Sep 5, 2008 (CIDRAP News) – Amid concern about rising resistance to oseltamivir (Tamiflu) in influenza A/H1N1 viruses, a Dutch team this week reported the death of a leukemia patient who was infected with an H1N1 virus that was resistant to the antiviral drug.In a letter in this week’s New England Journal of Medicine (NEJM), the Dutch authors said the case suggests that oseltamivir-resistant H1N1 viruses can cause disease, despite evidence from animal studies that the resistance mutation makes the viruses much less dangerous. The letter said the man’s virus was also resistant to amantadine, an older antiviral drug.On Aug 20, the World Health Organization (WHO) reported that 31% of influenza A/H1N1 isolates from 16 countries that conducted recent tests carried the H274Y mutation, which confers resistance to oseltamivir. Resistance levels ranged from 100% (10 of 10 isolates) in Australia to 13% (4 of 32 isolates) in Chile.Emergence of the oseltamivir-resistant H1N1 virus was first noted in Norway in January, and since then researchers have found the virus in 35 countries, including the United States and Canada.The spread of the oseltamivir-resistant H1N1 virus has puzzled experts because it has not been clearly linked to treatment with the drug.In the case report, authors from Erasmus University Medical Center in Rotterdam wrote that a 67-year-old man who was on chemotherapy in a 3-year battle with chronic lymphocytic leukemia was hospitalized with shortness of breath, a dry cough, and fever. On his second hospital day, he experienced acute respiratory failure, and his physicians placed him on a ventilator and started empirical antibiotic treatment.Computed tomography (CT) revealed that the patient had patchy lung infiltrates, and tests on samples from his respiratory tract showed he had influenza A/H1N1.On the sixth hospital day the man received oseltamivir, but by day 13 physicians discontinued the drug because sequence analysis of the virus revealed the H274Y mutation and there was no decrease in the viral load.The authors reported that the mutation was found in samples obtained before the patient began oseltamivir therapy. The man’s family and the hospital record revealed that he had had no contact with patients who were taking oseltamivir.On the 15th hospital day the man’s doctors prescribed amantadine, and after a few days his neutrophil count increased, a sign of bone marrow recovery, the group reported.On day 20 doctors took the patient off the ventilator and instituted zanamivir treatment. However, 2 days later the man had respiratory failure again, and his medical team put him back on the ventilator and discontinued zanamivir therapy. (Like osteltamivir, zanamivir is a neuramnidase inhibitor, but no increase in zanamivir resistance has been reported recently.)By day 26 physicians detected no influenza virus, but did note that sequence analysis showed an amantadine-resistance mutation in the viral M2 protein (L26F). They wrote that recovery of the immune system was probably responsible for clearing the virus, because the patient had received only three doses of zanamivir.A repeat CT scan taken on day 28 showed that pulmonary infiltrates had progressed. Because of the man’s poor prognosis, the ventilator was removed on day 34, and he died 3 days later.The authors cited animal studies indicating that oseltamivir resistance leaves H1N1 viruses “severely compromised.” Despite these reports, they wrote, “the case we describe suggests that this oseltamivir-resistant virus can be pathogenic, at least in an immunocompromised patient.”In an editorial published by Eurosurveillance in January, authorities said resistant viruses with the H274Y mutation had been seen in previous flu seasons but were rare and did not spread easily. But the more recent H1N1 isolates with the mutation were “fitter” and were spreading in the community, they wrote.Van der Vries E, Van den Berg B, Schutten M. Fatal oseltamivir-resistant influenza virus infection. N Engl J Med 2008 Sep 4;359(10):1074-76 [Full text]See also:Aug 25 CIDRAP News story “H1N1 viruses growing more resistant to Tamiflu”
