Haiti’s tuberculosis epidemic after earthquake offers key health lessons
Haiti.
That one word has conjured up so many phrases and images for people over the past 30 years.
Corrupt governments. Horrific oppression. Endemic poverty. Widespread devastation.
The last phrase was repeated in some variation over and over after the 2010 earthquake. Over the past five years, we have engaged more with Haiti and its problems than probably most of us ever had in our lifetimes. At the same time, Haitians are becoming less a group of foreign strangers and more and more number among our neighbors, friends and family. The Haitian population in the United States grew by more than five times between 1980 and 2012, from an estimated 92,000 to an estimated 606,000, according to data from the U.S. Census Bureau. At the current pace, the Haitian population in the U.S. could surpass 1 million sometime next year and certainly by 2020.
For all those reasons, when new health science comes out of Haiti it’s worth paying attention. A paper published by the Bulletin of the World Health Organization in May 2015 – “Tuberculosis in the aftermath of the 2010 earthquake in Haiti” – offers many insights into the health of the Haitian population in the wake of the earthquake. Lauren Hashiguchi, a member of my team at the Institute for Health Metrics and Evaluation, co-authored the paper independently from her work at IHME. Hashiguchi worked as part of the Haitian Group for the Study Group of Kaposi’s Sarcoma and Opportunistic Infections. When she brought the paper to my attention, I was struck by how many lessons were applicable to health policy and health reporting far beyond the tiny island nation. My top four are below.
Good systems can survive the worst-case scenario. How could an earthquake that killed more than 200,000 people and left an estimated 1.5 million people homeless not devastate basic health programs? The answer seems to be, in part, the dedication of health workers, the government, relief agencies, and the patients themselves. The chief example in the paper is the interplay between HIV and tuberculosis. After the earthquake, one would expect that more people with TB would end up with HIV and vice versa because of breaks in the supply chain for medicine, destruction of education programs, and lack of access to public health facilities. What the researchers found, though, was that the proportion of tuberculosis patients with an HIV infection stayed at about 20 percent from 2010 to 2014. The researchers also found that overall prevalence of HIV remained stable at 2.2 percent over the period.
“Haiti’s response to HIV is likely to be responsible for the lack of increase in HIV-associated tuberculosis after the earthquake,” the study’s authors wrote. “Although many HIV clinics were damaged in the earthquake and testing declined in 2010, the annual number of HIV tests rose above pre-earthquake levels by 2011 and 86 percent of tuberculosis patients were tested for HIV in 2013, compared to the regional average of 69 percent. Within months, 90 percent of the pre-earthquake patients had resumed antiretroviral therapy, reducing their risk of contracting tuberculosis.”
Those efforts were bolstered by an unprecedented amount of health aid flowing to Haiti beginning in 2010.
If you know you have a health problem in a community, a natural disaster may cause it to spread like wildfire. This is especially true in poor communities, the researchers found. Even before the earthquake, Haiti had the highest tuberculosis incidence in the Americas at a rate of 230 new cases for every 100,000 people. The researchers put that in perspective by noting that the rate is “nearly 10-fold higher than the regional incidence of 30 per 100,000 – and higher than the overall incidence of the world’s 22 high burden countries (166 per 100,000).” The researchers tested people for TB in an internally displaced persons camp between 2010 and 2011 and then again between 2011 and 2013. Over the two periods, the number of new cases detected grew from 693 per 100,000 to 1,165 per 100,000. That’s not a typo.
Separating more cases from more case reporting can be tricky. Even though the researchers had one window into one piece of the Haitian population in which they saw massive increases in new cases, they also were unsure of how to extrapolate these trends to the general population. The researchers wrote, “Without accurate data, it is difficult to distinguish whether a rise in the reported number of cases is due to a higher burden of disease or to improvements in case detection.”
There is only one source of tuberculosis data for Haiti overall: “Each tuberculosis clinic in Haiti provides quarterly data that the national tuberculosis programme tallies and submits to WHO,” the researchers wrote. “Tuberculosis prevalence has never been assessed from a population-based survey in Haiti, and there are no recent tuberculosis mortality data from a national vital registration system. WHO is therefore left with incomplete data on which to base their tuberculosis estimates for Haiti and as a result, confidence intervals are wide.”
What does that mean? It means that the estimated prevalence of tuberculosis in Haiti could be as low as 129 per 100,000 people (still quite high) to as high as 421 per 100,000. When you’re trying to track trends year over year, a confidence interval this wide makes it hard to detect any meaningful changes up or down.
Second best can sometimes turn out to be just as good, especially under tough circumstances. Under ideal circumstances, people would undergo a blood or skin test for tuberculosis before being evaluated for the disease. Post-earthquake Haiti was far from ideal. So, as the researchers wrote, “community health workers screened camp residents in their tents and referred those reporting a cough of more than two weeks’ duration for physician evaluation with smear microscopy and chest radiograph.” They found out that this was a pretty good indicator of whether people had TB. Out of 1,420 who were referred by this method during one period, 233 came back positive for TB, a rate of about 16 percent.
Overall, there’s a lot of hope in this paper, which makes me wonder if we’re on the verge of seeing a new phrase emerge as the thing you’re most likely to think of when you hear the word “Haiti.”
That phrase would be: “Rapid response.”
[Photo by Sombilon Photography via Flickr.]