Many Haitian medical centers housing cholera patients report fewer severe cases each day, prompting many in the country to think the outbreak may be slowing. But government organizations and many experts warn there are many reasons not to be fooled by the evident decline of people with physical symptoms of the so-called "silent" disease.
"The apparent slowing of cases is misleading since many people with cholera have minimal or no symptoms," said Dr. Pascal Imperato, professor of preventative medicine at State University of New York Downstate Medical Center.
Cholera can lay dormant in a person for weeks, until it is shed back into the environment and ingested by someone else. While drinking unclean water may be the obvious source of cholera contamination, health officials now warn people to also be cautious of buying food from street vendors as the epidemic spreads to urban areas like Haiti's capital city, Port au Prince.
While official reports by the Haitian Ministry of Health confirm more than 3,000 cases of the disease and 259 dead, Ministry of Health advisor Georges Dubuche said in a press conference Tuesday that health officials do not know the extent of the epidemic.
Most of the counted cases originated from towns along the Artibonite River and the afflicted were then taken to urban relief camps, Dubuche said.
Many of the unreported cases may be in rural areas in the central plateau region where most do not have access to chlorine tablets and are far from medical centers.
Also, James Wilson, director of the Haiti Epidemic Advisory System, a biosurveillance program operated by nonprofit organization Praecipio International, reported that numbers may be more inaccurate at the start of a new week, since many medical clinics and pharmacies are closed on Sunday.
"Haiti comes to a virtual halt on Sundays," Wilson said. "Therefore, there is the potential for an artificial decrease in cases."
Indeed, previous cholera outbreaks in other parts of the world show that the true pattern of the outbreak is impossible to predict. Peru's 1991 cholera epidemic spread along the continent and claimed more than 300,000 lives in one year.
"The factors that determine an outbreak of cholera, epidemic or pandemic are complex and ecological," said Dr. Stephen Jay, professor of medicine and public health at the Indiana University School of Medicine.
A simple rise in water temperatures could bring about the spread of the bacteria, Jay said.
"So decrease in cases may result from human intervention and-or the natural ebbing of cholera," he said.
However, he said, "A major outbreak is still a possibility and the 'full court press' of public health interventions should not cease prematurely."
Many health officials agreed. While it may be seem like new cases are tapering off, those on the ground emphasized the primary need to continue amping up relief and prevention efforts in Haiti.
"What we are seeing now may be the tip of the iceberg," Dubuche said.