Chase Allen topped the Saturday night main event for IMCA Modifieds at Abilene Speedway’s Ryan Bard Memorial Southern Challenge. (Photo by Michael Diers, Pole Position Photo)ABILENE, Texas (Oct. 14) – Another win at another late-season IMCA Modified special put another $2,000 in Chase Allen’s bank account.Allen aced Abilene Speedway’s Ryan Bard Memorial Southern Challenge main event, taking the lead early and running away from the rest of the 20-car field.“We got a little redemption this year, thankfully,” said Allen, who broke leading his previous Southern Challenge outing. “We had a tough Friday night in qualifying and tore up the car some but we got everything fixed and we were fast the next night.”The 2013 race winner, Allen started outside row two and passed tough customers Dean Abbey on the outside and Josh McGaha on the inside in making his way to the front.Abbey ended his night in second. Chris Elliott, Tommy Fain and McGaha rounded out the top five in the 25-lapper.Allen had raced his way onto the Fast Shafts All-Star Invitational ballot by winning Kennedale Speedway Park’s rescheduled Showdown special the previous weekend.Other winners at Abilene’s 23rd annual Southern Challenge were Andy Roller in the IMCA Sunoco Stock Cars, Jeffrey Abbey in the Scoggin-Dickey Parts Center Southern SportMods and Ryan Wilkerson in the IMCA Sunoco Hobby Stocks.Roller and Abbey both earned $1,700 while Wilkerson took home $650.A two-time Southern Challenge Hobby Stock winner, Roller got the best of Westin Abbey in a back-and-forth, side-by-side Stock Car feature that was decided by about half a car length.Roller had started outside the front row, fell back as far as fourth and got the lead back following an early restart. Cautions slowed the finish and Roller admitted that Abbey had the faster car, but he held on for the hotly contested checkers.Billy Wade, Dan Day and defending race winner Kirk Martin ran third through fifth, respectively.Jeffrey Abbey tuned up for defense of his Southern Challenge SportMod title by winning his Friday qualifier from 11th starting.He caught Kale Westover for the lead in lapped traffic, then held off Rodney White and Westover for the victory.Robert Scrivner was fourth and fifth went to Dustin Robinson.Wilkerson drew the pole, then tussled with 2016 race winner Gerald Spalding Jr. before getting the lead back – also in lapped traffic – for good just after midway.A seven-time winner at Abilene during the IMCA Speedway Motors Weekly Racing point season, Wilkerson was three car lengths ahead of Cody Stone at the finish.Completing the top five were Wesley Mayer, Cory Stone and Joseph Williams.Feature Results Modifieds – 1. Chase Allen; 2. Dean Abbey; 3. Chris Elliott; 4. Tommy Fain; 5. Josh McGaha; 6. Neal Flowers; 7. Brandon Hood; 8. Fred Wojtek; 9. Vince Ogle; 10. Chad Hertel; 11. Robby Edwards; 12. Mike McCarthy; 13. Cole Bishop; 14. Mark Patterson; 15. Kelly Allen; 16. Toby Herring; 17. Michael Svenlak; 18. Levi Ely; 19. Colin Deming; 20. Matt Guillaume.Stock Cars – 1. Andy Roller; 2. Westin Abbey; 3. Billy Wade; 4. Dan Day; 5. Kirk Martin; 6. Joe Spillman; 7. Mark Adams; 8. Jason Adcock; 9. Michael Lamb; 10. J.D. Davis; 11. Jack Miles; 12. Hunter Russell; 13. Mark Lord; 14. Chris Graenser; 15. Jordan O’Neil; 16. Danny Brown; 17. Anthony Otken; 18. Charles Brewer; 19. Jason Batt; 20. Cary White.Southern SportMods – 1. Jeffrey Abbey; 2. Rodney White; 3. Kale Westover; 4. Robert Scrivner; 5. Dustin Robinson; 6. Tim Clonch; 7. Michael Martin; 8. Bradley Poor; 9. Ronnie Bell Jr.; 10. Chris Florio; 11. Justin Shaw; 12. James Hanusch; 13. Kyle Wisdom; 14. Michael Maraschick; 15. Cory Williams; 16. Tyler Fain; 17. Rodger Pierce; 18. Frank Groves; 19. Charles Garza.Hobby Stocks – 1. Ryan Wilkerson; 2. Cody Stone; 3. Wesley Mayer; 4. Cory Stone; 5. Joseph Williams; 6. Gerald Spalding Jr.; 7. Jordan Kornegay; 8. Shawn Miles; 9. Aaron Childress; 10. Michaela Scott; 11. Jonathan Boles; 12. George Ross; 13. Rodney Sparks; 14. Ashton Hayes; 15. Clinton Brown; 16. Carolyn Botts; 17. Shaun Wright; 18. Mike Watkins.