Hong Kong study finds prenatal screening drastically reduces infant deaths, illness from common bacterial infection

Widespread prenatal screening significantly reduces severe illness and deaths in newborns from a common bacteria passed on by mothers during pregnancy, a joint study by Hong Kong health authorities has found.

The findings were based on the universal screening of 300,000 mothers-to-be for Group B Streptococcus (GBS) bacteria under an initiative rolled out by the Hospital Authority and Department of Health between 2012 and 2020.

GBS, a bacteria commonly found in the intestinal, urinary and reproductive tracts, is usually passed on from the mother to her infant during labour. It is one of the most common causes of infections in newborns globally, with around 5 to 10 per cent of cases resulting in severe illness or death. While preventive vaccines are in development, none are available yet.

The study found that the number of infants infected with GBS dropped from one in every 1,000 between 2009-11, to 0.2 in every 1,000 after the universal screening was introduced in 2012.

“GBS is carried by around 20 per cent of expectant mothers and is usually harmless to adults, but it can cause severe illnesses in babies because they have weak immunity,” said gynaecologist Viola Chan Ying-tze, who led the study.

The bacteria can potentially cause pneumonia as well as infections in the blood, bones, lungs or protective membranes covering the brain and spinal cord in babies within 30 days of their birth. Authorities did not provide statistics for death rates caused by GBS in newborns in Hong Kong.