There have been 275,987 suspected cholera cases and 1,634 deaths from the illness between April 27 and July 5, the WHO said in a statement Wednesday. Children under the age of 15 make up 41% of these cases, and people older than 60 account for 33% of the deaths.
"If you get caught early in the morning with this and you don't get treated by the end of the day, then you really have a problem," WHO spokesman Christian Lindmeier said. "A weak elderly person could really be dead by the end of the day."
The WHO said in a statement last week, "we are now facing the worst cholera outbreak in the world."
Cholera is caused by ingestion of Vibrio cholerae bacteria, which are spread through water or food that is contaminated with feces. Eighty percent of people with cholera don't have symptoms, but they are still capable of spreading it. Those who do show symptoms have a sudden onset of watery diarrhea, which can lead to death by severe dehydration. About 14.5 million people in Yemen don't have access to clean water and sanitation, according to the WHO.
All but two of the nation's governorates have been hit by the outbreak.
The WHO has partnered with the United Nations Children's Fund and local health authorities to deliver medication and aid to combat the ongoing outbreak, including the establishment of 45 diarrhea treatment centers and 236 oral rehydration therapy corners. Lindmeier said it is essential for people who are infected to rehydrate immediately.
"The biggest challenge is reaching people," he said. "This is great. This is a major effort and a huge logistical effort, but people need to know that they can get there. People need to know that they can find these places."
Efforts have been complicated by Yemen's civil war, which has left more than 18.8 million people in need of humanitarian assistance, according to the WHO. Many of the country's trained medical personnel have fled or been killed as the conflict intensified over the past two years, said Juliette Touma, UNICEF's regional chief of communications for the Middle East and North Africa.
Touma traveled to Yemen in early June to see what work was being done and said she was impressed by the dedication of health workers however, she couldn't help but think about all the people who still needed relief.
"What I kept thinking about was all of these children who couldn't actually make it to medical care because they live in the remote parts of Yemen and the rural areas where there are no facilities, or those who couldn't afford to pay," Touma said.
Since the outbreak began, campaigns and community volunteers across the country have been trying to spread the message of how to prevent cholera, she said, including how to clean water, to wash food before eating it and to take general hygienic measures.
But Touma said there is a lot more to be done.
"As long as we have more reports and suspected cases of cholera, and as long as the number of suspected cases increases -- and it has been increasing by the day -- we can't unfortunately say there has been progress," Touma said. "There is a cure for cholera, we can cure it, and that is very much dependent on getting in essential supplies, but we need to get more. We need to get more dedicated personnel."