As Covid-19 took hold over the last year, hospitals and nursing homes used and reused scarce protective equipment — masks, gloves, gowns. This desperate frugality helped prevent the airborne transfer of the virus.

But it also appears to have helped spread a different set of germs — drug-resistant bacteria and fungi — that have used the chaos of the pandemic to grow opportunistically in health care settings around the globe.

These bacteria and fungi, like Covid-19, prey on older people, the infirm and those with compromised immune systems. They can cling tenaciously to clothing and medical equipment, which is why nursing homes and hospitals before the pandemic were increasingly focused on cleaning rooms and changing gowns to prevent their spread.

That emphasis all but slipped away amid an all-consuming focus on the coronavirus. In fact, experts warn, the changes in hygiene and other practices caused by the Covid-19 fight are likely to have contributed to the spread of these drug-resistant germs.

WASHINGTON — President Biden’s coronavirus czar said Wednesday that the United States was woefully behind other nations in tracking potentially dangerous variants of the virus, and used the first White House public health briefing to issue a stark warning that Americans will remain vulnerable to the deadly pandemic unless Congress acts.

“We are 43rd in the world in genomic sequencing — totally unacceptable,” said Mr. Biden’s Covid-19 response coordinator, Jeffrey D. Zients, citing December data from the GISAID Initiative, which provides a global database of coronavirus genomes. In a brief interview later, he corrected himself, saying he had since learned that the United States was now behind 31 other nations.