What is Rabies?

Rabies is a serious viral disease that is both fatal and preventable. It can be transmitted to humans and pets through bites or scratches from an infected animal. The virus primarily affects the central nervous system, leading to severe neurological complications and death if medical treatment is not administered before symptoms manifest.

Immediate medical attention is essential following any potential exposure to rabies. This treatment, known as post-exposure prophylaxis (PEP), includes comprehensive wound care, the administration of human rabies immune globulin (HRIG), and a series of four or five rabies vaccines. These interventions should be initiated as soon as possible after exposure to effectively prevent the disease's onset. When PEP is administered promptly, it is nearly 100% effective. Approximately 60,000 Americans receive PEP each year after possible rabies exposure.

While rabies is rare in humans in the United States, with fewer than ten deaths reported annually, it poses a significant public health risk due to its high mortality rate. The virus is widespread among various wildlife species, and nearly three-quarters of Americans live in areas where raccoons, skunks, or foxes may be carriers.

Extra precautions should be taken by individuals who work with bats, as they are a common reservoir for rabies. Those involved in wildlife rehabilitation, research, or activities that may expose them to bats must be especially diligent about rabies prevention. Furthermore, travelers to regions where rabies is more prevalent, particularly those with limited medical resources, should consider receiving pre-exposure rabies vaccinations, especially if they plan to participate in activities that may bring them into contact with potentially rabid animals.

Program Management

For questions or more information about rabies protocols and the rabies vaccine, please contact UCR Occupational Health at ehsocchealth@ucr.edu. You may need to provide details about your IACUC protocol or Field Safety Plan to participate in the programs.

• UCR Protocol for Rabies Full Series:

  1.  Rabies Vaccine Series:

  • First Dose: Start the series by receiving your first rabies vaccine dose.
  • Second Dose: Seven days after your initial dose, you must receive your second rabies vaccine. Ensure that these vaccinations are scheduled and completed in coordination with the clinic staff.  

  2. Titer Assessment:

  • Four weeks after your second rabies vaccine, it is crucial to have your titer levels checked to confirm immunity.

  3.  Scheduling and Vaccine Availability:

  • Before leaving the clinic after your first vaccine dose, make sure to schedule your follow-up appointments. Notify the clinic in advance so they can arrange for the rabies vaccine for your second visit and prepare for the titer test required four weeks later.
• UCR Protocol for Rabies Booster Only:

  1.  A Single Booster:

  • Administered between three weeks and three years after the initial dose in the primary series.
  • The ACIP recommends that a minimum acceptable rabies antibody titer of 0.5 IU/mL be used to determine whether a booster dose is needed, consistent with guidance from the World Health Organization.

  2. Titer Assessment:

  • Four weeks after your rabies booster vaccine, it is essential to check your titer levels to ensure immunity.

  3.  Scheduling and Vaccine Availability:

  • Before leaving the clinic after receiving your rabies booster, coordinate with the clinic staff to schedule your titer assessment.
• Reporting Incidents

  All incidents involving rabies injuries should be reported to Environmental Health and Safety (EH&S) using the online reporting system. Given that rabies is classified as a reportable disease in the United States, it is essential to contact your state's public health officials immediately.

  Additional Important Information:

  • For guidance on post-exposure prophylaxis for rabies, refer to the Riverside County Rabies Post-Exposure Prophylaxis Guide: Rabies Flowchart.
  • Visit the California Department of Public Health's page for local health departments regarding rabies: CDPH Rabies Resources.
  • Relevant regulations include Title 17 of the California Code of Regulations (CCR) §2500, §2593, §2641.5-2643.20, and §2800-2812, which cover reportable diseases and conditions.
  • For additional protocols, you can view the San Diego County Rabies PEP Algorithm: PEP Algorithm.

  Please ensure to act swiftly and follow the proper reporting procedures to help manage rabies exposure effectively.

Rabies Information

• What causes rabies?

  Rabies is caused by the rabies virus, which typically enters the body through cuts or scratches, or through mucous membranes, such as those in the mouth and eyes. Once inside, the virus travels to the central nervous system, and from there, it spreads to the brain. The virus replicates in various organs as it progresses through the nervous system.

  The salivary glands play a crucial role in the transmission of rabies. When an infected animal bites another animal, the virus is transmitted through the saliva. Additionally, scratches from rabid animals can also pose a risk, as these animals often lick their claws, potentially contaminating them with saliva containing the virus.​

  For further details, you can explore more on rabies at the following sources:

  CDC Rabies Overview

  
  California Department of Public Health Rabies Information

• Who is at risk for rabies at University of California, Riverside (UCR) ?

