A United Nations panel of experts say the cholera outbreak in Haiti that killed almost 5,000 people was caused by contamination of the Artibonite River, which runs near a peacekeepers’ base.

The panel’s report released Wednesday found sanitation at the Nepalese peackeeper base was not sufficient enough to keep human waste from seeping into the tributaries of the river.

But the panel stopped short of directly blaming the peacekeepers, saying instead, the outbreak of the South Asian strain of cholera was caused by a “confluence of circumstances” and not the fault of, or deliberate action of, a group of individuals.

U.N. Secretary General Ban Ki-Moon says he will review the report’s findings and ensure a timely response.

The panel recommends peacekeepers heading to cholera affected areas be screened for the disease and immunized.

It also recommends that fecal materials be treated with chemicals to prevent the spread of cholera.

Haiti’s cholera epidemic broke out in October of last year.

Haiti is still struggling to recover from last January’s earthquake that left more than 200,000 people dead and 1 million homeless.