One Bite- One Risk: Understanding the Danger of Rabies

      One Bite- One Risk: Understanding the Danger of Rabies

¹dr.sandeep kumar ,²dr.Raj kumar berwal , ³dr. Rohit sharma & ⁴dr. vinay kumar

*1PhD Scholar, Department of LPT, RAJUVAS, Bikaner (Raj.)2 Assistant Professor, Department of LPT, RAJUVAS, Bikaner(Raj.)3 Assistant Professor, Department of AGB, ACVM, Jaipur (Raj.)4PhD Scholar, Department of VAHEE, RAJUVAS , Bikaner (Raj.)  *Corresponding Author Email: dr.saharans123@gmail.com

Abstract

Rabies is a deadly zoonotic disease caused by viruses in the Lyssavirus genus. It affects mammals globally, including humans, and is considered one of the most neglected tropical diseases. Although vaccines for pre- and post-exposure prophylaxis are available, rabies remains a significant public health threat, particularly in underdeveloped countries. This article briefly examines its transmission, symptoms, diagnostic challenges, and prevention. It stresses the need for broad immunization, innovative wildlife vaccination, and collaboration between veterinary and medical sectors. WHO’s rabies elimination goals rely on stronger surveillance and public education.

Keywords: Control, Lyssavirus, Rabies, Prevention, Zoonosis

 Introduction

Zoonoses are illnesses or infections that people can naturally contract from vertebrate animals  World Health Organization (WHO),(2024). Many zoonotic diseases—such as rabies, leishmaniasis, and anthrax—are often neglected, especially in developing countries where poor environmental conditions and limited healthcare contribute to their spread  Pal M. , (2018). Rabies is a highly lethal and often overlooked tropical disease. Its control is difficult as it is frequently dismissed as an endemic zoonotic illness. World Health Organization (WHO). ,(2015). This highly lethal viral zoonosis, spread by bats, infects humans and mammals— including pets, livestock, and wildlife—causing fatal encephalomyelitis.  Pal M,et al., (2024).Rabies is a viral, zoonotic disease that primarily affects mammals, including humans. It is caused by the rabies virus, a member of the Lyssavirus genus. The virus is typically transmitted through the saliva of infected animals via bites, scratches, or open wounds. In humans, rabies is almost always fatal once clinical symptoms appear, but it is preventable with prompt and appropriate medical intervention. Swinkels HM et.al., (2025) Rabies’ lethality in mammals stems from its impact on the nervous system. It is caused by a neurotropic, negative-sense, single-stranded RNA virus. Madhusudana SN, et al., (2012). Rabies almost always leads to death and is primarily transmitted from rabid animals to humans through bites or scratches involving infectious saliva. Humans can contract the disease from both domestic and wild animals, typically through bites. Pal M, et al., (2013) Transmission usually occurs when the saliva of an infected host is transferred to an uninfected animal. The most common route of rabies spread is through the bite or virus-contaminated saliva of an infected host. Wiedeman J, et al., (2012) Although rabies is preventable with vaccines, it remains a major public health issue in developing countries. The rabies vaccine can be used both pre- and post-exposure, with dog vaccination being highly effective in preventing human transmission and safe for all age groups.  World Health Organization., (2010)

Etiology

RABV and related rabies-like viruses are zoonotic, neurotropic, bullet-shaped RNA viruses of the genus Lyssavirus (family Rhabdoviridae, order Mononegavirales). Fooks AR et al., 2017 Enhanced surveillance and sequencing reveal high genetic diversity among lyssaviruses, with 14 species beyond RABV known to cause rabies. Some lineages are widespread, while others are rare and poorly characterized. RABV likely originated from bats and evolved through host-switching among dogs, bats, and other animals. Ma X et al., (2021)  Seven major RABV lineages exist globally, each tied to specific hosts and regions. Lacy M, et al., (2024) The most widespread lineage affects dogs and wildlife across Europe, Africa, the Americas, and Asia. Bat-associated strains in Latin America continue to infect humans and livestock. Ongoing viral diversification raises concerns about the long-term effectiveness of current rabies vaccines and HRIG. Lacy M, et al., (2024)

