The West AustralianFor Paul Effler, a stint on the front-line fight against the Ebola virus in West Africa still keeps him up at night.
"The situation was worse on the ground than I had anticipated," Dr Effler said. "The cases just kept escalating. They were doubling every two weeks.
"I still wake up at night thinking about the people back there. But it was definitely the right thing to do."
He took leave from his job as medical co-ordinator at WA Health's Communicable Disease Control Directorate to volunteer with the World Health Organisation in Liberia.
Dr Effler spent a month in Bomi County, near the capital Monrovia, and returned to Australia on September 20.
He was not directly involved in treating patients but oversaw the WHO's response for the area, which included logistics, training health workers, tracing people patients had contact with and meeting local chiefs.
Dr Effler recalls driving to Monrovia one day and feeling happy because "I got my hands on 50 body bags".
Mostly, though, was the sense of heartache. One memory that stood out was nurses wailing throughout Bomi's treatment centre when they learnt a doctor's assistant had died.
Another was forged when soldiers stopped him at a medical checkpoint.
Nearby a sick woman was left by herself on the road as she waited for an ambulance.
The treatment centre in Bomi County had 12 beds for Ebola patients but other rooms were overflowing with victims.
Dr Effler said it was crucial the world acted now to stop Ebola spreading. "This is the classic example of whether we rather fight it over there or fight it over here," he said.