patient factors. Results: Out of 376 participants, just over half (53.5%) were males. The majority of participants (54.0%) were 15 years or older and 28.5% had no formal education. Just over three-quarters (77.9%) had category II dog bite wounds. Nearly 40% delayed to receive PEP, and median (inter quartile range) lag time between bite event and seeking medical care of 18 (41) hours. Compared to education level of secondary or above, patients with no formal education (adj. PR=4.06, 95% CI: 2.69 -  6.10) or primary education (adj.PR=2.15, 95% CI: 1.37 -  3.35), belonging to the lowest socio-economic tertile as compared to the highest (adj.PR=1.58, 95% CI: 1.10 - 2.28), knowing the owner of the biting dog (adj.PR=1.30, 95% CI: 1.02 - 1.65) and having category II wounds (adj.PR=2.31, 95% CI: 1.43 - 3.71) were all associated with delayed presentation for PEP. Conclusions and recommendations: Delays to receive PEP are common and are associated with poor level of education or low socio-economic status, knowledge of who the dog owner is and less severity of bite wounds. Seeking care irrespective of wound severity or knowledge of dog owner should be promoted.

Delays in initiating rabies post-exposure prophylaxis among dog bite victims in Wakiso and Kampala districts, Uganda

Background: Although rabies in dog bite patients is preventable through timely initiation of post-exposure prophylaxis (PEP), a number of barriers to achieving PEP exist. This study investigated the delays to initiation of PEP among dog bite patients in the emergency departments of two PEP centers in Uganda. Methods: A cross-sectional study was conducted among dog-bite patients that presented to two selected rabies PEP centers. A semi-structured questionnaire was used to collect data. Delay to receive PEP was defined as reporting for PEP beyond 24 hours after the bite event. Generalized linear models were used to calculate prevalence ratios and the 95% confidence intervals as a measure of association between delay and patient factors. Results: Out of 376 participants, just over half (53.5%) were males. The majority of participants (54.0%) were 15 years or older and 28.5% had no formal education. Just over three-quarters (77.9%) had category II dog bite wounds. Nearly 40% delayed to receive PEP, and median (IQR) lag time between bite event and seeking medical care of 18 (41) hours. Compared to education level of secondary or above, patients with no formal education (adj. PR=4.06, 95% CI: 2.69 -  6.10) or primary education (adj.PR=2.15, 95% CI: 1.37 -  3.35), belonging to the lowest socio-economic tertile as compared to the highest (adj.PR=1.58, 95% CI: 1.10 - 2.28), knowing the owner of the biting dog (adj.PR=1.30, 95% CI: 1.02 - 1.65) and having category II wounds (adj.PR=2.31, 95% CI: 1.43 - 3.71) were all associated with delayed presentation for PEP. Conclusions and recommendations: Delays to receive PEP are common and are associated with poor level of education or low socio-economic status, knowledge of who the dog owner is and less severity of bite wounds. Seeking care irrespective of wound severity or knowledge of dog owner should be promoted.

Estimating the Volume of Equine Rabies Immunoglobulin (eRIG) Required for Local Infiltration in Soft Tissue Animal Bites in Children Using a Wound Size-Based Approach

INTRODUCTION

Post-exposure prophylaxis using rabies immunoglobulin (RIG) is universal recommendation for category III exposures. This study was conducted to determine quantity of RIG used to infiltrate animal bite wounds in relation to longest dimension and area of wound.

METHODS

Children aged 2-18 years reporting within 7 days of category III animal bite were included. eRIG (300 IU/ml) was used in all subjects. A predesigned proforma was filled for clinical and epidemiological details of subjects. Maximum length and width of wounds was measured by using non-stretchable measuring tape. RIG was infiltrated in wounds as per WHO recommendations and volume infiltrated was noted.

RESULTS AND CONCLUSION

A total of 100 subjects were enrolled. The mean (±SD) volume of RIG infiltrated in wounds per unit length was 0.75 (±0.21) ml/cm and per unit area was 3.18 (±1.75) ml/cm2. Regression equations were calculated. Proposed equations y = 0.6x + 0.3, where y is the volume of RIG (ml) and x is the length of the wound (cm) and y = 0.9x + 1.1, where y is the volume of RIG (ml) and x is the area of the wound (cm2) can prove to be a useful tool in RIG volume calculation for primary health care providers.

"As long as the patient tells you it was a dog that bit him, why do you need to know more?" A qualitative study of how healthcare workers apply clinical guidelines to treat dog bite injuries in selected hospitals in Uganda

Dog-mediated rabies is on the increase in Uganda despite the availability of post-exposure prophylaxis (PEP). PEP procedures are expounded in the Uganda Clinical Guidelines (UCG) of 2016. We assessed adherence by health workers to UCG while managing dog bites in two PEP centers and obtained insights into motivations of their practices. Using qualitative methods, we observed the health worker-patient encounters, reviewed medical records, and interviewed 14 health workers that were involved in managing dog bite injuries. We used deductive thematic analysis to identify codes in themes developed from UCG. We found that much of the history of the bites was taken, but it was neither verified nor written down on the patient's file. Classification of wounds was inaccurate and ancillary laboratory assessments like culture and sensitivity tests were not conducted in all cases. Although antibiotics were given for both treatment and prophylactic purposes, the prescription was based on availability and affordability, not UCG recommendations. Rabies immunoglobulin (RIG) was not administered to deserving patients due to unavailability and high costs to the patient. Anti-rabies vaccine (ARV) was prescribed indiscriminately and some health workers attributed this to pressure from patients. Health education regarding prevention of dog bites was not given to patients due to time constraints on the side of the providers as a result of high caseloads at the emergency departments. Challenges to adherence to guidelines were identified as frequent ARV stock outs; inadequate cooperation among health facilities; and insufficient knowledge and skills on how injuries and rabies should be managed. We conclude that clinical management of dog bites is not fully in line with UCG. We argue that adoption of an integrated bite case management and cost-saving strategies as well as continuing medical education programs on rabies control and management could improve the clinical management of dog bites.

