Summer 2017

Vaccination campaign necessary to stop the spread of cholera in Haiti

By Evan Barton

A mathematical model of cholera transmission in Haiti following the 2010 earthquake suggests that current approaches to cholera control and elimination, which focus primarily on improving sanitation, are not likely to solve the problem.  However, eradication of cholera is possible with use of oral cholera vaccine.

“We need to focus on routine vaccination in areas that are at risk of cholera transmission in Haiti,” said Ira Longini, a professor in the College of Public Health and Health Professions and the College of Medicine’s department of biostatistics. Longini is the senior author of the report.

Previous cholera elimination strategies have emphasized the need for infrastructure improvements; the authors, however, suggest that this approach has led to few if any changes in Haiti’s water and sanitation infrastructure. According to the authors, resources should be allocated toward administering oral cholera vaccines, or OCVs, in order to end transmission over the next few years.

Longini stressed the need for urgency, citing climatic instability as a factor that could increase disease occurrence.

“We need to start now,” he said. “We don’t know when the next disaster is coming – the next hurricane or the next earthquake – that could cause another big jump in transmission. We know it is going to happen. We just don’t know when.”

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Findings from human immune system study could lead Haiti closer to malaria eradication

By Evan Barton

A comparison of immune system responses among Haitian malaria patients revealed unique traits among those with the highest risk of transmitting the disease to others. Identifying such patients could lead to a sharp decline in malaria transmission in the country, according to a University of Florida researcher.

‘‘Asymptomatic patients are responsible for the bulk of malaria transmission in Haiti, said Anthony Cannella, M.D., M.Sc. an assistant professor in the Department of Medicine’s Division of Infectious Diseases and Global Medicine at the UF College of Medicine and a member of the Emerging Pathogens Institute. Finding these carriers could play a key role in eradicating malaria from Haiti by 2020, a goal established in 2015 by the Centers for Disease Control and Prevention.

“This research demonstrates a profound step forward in identifying asymptomatic from symptomatic patients based on immune responses to the local malaria parasite,” Cannella said. “My belief is that by identifying these asymptomatic individuals, it is feasible to treat and monitor them, thus reducing malaria transmission over time. These findings provide the scientific community insight into how malaria could be eliminated not only in Haiti, but also in other parts of the globe.”

The results were published in the April edition of PLOS ONE.

Cannella worked with Jason Lehmann, Ph.D., a former postdoctoral fellow in the department of medicine’s division of infectious diseases and global medicine, to analyze the immune system data. The study’s patients come from Sud-Est on Haiti’s southern peninsula, south of Port-au-Prince.

By analyzing the immune systems of malaria patients, Cannella found that asymptomatic patients displayed a unique set of immune responses that most likely is muting a robust inflammatory response to the malaria infection.

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