The University of Sydney led study found many antibiotics recommended by the World Health Organization (WHO) had less than 50 per cent effectiveness in treating childhood infections such as pneumonia, sepsis (bloodstream infections) and meningitis.
The most seriously affected regions are in South-East Asia and the Pacific, including neighbouring Indonesia and the Philippines, where thousands of unnecessary deaths in children resulting from antibiotic resistance occur each year.
Lead author Phoebe Williams from the University's School of Public Health, said there are increasing cases of multidrug-resistant bacterial infections in children around the world.
AMR is more problematic for children than adults, as new antibiotics are less likely to be trialled on, and made available to, children.
Dr Williams said the study should be a wake-up call for the whole world.
"The burden of antimicrobial resistance is on our doorstep," she said.
"Antibiotic resistance is rising more rapidly than we realise. We urgently need new solutions to stop invasive multidrug-resistant infections and the needless deaths of thousands of children each year."
The WHO has declared antimicrobial resistance (AMR) is one of the top 10 global public health threats facing humanity. In newborns, an estimated three million cases of sepsis occur globally each year, with up to 570,000 deaths: many of these are due to lack of effective antibiotics to treat resistant bacteria.
The research reveals the urgent need for global antibiotic guidelines to be updated, to reflect the rapidly evolving rates of AMR. The most recent guideline from the WHO was published in 2013.
Further, the study found one antibiotic in particular, ceftriaxone, was likely to be effective in treating only one in three cases of sepsis or meningitis in newborn babies.
Another antibiotic, gentamicin, was found likely to be effective in treating fewer than half of all sepsis and meningitis cases in children.
Gentamicin is commonly prescribed alongside aminopenicillins, which the study showed also has low effectiveness in combating bloodstream infections in babies and children.
The study analysed 6,648 bacterial isolates from 11 countries across 86 publications to review antibiotic susceptibility for common bacteria causing childhood infections.
Wiliams said the best way to tackle antibiotic resistance in childhood infections is to make funding to investigate new antibiotic treatments for children and newborns a priority.
"Antibiotic clinical focus on adults and too often children and newborns are left out. That means we have very limited options and data for new treatments." IANS/KB