Benefit-Risk Assessment of the French Surveillance Protocol of Apparently Healthy Biting Dogs and Cats for Human Rabies Prevention

In France, apparently healthy dogs and cats that bite humans must undergo an observation period of 15 days with three veterinary visits to ascertain that they remain healthy, indicating that no zoonotic transmission of rabies virus occurred via salivary presymptomatic excretion. This surveillance protocol is mandatory for all pets that have bitten humans, despite France’s rabies-free status in non-flying mammals (i.e., a very low rabies risk). In this context, we aimed to perform a benefit–risk assessment of the existing regulatory surveillance protocol of apparently healthy biting animals, as well as alternative surveillance protocols. A scenario-tree modelling approach was used to consider the possible successions of events between a dog or cat bite and a human death attributed to either rabies or to lethal harm associated with the surveillance protocol (e.g., lethal traffic accidents when traveling to veterinary clinics or anti-rabies centers). The results demonstrated that the current French surveillance protocol was not beneficial, as more deaths were generated (traffic accidents) than avoided (by prompt post-exposure prophylaxis administration). We showed here that less stringent risk-based surveillance could prove more appropriate in a French context. The results in this study could allow policy-makers to update and optimize rabies management legislation.

Delayed rabies post-exposure prophylaxis treatment among Dutch travellers during their stay abroad: a comprehensive analysis

BACKGROUND

After an animal-associated injury (AAI) in rabies-endemic regions, post-exposure prophylaxis (PEP) is needed to prevent infection.1,2 PEP consists of rabies vaccinations (RV) and in some cases also additional rabies immune globulins (RIG). Not always PEP medication, and RIG in particular, is accessible. Along with an increased number of exposure notifications among Dutch travellers, this might lead to treatment delay and thus to increased health risks. Until now, research mainly focused on factors associated with exposition, but none on which factors are associated with PEP delay. This study aimed to identify which general sample characteristics are associated with PEP delay while being abroad.

METHODS

A quantitative retrospective observational study was conducted. The study population consisted of insured Dutch international travellers who actively contacted their medical assistance company (2015-2019) because of an animal-associated injury (AAI) (N = 691). The association between general sample characteristics and delay of different PEP treatments was studied using survival analysis.

RESULTS

Travellers without pre-exposure prophylaxis (PrEP) had an increased hazard, and therefore a shorter delay, for receiving their first RV as compared to travellers with PrEP (HR:1.11, 95%CI:1.01-1.22). The travellers needing both RV and RIG had a decreased hazard, and therefore a longer delay, as compared to travellers only needing RV (HR:0.81, 95%CI:0.67-0.96). General sample characteristic associated with RIG administration delay was travel destination. Travellers to Central and South America, East Mediterranean and Europe had a decreased hazard, and therefore a longer delay, for receiving RIG treatments relative to travellers to South East Asia (HR:0.31, 95%CI:0.13-0.70; HR:0.34, 95%CI:0.19-0.61; HR:0.46, 95%CI:0.24-0.89; HR:0.48, 95%CI:0.12-0.81, respectively).

CONCLUSIONS

Our results suggest that the advice for PrEP should be given based on travel destination, as this was found to be the main factor for PEP delay, among travellers going to rabies-endemic countries.

Rabies vaccination and multiple sclerosis relapse: A retrospective cohort study

BACKGROUND

No studies assessing rabies vaccine (RV) tolerability in persons with multiple sclerosis (MS) have been conducted. Given the lack of safety data, RV is recommended essentially only for post-exposure prophylaxis, which is difficult to administer effectively in many rabies-endemic countries. We sought to determine whether RV administration as pre-exposure prophylaxis was associated with MS relapse.

METHODS

This retrospective cohort study compared the clinical courses of MS patients in the year before and after rabies vaccination. The year before vaccination was defined as the pre-exposure risk period, the three months thereafter as the exposure-risk period, and the following nine months as the post-risk period. All adult MS patients immunized with RV between 2014 and 2018 and with available medical records in the two-year window were included. The primary outcome was the incidence of symptomatic MS relapse in the exposure-risk period versus the pre-exposure period.

RESULTS

Fifty-five patients received at least one dose of RV. Most (38/55, 69%) were female; mean age was 38.5 years (SD ±9.2). While 21 (38%) patients experienced 24 relapses in the year before vaccination, only three (5%) experienced one relapse each in the post-vaccination exposure-risk period; three others (5%) experienced a total of four relapses in the subsequent post-risk period. The annualized relapse rates in the pre-exposure, exposure-risk, and post-risk periods were 0.44, 0.22, and 0.10, respectively (rate ratio for exposure-risk to pre-exposure periods, 0.509 [95% CI 0.098-1.677]).

CONCLUSIONS

In this cohort, rabies vaccination was not associated with clinical MS relapse. Larger, prospective studies are needed to confirm these results.

Rabies encephalitis in a preschool child following postexposure prophylaxis

We report a case of rabies encephalitis in a 4½-year-old male child with an exposure to a suspect rabid dog. The child developed rabies 25 days after receiving postexposure prophylaxis. Rabies immunoglobulin (RIG) is currently administered according to body weight. In high-risk exposures over the head and neck, local administration of RIG over and above the body weight depending on the site, size, and severity of exposure may help to prevent rabies death. There is a need for further studies to generate new evidence in this regard.

RABIES IMMUNOGLOBULIN: Brief history and recent experiences in Côte d'Ivoire

BACKGROUND

Rabies is a fatal viral zoonosis mainly transmitted via dog bites. The estimated 59'000 annual deaths caused by the disease are preventable through correct and timely administration of post-exposure prophylaxis (PEP). PEP should be initiated as soon as possible after an exposure to a rabies suspected animal and consists of a course of active vaccinations and administration of rabies immunoglobulin (RIG) in case of severe exposure. However, RIG is not accessible in most rabies endemic countries and its impact on survival in combination with modern vaccines and its cost-effectiveness is unclear. We examined the effect of equine RIG (eRIG) in a field-trial in Côte d'Ivoire, a developing country with low but chronic rabies burden and persistent lack of RIG, similar to a majority of rabies endemic countries attempting elimination of the disease.

