Malaria-a mosquito-borne disease common in some developing countries that kills hundreds of thousands of people each year-is a serious threat to the health of even healthy humans. But as a new guidance document released on 19 August 2013 by the US Food and Drug Administration (FDA) notes, the disease isn't just confined to the developing world. There is a risk, albeit a small one, of malaria being transmitted during blood transfusions-a risk FDA believes is no longer reflected in tourists to one region of Mexico popular with US tourists.
Perhaps no other disease causes as many deaths each year as malaria, which by World Health Organization (WHO) estimates caused 660,000 documented deaths in 2010, and hundreds of thousands more in estimated but undocumented deaths.
While these deaths occur primarily outside of the US in Africa, Asia and South America, the global proliferation of goods and persons means that the disease can occasionally be found within US borders, particularly by way of people returning from trips to malaria-prone regions.
And when it comes to people giving blood, the presence of malaria can have serious consequences. Fortunately, FDA notes in its new guidance, "transfusion-transmitted malaria occurs rarely, but is a serious concern in transfusion medicine."
The other problem noted by regulators is that there used to be no licensed test for screening donors for the presence of malaria, requiring blood collection and processing entities to rely on proxy measures to reduce the chances of malaria being present. For example, if a person has had a confirmed infection of malaria or has potentially been exposed to malaria, that person would likely be disqualified from giving blood for between one year (potential exposure) and three years (confirmed exposure).
Since the release of its June 2000 draft guidance, FDA has sought more input from public stakeholders, reportedly in response to claims that definitions needed to be better standardized. A July 2006 workshop on the subject, for example, sought to assess new scientific breakthroughs in malarial antibody testing on donor assessments, and to take a more nuanced approach toward donors who had recently traveled to certain regions of Mexico.
Mexico and Malaria: A Nuanced Approach
And while officials ultimately said scientific testing required further validation before it could be fully relied upon, the data on Mexico has yielded far different results.
A subsequent 2009 meeting showed that malarial transmission in Mexico as a whole was very low, and particularly low in the state of Quintana Roo, which contains the tourist hotspots of Cancun and Cozumel. If this region was whitelisted, approximately 70% of all donors deferred due to reasons related to malaria would be eligible to donate, regulators said. This would only increase risk to the blood supply by 1.1%, FDA estimated, or one infected blood unit per 60 years of donations.
As a result, FDA is now removing the Mexican states of Quintana Roo and Jalisco from its definition of malaria-endemic areas, it said.
"Based on the revised definition of malaria-endemic area and current epidemiological data, donors who travel to the Mexican States of Quintana Roo or Jalisco would be eligible for donation without any deferral, provided the donors meet all other eligibility criteria," FDA explained in a Federal Register posting on 19 August 2013.
This exclusion, however, comes with a caveat: If rates of malaria in these states "changes over time"-that is, increase-"donor deferral recommendations would encompass donors who travel to these areas."
Guidance for Industry: Recommendations for Donor Questioning, Deferral, Reentry and Product Management to Reduce the Risk of Transfusion-Transmitted MalariaFederal Register Notice on the Guidance