Last week, the “Final Report of the Independent Panel of Experts on the Cholera Outbreak in Haiti” was released. The outbreak occurred ten months after the January 12, 2010 earthquake, and it claimed 4500 lives and sickened 300,000 people. Cholera as an infectious disease had been absent from Haiti for nearly a century, although non-pathogenic strains are present in Haiti. Now a pathogenic strain has spread throughout Haiti as a result of the confluence of numerous factors, including:
1. Introduction of a pathogenic strain of the current South Asian type Vibrio cholerae, resulting from an infected UN worker(s) and improper disposal of human waste at a MINUSTAH (United Nations Stabilization Mission in Haiti) camp. The waste contaminated a tributary of the Artibonite River, Haiti’s longest and most important.
2. Salinity gradient of the Artibonite River delta that favored rapid bacterial proliferation
3. Widespread use of the river water for washing, bathing, drinking, agriculture, and recreation
4. Lack of immunity in the Haitian population.
5. Poor water and sanitation conditions
6. Migration of infected individuals to home communities and treatment clinics
7. Pathogenicity of the cholera strain related to increased toxin production
8. Deficiencies in medical facilities to contain disease spread to health care workers and other patients
News releases on this tragic situation highlighted the cause of the outbreak (UN peacekeepers) but failed to discuss environmental and behavioral factors that lead to the dissemination of the disease and its long term impact.
Natural disasters have an immediate impact on life and limb, but they also disrupt or destroy infrastructures critical to human health (water treatment, sewage disposal, medical facilities). The Great East Japan earthquake was the most powerful earthquake to have hit Japan, but it was the resulting tsunami that obliterated coastal towns and villages. The death toll from this disaster was far less than that reported in Haiti (approximately 25,000 versus 230,000); but post event, there have been significant public health consequences that stand in stark contrast to the cholera epidemic in Haiti.
Japan initially struggled to reach and bring aid to survivors because the earthquake and tsunami destroyed transportation infrastructure (road, rail and air). Survivors, many of them elderly, suffered from the cold and a lack of food and water leading to problems with hypothermia, upper respiratory infections, and gastroenteritis. Endemic diseases, such as Japanese encephalitis, could have created additional problems had the weather been much warmer and the mosquito vector able to breed in standing water created by the tsunami. However, as a highly industrialized nation, Japan has been able to relocate 300,000 survivors to the safety of its cities and reduce public health risks.
The health crisis created by the Japan earthquake was the result of the nation’s industrialization, specifically its reliance upon nuclear energy. The earthquake caused the Fukushima Daiichi Nuclear Power Plant to shut down its reactors as a precaution, but the tsunami damaged the diesel electric generators that operated the cooling systems for the reactors and storage ponds. Overheating in the reactors led to hydrogen explosions and radiation leaks resulting in a nuclear accident second only to Chernobyl in severity. Based upon radiation levels from fallout, the population in a 30 km zone around the plant was evacuated. The Department of Energy has mapped the one year exposure dose in areas that were contaminated; and there is a hot zone 50 kilometers northwest of the plant where exposures exceed 2000 mrems/year. This level of exposure could result in one extra cancer case in 500 young adults and is not insignificant. However, this highest level of exposure is exceeded by natural background radiation is parts of the world and will decline over time. Morbidity and mortality from the incident is expected to be limited to those directly working around the damaged power plant and with delayed consequences, e.g., increased incidence of cancer.
In two societies at both ends of the developmental spectrum, natural disasters created long term health sequelae – one for lack of technology (adequate sanitation) and one because of technology (nuclear power). In Haiti, their major river now harbors a highly pathogenic strain of Vibrio cholerae, whose impact on national health and potential transmission to other countries in the Americas has yet to be fully determined. Destruction and release of radiation at the Fukushima Power Plant appears to have a more far reaching impact – not from human morbidity and mortality but from international concerns over the safety of nuclear power.
PRSI ContributorDr. David Danley, COL (ret) spent his career in medical research and developing products (detectors, drugs, and vaccines) against biological and chemical threat agents. Currently, he is employed as a consultant focused on recognizing evolving threats to human health and promoting technologies to mitigate their risks.