METHODS

Data from 3367 patients attending anti-rabies centers (Centres Anti-Rabiques, CARs) of the National Institute for Public Hygiene (Institut National d'Hygiène Publique, INHP) in the departments of Bouaké and San Pédro in Côte d'Ivoire was prospectively collected between April 2016 and March 2018. We identified 1594 patients at risk of rabies infection as eligible for RIG administration. Depending on local availability of eRIG and vaccination protocol applied, PEP consisted of active immunization only (non-eRIG group, n = 1145) or active and passive immunization (eRIG group, n = 449). Patients were followed-up by phone interviews at least 15 months after their exposure to assess for rabies suspected deaths.

RESULTS

Follow-up data was available for 641 patients in the non-eRIG group (56%) and 242 in the eRIG group (54%). Three suspected or possible rabies deaths occurred in each of the two groups, corresponding to a possible rabies mortality of 1.2% (95% CI 0.3-3.6%) in the eRIG group and 0.5% (95% CI 0.1-1.4%) in the non-eRIG group. The difference in proportions was small and not statistically significant (0.7%, p = 0.21). Deaths in both groups were associated with treatment delay after exposure and non-compliance to PEP protocol. No death occurred after correct and timely active immunization independent of eRIG administration.

CONCLUSION

The provision of eRIG did not lead to a measurable reduction of rabies burden in our study population. This underlines that improved access to active vaccines will be effective in reducing rabies deaths even if access to eRIG remains difficult in developing countries. A possible benefit of eRIG administration for severely exposed patients cannot be excluded based on these results.

Death from rabies: The reason being poor compliance to vaccination or it's failure

Rabies is endemic in India and responsible for 20,000 human deaths every year. It is 100% preventable when the vaccine is taken along with proper wound care and rabies immunoglobulin administration though update continues regarding the requirement of the number of vaccine doses, the need for immunoglobulin, and if required their types. We study four cases of rabies having street dogs' bite category grade 3. Everyone took vaccines at least three doses but none of them took rabies immunoglobulin. They developed symptoms of rabies with a gap of 15-28 days after the bites and admitted to a tertiary care center. One patient was left against medical advice and three patients were treated according to the modified Milwaukee protocol. But, none of them could be saved. So, it may be proposed that the reason of deaths may be due to lack of administration of rabies immunoglobulin (passive vaccination) or failure of vaccines. Hence, the government may focus on the administration of complete and quality post-exposure prophylaxis in all cases of animal bites. Although Milwaukee protocol saves few lives, it may be further improved or other treatment modalities may be developed for rabies treatment.

Epidemiology and preclinical management of dog bites among humans in Wakiso and Kampala districts, Uganda: Implications for prevention of dog bites and rabies

In rabies endemic areas, appropriate management of dog bites is critical in human rabies prevention. Victims must immediately wash bite wound for 15 minutes with water, soap, and a disinfectant before seeking medical care. This study investigated the epidemiology of dog bites and the determinants of compliance to these pre-clinical guidelines requirements among dog bite victims from high rabies-burden areas of Wakiso and Kampala, Uganda. An explanatory sequential mixed-methods study design was used. Quantitative data were collected from 376 dog-bite patients at two healthcare facilities. Qualitative data were also collected through 13 in-depth interviews with patients, healthcare workers, herbalists, and veterinarians. Qualitative data were analyzed using a deductive thematic approach. Generalized linear models were used to determine factors associated with compliance. Nearly half (190, 51%) of the patients were from Wakiso District and 293 (77.9%) had grade II wounds. Most of the wounds (171, 45.5%) were on the legs. Two-thirds of the bites occurred in public places. Only 70 (19%) of the bite patients had complied with pre-clinical guidelines. Nearly half of the patients had applied substances that were not recommended e.g. herbs (47/193), antiseptics (46/193), "black stone" (25/193), and unknown creams (10/193). Factors negatively associated with compliance included: being aged 15 years or older, adjPR = 0.70 (0.47-0.92) and knowing the dog owner, adjPR = 0.65 (0.36-0.93). However, attainment of secondary or higher education, adjPR = 1.76 (1.24-3.79), being in employment, adjPR = 1.48 (1.09-2.31), perception that the dog was sick, adjPR = 1.47 (1.02-2.72) and knowledge about the dog's subsequent victim(s) adjPR = 0.35 (0.17-0.70) were positively associated with compliance. High occurrence of dog bites in public places by free-roaming dogs suggests the need for deliberate promotion of responsible dog ownership. Additionally, targeted health education may be required to improve the low compliance to pre-clinical guidelines.

A cross-sectional study of awareness and practices regarding animal bites in rural community, North India

INTRODUCTION

Repeated epidemiological studies to monitor trends of knowledge and practices are needed to guide strategies to control rabies. We conducted a study to assess the current knowledge, attitudes, and practices in relation to animal bites in the rural area of north India.

METHODS

House to house survey to collect data on animal bites was conducted among 300 households (assuming awareness regarding animal bites to be 25%, precision 95%, and power of 80%) from the rural area of Punjab, north India. A pretested semi-structured questionnaire comprising of items that explored sociodemographic details (age, educational qualification, occupation, socioeconomic status (assessed through Udai Pareek scale), and awareness regarding rabies, knowledge about first aid, attitude, and practices regarding anti-rabies vaccination (ARV) was used. Detailed questions were asked to those who owned pets.

RESULTS

A total of 300 households were included in the analysis. Among all respondents, 30.4% (117) had an episode of animal bite in their family giving a bite incidence rate of 78/1000 population. Bites were more frequent in males (65.8%, n = 77). The commonest site of the bite was lower limb (65%) followed by upper limb (21.4%), and head and neck (5.1%). The participants said that bites by pet animals (47%) are more common than those by stray animals (35.9%), followed by wild animals (12.8%). Almost 91% of respondents told that they would prefer govt. hospital for the treatment. Class I bite was most common (88.9%) followed by class II (8.5%) and class III (1.7%). A lot of respondents (41.4%) did not know about the symptoms of rabies in humans. Only 17.5% knew the appropriate wound care. Inappropriate practices like applying chilly (48.8%), lime (13.1%), tying the limb above the wound (5.1%), and others were common. Only 15.5% washed their wound with soap and water. Most of those who were bitten received post-exposure prophylaxis (PEP) (80%). Most of the respondents (98.3%) had heard about ARV but didn't know about the site of injection. Almost everyone (99.35) said that no awareness camps/programs had been conducted in their villages/school/health center to date.

