How To Stop The World's Worst Cholera Outbreak

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Yemen is struggling to control a cholera outbreak that the U.N. is calling "the worst ... in the world."

As of June 26, the World Health Organization estimates that there have been nearly 219,000 cases and 1,400 deaths since the start of the outbreak in late April. The outbreak is adding to a humanitarian crisis brought on by a civil war that's lasted more than two years.

WHO has approved use of a vaccine in Yemen, but it works best if given before an outbreak starts. The organization is considering whether provinces neighboring those with rampant cholera would make good targets for a vaccine campaign. Some areas may not be safe or accessible for vaccine workers because of fighting.

The rate of new infections seems to be slowing, although it's not entirely clear why, according to Ahmed Zouiten, WHO's senior emergency adviser for Yemen. The case fatality rate — the proportion of deaths among cases — has also been low so far, about a half a percent, or one death for every 200 cases. WHO considers a one percent case fatality rate in a population a sign that the treatment has been appropriate and timely.

Despite these encouraging statistics, the risk for spread remains, and the ongoing civil war is battering the country's health-care infrastructure. Fewer than half of Yemen's hospitals and clinics are operating. Here's what specialists say needs to happen to quell this outbreak.

Treat sick people – fast. Cholera causes violent diarrhea, vomiting and dehydration severe enough to send a person into shock in a matter of hours. The symptoms can be treated by replacing lost fluids, but it's essential to rehydrate a symptomatic person as soon as possible, orally for mild cases or intravenously for serious cases. Moreover, severe cases are more likely to lose more fluids, potentially spreading more cholera bacteria in the environment. WHO has set up emergency rehydration centers since so many local health centers have been shut down.

Provide clean drinking water. Cholera is waterborne and is often spread when drinking water is contaminated by sewage water that has fecal matter from infected people. Even before the war, nearly a quarter of Yemenis didn't have access to toilets and defecated in the open. The war has only made the situation worse. In the short term, agencies are trucking in tanks of chlorinated water for residents in outbreak areas. As the civil war continues, it will be important to keep water treatment facilities running to ensure a sustainable supply of clean water. UNICEF has already had to step in, providing funds to reopen the water treatment plant in Sanaa after it had shut down due to power shortages.

Get food to people. Malnourished people, especially children, have weak immune systems, which makes them vulnerable to infections, particularly diarrheal infections like cholera. Being infected by cholera, in turn, makes it difficult for people to properly absorb nutrients from the food they take in, exacerbating any existing malnutrition. The combination of cholera and malnutrition can lead to a vicious downward spiral. The war has shut down markets and cut off transportation routes, leading to massive food shortages and sky-high prices.

The World Food Programme reports that 60 percent of Yemeni people don't have a reliable source of food and estimates that $26.6 million is needed to procure and transport food to those who need it.

"People are really struggling to put food on the table and malnutrition rates are high," said Zvidzai Maburutse, deputy director for the International Rescue Committee's Yemen Program. "Donors should be investing more money to address the humanitarian crisis in Yemen."

Tell individuals what to do to prevent spread. In the middle of an outbreak like this, cholera specialists say, it's critical to send clear messages to the public about how to stay safe. Agencies like WHO and UNICEF are teaching people in outbreak areas how to properly handle food and how to use hygiene kits that have supplies like soap and chlorination tablets. They're also encouraging frequent hand-washing before eating or cooking and after defecating or changing a baby's diapers. They're also directing people to head to a rehydration center if they develop symptoms.

Protect the country's infrastructure. In addition to the emergency measures put in place now, long term strategies to keep infrastructure systems, from health care to water sanitation, from crumbling further are needed. Fewer than half the country's hospitals and clinics are operating. The country's economy has collapsed, meaning people are unable to buy sufficient food, leading to malnourishment. There have also been reports of doctors and other health care workers not being paid in more than nine months.

UNICEF has been propping up water sanitation. They paid to keep the water treatment plant in Sana'a operating after it shut down because power plants weren't operating. "Once systems go beyond a critical point of collapse, it is very difficult to bring them back," said Dr. Sherin Varkey, UNICEF's acting representative in Yemen.

Stop the war. Right now, there is no sign that either side in the conflict is ready to negotiate peace, although representatives from the United Nations are attempting to bring them to the table. International aid can provide emergency services, but only sustained peace in the country will allow its residents to rebuild its health and sanitation sectors enough to keep diseases like cholera in check. "If we don't have a peaceful resolution, the situation will remain," Varkey said. "Both parties to the conflict need to see the importance of safeguarding the population."

Rina Shaikh-Lesko is a science journalist who writes about medicine, global health and the life sciences. She can be reached @rinawrites