Species Affected

All mammals can potentially contract rabies, but only certain species act as reservoir hosts. These are mainly in the families Canidae (e.g., dogs, foxes, jackals), Mustelidae (skunks, ferret badgers), Viverridae (mongooses, genets), Procyonidae (raccoons), and the order Chiroptera (bats). Unusual reservoirs include marmosets (Callithrix jacchus) in Brazil and greater kudu (Tragelaphus strepsiceros) in parts of Africa. While cats can get rabies, no cat-adapted variants have been identified. Birds can be experimentally infected and, in rare cases, naturally infected. Center for Food Security and Public Health (CFSPH).,2021

Rabies Virus Distribution and Sources of Transmission

Rabies viruses are found worldwide except in Antarctica and can infect all mammals, including pets, livestock, and wildlife.Fooks AR, et al.,(2017) While most Lyssaviruses are bat-borne, RABV is primarily maintained by mesocarnivores like dogs, raccoons, mongooses, and skunks.Fooks AR, et al.,(2017) Even rabies-free countries may harbor other Lyssaviruses. RABV accounts for the vast majority of the global rabies disease burden (CDC Yellow Book).Though wild animals can transmit rabies, over 99% of human cases globally come from unvaccinated domestic dogs. Gibbons K, Dvoracek K. (2023) In contrast, wildlife accounts for over 90% of RABV cases in the U.S.Gibbons K, Dvoracek K. (2023)  In 2022, 3,579 animal rabies cases were reported, mainly in bats (34.0%), raccoons (28.3%), skunks (18.4%), and foxes (27.5%). Ma X et al.,(2021) Most domestic animal cases involved unvaccinated cats (6.2%), dogs (1.4%), and cattle (1.2%). Rabies is most common in areas where raccoon variant RABV is enzootic and spills over into other species. Fooks AR, et al., (2017) Small rodents, rabbits, and hares are rarely infected with rabies and are not known reservoirs; no human transmission has been reported in the U.S. However, larger rodents like groundhogs and beavers can act as reservoirs, and rodents transmit Lyssaviruses in parts of Africa. Fooks AR, et al.,(2017) Rare transmission has occurred via corneal, organ, or vascular transplants, or aerosolized virus in caves or labs. Human-to-human transmission outside these scenarios is extremely rare (CDC Yellow Book).

Transmission and Incubation

Rabies is most commonly transmitted through bites from infected dogs, which are responsible for approximately 99% of human cases. Other animals, such as bats, raccoons, and foxes, can also transmit the virus. The incubation period—the time from exposure to the onset of symptoms—can vary, typically ranging from one week to one year, depending on factors like the location of the entry site and the amount of virus introduced. All warm-blooded animals can transmit lyssaviruses, and cold-blooded animals’ cells may support viral replication.Mustafa M, et al., (2015) Transmission typically occurs through bites, as the virus is present in saliva.Langley RL.  2009 Saliva-contaminated scratches can also spread the virus, though much less efficiently—about 50 times lower. Fishbein DB, et al.,(1993) Rare human-to-human transmission has occurred through organ transplants, but it is otherwise extremely uncommon. Srinivasan A, et al., ( 2005)

Clinical Sign of Rabies

Rabies symptoms in animals are often non-specific.Slate D,  et al., ( 2009 )Common signs include behavioral changes, fever, appetite loss, altered vocalization, aggression, jaw paralysis, and excessive salivation.Most infected animals show central nervous system (CNS) disturbances, with variations by species. The disease typically progresses through three phases: prodromal, excitative (furious), and paralytic (end-stage). Shankar SK, et al.,(2012) Initial symptoms of rabies are often nonspecific and may include fever, headache, and general weakness or discomfort. As the infection progresses, more severe symptoms can develop, including:

• Anxiety, confusion, agitation
• Hydrophobia (fear of water)
• Aerophobia (fear of drafts or fresh air)
• Paralysis
• Hallucinations
• Insomnia

There are two forms of rabies:

• Furious rabies: Characterized by hyperactivity, excitability, and hydrophobia.
• Paralytic rabies: Involves gradual paralysis, starting at the site of the bite or scratch.