CONCLUSION

There is a high incidence of animal bites in rural areas. Awareness regarding the need for rabies vaccine of animals and PEP after an animal bite is quite high and is practiced. However, there is a lack of awareness regarding the course of action to be followed when an animal does develop rabies. Traditional and inappropriate practices of wound management persist and need to be countered. Improving the availability of ARV and rabies immunoglobulin through the public health system may further augment the uptake of PEP and completion of treatment while at the same time reducing out of pocket expenditure and the overall economic cost of rabies. Solid waste management in rural areas along with oral ARV is likely to reduce the incidence of rabies in rural areas.

Severe multiple rabid dog bite injuries in a child in central China: Continuous 10-year observation and analysis on this case

Dog bites are common in rural areas of underdeveloped countries or regions, affecting persons of different ages. Suspected rabid dog bites will lead to more severe outcomes, especially in children because injuries often occur on their heads and faces that are highly innervated parts of the body. In such circumstances, immediate and complete post-exposure prophylaxis (PEP) will be essential, though vaccine hesitancy is a problem. Herein, we report a 4-y-old girl who was seriously bitten by a confirmed rabid dog in rural China. Multiple lacerations and punctures distributed on her head, neck, face, extremities, and back after being bitten. It was in question that surgery or PEP should be performed in priority when the dog was not confirmed rabid at first, but considering the risks of rabies, immediate PEP was provided to her, along with immunogenicity tests to ensure an adequate protective immune response. Because of the severity of her injuries, medical practitioners suggested her parents to bring her to take immunogenicity tests in 1-, 5-, and 10-y intervals to ensure adequate rabies virus-neutralizing antibodies (RVNA) titers. Her parents had a good preference for medical advices, and in the 10-y interval, it was found that her RVNA titer was below protection level, so a booster vaccination was given to her, and 14 d after that, according to immunogenicity test, RVNA titer arose quickly above the protection level.

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.

Failure of postexposure prophylaxis in a girl child attacked by rabid dog severing her facial nerve causing possible direct entry of rabies virus into the facial nerve

On January 4, 2019 an eight-year-old girl child was bitten by a suspected rabid dog over the left parotid region. After a 17-h delay, the child was brought for rabies postexposure prophylaxis (PEP) at Civil Hospital Theog and was administered complete PEP. On January 29, 2019, the child was again brought to Theog Hospital with complaints of having fever, difficulty in walking, neck drop, and ptosis. On examination, pediatrician found photophobia, phonophobia, and hydrophobia and subsequently the patient died of cardiac arrest. On postmortem examination, the facial nerve was found dissected and injured at the inner end of the parotid gland. A severed end toward the brain was swollen and edematous. The entire brain was extracted and sent to Central Research Institute Kasauli for confirmation of rabies, where it tested positive for rabies by Fluorescent Antibodies Test and Biological Test. In situations where sensitive parts such as the face are involved, a thorough wound wash with soap and water and application of antiseptics along with immediate PEP may save some lives by not allowing the virus enough time to attach to and infect the nerve cells.

Utility of rabies neutralizing antibody detection in cerebrospinal fluid and serum for ante-mortem diagnosis of human rabies

Background

Early ante-mortem laboratory confirmation of human rabies is essential to aid patient management and institute public health measures. Few studies have highlighted the diagnostic value of antibody detection in CSF/serum in rabies, and its utility is usually undermined owing to the late seroconversion and short survival in infected patients. This study was undertaken to examine the ante-mortem diagnostic utility and prognostic value of antibody detection by rapid fluorescent focus inhibition test (RFFIT) in cerebrospinal fluid (CSF)/serum samples received from clinically suspected human rabies cases from January 2015 to December 2017.

Methodology/Principal findings

Samples collected ante-mortem and post-mortem from 130 and 6 patients with clinically suspected rabies respectively, were received in the laboratory during the study period. Ante-mortem laboratory confirmation was achieved in 55/130 (42.3%) cases. Real time PCR for detection of viral nucleic acid performed on saliva, nuchal skin, brain tissue and CSF samples could confirm the diagnosis in 15 (27.2%) of the 55 laboratory confirmed cases. Ante-mortem diagnosis could be achieved by RFFIT (in CSF and/or serum) in 45 (34.6%) of the 130 clinically suspected cases, accounting for 81.8% of the total 55 laboratory confirmed cases. The sensitivity of CSF RFFIT increased with the day of sample collection (post-onset of symptoms) and was found to be 100% after 12 days of illness. Patients who had received prior vaccination had an increased probability of a positive RFFIT and negative PCR result. Patients who were positive by RFFIT alone at initial diagnosis had longer survival (albeit with neurological sequelae) than patients who were positive by PCR alone or both RFFIT and PCR.

Conclusions/Significance

Detection of antibodies in the CSF/serum is a valuable ante-mortem diagnostic tool in human rabies, especially in patients who survive beyond a week. It was also found to have a limited role as a prognostic marker to predict outcomes in patients.

Ante-mortem diagnosis of human rabies is essential for patient management and public health measures. The detection of virus specific antibodies in the CSF/serum of patients with suspected rabies is thought to have a limited diagnostic role owing to late seroconversion and short survival in rabies. We examined the diagnostic and prognostic utility of antibody detection by rapid fluorescent focus inhibition test (RFFIT) in CSF/serum samples received from clinically suspected human rabies cases (2015–2017). RFFIT (in CSF and/or serum) could confirm ante-mortem diagnosis in 45 (34.6%) of the 130 clinically suspected cases, accounting for 81.8% of the total 55 laboratory confirmed cases. The sensitivity of CSF RFFIT increased with the day of sample collection (post-onset of symptoms) and was found to be 100% after 12 days of illness. Patients who had received prior vaccination had an increased likelihood of a positive RFFIT and negative PCR result. Patients who were positive by RFFIT alone at initial diagnosis had longer duration of survival, although with poor functional outcomes. Antibody detection by RFFIT in CSF/serum was found to have a diagnostic utility especially in patients who survived beyond a week and a limited prognostic role in human rabies.

