Fighting infectious disease, one blood donation at a time

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We fight infectious diseases by responding quickly to blood safety threats.

Infectious diseases are illnesses you get when microorganisms such as bacteria, parasites, or viruses invade your body. They’re one of the major causes of death worldwide. Every year, 1.45 million people die of viral hepatitis.1 In 2014 alone, 1.2 million died of AIDS-related causes.2

Some of these diseases turn into epidemics that need to be contained before becoming global crises. After the 2014 Ebola outbreak, for example, Zika became the next public health concern.

A new health emergency

Many microorganisms that cause infectious diseases are present in the blood and can be spread through blood transfusions. And because people who generously donate blood do not always know they are infected, we need to be careful.

With the right tools, we can protect patients by testing blood for signs of infection. Occasionally, however, there are new threats to the blood supply that can’t be found by existing technology.

The Zika virus was one of these threats.

Although symptoms in adults are generally mild, Zika can be devastating for patients with weaker immune systems, such as the elderly or people living with cancer.

When a study confirmed that Zika infection during pregnancy can cause severe brain defects in a foetus, including microcephaly,3 the risks became undeniable.4

In February 2016, the World Health Organisation (WHO) declared Zika a Public Health Emergency of International Concern, with 33 countries reporting Zika infections. The speed at which it spread, especially throughout the Americas, was shocking.

In Puerto Rico, over 700 confirmed Zika cases were reported by March 2016,5 with thousands more unreported cases suspected. Because it was so rampant and yet hard to detect, the US Food and Drug Administration (FDA) reacted by stopping local blood donations. As a result, in the weeks that followed, all blood products for patients in need had to be imported from continental US.

A rapid response to a growing crisis

On 2 April—less than one month after suspending blood collection—local donations resumed, thanks to new screening technologies allowed by the FDA under an Investigational New Drug application (IND) announced just days earlier.

“We recognised the need for a blood screening assay very early in the epidemic,” said Dr. Lisa Lee Pate, Director of Clinical Science for Blood Screening at Roche Molecular Systems. “Today, we are leading the effort to protect the blood supply in Puerto Rico and the United States from Zika.”

The good news? Over 2.5 million blood donations have been screened for the Zika virus using Roche technologies since April 2016. Of these, over 430 units tested positive for Zika and were removed from the blood supply, preventing as many as 1290 potential recipients from contracting the virus.6

“This is quite significant considering that blood could not be screened for Zika before our assay was approved,” said Lisa. “Within a few hours, testing labs throughout the United States and Puerto Rico can tell which units have Zika and which do not. This enables a much safer blood supply overall.”

Protecting the most vulnerable

With reliable screening in place, pregnant women and the immunocompromised can feel confident that a blood transfusion will not put them at risk.

The power of diagnostics is that it continues to protect us with a safe blood supply. Although we cannot predict which infectious disease will become the next big worry, we can provide the right tools, at the right time.

References

  1. World Health Organization, World Hepatitis Day. Last accessed May 2016 at http://who.int/campaigns/hepatitis-day/2015/en/
  2. World Health Organization, HIV/AIDS fact sheet. Last accessed May 2016 at www.who.int/mediacentre/factsheets/fs360/en/
  3. Rasmussen, Sonja A. et al. Zika Virus and Birth Defects – Reviewing the Evidence for Causality. DOI: 10.1056/NEJMsr1604338, 13 April 2016. Last accessed May 2016 at www.nejm.org/doi/full/10.1056/NEJMsr1604338
  4. Last accessed May 2016 at http://bigstory.ap.org/article/79f964354fe04abe8da34510d1b762a1/puerto-rico-reports-1st-zika-related-microcephaly-case
  5. McNeil, Donald G. Puerto Rico Reports First Microcephaly Case Linked to Zika. The New York Times, 13 May 2016. Last accessed May 2016 at www.nytimes.com/2016/05/14/health/puerto-rico-reports-first-microcephaly-case-linked-to-zika.html?_r=0
  6. The total number of donations screened (8,686) and the total number of units reactive for Zika (30) is drawn from data tracked by the Roche screening instrument and transmitted to the Roche Molecular Systems clinical study database established under the FDA Investigational New Drug framework. Weekly reports are shared with the FDA, the Centers for Disease Control and Prevention, the AABB and others monitoring the Zika outbreak in Puerto Rico. The number of patients prevented from contracting the virus (as many as 90) is calculated based on information provided by the American Red Cross, which notes that “a single blood donation may help up to three different people”. See: www.redcrossblood.org/donating-blood/donation-faqs.

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