Diagnosis

Diagnosis is challenging before the onset of symptoms and typically relies on a history of exposure to potentially rabid animals and clinical signs. Once symptoms appear, rabies is nearly always fatal. Accurate rabies diagnosis relies on WHO- and OIE-recommended lab tests to detect the virus or its components. World Health Organization (WHO) ,2024. This is vital in animals to guide timely human post-exposure prophylaxis (PEP), which includes vaccination and immunotherapy. Diagnosis can occur in vivo or post-mortem, Consales CA, Bolzan VL.  (2007) though ante-mortem testing is difficult. Confirmation typically requires CNS tissue analysis after death. Yousaf MZ, et al.,( 2012) While signs like hydrophobia may suggest rabies, no symptoms are definitive. The use of Negri bodies is outdated due to low sensitivity, and more reliable lab-based tests are now standard Abera E,  et al., ( 2015).

Differential Diagnosis

The differential diagnoses for rabies include the following:

• Guillain–Barré syndrome
• Psychosis
• Seizures
• Poisoning with belladonna alkaloids
• Cerebral malaria
• Meningitis
• Acute encephalitis from any other infectious or noninfectious causes
• Poliomyelitis
• Poisoning
• Metabolic causes such as hypoglycemia and thiamine deficiency
• Cerebrovascular accident
• Creutzfeldt–Jakob disease
• Brain tumor
• Neurosyphilis
• Tetanus
• Autoimmune encephalitis

Treatment

Post-exposure prophylaxis (PEP) is the standard treatment following potential exposure to rabies. PEP involves:

• Immediate and thorough wound cleaning with soap and water
• Administration of a series of rabies vaccinations
• In some cases, rabies immunoglobulin (RIG) to provide immediate passive immunity

PEP is highly effective when administered promptly and correctly.

Pre-exposure rabies management, as recommended by the WHO, includes preventive vaccination for anyone handling infected or potentially infected materials. The schedule involves three doses on days 0, 7, and 28. Antibody levels should be tested 1–3 weeks after the final dose. Lab workers require re-evaluation every 6 months, while other professionals should be tested every 2 years. Boosters are advised if antibody levels drop below 0.5 IU/mL or, in the absence of testing, annually with follow-up boosters every 1–3 years. Blanton JD, et al., ( 2007).

Post-exposure control requires animals exposed to suspected rabid animals to undergo a strict 6-month quarantine. A rabies vaccine should be given before or one month prior to release. Currently, no licensed PEP products exist for unvaccinated domestic animals. Vaccines alone may not always provide full protection. Garedaghi Y, Bahavarnia SR., (2014) Decisions on boosters should be made on a case-by-case basis, factoring in exposure risk, time since last dose, vaccination history, animal health, and local rabies trends.Garedaghi Y ,et al., (2020)

Prognosis

Rabies is almost always fatal once symptoms develop, but post-exposure prophylaxis (PEP) is nearly 100% effective when given promptly and correctly. Treatment failures usually result from delays in starting PEP, improper administration of rabies immunoglobulin (RIg) or vaccine, or the use of substandard or counterfeit biologics. Once the virus reaches the central nervous system, PEP is no longer effective.

Complications

Complications associated with rabies can include:

• Seizures
• Fasciculations (muscle twitches)
• Psychosis
• Aphasia (loss of the ability to speak or understand language)
• Autonomic instability (issues with heart rate, blood pressure, etc.)
• Paralysis
• Coma
• Death

Consultations

Consultations typically requested for patients with rabies include:

• Neurologists– to manage neurological complications such as seizures, paralysis, and cognitive issues.
• Infectious disease physicians– to assist with the diagnosis, management, and treatment of rabies and associated infections.
• Intensivists– for critical care management, especially in cases involving coma or severe autonomic instability.
• Local or state public health authorities or the National Center for Disease Control– to assist with disease surveillance, reporting, and coordinating public health efforts.

Prevention and Control of Rabies

Rabies is a widespread, legally notifiable disease, except in bats. It is preventable with timely vaccination, even after exposure. Vaccines are available for dogs, cats, and livestock. Unvaccinated dogs, cats, or ferrets exposed to rabies should be euthanized. Vaccination should occur at quarantine entry or at least 28 days before release. Regardless of vaccination status, exposed healthy animals should be observed for 10 days. Garedaghi Y. (2013). Rabies control is mainly handled by veterinary authorities, but highlighting its public health impact can motivate the health sector to engage. Collaboration between medical and veterinary sectors is essential. Prevention in humans involves responsible pet ownership, regular vet care, vaccination, and public awareness. High-risk individuals—like vets, lab staff, and animal handlers—should get pre-exposure vaccines. If exposed, timely post-exposure prophylaxis (PEP), including wound care, immunoglobulin, and vaccines, can prevent the disease. Garedaghi Y. (2020).