The potential effect of improved provision of rabies post-exposure prophylaxis in Gavi-eligible countries: a modelling study

BACKGROUND

Tens of thousands of people die from dog-mediated rabies annually. Deaths can be prevented through post-exposure prophylaxis for people who have been bitten, and the disease eliminated through dog vaccination. Current post-exposure prophylaxis use saves many lives, but availability remains poor in many rabies-endemic countries due to high costs, poor access, and supply.

METHODS

We developed epidemiological and economic models to investigate the effect of an investment in post-exposure prophylaxis by Gavi, the Vaccine Alliance. We modelled post-exposure prophylaxis use according to the status quo, with improved access using WHO-recommended intradermal vaccination, with and without rabies immunoglobulin, and with and without dog vaccination. We took the health provider perspective, including only direct costs.

FINDINGS

We predict more than 1 million deaths will occur in the 67 rabies-endemic countries considered from 2020 to 2035, under the status quo. Current post-exposure prophylaxis use prevents approximately 56 000 deaths annually. Expanded access to, and free provision of, post-exposure prophylaxis would prevent an additional 489 000 deaths between 2020 and 2035. Under this switch to efficient intradermal post-exposure prophylaxis regimens, total projected vaccine needs remain similar (about 73 million vials) yet 17·4 million more people are vaccinated, making this an extremely cost-effective method, with costs of US$635 per death averted and $33 per disability-adjusted life-years averted. Scaling up dog vaccination programmes could eliminate dog-mediated rabies over this time period; improved post-exposure prophylaxis access remains cost-effective under this scenario, especially in combination with patient risk assessments to reduce unnecessary post-exposure prophylaxis use.

INTERPRETATION

Investing in post-exposure vaccines would be an extremely cost-effective intervention that could substantially reduce disease burden and catalyse dog vaccination efforts to eliminate dog-mediated rabies.

FUNDING

World Health Organization.

Intradermal rabies post-exposure prophylaxis can be abridged with no measurable impact on clinical outcome in Cambodia, 2003-2014

Rabies causes 60,000 deaths worldwide annually. Rabies post-exposure prophylaxis is highly effective but often geographically and financially beyond reach in endemic developing countries. We conducted a retrospective study on clinical outcome at ≥6 months in 3318 Cambodians who received intradermal Vero cell vaccine post-exposure prophylaxis after a bite by a rabid or sick-looking but untested dog in 2003-2014. An external expert panel examined verbal autopsy reports to identify rabies deaths. 1739 (93.65%) persons bitten by rabid- and 1066 (72.96%) bitten by sick-looking but untested dogs were traced and 513 were lost to follow-up. Among the former, 1591 (91.49%) and 129 (7.42%) patients referred for 4+ and 3 post-exposure prophylaxis sessions, respectively. Three persons died of probable rabies so that the overall percentage of survival was 99.83% (95% exact confidence interval: 99.49-99.96%) in post-exposure prophylaxis recipients bitten by confirmed rabid dogs. No significant difference was found in survival among patients who received 3 vs. 4+ sessions (with or without rabies immunoglobin). The power of the study, however, was limited. The current four sessions/one month intradermal regimen can be reduced to a three sessions/one week at no detectable added risk to patients, with the limitation of study power at 49%. A clinical follow-up system should be adopted by rabies prevention centers, especially to monitor implementation of an abridged course. The Institut Pasteur in Cambodia regimen will improve vaccine equity by treating 33% more patients with available doses, reduce direct cost of vaccination, transportation and other indirect costs to vaccinees.

A CpG oligodeoxynucleotide enhances the immune response to rabies vaccination in mice

Background

Rabies is a fatal disease that is preventable when post exposure prophylaxis (PEP) is administered in a timely fashion. CpG oligodeoxynucleotides (ODNs) can trigger cells that express Toll-like receptor 9, and their immunopotentiation activity in an inactivated aluminum-adjuvanted rabies vaccine for dogs has been identified using mouse and dog models.

Methods

A human diploid cell rabies vaccine (HDCV) of humans and a CpG ODNs with cross-immunostimulatory activity in humans and mice were used to evaluate the immunogenicity and protective efficacy of CpG ODN in a mouse model that simulates human PEP.

Results

HDCV combined with CpG ODN (HDCV–CpG) stimulated mice to produce rabies virus-specific neutralizing antibody (RVNA) earlier and increased the seroconversion rate. Compared with HDCV alone, either HDCV–1.25 μg CpG or HDCV–5 μg CpG increased the levels of RVNA. In particular, 5 μg CpG ODN per mouse significantly boosted the levels of RVNA compared with HDCV alone. IFN-γ producing splenocytes generated in the HDCV-5 μg CpG group were significantly increased compared to the group treated with HDCV alone. When the immunization regimen was reduced to three injections or the dose was reduced to half of the recommended HDCV combined with CpG ODN, the RVNA titers were still higher than those induced by HDCV alone. After viral challenge, 50% of mice immunized with a half-dose HDCV–CpG survived, while the survival rate of mice immunized with HDCV alone was 30%.

Conclusions

The immunopotentiation activity of CpG ODNs for a commercially available human rabies vaccine was first evaluated in a mouse model on the basis of the Essen regimen. Our results suggest that the CpG ODN used in this study is a potential adjuvant to rabies vaccines for human use.

Electronic supplementary material

The online version of this article (10.1186/s12985-018-1089-1) contains supplementary material, which is available to authorized users.

