In recent years, movies like World War Z and 28 Days Later have captivated our imagination with apocalyptic scenarios where mutating infections turn people into flesh-eating zombies.
Add to that the memory of the SARS virus, which spread in the early 2000s, and the Zika virus that has become a global concern and the threat actually starts to sound real.
But according to a broad consensus among health experts, the biggest worry for the world right now is the increasing number of infections, which have started to resist antibiotics of last resort.
Last week a report emerged about a woman in the US who was found to be carrying a bacteria, which is resistant to colistin, an antibiotic reserved to fight ‘nightmare bacteria.’
The 49-year-old woman from Pennsylvania visited a clinic in April with the complaint of a common urinary tract infection. But the tests showed that her infection had traces of a gene called mcr-1.
The mcr-1 was first found in China last year in people and pigs.
It is being classified as the first case of its kind, raising alarm bells that easily treatable infections could become a serious problem.
"We risk being in a post-antibiotic world," said Thomas Frieden, director of the US Centers for Disease Control and Prevention, referring to the Pennsylvania woman who had not travelled within the prior five months.
The infection was reported in a study appearing in Antimicrobial Agents and Chemotherapy, a publication of the American Society for Microbiology.
"(This) heralds the emergence of truly pan-drug resistant bacteria," said the study, which was conducted by the Walter Reed National Military Medical Center. "To the best of our knowledge, this is the first report of mcr-1 in the USA."
Every year 700,000 people die because of superbugs around the world, according to the most recent UK sponsored report on antimicrobial resistance.
And this number could go up to 10 million a year by 2050 if immediate steps are not taken.
There was a time when the antibiotic resistant bacteria was confined to hospitals. But now people share stories of catching it from everywhere – from used clothes to getting a scratch on the knee.
Overprescribing of antibiotics by physicians in hospitals and their extensive use in food livestock have contributed to the crisis.
More than half of all hospitalised patients will get an antibiotic at some point during their stay. But studies have shown that 30 percent to 50 percent of antibiotics prescribed in hospitals are unnecessary or incorrect, contributing to antibiotic resistance.
Many drugmakers have been reluctant to spend the money needed to develop new antibiotics, preferring to use their resources on medicines for cancer and rare diseases that command very high prices and lead to much larger profits.