Cholera's challenge to Haiti and the world
Debate about the public health response to Haiti's cholera epidemic continues as the crisis enters its ninth month, with some experts arguing that a vaccination campaign in Haiti would be neither feasible nor cost-effective, and advocating putting forth other measures. In a viewpoint article published on May 31st in the open-access journal PLoS Neglected Tropical Diseases, a coalition of medical and public health researchers, policymakers, and practitioners, led by Paul Farmer, cofounder of Partners In Health and United Nations Deputy Special Envoy to Haiti, argue that a universal vaccination campaign is essential to ending the crisis.
Before last October, cholera had never been reported in Haiti. Even after the January 2010 earthquake, the U.S. Centers for Disease Control and Prevention (CDC) and other public health authorities deemed it "very unlikely to occur." Largely because Haiti's population was "immunologically naïve," initially the outbreak exhibited a 7 percent case-fatality rate among the highest recorded in recent history. In "Meeting Cholera's Challenge to Haiti and the World: A Joint Statement on Cholera Prevention and Care," the 44 authors maintain that "vaccination has a significant role to play in Haiti given the vulnerability of the post-earthquake health, water, and sanitation systems and the observed virulence of the El Tor strain the MSPP (Haitian Ministry of Public Health) has called for nothing less than a universal vaccination campaignan end goal this document endorses."
There are currently fewer than 400,000 vaccine doses ready for shipment but the authors assert that "advance purchase commitments could increase availability to several million. Past experience underscores the value of publicly-ensured purchases . such funding can boost production, lower prices, and expand vaccine access." Furthermore, the authors argue that economies of scale contribute to lower production costs, as observed during the scale-up of antiretroviral therapy for HIV/AIDS. Scaling up efforts in Haiti would also create momentum to prevent similar vaccine shortages during future outbreaks.
As a first step in the vaccination campaign, Farmer and coauthors recommend that WHO endorse the development of a two million dose stockpile for Haiti, coupled with a large-scale demonstration in Haiti comparing the effectiveness of cholera control efforts with and without mass vaccination. "If this demonstration were deemed successful," they write, "we would suggest the production of cholera vaccine be ramped up to develop a global stockpile of 10 million doses."
Haitians are especially susceptible to cholera infection because of several factors, including the large numbers of people left homeless and displaced by the earthquake that have been living in rural areas or large rural slums, where the epidemic has been most severe. "These communities were charged with hosting hundreds of thousands of displaced people after the earthquake, placing greater demands on their already-scarce resources, including water," write Farmer and his coauthors. However, a cholera vaccination campaign could leverage existing health worker networks without taking doctors and nurses away from the provision of acute care.