A Cost Effective Easy Competitive Enzyme-Linked Immunosorbent Assay Suitable for Monitoring Protective Immunity against the Rabies Virus in the Serum of Humans and Dogs

The coverage of rabies vaccinations has been reported at 70-80% of dogs in annual reports. However, there are still outbreaks of rabies among humans and dogs in Thailand, thus indicating the necessity of ensuring seroprevalence in vaccinated dogs and efficacy of human immunization. A cost effective easy competitive enzyme-linked immunosorbent assay (CEE-cELISA) was developed here for monitoring protective immunity against the rabies virus in human and dog serum samples using monoclonal antibody clone 1-46-12, which recognizes a conformational epitope of the rabies G protein. The ELISA plate is coated with the whole viral antigen from a commercial vaccine. The serotiter measured by the CEE-cELISA and by the gold standard assay (rapid fluorescent focus inhibition test), detecting the neutralizing antibody, showed a strong correlation, with an R value of 0.958 and 0.931 in humans and dogs, respectively. These correlations were detected in the serum samples from humans and dogs at antibody concentrations up to 100 and 10 IU/ml, respectively. This CEE-cELISA could be an alternative assay for evaluating mass rabies vaccination rapidly at a low cost as well as for detecting antirabies antibodies in the serum of not only humans but also other animal species.

Analysis on the risks of severe adverse events in rabies post-exposure prophylaxis and appropriate decision-making procedure

Severe adverse events (AEs) following post-exposure rabies vaccination had been occasionally described in previous studies. Once AEs occurred, immediate medical treatment and appropriate change of vaccine and vaccination schedule were of significance. It was also important and challengeable to determine the relationship among adverse reactions, vaccines residues and laboratory tests for patients, to choose a proper vaccine in resumed vaccination, to avoid the reoccurrence of AEs and to ensure adequate immune response. Here, we present steps about how to cope with AEs by giving an example with a two-year-old girl who was identified as category II exposure to rabies, suffered from anaphylaxis after first dose administration with human diploid rabies vaccine (HDCV) so vaccination was temporarily suspended. Dexamethasone was prescribed to her in anti-allergy therapy. Allergy tests indicated that the patient was not sensitive to allergens and heterologous proteins. Vaccine test report showed that residual kanamycin existed in that batch of vaccines. This reminded us to provide her antibiotic skin sensitivity test which found she was allergic to kanamycin. Thus, we could conclude it was the cause of AEs. Then, 0.5 mL lyophilized Purified Vero Cell Rabies Vaccine (PVRV) without any residues was enrolled in the resumed vaccination. To ensure successful immunization, immunogenicity test was also provided which showed adequate immune response (RVNA ≥ 0.5 IU/mL) starting from day14. Besides, no further AEs occurred afterward. This study emphasized the importance of in-depth survey, analysis and implied the necessity to scientifically and properly choose the optimal vaccine for patients and appropriately provide treatments if AEs occurred.

New human rabies vaccines in the pipeline

Rabies remains endemic in more than 150 countries. In 99% of human cases, rabies virus is transmitted by dogs. The disease, which is nearly always fatal, is preventable by vaccines given either before and/or after exposure to a rabid animal. Numerous factors including the high cost of vaccines, the relative complexity of post-exposure vaccination protocols requiring multiple doses of vaccine, which in cases of severe exposure have to be combined with a rabies immune globulin, lack of access to health care, and insufficient surveillance contribute to the estimated 59,000 human deaths caused by rabies each year. New, less expensive and more immunogenic rabies vaccines are needed together with improved surveillance and dog rabies control to reduce the death toll of human rabies. Here, we discuss new rabies vaccines that are in clinical and pre-clinical testing and evaluate their potential to replace current vaccines.

Assessing rabies knowledge gaps in human and animal healthcare professionals practicing in Washington, DC-A one health approach

Once a person is exposed to the rabies virus, it is universally fatal unless postexposure prophylaxis (PEP) is administered promptly. In the United States, determining whether PEP recommeded is often a collaborative effort where health departments work with both animal and human healthcare professionals to enact animal quarantines (or rabies testing), recommending PEP when appropriate. A failure in the knowledge base of either profession can result in incorrect PEP recommendations and an increased risk of adverse outcomes. To assess rabies knowledge in licensed physicians and veterinarians practicing in Washington, DC, we conducted a survey from December 2, 2016, to January 2, 2017, assessing their knowledge of the clinical signs, epidemiology and the primary vectors of rabies. These responses were compared between the two groups. Physician-specific or veterinary-specific questions regarding the correct PEP schedule and administration site or animal quarantine recommendations, respectively, were also included. Nine hundred and fifty-two physicians and 125 veterinarians responded. Veterinarians were more likely to select the correct vectors and clinical signs in animals than physicians. Physicians more likely selected the correct transmission routes. Less than half of physicians identified the correct PEP schedule (39.4%) and administration site (49.0%). Half of veterinarians (50.0%) correctly identified quarantine length for wildlife-exposed vaccinated dogs compared to only 19.4% for unvaccinated dogs. Several knowledge gaps were identified amongst physicians and veterinarians. Due to the fatal nature of rabies, it is important that all healthcare providers have an understanding of current recommendations. Health departments can work to correct these gaps and serve as a bridge between human and animal healthcare professionals.

Using an Emergency Department Syndromic Surveillance System to Evaluate Reporting of Potential Rabies Exposures, Illinois, 2013-2015

OBJECTIVES

Mandatory reporting of potential rabies exposures and initiation of postexposure prophylaxis (PEP) allow local health authorities to monitor PEP administration for errors. Our objectives were to use an emergency department (ED) syndromic surveillance system to (1) estimate reporting compliance for exposure to rabies in suburban Cook County, Illinois, and (2) initiate interventions to improve reporting and reassess compliance.

METHODS

We queried ED records from 45 acute care hospitals in Cook County and surrounding areas from January 1, 2013, through June 30, 2015, for chief complaints or discharge diagnoses pertaining to rabies, PEP, or contact with a wild mammal (eg, bat, raccoon, skunk, fox, or coyote). We matched patients with ≥1 ED visit for potential rabies exposure to people with potential rabies exposure reported to the Cook County Department of Public Health. We considered nonmatches to have unreported exposures. We then initiated active surveillance in July 2015, disseminated education on reporting requirements in August and September 2015, and reassessed reporting completeness from July 2015 through February 2016.

RESULTS

Of 248 patients with rabies-related ED visits from January 2013 through June 2015, 63 (25.4%) were reported. After interventions were implemented to increase reporting compliance, 53 of 98 (54.1%) patients with rabies-related ED visits from July 2015 through February 2016 were reported. Patients with ED visits for potential rabies exposure were twice as likely to be reported postintervention than preintervention (risk ratio = 2.1; 95% CI, 1.6-2.8). The volume of potential rabies exposure cases reported to the health department from July 2015 through February 2016 increased by 252% versus the previous year.

