What is the deadliest bacterial infection?

The deadliest bacterial infection in terms of total deaths globally is tuberculosis, caused by Mycobacterium tuberculosis, which kills about 1.3 to 1.5 million people every year despite being treatable, making it the leading infectious disease killer worldwide after COVID during pandemic years. Tuberculosis primarily affects the lungs, spreads through airborne particles when infected people cough, and can remain latent for years, requiring negative pressure rooms for containment in hospitals. Other extremely deadly bacterial infections include sepsis, which is a life-threatening response to bacterial infection that kills an estimated 11 million people annually worldwide when bacteria enter bloodstream, pneumonia caused by Streptococcus pneumoniae and other bacteria which kills hundreds of thousands of children and elderly each year, and cholera caused by Vibrio cholerae which can kill within hours from dehydration in outbreaks. Historically, plague caused by Yersinia pestis killed tens of millions, and remains deadly without treatment. In terms of case fatality rate, untreated bacterial infections like anthrax inhalation, bacterial meningitis, and necrotizing fasciitis caused by flesh-eating bacteria have very high death rates of 20 to 50 percent. The deadliness depends on access to antibiotics, healthcare, vaccination, and whether bacteria are antibiotic resistant, with drug-resistant TB and MRSA becoming increasingly deadly. Good ventilation, HEPA filtration, and prompt antibiotic treatment are critical for prevention and survival.