Anthrax (Bacillus anthracis) Liz Schwabel Wildlife Diseases
Background Information One of the oldest known diseases – B. anthracis was the first bacterium that was linked to disease Discovered by Robert Koch in 1877 – Mentioned in Greek and Roman literature – The 5 th plague in the Bible might have been anthrax – It could be used as biological warfare as demonstrated with the Anthrax letters in 2001
Bacillus anthracis – Gram Positive – Rod shaped – Produces lethal poison Poisons leave the cell and affect the area around it – Lives in the soil Alkaline rich soil is a good place to grow – Contain spores – It is the only bacterium known to synthesize a protein capsule – Are highly resilient bacteria that can survive harsh temperatures, chemicals, or low nutrient environments
Figure 1. Robert Koch's original photomicrographs of Bacillus anthracis, the agent of anthrax.
Who is Affected? Can strike all warm blood animals Requires iron to grow – Mostly cattle, sheep, pigs, goats etc. Is a problem in livestock of developing countries where they are not regularly vaccinated – Can also affect antelope, impala, elephants, and hyenas Birds are normally naturally immune to anthrax, although they can carry spores on their talons and feathers. – Includes humans, although livestock is at a higher risk
Transmission Three ways of transmission: – Ingesting infected food – Through contact with spore – Or contact with infected animals Causes three types of Anthrax – Cutaneous (most common form for humans) – Intestinal (most common for wildlife) – Respiratory ( most lethal for humans)
Infection Livestock ingest spores from contaminated food Bacteria lose capsule and germinate inside animal Release toxins that reduce permeability in blood capillaries, causing them to leak, and blood can not clot. Animal dies and is found with blood leaking from nose and mouth.
Symptoms Wildlife Sudden death of unknown cause Cutaneous – Lesions on the body Intestinal Respiratory – Trembling – Tongue, neck, throat swollen – Rapid breathing Humans Cutaneous – Boil like lesions on the face, hands or neck with black center – Lymph nodes under arms swell Intestinal – Stomach ache, nausea Respiratory – Symptoms like common cold and then escalate to difficult breathing and death
Treatment There is a human vaccine for Anthrax – Right now only military personnel and people who have an occupation that puts them at risk - Penicillin is used for treatment, although some strands are resistant to Penicillin Ciprofloxcin and doxycycline can also be used. Treatment of anthrax must continue for an extended period, generally sixty days.
Treatment continued There is also a vaccine for animals that lasts for about 9 months. Antibiotics are given to any animals showing slight symptoms of Anthrax
Management Vaccine is given to animals in an area where a case is confirmed Animals suspected may be quarantined Carcasses suspected of anthrax are not opened
Case Study Good et al Cheetahs in Jwaneng, Botswana – Cheetahs are unusually susceptible to anthrax This is thought to be because there lack of scavenging behavior and therefore can not build up an immunity to anthrax Outbreak occurred in 2004, having about 142 observed animals died from anthrax, including zebras, hartebeest, springbok, and a giraffe – Three captive cheetah died in November 2004 from Anthrax Anthrax came from infected meat given to the cheetahs Since many cheetahs were free-roaming on the game reserve, scientist took regular samples of them. – 12 samples were collected before the outbreak in March-Sept 2004 and 14 were taken after the outbreak between June and Oct 2005 – Samples were tested by ELISA for the PA of Bacillius Anthracis
Case Study continued Natural antibodies in one male cheetah – It was thought that he developed antibodies after being exposed to it in his homeland – First case of cheetah producing antibodies naturally Lions have been known to develop protective immunity to anthrax when living in areas with it
Conclusion Anthrax is caused by Bacillus Anthracis – One of the oldest discovered bacteria Affects mostly livestocks, but some humans as well – Birds are naturally resistant Can affect body in three ways – Cutaneous ( most common in humans) – Intestinal (most common in wildlife) – Respiratory Cheetahs may have antibodies for Anthrax There is a vaccine for both humans and wildlife
Sources "Anthrax (Bacillus Anthracis)." CSA. Web. 12 Feb "Anthrax: MedlinePlus." National Library of Medicine - National Institutes of Health. Web. 12 Feb "Bacillus Anthracis and Anthrax." Online Textbook of Bacteriology. Web. 11 Feb "Bacillus Anthracis Description." Pathema. Web. 15 Feb "CDC Anthrax." CDC Emergency Preparedness & Response Site. Web. 12 Feb Good, Kyle M. "Naturally Acquired Anthrax Antibodies in a Cheetah (Acinonyx Jubatus) in Botswana -- Good Et Al. 44 (3): 721." Journal of Wildlife Diseases. 3 July Web. 15 Feb "Spotlight: Anthrax in Animals." FAO: FAO Home. Web. 24 Feb Stoltenow, Charles L. "Anthrax." North Dakota State University, Web..
Questions?