CONCLUSIONS

Potential rabies exposures and PEP initiation are underreported in suburban Cook County. ED syndromic surveillance records can be used to estimate reporting compliance and conduct active surveillance.

Improper wound treatment and delay of rabies post-exposure prophylaxis of animal bite victims in China: Prevalence and determinants

Background

Rabies is invariably a fatal disease. Appropriate wound treatment and prompt rabies post-exposure prophylaxis (PEP) are of great importance to rabies prevention. The objective of this study was to investigate the prevalence and influencing factors of improper wound treatment and delay of rabies PEP after an animal bite in Wuhan, China.

Methodology

This cross-sectional study was conducted among animal bite victims visiting rabies prevention clinics (RPCs). We selected respondents by a multistage sampling technique. A face-to-face interview was conducted to investigate whether the wound was treated properly and the time disparity between injury and attendance to the RPCs. Determinants of improper wound treatment and delay of rabies PEP were identified by a stepwise multivariate logistic regression analysis.

Principal findings

In total, 1,015 animal bite victims (564 women and 451 men) responded to the questionnaire, and the response rate was 93.98%. Overall, 81.2% of animal bite victims treated their wounds improperly after suspected rabies exposure, and 35.3% of animal bite victims delayed the initiation of PEP. Males (OR = 1.871, 95% CI: 1.318–2.656), residents without college education (OR = 1.698, 95% CI: 1.203–2.396), participants liking to play with animals (OR = 1.554, 95% CI: 1.089–2.216), and people who knew the fatality of rabies (OR = 1.577, 95% CI: 1.096–2.270), were more likely to treat wounds improperly after an animal bite. Patients aged 15–44 years (OR = 2.324, 95% CI: 1.457–3.707), who were bitten or scratched by a domestic animal (OR = 1.696, 95% CI: 1.103–2.608) and people who knew the incubation period of rabies (OR = 1.844, 95% CI: 1.279–2.659) were inclined to delay the initiation of PEP.

Conclusions

Our investigation shows that improper wound treatment and delayed PEP is common among animal bite victims, although RPCs is in close proximity and PEP is affordable. The lack of knowledge and poor awareness might be the main reason for improper PEP. Educational programs and awareness raising campaigns should be a priority to prevent rabies, especially targeting males, the less educated and those aged 15–44 years.

Although the incidence of animal bites is increasing in China, residents’ knowledge about appropriate wound treatment and prompt PEP is insufficient. A face-to-face interview was conducted to investigate whether the wound was treated properly and to determine the time disparity between injury and consultation to the RPCs among animal bite victims. We discovered that a minority of people treated wounds appropriately, and more than one-third of participants delayed the initiation of PEP. A stepwise multivariable logistic regression analysis was used to identify the influencing factors of improper wound treatment and the delay of rabies PEP. Males (OR = 1.871, 95% CI: 1.318–2.656), residents without college education (OR = 1.698, 95% CI: 1.203–2.396), respondents liking to play with animals (OR = 1.554, 95% CI: 1.089–2.216), and people who knew the fatality of rabies (OR = 1.577, 95% CI: 1.096–2.270), were likely to treat wounds improperly after an animal bite. Participants aged 15–44 years (OR = 2.324, 95% CI: 1.457–3.707), residents bitten or scratched by a domestic animal (OR = 1.696, 95% CI: 1.103–2.608), and people who knew the incubation period of rabies (OR = 1.844, 95% CI: 1.279–2.659) tended to delay the initiation of PEP. The results also showed that knowledge of rabies among residents is insufficient. These findings highlight the urgent need for public educational and awareness-raising programs that would improve appropriate wound treatment and prompt PEP to prevent rabies-related deaths.

Heterogeneity of Rabies Vaccination Recommendations across Asia

Asian countries bear the greatest burden of the disease, with a majority (59%) of rabies-related deaths occurring in Asia. In order to promote best practices, we summarized national human vaccination guidelines across this region, to highlight differences and similarities and to discuss the aspects that would benefit from updates. National management guidelines for rabies were retrieved from various sources to extract information on rabies pre- and post-exposure prophylaxis (PrEP, and PEP), booster vaccination, and route of administration. Rabies guidelines recommendations for wound management and PrEP across Asia are broadly aligned to the World Health Organization (WHO) guidelines. For PEP, the 5-dose Essen, and the 4-dose Zagreb are the regimens of choice for intramuscular (IM), and the Thai Red Cross regimen for intradermal (ID), administration. Several national guidelines have yet to endorse ID vaccine administration. Most guidelines recommend rabies immunoglobulin in category III exposures. Booster recommendations are not included in all guidelines, with limited clarity on booster requirement across the spectrum of risk of rabies exposure. In conclusion, national recommendations across Asian countries differ and while some guidelines are closely aligned to the WHO recommendations, resource-saving ID administration and use of rational abbreviated schedules have yet to be endorsed.

Protection Against CNS-Targeted Rabies Virus Infection is Dependent upon Type-1 Immune Mechanisms Induced by Live-Attenuated Rabies Vaccines

Rabies remains a major public health issue worldwide, especially in developing countries where access to medical care can represent a real challenge. While there is still no cure for rabies, it is a vaccine-preventable disease with pre- and post-exposure prophylaxis regimens approved by the World Health Organization (WHO). However, many rabies-exposed individuals have limited access to vaccines and virus-neutralizing antibodies approved for post-exposure prophylaxis. Unfortunately, any delay in the administration of these reagents can have lethal consequences. This highlights the need to develop cost-effective immunological reagents with a greater window of efficacy. Live-attenuated vaccine strains of rabies virus presents a potential treatment in filling this gap. We show here that immunization with live-attenuated vaccines provide long-lasting rabies immunity, superior to the protection induced by inactivated vaccines. In the absence of an immunostimulatory adjuvant, vaccination with multiple doses of inactivated rabies virus induces a type-2 immune response. This type of immunity is highly effective at inducing neutralizing antibody but has limited efficacy in clearing the virus from central nervous system (CNS) tissues. In contrast, a single infection with live-attenuated rabies vaccine safely drives a type-1 immune response, associated with both the production of a neutralizing antibody and the clearance of wild-type rabies virus from CNS tissues. These results indicate that live-attenuated rabies strains have the potential to be more effective in post-exposure prophylaxis than conventional inactivated vaccines.

