Largest-ever global deployment of cholera rapid diagnostic tests for better disease control

The arrival of rapid diagnostic test (RDT) kits for cholera in Malawi today signals the start of a global programme that will see more than 1.2 million tests distributed to 14 countries at high risk for cholera over the next several months. Countries that will receive kits in the coming weeks in this largest-ever global deployment include those currently severely impacted by cholera outbreaks, such as Ethiopia, Somalia, Syria, and Zambia. This programme will improve the timeliness and accuracy of outbreak detection and response by boosting routine surveillance and testing capacity and helping rapidly identify probable cholera cases. Critically, it will also help countries monitor trends and build an evidence base for future preventive programmes, supporting the achievement of national cholera control and elimination targets.

The global cholera diagnostics programme is funded and coordinated by Gavi, the Vaccine Alliance (Gavi), with procurement and delivery to countries led by UNICEF, and undertaken in collaboration with the Global Task Force on Cholera Control (GTFCC), and WHO. It was developed in partnership with FIND, who led development of a target product profile describing the required characteristics of cholera RDTs, and other organizations. These initial shipments signal the start of the programme, which aims to see partners deploy RDTs to additional countries that have expressed interest in the future. Long-term sustainability of the programme depends on successful fundraising for Gavi's next strategic period, from 2026 to 2030.

Through this effort, rapid diagnostic tests from two manufacturers – that have to-date been supplied via WHO and UNICEF for use in outbreak response – will now be used routinely for cholera surveillance. Pilot studies across the Democratic Republic of the Congo (DRC), Niger and Nepal, funded by Gavi and led by the United States Centers for Disease Control and Prevention (CDC), Johns Hopkins University (JHU) and Epicentre/ Médecins Sans Frontières have helped increase understanding of effective rapid testing strategies. Preliminary insights from these studies, which are still ongoing, have helped inform programme design – making the rollout of these tests at scale more effective.

Cholera has been surging globally since 2021, with high case fatality rates despite availability of simple, effective and affordable treatment. The large number of outbreaks has led to unprecedented demand for vaccines from impacted countries. While global oral cholera vaccine supply has increased eighteen-fold between 2013 and 2023, the large and sustained spike in demand compared to the current availability has put a strain on the global stockpile. Preventive vaccination campaigns have had to be delayed to preserve doses for emergency outbreak response efforts. Recurring outbreaks in countries where emergency vaccination campaigns have already been implemented further highlight the need for improved speed and accuracy in identifying areas with new or persistent transmission – enabling these areas to be targeted during initial outbreak response efforts.

In 2021, the Gavi Board approved US$ 55 million in funding to support a diagnostics programme between 2022 and- 2025 across cholera, yellow fever, measles, rubella, meningococcal meningitis and typhoid – with the aim to improve disease surveillance, outbreak detection and response and the design of preventive programmes. Gavi then opened a cholera diagnostics application window in June 2023 – which is still open – and so far 14 countries have submitted applications and been approved by an Independent Review Committee of experts. In 2023, Gavi also launched a preventive cholera vaccination programme, to support countries with long-term cholera control – a strategy that has successfully led to a decrease in outbreaks of diseases such as yellow fever and meningitis.

Cholera is an acute intestinal infection that spreads through food and water contaminated with faeces containing the bacterium Vibrio cholerae. The rise in cholera is driven by continued gaps in access to safe water and sanitation, and failure to quickly detect outbreaks and limit their spread. The communities impacted often do not have access to basic health services, a situation made worse by climate-related factors, conflict and population displacement. In the face of the ongoing surge, partners working on cholera control have urgently called on countries, manufacturers and other partners to invest in the timely outbreak response and case management, rapid access to treatment, increased production of affordable vaccines, and urgent improvements in access to basic water and sanitation services in impacted communities.

To be effective, these multisectoral strategies for the control of cholera must be guided by timely and reliable cholera surveillance data. Surveillance not only supports the early detection of and quick response to an outbreak, but also plays a central role in providing stakeholders in other cholera prevention and control pillars with the data they need to target, design, implement, and evaluate interventions. In 2023, the GTFCC updated recommendations in favor of strategic, routine and systematic testing of suspected cholera cases and the expanded use of RDTs to strengthen cholera surveillance. The global cholera RDT procurement program provides the additional support required for eligible countries to implement these recommendations.

We are experiencing an unprecedented multi-year upsurge in cholera cases worldwide, and today's announcement provides a critical boost in the fight against the disease. The rise in infections is being driven by continued gaps in access to safe water and sanitation, and our inability to reach vulnerable communities that are being put further at risk by climate change, conflict and displacement. Routine use of diagnostics will bolster cholera surveillance in impacted countries, and must be leveraged to better target vaccination efforts, which play a critical role in multisectoral cholera prevention and control programmes."

Aurélia Nguyen, Chief Programme Officer at Gavi, the Vaccine Alliance

"Despite cholera being preventable and easily treatable, children continue to suffer from this potentially fatal disease. This is why we are working with partners on all fronts and in novel ways to stem outbreaks," said Leila Pakkala, Director of UNICEF Supply Division. "Surveillance diagnostics help pinpoint hotspots with great precision. This allows partners to target cholera vaccines to exactly the time and place where the limited supply will save the most lives."

"It's a tragedy that cholera-;a preventable and treatable disease-;continues to afflict and kill today. We need urgent action on all fronts, including commitment by countries to clean water, sanitation and hygiene," said Dr Michael Ryan, Executive Director of WHO's Health Emergencies Programme. "WHO welcomes the deployment of these rapid cholera tests. They will equip health workers with the critical and timely data needed to stop outbreaks early and direct efforts to better prevent and treat cholera."

"Cholera is now spreading to areas that have been free from the disease for many years, demanding a swift, multifaceted strategy to direct limited resources to critical areas and save lives. Accurate and high-quality testing and surveillance measures are vital to spot the disease where it is emerging, confirm cholera cases amidst other diarrheal illnesses, and evaluate the success of preventative measures such as vaccines," said Dr Sergio Carmona, Acting CEO and Chief Medical Officer at FIND.