Health Spectator

Friday happens to be Malaria Day in the Americas 2009, and while malaria is not much of a problem here in the United States, it does affect our neighbors to the south and is a major problem in Africa. So we thought we’d take the time to acquaint you with the issues.

Malaria kills more than one million people a year, most of them children. (Most of the remaining fatalities are pregnant women.) Somewhere between 350 million and 500 million people are infected with malaria annually, at great economic cost, especially to families, since breadwinners are often unable to work for weeks, even if they eventually recover.

The main efforts being taken to combat malaria involve encouraging the use of bed nets in malaria-infested regions, particularly long-lasting insecticide-treated bed nets, which are the state of the art, and combating antimalarial resistance. So far, resistance to antimalarials —the ineffectiveness of malaria medications due to evolving strains of malaria that are not killed by them—has cost us the use of the cheapest and all but the very best antimalarial medications. Indeed, the World Health Organization (WHO) has mandated that artemisinin, the best of the antimalarials available currently, not be given as a monotherapy. In other words, artemisinin must be adminstered with at least one other antimalarial drug to comply with WHO guidelines.

In the Americas, targets for 2015 include:

• Decreasing annual malaria cases from approximately 1.15 million in the year 2000 to 575,000 by 2010 (50% reduction) and to 287,000 by 2015 (additional 25% reduction)
• Reducing malaria deaths from 348 in the year 2000 to less than 174 (50% reduction) by 2010 and to less than 87 (additional 25% reduction) by 2015

The effectiveness of long-term malaria control is governed by the strength of health systems. Strong health systems can deliver effective, safe, high-quality interventions when and where they are needed and assure access to reliable health information and effective disease surveillance. At the same time, integrating malaria treatment, prevention and surveillance into existing health programs and activities in endemic countries will ensure that funding earmarked for malaria control contributes to the development, expansion and continuous improvement of national health systems.

While the malaria situation in Africa is particularly dire, in the Americas there have been some successes since the turn of the century. Specifically, between 2000 and 2008, we have seen

• a 50.4% reduction of malaria cases in the region
• Approximately a 77% reduction in malaria mortality
• Seven countries have witnessed a greater than 75% reduction in annual malaria cases
• Five countries have shown a reduction in annual malaria cases between 50% and 74%
• Six countries have decreased annual malaria cases by less than 50%

Just in the Americas, the investment needed for malaria control and elimination are $227 million in 2009 and $261 million in 2010.

In a major health crisis, the BBC is reporting that Irish city Galway has been struck by a cryptosporidium outbreak.

Cryptosporidium is a protozoan that can cause severe vomiting, diarrhea, and stomach cramps in humans (cryptosporodiosis). What’s worse, infestation by this intestinal parasite can be fatal to children, the elderly, and those with compromised immune systems, such as AIDS patients.

Galway is not the first city to be struck by such a crisis, nor is it likely to be the last. Cryptosporidium spreads by use of an oocyst phase that is not affected by chlorine or most other common disinfectants. Once this water-borne parasite invades a water supply, it is likely to cause illness in up to 50% of the citizens drinking the affected water.

A major outbreak of cryptosporidium in Milwaukee, Wisconsin in 1993 killed more than 100 people out of an estimated 880,000 served by the affected water treatment facility. The plant was shut down, but during the two week period that it remained open, 403,000 residents became ill. This was the worst waterborne disease outbreak documented in the United States.

Ozonation and treatment with ultraviolet light have been shown to be effective treatments for disabling the protozoan, but filtration and boiling are the most commonly used methods to achieve water safety.

Unlike many parasites, cryptosporidium passes its entire life cycle in a single host, so an infected host will excrete oocysts in its feces. If those oocysts can reach a water supply, the cycle continues.

Some recent reports indicated that the Galway outbreak occurred through leakage from a sewage treatment plant. However, others have reported that the contamination-causing waste was animal as well as human, indicating that agricultural runoff could be involved as well.