Injecting rabies immunoglobulin (RIG) into wounds only: A significant saving of lives and costly RIG

An increasing number of dog bite victims were being presented to public hospitals in Himachal Pradesh in 2014 amidst virtual non availability of any rabies immunoglobulin (RIG). Only a small quantity of equine rabies immunoglobulin (eRIG) was available from the government owned Central Research Institute (CRI) Kasauli. This available eRIG was used in 269 patients as an emergency response and only for local infiltration of severe bite wounds by suspected rabid dogs. This was followed by rabies vaccination, using the WHO approved intra-dermal Thai Red Cross Society vaccination schedule. A subgroup of 26 patients were later identified who had been severely bitten by laboratory confirmed rabid dogs. They were followed for more than one year and all were found to be alive.

Emerging Zoonotic and Vector-Borne Viral Diseases

Many vector-borne and zoonotic diseases are considered to be emerging; since they are either newly reported to cause human disease, or are causing disease in geographical locations or species not previously documented. In the past 15 years, significant outbreaks of Severe Acute Respiratory Syndrome (or SARS) and Middle Eastern Respiratory Syndrome (or MERS), Nipah and Hendra, Ebola virus disease and Zika fever and others have been reported. In this chapter the clinical characteristics, epidemiological aspects, treatment and prevention and information related to the laboratory investigation of important zoonotic and vector-borne diseases that have emerged in the past 10 years, and how this affects children, will be discussed. Furthermore rabies, considered a neglected viral disease with the majority of victims in Africa being children, will also be addressed.

Post-exposure Treatment with Anti-rabies VHH and Vaccine Significantly Improves Protection of Mice from Lethal Rabies Infection

Post-exposure prophylaxis (PEP) against rabies infection consists of a combination of passive immunisation with plasma-derived human or equine immune globulins and active immunisation with vaccine delivered shortly after exposure. Since anti-rabies immune globulins are expensive and scarce, there is a need for cheaper alternatives that can be produced more consistently. Previously, we generated potent virus-neutralising VHH, also called Nanobodies, against the rabies glycoprotein that are effectively preventing lethal disease in an in vivo mouse model. The VHH domain is the smallest antigen-binding functional fragment of camelid heavy chain-only antibodies that can be manufactured in microbial expression systems. In the current study we evaluated the efficacy of half-life extended anti-rabies VHH in combination with vaccine for PEP in an intranasal rabies infection model in mice. The PEP combination therapy of systemic anti-rabies VHH and intramuscular vaccine significantly delayed the onset of disease compared to treatment with anti-rabies VHH alone, prolonged median survival time (35 versus 14 days) and decreased mortality (60% versus 19% survival rate), when treated 24 hours after rabies virus challenge. Vaccine alone was unable to rescue mice from lethal disease. As reported also for immune globulins, some interference of anti-rabies VHH with the antigenicity of the vaccine was observed, but this did not impede the synergistic effect. Post exposure treatment with vaccine and human anti-rabies immune globulins was unable to protect mice from lethal challenge. Anti-rabies VHH and vaccine act synergistically to protect mice after rabies virus exposure, which further validates the possible use of anti-rabies VHH for rabies PEP.

Rabies is an infectious disease causing 59,000 deaths and millions are exposed each year worldwide. Post-exposure prophylaxis (PEP) against rabies consists of a combination of passive (immune globulins) and active immunisation (vaccine) directly after viral exposure. Currently used plasma-derived anti-rabies immune globulins are expensive and scarce, urging the development of alternatives. Nanobodies or VHH are the smallest antigen-binding fragments of camelid heavy chain antibodies and are easy to produce with intrinsic good thermal stability and solubility. Combined treatment with anti-rabies VHH and vaccine gave significantly better protection than either compound alone in an intranasal rabies challenge model in mice, which validates the potential use of anti-rabies VHH as replacement of immune globulins in PEP.

Should travellers to rabies-endemic countries be pre-exposure vaccinated? An assessment of post-exposure prophylaxis and pre-exposure prophylaxis given to Danes travelling to rabies-endemic countries 2000-12

BACKGROUND

Since 2000, a steady increase of vaccines used for both rabies Post-exposure prophylaxis (PEP) and rabies Pre-exposure prophylaxis (PrEP) given to Danish travellers was observed. This study aims to evaluate whether the increase of PEP and PrEP was due to increased travelling, increased awareness of the need for PrEP, or more animal bites per travel, leading to more PEP being administered, in order to assess the need for changing the recommendations. We also described in which countries Danish travelers most frequently reported possible exposure to rabies, and evaluated the timeliness of rabies PEP, including rabies immunoglobulin (RIG).

METHODS

We included all Danes reported to the National Database for Rabies Treatment as having started rabies PEP either abroad or after returning to Denmark, between 2000 and 2012. Data on the yearly number of Danish travelers from 2004 to 2012 to Thailand were collected to calculate the incidence of animal bites at this destination. We also included data on rabies vaccines sold for PrEP or for booster vaccination in Denmark.

RESULTS

PEP after possible exposure to rabies abroad increased yearly by 8.8 %. Likewise vaccines sold for PrEP increased by 8.2% annually. The number of Danish travelers to Thailand increased by 7.3% per year, resulting in a stable incidence of animal bites per 100,000 travelers. Seventy-five % started PEP in the country of exposure, while only 10 % received RIG.

CONCLUSIONS

The yearly increase in PEP and PrEP are parallel to the yearly increase in number of travelers, and can thus be explained by the increased rate of traveling, and not by a rise in awareness of rabies risk or more bites per traveler.Even short term travelers should be given the option of including PrEP in their travel immunisation program, as PEP and especially RIG is not always available in rabies-endemic countries.