Preventing rabies involves several strategies:

• Vaccination of dogs: Mass dog vaccination programs are the most effective way to prevent rabies in humans, as dogs are the primary source of transmission.
• Public education: Teaching communities about avoiding animal bites, recognizing symptoms of rabies, and seeking immediate medical care after potential exposures.
• Pre-exposure prophylaxis (PrEP): Vaccinating individuals at high risk of exposure, such as veterinarians and animal handlers, before potential contact with rabies-infected animals.

Global Impact and Control Efforts

Rabies remains a significant public health issue in many parts of the world, particularly in Asia and Africa. The World Health Organization (WHO) has initiated the “Zero by 30” strategy, aiming to eliminate dog-mediated human rabies by 2030 through mass dog vaccination, improved access to PEP, and enhanced public awareness campaigns.

Conclusion and Recommendations

Rabies is a neglected tropical disease and a major global health concern, especially in regions with limited resources for prevention and control. Caused by the Lyssavirus genus, it is a deadly zoonotic disease that affects mammals worldwide, threatening both humans and animals. Although effective vaccines exist for dogs, cats, and livestock, rabies continues to persist in many developing countries.

Recommendations Based on the Above Conclusion:

• Promote Responsible Pet Ownership:Encourage the public to care properly for pets, ensure regular veterinary check-ups, and participate in widespread vaccination programs.
• Enhance Public Education:Increase awareness about rabies symptoms, transmission, and prevention through community outreach and education initiatives.
• Support Global Eradication Efforts:Achieving the WHO’s 2030 goal to eliminate rabies as a public health threat requires continuous research, robust surveillance systems, and strong international collaboration.

