We need a better strategy to fight against cholera

People bathe and clean clothes in a river cutting through Roche a Bateau, Haiti, after the devastation caused by Hurricane Matthew.
People bathe and clean clothes in a river cutting through Roche a Bateau, Haiti, after the devastation caused by Hurricane Matthew. pfarrell@miamiherald.com

With the number of suspected cases of cholera in Haiti now in the hundreds, the race is on to try to prevent further death and devastation following Hurricane Matthew.

With one million doses of cholera vaccine due to arrive this week, the hope is that we can prevent a repeat of the horrific outbreak in 2010 that infected nearly 800,000 Haitians, killing more than 9,000 people. But, even if we are successful in Haiti, the fact is for a highly preventable disease like cholera, vaccine stockpiles while certainly helpful cannot be a long-term solution.

Ten million people live in Haiti alone, and yet fewer than 6 million doses of cholera vaccine are currently produced each year, to maintain a global emergency stockpile of 2.2 million, with two doses recommended per person. At first glance this may look hopelessly short of the mark, but for a highly preventable disease such as cholera, the vaccine stockpile is not meant to be used on a national scale and is only intended as a last resort to plug the gaps left by other interventions.

The problem is cholera is such a neglected disease, as are its causes, that these gaps can be vast. While we have now almost come to expect outbreaks whenever natural disasters hit poor parts of the world, conditions in Haiti were already ripe for cholera even before Hurricane Matthew hit. In fact, a campaign was already planned for 2017, where 1.5 million people were to be vaccinated. Given the utter decimation of infrastructure in Haiti and the resulting conditions, this kind of scale of campaign is both necessary and appropriate. The question is, how sustainable is this type of response?

A growing concern now is that in the face of pressures, such as mass urbanization and climate change, such conditions could become increasingly more common across Africa and Asia as cities swell. The combination of more people living in less space will place even more strain on already limited water resources and sanitation, but on a potentially much bigger and even less manageable scale than in Haiti.

This means there is a lot more riding on how we handle this crisis than preventing an immediate outbreak. Because if we can’t figure out long-term, sustainable solutions to prevent cholera in a country the size of Haiti, what hope have we for impoverished megacities like Dhaka, Lagos and Kinshasa as these cities become more and more crowded and resources are placed under ever greater strain?

Vaccines alone can’t cope with growing worldwide threat

The tragedy is that cholera is entirely preventable. There is no reason why anyone should become infected, let alone die of the disease. It is true that for a nation such as Haiti, resources can be extremely limited, and certainly it has made some progress in recent years towards in improving access to drinkable water, better sanitation and hygiene. But it still has a long way to go. You need only glance across the border into the Dominican Republic to get a sense of that.

There are many historical and political reasons why Haiti has ended up in this situation, but arguably the most critical difference is poverty. Haiti has a gross national income per capita that is less than one seventh of the size of its neighbor. As a result, historically there has been a lack of investment in water, sanitation and hygiene (WaSH), particularly in long-term infrastructure, a situation made worse by the 2010 earthquake, and now again by Hurricane Matthew.

Right now, the immediate focus and hope is that we can prevent a large outbreak in Haiti by leveraging vaccine stockpiles to buy us time while WaSH interventions are improved or put in place. But for the long-term we need to find other solutions to prevent cholera, rather than relying upon outbreak response as the last resort, especially given current global population trends.

That’s because the number of people in Africa is expected to double by 2050 and quadruple by 2100. Add to that pressures from climate change, such as desertification, land degradation and rising sea levels, and urbanization, and we can expect increases in population density and marginalized populations without access to water and sanitation which is directly related to transmission of diseases like cholera.

Given that you can have more than 10 million people living in just one city, like Lagos, Nigeria, with a big outbreak, the potential for overstretching cholera vaccine supplies is vast, with or without natural disasters. We saw this just recently with yellow fever in Angola and the Democratic of Congo, where urban outbreaks left stockpiles depleted. The global health community could increase stockpiles to reflect the increase in risk, but how big is big enough?

Clearly, when a disease is as preventable as cholera the focus has to be on preventing the causes in the first place through investment in WaSH infrastructure. For now, though, in Haiti let us just hope that one million doses of vaccine will be enough.

Dr. Seth Berkley is CEO of Gavi, an international vaccine alliance with headquarters in Geneva.