Disease Forecasting Gets an Upgrade

Cholera is a waterborne bacterial disease that infects millions each year and kills hundreds of thousands. Many coastal communities regularly deal with small cholera outbreaks and are well prepared for them. Other outbreaks however, can be much less predictable and can take communities by surprise. The majority of cases occur in developing countries and are made worse by poor sanitation and over crowding.

In May of 2017 scientists used satellite data to see whether an outbreak would occur in Yemen, and ended up unexpectedly predicting an outbreak that spread across the country the next month. As explained in Scientific American:

The team used a handful of satellites to monitor temperatures, water storage, precipitation and land around the country. By processing that information in algorithms they developed, the team predicted areas most at risk for an outbreak over the upcoming month.

Weeks later an epidemic occurred that closely resembled what the model had predicted. “It was something we did not expect,” Jutla says, because they had built the algorithms—and calibrated and validated them—on data from the Bengal Delta in southern Asia as well as parts of Africa.

Because cholera progresses so rapidly, advance warning of an epidemic would allow communities to stockpile re-hydration supplies and vaccines. This could significantly alter the deadly outcome of the disease.

The Worst Cholera Outbreak in History

The size of the cholera epidemic in Yemen is hard to grasp. According to an article in the Guardian in October:

The World Health Organization has reported more than 815,000 suspected cases of the disease in Yemen and 2,156 deaths. About 4,000 suspected cases are being reported daily, more than half of which are among children under 18. Children under five account for a quarter of all cases.

Those statistics, which are really thousands upon thousands of helpless people and children dying terribly tragic deaths, are sobering.

The spread of the outbreak, which has quickly surpassed Haiti as the biggest since modern records began in 1949, has been exacerbated by hunger and malnutrition. While there were 815,000 cases of cholera in Haiti between 2010 and 2017, Yemen has exceeded that number in just six months.

Save the Children has warned that, at the current rate of infection, the number of cases will reach seven figures before the turn of the year, 60% of which will be among children.

Tamer Kirolos, Save the Children’s country director for Yemen, said an outbreak of this scale and speed is “what you get when a country is brought to its knees by conflict, when a healthcare system is on the brink of collapse, when its children are starving, and when its people are blocked from getting the medical treatment they need”.

Kirolos said: “There’s no doubt this is a man-made crisis. Cholera only rears its head when there’s a complete and total breakdown in sanitation.

There is perhaps a glimmer of optimism, however small, as the rate of new cases have started to slow, and the mortality rate has begun to decline. Cholera is easily preventable and treatable with access to clean water and oral re-hydration salts, but in a war ravaged country like Yemen, those things are often insurmountable challenges.

“Whatever decline we’re seeing now is due to the heroic efforts of workers at the scene,” said Sherin Varkey, the officiating representative of Unicef Yemen.

Varkey said the situation would not be solved until there was peace in the country.

“There are no signals that give us any reason for optimism. We know that both parties to the conflict are continuing with their blatant disregard of the rights of children,” he said. “We’re at a cliff and we’re staring down and it is bottomless. There seems to be no hope.