2001 Anthrax Attacks Fast Facts Here’s a look at the 2001 anthrax attacks, also referred to as Amerithrax. Facts about anthrax There are three types of anthrax infection: cutaneous (through the skin), inhalation (through the lungs; the most deadly) and gastrointestinal (through digestion). There has been a fourth type of anthrax identified as injection anthrax. This is common in heroin-injecting users in northern Europe. This has never been reported in the United States. It can be contracted by handling products from infected animals or by breathing in anthrax spores and by eating undercooked meat from infected animals. Anthrax has been blamed for several plagues over the ages that killed both humans and livestock. It emerged in World War I as a biological weapon.