The Geneva-based body has frequently warned about other life-saving programs being impacted by the pandemic and has sent countries mitigation advice, but the survey yielded the first WHO data so far on the scale of disruptions.

“The impact of the COVID-19 pandemic on essential health services is a source of great concern,” said a report on the study released on Monday. “Major health gains achieved over the past two decades can be wiped out in a short period of time…”

The Eastern Mediterranean Region, which includes Afghanistan, Syria and Yemen, was most affected followed by the African and Southeast Asian regions, it showed. The Americas was not part of the survey.

Since COVID-19 cases were first identified in December last year, the virus is thought to have killed nearly 850,000 people, the latest Reuters tally showed.

The WHO survey said it was “reasonable to anticipate that even a modest disruption in essential health services could lead to an increase in morbidity and mortality from causes other than COVID-19 in the short to medium and long-term.” Further research was needed.

It also warned that the disruptions could be felt even after the pandemic ends. “The impact may be felt beyond the immediate pandemic as, in trying to catch up on services, countries may find that resources are overwhelmed.”