Ending cholera for all

Lancet Infectious Diseases
Oct 2018 Volume 18 Number 10 p1047-1160 e295-e338

Ending cholera for all
The Lancet Infectious Diseases
Cholera, a bacterial diarrhoeal infection caused by Vibrio cholerae and transmitted by the faecal–oral route, is not a disease recently associated with Algeria. Indeed, in a report published by the Global Task Force on Cholera Control (GTFCC) on Oct 3, 2017, Ending Cholera—A Global Roadmap to 2030, Algeria is not listed among the 47 countries affected by the disease. But, having had no cases since 1994, from Aug 7–30, 2018, 74 confirmed cholera cases including two deaths were reported in six northern and coastal districts of the country. V cholerae has been isolated from a natural water source, not connected to the public water system, in the region of Tipaza. How the water source became contaminated is unclear; spread of the disease to other regions of Algeria via contaminated fruit and vegetables is a possibility. The outbreak in Algeria, although small in scale, is a timely reminder that cholera is an epidemic infection that can reappear after disease-free decades in circumstances of unsafe water supply and sanitation.

The vulnerability of people to cholera from unsafe drinking water sources was emphasised in a commitment made by African health ministers on Aug 28—at the same time as the Algeria outbreak—to implement strategies to end cholera in the Africa region by 2030. 17 African countries reported more than 150 000 cholera cases in 2017, and currently eight countries on the continent are dealing with outbreaks. The commitment made by African governments is an endorsement of the strategies set out in the Global Roadmap published last year. This plan aims to support countries to reduce cholera deaths by 90% by 2030, with up to 20 countries having eliminated the disease as a public health threat.

As we noted in an Editorial in 2017, cholera is a disease of poor and vulnerable populations, notably in conflict situations and where sanitation and hygiene are inadequate. Known pandemics of cholera, originating from south and southeast Asia, have occurred since the early 19th century, affecting all parts of the world. However, improvements in safe water and sewage disposal eliminated the disease from high-income countries during the 20th century. The outbreaks currently affecting the world, which kill an estimated 107 000 people per year, are remnants of the seventh pandemic, which began in Indonesia in 1961. That 57 years later—despite having the knowledge and means to hand to effect change—the disease is still a threat to human health marks a failure of global public health.

The Global Roadmap admits that the GTFCC, which was created in 1992, “became inactive after elimination of cholera in the Americas” in the early 2000s. It took a World Health Assembly resolution in 2011 to revitalise cholera control efforts. A paper published online by the Journal of Infectious Diseases on Sept 1, notes four factors that have converged to make cholera elimination feasible: increased emphasis on equity, as exemplified by the Sustainable Development Goals, with occurrence of cholera indicative of people’s access to basic water and sanitation services; the technical capacity to detect cholera quickly; availability of oral cholera vaccine (OCV) in sufficient quantity to manage large outbreaks; and an increasing degree of politic commitment in affected countries (as shown by the African health ministers’ declaration).

The objectives for 2030 in the Global Roadmap are based on three axes: early detection and response to contain outbreaks through, for example, surveillance systems, prepositioning essential supplies, monitoring water sources, and mass vaccination campaigns; targeting cholera hotspots through, in addition to the above, providing sustainable safe water and sanitation networks and building the capacity of health-care systems; and effective coordination of technical support and resources at local and global levels.

Of the various resources needed to achieve global cholera control, the availability of OCVs is encouraging, with 25 million doses predicted to be in the stockpile this year. And there is evidence of national political commitment, with the Government of Uganda launching on Sept 5, an OCV campaign targeting 1·6 million people living in cholera hotspots. But ultimately cholera control requires civil engineering through building a robust infrastructure of clean water supply and sewage disposal and treatment. The initial investment may seem great, but it is less so when considered per head of population over decades, for the reduction in other water-related diseases, and for the increased wellbeing and productivity of a country’s people.