  At the University of California, Riverside (UCR), certain groups are at a higher risk for rabies exposure due to their activities and interactions with animals. Those most at risk include:

  1. Veterinary and Animal Care Staff: Individuals working with pets, livestock, or wildlife are at a higher risk due to potential bites or exposure to saliva from infected animals.
  2. Research Personnel: Those involved in laboratory work with potentially rabid animals or viral samples may be exposed to the rabies virus during their research activities.
  3. Wildlife Handlers: Employees or students engaged in fieldwork that involves interaction with wildlife, particularly bats, skunks, and raccoons, are at increased risk. These animals are common carriers of rabies.
  4. Recreational Users: Anyone who frequently visits areas where bats or other wildlife are present, such as caves or parks, may also be at risk.
  5. Pet Owners: Individuals with pets, particularly those that may interact with wildlife, should be aware of the risks and ensure their pets are vaccinated against rabies.

  To mitigate the risk, it is advised that individuals in these groups take precautions such as avoiding contact with wild animals, using protective equipment when handling animals, and ensuring timely vaccination of pets. If bitten or exposed to potentially rabid animals, it is critical to seek medical attention immediately:

  Spotlight On Safety: Rabies

• What are the sign and symptoms?

  After a rabies exposure, the virus must travel to the brain before symptoms develop. This period, known as the incubation period, can last from weeks to months.

  Initially, the symptoms of rabies may resemble those of the flu, including weakness, discomfort, fever, and headaches. Individuals may also experience sensations such as discomfort, prickling, or itching at the bite site. These early symptoms can persist for several days. Severe neurological symptoms typically manifest within two weeks after the onset of initial symptoms, indicating brain dysfunction. Common signs during this stage include anxiety, confusion, agitation, and hallucinations.

  Once clinical symptoms appear, rabies is almost always fatal, and treatment focuses primarily on supportive care.

  Assessing Suspected Rabies Exposure
  While most rabies exposures require prompt medical attention, an immediate emergency room visit may not be necessary unless the wound requires urgent care. A patient should be assessed for rabies-related treatment under the following circumstances:

  • Direct contact with bats, unless it can be definitively ruled out that no bite or scratch occurred.
  • Exposure to high-risk animals, which generally include bats, raccoons, skunks, foxes, and mongooses.
  • Severe exposures, such as multiple bites or those affecting the head and neck.
  • Involvement of young children, who may be more vulnerable.

  When evaluating the need for post-exposure prophylaxis (PEP) after a suspected rabies exposure, several factors should be considered:

  1. Geographic Location: Bats pose a rabies risk in every state except Hawaii. Other high-risk animals are typically region-specific in the U.S. In many countries outside the U.S., domestic dogs present the highest rabies risk.
  2. Type of Animal: Although all mammals can contract rabies, certain species are more likely to transmit the virus to humans, including bats, raccoons, skunks, foxes, and mongooses.
  3. Animal Behavior: Rabies can cause behavioral changes in animals that may not become apparent until several days after they become infectious. Unprovoked bites or scratches and visible signs of illness are often associated with rabid animals.

  A risk assessment should always be conducted by a health official knowledgeable about rabies. For assistance with a rabies risk assessment, contact your state or local health department​.  

  For further details, please refer to the links below:

  CDC Rabies Overview 

  California Department of Public Health's resources on rabies.

• What is Rabies Pre-Exposure Vaccination (PrEV) and what are the recommendations?

  While most people in the U.S. have a low risk of encountering rabies, certain groups face higher risks, such as those working closely with animals or traveling to regions where rabies is common. These individuals should receive rabies pre-exposure vaccination (PrEV), a series of doses to protect against rabies before potential exposure.

  Key updates to ACIP recommendations (2022):

  • New Schedule: A 2-dose PrEV schedule (days 0 and 7) has replaced the former 3-dose schedule, offering protection for up to 3 years.
  • Risk Groups: Five risk categories have been defined.
  • Booster and Titer Guidelines: Laboratory values to determine booster needs have been standardized, with many individuals requiring fewer titer checks or boosters.
    Many people for whom serial titers were recommended every 2 years now require only a one-time titer (and booster if below a certain level) OR a one-time booster.
    For detailed information about these recommendations, please refer to the published:

  Morbidity and Mortality Weekly Report (MMWR) 

  Information is taken from:

  Rabies Pre-exposure Prophylaxis

  Risk category	Who this typically affects	Recommendations
  Risk category 1 (Highest risk)	People who work with live or concentrated rabies virus in laboratories.	2 doses, days 0 and 7 Check titer every 6 months
  Risk category 2	People who frequently do at least one of the following: handle bats, have contact with bats, enter high-density bat environments like caves, or perform animal necropsies.	2 doses, days 0 and 7 Check titer every 2 years
  Risk category 3	People who interact with, or are at higher risk to interact, with mammals other than bats that could be rabid, for a period longer than three years after they receive PrEP. This group includes: Most veterinarians, veterinary technicians, animal control officers, wildlife biologists, rehabilitators, trappers, and spelunkers. (cave explorers) Certain travelers to regions outside of the United States where rabies in dogs is commonly found.	2 doses, days 0 and 7, plus: Either a one-time titer check after 1 year and up to 3 years following the first 2-dose vaccination Or 1-dose booster between 3 weeks and 3 years following the first vaccine in the 2-dose vaccination
  Risk category 4	Same population as risk category 3, but at a higher risk for ≤ three years after they receive PrEV.	2 doses, days 0 and 7
  Risk category 5 (Lowest risk)	General U.S. population.	None

   

   

• When is Rabies Post-exposure Prophylaxis (PEP) recommended?

  Rabies PEP is an essential treatment for preventing rabies after potential exposure. It involves a combination of wound care, administration of Human Rabies Immune Globulin (HRIG), and rabies vaccinations. The Advisory Committee on Immunization Practices (ACIP)sets the guidelines for how rabies vaccines should be administered to prevent the disease.

  PEP Overview:

  1. Wound Washing: Immediate and thorough cleaning of the wound with soap and water or a povidone-iodine solution can reduce the risk of rabies and other infections.
  2. HRIG and Vaccine: For those not previously vaccinated, PEP includes HRIG and rabies vaccine given on the first visit, followed by additional doses on days 3, 7, and 14. Pregnant individuals can safely receive rabies PEP, and exposure does not require pregnancy termination.

  Wound Care

  • Prompt cleaning of bite wounds reduces infection risk, especially when treated with water or a povidone-iodine solution.
  • Thorough cleansing is critical in rabies prevention, as it significantly lowers the likelihood of infection.
  • Antibiotics and wound closure should be decided in consultation with a healthcare provider.

  Rabies Vaccine

  • Individuals who have never been vaccinated against rabies should receive HRIG and the rabies vaccine after any bite or non-bite exposure, regardless of the time since exposure.
  • Those who have previously been vaccinated or received pre-exposure vaccination for rabies do not need HRIG and will only require two doses of the rabies vaccine, spaced 3 days apart.
  • It is important to follow the recommended vaccine schedule closely, though minor delays are acceptable. Longer deviations may reduce effectiveness.

  Human Rabies Immune Globulin (HRIG)

  • HRIG is administered only at the start of the PEP regimen to provide immediate antibodies until the vaccine induces a longer-term immune response.
  • The recommended dose is 20 IU/kg of body weight for all age groups.
  • HRIG should be injected around the wound, with any remaining amount given intramuscularly at a site away from where the vaccine was administered.
  • HRIG and the vaccine should never be given in the same syringe or at the same injection site.

  Key PEP Recommendations For Non-immunized Individuals:

  1. Wound Cleansing: Clean all wounds with soap and water immediately, followed by a virucidal agent such as povidone-iodine if available.
  2. HRIG: Administer the full HRIG dose around the wound(s), with any remaining amount given intramuscularly at a site distant from the vaccine administration.
  3. Vaccine: Administer 1.0 mL of HDCV or PCECV intramuscularly (deltoid for adults, anterolateral thigh for children) on days 0, 3, 7, and 14. A fifth dose on day 28 is recommended for individuals with immune disorders.

  For Previously Immunized Individuals:

  1. Wound Cleansing: Begin with immediate thorough cleaning of all wounds.
  2. HRIG: Should not be administered to previously vaccinated individuals.
  3. Vaccine: Administer 1.0 mL of HDCV or PCECV intramuscularly on days 0 and 3 (deltoid for adults, anterolateral thigh for children).

  PEP for International Exposure:

  • Rabies PEP received outside the U.S. may involve medications not used domestically. Upon return, further therapy may be required based on World Health Organization (WHO) guidelines.
  • If the PEP regimen abroad deviates from WHO recommendations or was incomplete, additional doses may be necessary.
  • In some countries, Equine Rabies Immune Globulin (ERIG) or unpurified anti-rabies serum might be used when HRIG is unavailable. ERIG is generally safe, but unpurified serum can lead to more severe reactions.

  PEP failures are rare in the U.S. but have occurred in other countries due to deviations from recommended protocols, such as improper wound cleaning or administering the vaccine in the wrong area (e.g., the gluteal area). It’s important to follow the correct regimen to prevent failure of PEP.

  For further information, consult international WHO guidelines on rabies post-exposure treatment.

  WHO Guidelines

• Resources

  American Veterinary Medical Association (AVMA)

  Biosafety Practices When Working with Bats: A Guide to Field Research Considerations

  Centers for Disease Control and Prevention - Rabies

  World Health Organization (WHO) Rabies