 Reference-

1. Abera E, Assefa A, Belete S, Mekonen N. Review on rabies, with emphasis on disease control and eradication measures. Int J Basic Appl Virol. 2015;4(2):60-70. doi: 10.5829/idosi. ijbav.2015.4.2.95273.
2. Blanton JD, Palmer D, Christian KA, Rupprecht CE. Rabies surveillance in the United States during 2007. J Am Vet Med Assoc. 2008;233(6):884-97. doi: 10.2460/javma.233.6.884.
3. Center for Food Security and Public Health (CFSPH). Rabies and Rabies-Related Lyssaviruses. Iowa State University; 2021. Available from: https://www.cfsph.iastate.edu/.
4. Consales CA, Bolzan VL. Rabies review: immunopathology, clinical aspects and treatment. J Venom Anim Toxins Incl Trop Dis. 2007;13(1):5-38. doi: 10.1590/s1678 91992007000100002.
5. Fishbein DB, Yenne KM, Dreesen DW, Teplis CF, Mehta N, Briggs DJ. Risk factors for systemic hypersensitivity reactions after booster vaccinations with human diploid cell rabies vaccine: a nationwide prospective study. Vaccine. 1993;11(14):1390-4. doi: 10.1016/0264-410x(93)90167-v.
6. Fooks AR, Cliquet F, Finke S, Freuling C, Hemachudha T, Mani RS, Müller T, Nadin-Davis S, Picard-Meyer E, Wilde H, Banyard AC. Rabies. Nat Rev Dis Primers. 2017 Nov 30;3:17091. [PubMed]
7. Garedaghi Y, Bahavarnia SR. Repairing effect of Allium cepa on testis degeneration caused by Toxoplasma gondii in the rat. Int J Womens Health Reprod Sci. 2014;2(2):80-9. doi: 10.15296/ijwhr.2014.12.
8. Garedaghi Y, Shabestari Asl A, Shokri A. Prevalence of Toxocara cati in pet cats and itʼs zoonotic importance in Tabriz city, Iran. J Zoonotic Dis. 2020;4(3):61-6. doi: 10.22034/ jzd.2020.11282.
9. Garedaghi Y. Prevalence and fertility of hydatid cyst in slaughtered farm animals of Tabriz city, Iran. Life Sci J. 2013;10(Suppl 5):190-3.
10. Garedaghi Y. Protection of parasites against COVID-19 and other viruses. Int J Med Parasitol Epidemiol Sci. 2020;1(1):1-2. doi: 10.34172/ijmpes.2020.01.
11. Gibbons K, Dvoracek K. Rabies postexposure prophylaxis: What the U.S. emergency medicine provider needs to know. Acad Emerg Med. 2023 Nov;30(11):1144-1149. [PubMed]
12. Lacy M, Phasuk N, Scholand SJ. Human Rabies Treatment-From Palliation to Promise. Viruses. 2024 Jan 22;16(1) [PMC free article] [PubMed]
13. Langley RL. Human fatalities resulting from dog attacks in the United States, 1979-2005. Wilderness Environ Med. 2009;20(1):19-25. doi: 10.1580/08-weme-or-213.1.
14. Ma X, Bonaparte S, Corbett P, Orciari LA, Gigante CM, Kirby JD, Chipman RB, Fehlner-Gardiner C, Thang C, Cedillo VG, Aréchiga-Ceballos N, Rao A, Wallace RM. Rabies surveillance in the United States during 2021. J Am Vet Med Assoc. 2023 Jul 01;261(7):1045-1053. [PubMed]
15. Madhusudana SN, Subha S, Thankappan U, Ashwin YB. Evaluation of a direct rapid immunohistochemical test (dRIT) for rapid diagnosis of rabies in animals and humans. Virol Sin. 2012;27(5):299-302. doi: 10.1007/s12250-012-3265-6.
16. Mustafa M, Ellzam EM, Sharifa AM, Rahman MS, Sien MM, Nang MK. Rabies a zoonotic disease, transmission, prevention and treatment. J Dent Med Sci. 2015;14(10):82-7.
17. Pal M, Hailu A, Agarwal RK, Dave P. Recent developments in the diagnosis of rabies in humans and animals. J Vet Public Health. 2013;11(2):77-82.
18. Pal M, Rebuma T, Regassa M, Gutema C, Mazzeo A. Endemic rabies in Ethiopia in the one health era. Am J Public Health Res. 2024;12(2):22-32. doi: 10.12691/ajphr-12-2-2.
19. Pal M. Anthrax: a neglected bacterial zoonosis of major public health concern. Acta Sci Microbiol. 2018;1(5):78-9.
20. Shankar SK, Mahadevan A, Sapico SD, Ghodkirekar MS, Pinto RG, Madhusudana SN. Rabies viral encephalitis with proable 25-year incubation period! Ann Indian Acad Neurol. 2012;15(3):221-3. doi: 10.4103/0972-2327.99728.
21. Slate D, Algeo TP, Nelson KM, Chipman RB, Donovan D, Blanton JD, et al. Oral rabies vaccination in North America: opportunities, complexities, and challenges. PLoS Negl Trop Dis. 2009;3(12):e549. doi: 10.1371/journal.pntd.0000549.
22. Srinivasan A, Burton EC, Kuehnert MJ, Rupprecht C, Sutker WL, Ksiazek TG, et al. Transmission of rabies virus from an organ donor to four transplant recipients. N Engl J Med. 2005;352(11):1103-11. doi: 10.1056/NEJMoa043018.
23. Swinkels HM, Koury R, Warrington SJ. Rabies. [Updated 2025 Mar 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448076/
24. Wiedeman J, Plant J, Glaser C, Messenger S, Wadford D, Sheriff H, et al. Recovery of a patient from clinical rabies California, 2011. JAMA. 2012;307(13):1364-7.
25. World Health Organization (WHO). Rabies – Bulletin – Europe. Available from: https://www.who-rabies-bulletin.org. Accessed January 14, 2024.
26. World Health Organization (WHO). The Control of Neglected Zoonotic Diseases: From Advocacy to Action: Report of the Fourth International Meeting Held at WHO Headquarters. Geneva, Switzerland: WHO; 2015.
27. World Health Organization (WHO). Zoonoses. Available from: https://www.who.int/news-room/fact-sheets/detail/ zoonoses. Accessed January 13, 2024.
28. World Health Organization. Rabies vaccines: WHO position paper. Wkly Epidemiol Rec. 2010;85(32):309-20.
29. Yousaf MZ, Qasim M, Zia S, Khan M, Ashfaq UA, Khan S. Rabies molecular virology, diagnosis, prevention and treatment. Virol J. 2012;9:50. doi: 10.1186/1743-422x-9-50.

Please follow and like us: