In a single month last August, three people in the United States died of bat rabies

CDC: Three Human Rabies Deaths Attributed to BatExposures — United States, August 2021 – Died of Rabies due to exposure to bats in August 2021

(A special reminder to patients with phobia: According to the available research data, bat rabies currently causes a certain degree of harm in the Western Hemisphere. And throughout the Eastern Hemisphere, the harm of bat rabies is actually very small! To date, no directly confirmed case of bat rabies has been reported in major Asian countries, such as China and India. ）

Between September 28 and November 10, 2021, the U.S. Centers for Disease Control and Prevention (CDC) confirmed that three people died from rabies, all of whom did not seek post-exposure prophylaxis (PEP) measures after exposure to bats in August 2021. In the United States, in the 4 years before the increase in the number of bat-related human rabies deaths, only 3 people died of rabies in total. The three cases in the fall of 2021 were two adults and one child, both male, in Idaho, Illinois and Texas.

Initial symptoms include pain and paresthesias near the exposed site and gradually progress to dysphagia, altered mental status, paralysis, epileptic behavior, and autonomic instability. All 3 patients were confirmed to have direct contact with bats (such as bites or collisions) about 3-7 weeks before symptoms appeared and died about 2-3 weeks after symptoms appeared.

These deaths were linked to three species of bats: the silver-haired bat (Lasionycteris noctivagans), the Mexican tailless bat (Tadarida brasiliensis) and the great brown bat (Eptesicus fuscus) (pictured). All three species of bats are common in the United States and have been involved in previous cases of rabies. One patient submitted the bat that caused the exposure for testing, but refused to do the PEP, even though the bat's rabies virus test was positive because of the patient's long-standing fear of vaccines.

The other two patients were unaware of the risk of exposure to rabies, either because they did not notice bites or scratches or because they did not realize that bats were a potential source of rabies. Case and exposure investigations are conducted by the relevant state and local health departments, and all laboratory tests involving humans are conducted at CDC. This activity is reviewed by the U.S. CDC and conducted in accordance with applicable federal laws and U.S. CDC policies.

Three species of bats are illustrated in connection with three human rabies exposures in the United States in August 2021:

A) Great brown bat (Eptesicus fuscus),

B) Silver-haired bats (Lasionycteris noctivagans),

C) Tadarida brasiliensis

Photo-related patients: A / unidentified patients; Photo B/Mark Mayfield; Photo C/Stephen Gergeni.

Rabies is a zoonotic disease that is transmitted mainly by the saliva of the virus after being bitten by an infected mammal. The typical incubation period from exposure to the onset of symptoms is 3 - 12 weeks. Rabies is almost always fatal once symptoms develop, but rabies is almost always preventable, as long as the PEP is implemented in accordance with the recommendations of the Advisory Committee on Immunization Practices (ACIP).

In the 58 years from 1960 to 2018, a total of 89 cases of human rabies occurred in the United States, of which about 70% of the cases were due to exposure to bats. Although human rabies deaths in the United States are rare, rabies-stricken animals and rabies exposure are relatively common. Bats with rabies have been reported in all states except Hawaii since 2014. In 2020, public health programs tested about 24,000 bats for rabies, of which 1,401 (5.8%) were confirmed positive (Note: The vast majority of bats selected for testing were suspected of having contact with humans or with suspected rabies symptoms). The positivity rate in ordinary bats cannot be so high).

The CDC estimates that 60,000 people are treated each year with rabies PEP after exposure to animals, and about two-thirds of them may be attributed to bats, depending on the local rabies epidemiology.

Preventing the spread of rabies from bats to humans can be achieved by: 1) avoiding contact with bats; 2) Safe capture and rabies testing of bats associated with human exposure; 3) When direct contact with bats occurs and rabies cannot be ruled out, seek a rapid assessment of the necessity of PEP.

Of the bat-related cases that occurred in the fall of 2021, two were thought to have been avoidable exposures: one due to bats roosting in the patient's home, and the other due to the patient picking up the bat with his bare hands. Safely removing bats from their homes and warning people against bat exposure can prevent exposure to rabies. Two patients released the bat after already contact, rather than capturing it and testing it. When a person knows that bats have been or are likely to be exposed (e.g., while sleeping), the bat should be captured as safely as possible and tested for rabies in a qualified laboratory.

Timely bat rabies detection can save lives by ensuring that people at high risk of rabies have access to PEP and reduce the cost, time, and waste of resources associated with unnecessary PEPs. PEP should be considered for anyone who has direct contact with bats, unless the bat tests negative for rabies or public health officials can reasonably determine that there is no risk of exposure.

Bats have seasonal patterns of activity and are critical species from an ecological point of view. Although bat activity decreases during the winter, from late spring to early autumn, the chances of human contact with bats often increase again. Avoiding contact with bats is the best way to protect the health of bats and humans. When human contact with bats is inevitable, rabies testing for bats and PEPing people are very effective strategies to save human lives.

bibliography:

Three Human Rabies Deaths Attributed to BatExposures — United States, August 2021 (3 people in the United States died of rabies from bat exposure), Morbidity and Mortality Weekly Report (MMWR) / January 7, 2022 / Vol. 71 / No.1.

https://www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7101a5-H.pdf