In fighting cholera , the international community usually favors responsive actions which have limited and short-term effectiveness. Such actions are often mobilized in responses to sudden epidemics, such as those in Yemen and Zimbabwe. However, there is a lack of evidence for how longer-term interventions , which are usually harder to achieve, can be delivered effectively.
New research addressing this gap is currently underway in the city of Uvira, South Kivu, DRC, to provide evidence for improving the supply of safe drinking water as a public health priority.
A critical issue in guiding the public fight against cholera
According to the World Health Organization (WHO), diarrhoeal diseases related to unsafe water, sanitation and hygiene cause over 1,000 deaths a day in Africa. And, every year, cholera alone accounts for the deaths of 100,000 to 120,000 people.
Yet, the debate as to what is the most efficient way to prevent and control cholera persists . Some attention to focus on rapid short-term responses, where the cost of interventions is relatively low – home chlorination / filtration kits, the distribution of small quantities of water only for drinking, raising hygiene awareness.
Moreover, oral cholera vaccines (OCV) are increasingly presented as a priority. There are many new OCV studies that have attracted substantial attention; but, while the findings are generally positive, the effectiveness of these vaccines can be limited and short-lived.
To date though there has been limited rigorous research to evaluate the effectiveness of investment in drinking water supply infrastructure to prevent cholera. There are two reasons behind this: on the one hand, the cholera disease burden is concentrated in low income settings, many of which are affected by political instability, where building and maintaining largescale public health infrastructure is challenging.
On the other hand, public health research increasingly values experimental trials which require a random allocation of treatment and control groups. Whilst pills or awareness-raising sessions can be randomly allocated with relative ease, doing this with piped water connections presents various logistical and ethical challenges.
At a time when the evidence-based policy paradigm reigns supreme (requiring that public investment decisions be founded upon high quality scientific evidence), these challenges may discourage national and international investment in preventive actions as we lack strong scientific evaluations of their effectiveness.
Uvira: new results that challenging some preconceptions about cholera
Cholera is endemic in the city of Uvira, located on the shores of Lake Tanganyika, and is often presented as one of the starting points for the epidemic outbreaks affecting this region of DRC. Supported by the French Development Agency, the Veolia Foundation, the European Union and OXFAM Great Britain, a project to rehabilitate Uvira's drinking water supply network has provided a unique opportunity to perform a rigorous health impact evaluation of this investment.
The research continues despite challenging conditions
Forthcoming findings should help to assess the relative health benefits of different levels of water supply connections and improved continuity of water supply; for example, between after a shared standpipe and an individual household connection. Molecular biology will help to better understand the ways in which cholera spreads, as well as to understand the other causes of acute diarrhoea that affect this population.