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We explore the history of blood types and how they are classified to find out what makes the Rh-null type important to science and dangerous for those who live with it. KEVIN DICKINSON 07 October, 2018 Fewer than 50 people worldwide have 'golden blood' — or Rh-null. Blood is considered Rh-null if it lacks all of the 61 possible antigens in the Rh system. It's also very dangerous to live with this blood type, as so few people have it. Golden blood sounds like the latest in medical quackery. As in, get a golden blood transfusion to balance your tantric midichlorians and receive a free charcoal ice cream cleanse. Don't let the New-Agey moniker throw you. Golden blood is actually the nickname for Rh-null, the world's rarest blood type. As Mosaic reports, the type is so rare that only about 43 people have been reported to have it worldwide, and until 1961, when it was first identified in an Aboriginal Australian woman, doctors assumed embryos with Rh-null blood would simply die in utero. But what makes Rh-null so rare, and why is it so dangerous to live with? To answer that, we'll first have to explore why hematologists classify blood types the way they do. Read more:
Guest posted a topic in Health & Medicine's TopicsDonated blood at a bank in Indianapolis. The F.D.A. has recommended that all donated blood in the United States be screened for the Zika virus. CreditMichael Conroy/Associated Press The Food and Drug Administration on Friday took steps to safeguard the nation’s blood supply from the Zika virus, calling for all blood banks to screen donations for the infection even in states where the virus is not circulating. The recommendations are an acknowledgment that sexual transmission may facilitate the spread of Zika even in areas where mosquitoes carrying the virus are not present. Officials also want to prepare for the possibility that clusters of local infection will continue to pop up in parts of the United States for years to come. “There could be multiple outbreaks of Zika happening outside the known current ones in South Florida, but because we are not actively looking they could be happening silently,” said Dr. Peter J. Hotez, the dean of the National School of Tropical Medicine at Baylor College of Medicine, who applauded the F.D.A.’s move. Without federal funds, it is generally not possible for local health departments to conduct active surveillance for Zika virus in the blood or urine of patients with fever or rash, he added. “In some ways the inaction from Congress has forced the F.D.A. to adopt this position,” Dr. Hotez added. “They have no other choice.” The agency urged blood centers to use one of two experimental tests intended to detect active infections, called nucleic acid tests, before releasing donated blood for use in transfusions. As an alternative, banks may decontaminate plasma and platelets with so-called pathogen reduction technology. But the recommendations are likely to pose a significant challenge for some blood banks and for the third-party labs that perform much of the blood screening nationwide, some experts said. Eleven states must put the new safeguards into place within four weeks. They include Alabama, Arizona, California, Georgia, Louisiana, New York and Texas, which have many residents who travel to Zika-affected countries or are near an area that already has locally acquired mosquito-borne cases. Other states have 12 weeks to carry out the recommendations. “This is a bombshell, because this is extremely rapid introduction of a new test nationwide that’s almost unprecedented,” said Dr. Jeffrey McCullough, emeritus professor of laboratory medicine and pathology at the University of Minnesota Medical School. “To try to implement this, in four weeks, is really, really difficult.” Yet the new safeguards also are necessary, Dr. McCullough said. Under current guidelines, it is too difficult to identify infected donors by “trying to sort out risky donors by history of where they’ve been or what they’ve exposed to.” Nationwide, nearly 14 million units of whole blood and red blood cells are collected each year from about seven million donors. Every day, as many as 36,000 units of red blood cells are given to patients, along with 7,000 platelet units and 10,000 units of plasma. Consistent screening of the blood supply is an enormous task. There are more than 11,500 confirmed cases of Zika virus in states and territories, according to the C.D.C. Nearly 2,500 of them are people in the continental United States who traveled abroad where Zika-infected mosquitoes are circulating. More than 30 cases were acquired in Florida. Puerto Rico has been screening all blood donations since March. TheCenters for Disease Control and Prevention in June found that asurprisingly high percentage of donors had signs of active infection with the Zika virus. The F.D.A. provisionally approved two screening tests for Zika in blood donations on an investigational basis in March and June respectively. The first is made by Roche Molecular Systems, and the second by a collaboration between Hologic Inc. and Grifols. Neither test is fully F.D.A approved yet, and the facilities using them are enrolled in a continuing study. As part of Roche’s investigation, four centralized testing labs that screen blood for multiple banks in the South have been “collecting and testing blood for weeks now,” said Tony Hardiman, who leads the blood screening operations at Roche. For the 11 states that need to be ready in a month, he said, “we are pretty much locked and loaded.” “Our focus now is what do we do for the rest of the country to bring them up in 12 weeks,” he added. Officials at Blood Systems, which operates blood banks in 24 states, said they will be able to test blood donations in California and some Southern states like Mississippi in a month. The company will then work on getting sites in the Rocky Mountain States operational, said Dr. Ralph R. Vassallo Jr., the chief medical and scientific officer. Creative Testing Solutions, a large blood donor testing lab, already is using both experimental Zika screening tests. In Tampa, the company has relied on Roche’s test since the Zika outbreaks began in Miami-Dade County. In its Dallas and Phoenix outposts, C.T.S. has installed two so-called Panther machines to be able to screen tubes of blood with the Hologic-Grifols test, in case Zika-infected mosquitoes arrive along the Gulf Coast. In light of Friday’s F.D.A. recommendations, officials said they will have to train more employees to use new tests and significantly scale up. “We test 35 percent of the blood supply, so in order to be able to do that in all states in 12 weeks, we are going to need additional pieces of equipment,” said Marc Pearce, a spokesman for C.T.S. — 12 more Panthers and one more machine that runs the Roche test. Asked on a conference call with reporters about funding the new safeguards, Dr. Peter Marks, the director of the F.D.A.’s Center for Biologics Evaluation and Research, said, “I can’t speak to the cost of implementation at this time.” Hospitals may wind up paying more for each unit of blood because of additional screening costs, some experts said. “When hospitals hear this, they will be concerned that they could see a cost increase of up to $8 more per unit,” Dr. Vassallo said, which is roughly how much it costs to screen each unit for the Zika contamination. This month, after the first cases of local transmission in Miami were discovered, some blood banks near Zika hot zones in Florida began screening blood donations. According to Dr. Marks, one donation contaminated with the virus had been found in recent weeks in the state. The bag of contaminated blood was discarded. “The system worked correctly,” Dr. Marks said.
