Are rehydration therapy and antibiotics the best treatments out there?
Yes. But what I have not seen is what the sensitivity pattern is for the antibiotics. We've seen in previous outbreaks that people don't know what the patterns are and they ship the wrong antibiotics.
So different antibiotics are needed to treat different strains of cholera?
Yes. That's why it's important to know the sensitivity of this strain. And you have to keep monitoring it because it could change in the future.
What are the best ways to keep the disease from spreading to more people? Is it mostly an issue of clean water?
There are different ways of making your water clean. One thing I haven't seen out there so far is consideration of the vaccine, which is available now. It has only been since March this year that the World Health Organization has recommended the use of the cholera vaccine on a wide scale. I think this is a situation where it might be considered.
From the numbers that have come out so far, it seems that there's been a mortality rate of roughly eight percent. Is that a pretty standard number of expected deaths?
Standard mortality should be zero. I've worked in Bangladesh for many years, and in our hospital, we treated thousands of patients, and nobody died of cholera. So no deaths are inevitable if you provide the right treatment.
Nobody's had much experience with it in Haiti, so case mortality rates become very high at first, but as facilities become more experienced and people learn where to get treatment, the case mortality rates should come down very quickly.
Cholera seems like a disease of the past—will it ever be eradicated?
No, because of its environmental reservoir. I don't see any way we could eradicate it like eradicating polio or smallpox. As long as you have an environment, you will have cholera.
How does Haiti's outbreak compare with others in recent years?
In Bangladesh, we have thousands of cases every year, but it doesn't make it into the newspapers because we have it every year.
Theoretically, governments and health ministries are supposed to report cases to WHO, but in general many of them don't do it at all. Cholera is a very sensitive subject. Many countries just don't want to report it for fear of its impact on trade and travel—and that used to be a reasonable fear, but I'm afraid now that they haven't been reporting it because it's become a tradition.
In the past we used to assume that cholera outbreaks would arise quickly then go away quickly—and by "quickly" I mean one to two months. But the outbreak in Zimbabwe a year ago has taught us that cholera outbreaks can persist for a year. I think it's becoming harder to predict how long we can expect this outbreak to persist.
Is that because we have a better understanding now about the outbreaks, or has there been a change in the disease spread itself?
It seems to be a difference in how it's transmitted, not so much our understanding. It's behaving differently now than it did in the past. Clearly it keeps changing its genetics. So, for example, recently the toxin that the organism produces has changed genetically, and it appears that the change has resulted in a more severe illness. But this organism is in the environment, and its genes are exchanged frequently with the environmental strains, so there's a lot of re-sorting that's going on. And when people get infected, the people themselves act as the amplifier and selector of the most virulent strain.