A leading infectious disease doctor is warning that not only is the virus sexually transmitted but that it could affect blood donations New concerns have emerged over the widespread Zika epidemic as it's feared the virus can be spread through sex and can impact blood donations. Scientists probing the rapid onslaught of the virus claim pregnant women can catch it through unprotected sex. At least one UK resident was warned not to have sex without a condom after contracting the virus. Leading infectious diseases expert Dr Amesh Adalja at the University of Pittsburgh Medical Center says it has been well documented and part of that research was focused in the UK. And there's fresh concerns that it could end up contaminating emergency blood supplies . Only one in five people show symptoms of the disease and don't seek medical treatment - meaning Zika is a benign illness for the vast majority of patients. Read more: Was Zika outbreak caused by release of genetically modified mosquitoes in Brazil? Dr Amesh A. Adalja is a leading infectious disease researcher at the University of Pittsburgh Medical Center But this opens up major concerns for doctors worried that the disease can spread person to person - and infect unborn babies - without a mosquito bite. Dr Adalja said: "There have been cases of sexual transmission of Zika from male to female and, if the woman is pregnant , the virus could theoretically pass to the gestating fetus. There are fears that the virus could end up contaminating emergency blood supplies "At least one case report of a sexual transmission event that spread Zika in the medical literature. "It involved a male scientist who was in Senegal in 2008 and then traveled home to Colorado. "Both he and his wife developed Zika virus, though she had not traveled to any Zika prevalent areas but had engaged in sexual intercourse. "Interestingly, his symptoms included having blood in his semen (hematospermia). Getty The Zika virus can be transmitted through unprotected sex "Hematospermia was also reported in a Tahitian patient in 2013 and the Zika virus was subsequently isolated from the semen. "The US CDC has not made a recommendation regarding sexual transmission to pregnant women however, as a precaution, Public Health England has recommended condom use in a male patient returning from Zika-affected areas for 28 days and for 6 months in those with confirmed Zika. "More evidence of sexual transmission including its likelihood and its timeframe are needed." James Breeden Six young babies with microcephaly and their parents wait to be seen by medics in Brazil Millions of British people visit the 24 infected countries each year and the Government is warning pregnant women not to travel. However, these new revelations are worrying not only for pregnant women but for millions of people who rely on blood donations. Speaking exclusively to Mirror Online , Dr Adalja, added that there are very real concerns over blood transfusions. He added: "There is also concern for the virus being transmitted via blood transfusion. "The UK is not home to Aedes mosquitoes but still has to be prepared to identify and diagnose infected travelers. Getty Dr. Angela Rocha examines Ludmilla Hadassa Dias de Vasconcelos "The risk of contracting Zika via a blood transfusion was established via screening asymptomatic donors in French Polynesia a few years ago and there has been at least one report of the virus being acquired in this manner. "The blood banking industry and regulatory agencies are rapidly developing donor guidance to minimize this risk." Dr Adalja says any real vaccine offering could be at least 10 years off and British doctors have to be prepared for the real possibility that the virus could spread exponentially in the UK. He added: "Vaccine development is generally measured on the scale of years. Getty A health care employee examines blood infected with the Zika virus in a health centre in Caracas, Venezuela "However, there are a few extant vaccines that may be able to reconfigured for Zika allowing the proceed to be accelerated but it will still be some time before vaccine is widely available. "It usually takes about a decade to fully commercialize a novel vaccine. "There are many new technologies that have been developed that may be able to accelerate the development and there are emergency use provisions facilitating human use earlier in clinical development than usual. "This acceleration will be dependent on how easy it is to devise a vaccine against Zika which will include deciding what part of the virus to target to stimulate protective immunity while not triggering autoimmune reactions, which may be an issue given the cases of Guillain-Barre Syndrome that have been linked to Zika. REUTERS/Denis Balibouse World Health Organization (WHO) headquarters in Geneva has declared an emergency "However, once the vaccine development, safety, efficacy, storage and dosing studies all take time so it is hard to put an exact timeline on to a novel vaccine." Five cases of Zika virus have been diagnosed in UK travellers as part of this outbreak. There has only been one additional case of Zika virus infection diagnosed in the UK to date. Getty David Henrique Ferreira, 5 months, who was born with microcephaly which is believed to be linked to Zika This case was diagnosed in 2014 following travel to the Cook Islands and is not part of the ongoing outbreak in South and Central America and the Caribbean. Almost 1.4 million UK residents travelled to South and Central America and the Caribbean on average each year between 2010 and 2014.