May 15, 2008 (CIDRAP News) – Certain mutations that make the H5N1 influenza virus resistant to the antiviral drug oseltamivir (Tamiflu) leave it susceptible to zanamivir (Relenza), a finding that suggests nations should not rely on oseltamivir alone in preparing for a flu pandemic, according to a report published by British scientists this week.Writing in the journal Nature, the scientists describe the properties and molecular structures of the neuraminidase proteins from two H5N1 variants that have been found in some humans who were treated with oseltamivir. Their findings show that these mutant forms are resistant to oseltamivir but still susceptible to zanamivir and have structural peculiarities that explain this difference.In combination with other recent findings about oseltamivir-resistant forms of H5N1 and the seasonal flu virus H1N1, “our results indicate that it would be prudent for pandemic stockpiles of oseltamivir to be augmented by additional antiviral drugs, including zanamivir,” says the report by Patrick J. Collins, of the National Institute for Medical Research in London, and colleagues.Oseltamivir makes up 80% to 85% of the US stockpile of antiviral drugs for flu, with zanamivir constituting the rest, according to a recent report by the congressionally chartered Institute of Medicine. The report recommended increasing the stockpile, which contained about 71 million treatment courses as of last month.Neuraminidase, which corresponds to the “N” in virus labels such as H5N1, is a viral surface protein that gives new copies of the virus within infected cells the ability to slip through the cell membrane and find other cells to infect. The British scientists studied the neuraminidase found in wild-type H5N1 viruses and N1 forms of neuraminidase that contained three different mutations:His274Tyr, which has been linked to oseltamivir resistance in some fatal human H5N1 cases and was also found in a number of H1N1 viruses from seasonal flu cases this past winterAsn294Ser, which has been found in more than one subtype of flu virus from patients treated with oseltamivirTyr252His, which has been found in one clade of H5N1 virus and has not been linked with drug treatmentThe researchers analyzed the ability of both antivirals to bind to and inhibit these neuraminidases. They found that, compared with the wild-type neuraminidase, the His274Tyr and Asn294Ser variants showed strong resistance to oseltamivir, while the Tyr252His form was actually more susceptible to the drug. None of the mutant forms showed much increase in resistance to zanamivir.The scientists used x-ray crystallography to examine the structure of the neuraminidases in the hope of finding a physical explanation for the oseltamivir resistance. They detected and diagrammed specific structural characteristics of the oseltamivir-neuraminidase and zanamivir-neuraminidase complexes that appear to account for the differences in resistance.The structural basis for the differences has to do with “an altered hydrophobic pocket in the active site of the enzyme required for oseltamivir binding,” the report says.The researchers note that the His274Tyr mutant was found recently in many oseltamivir-resistant H1N1 viruses isolated from flu patients in Europe, even though the patients had no known exposure to the drug. Like the neuraminidase variants used in the study, the H1N1 isolates remained susceptible to zanamivir.”Evidently, if the His274Tyr mutation also becomes common in avian H5N1, the effectiveness of oseltamivir would be limited and the value of stockpiles compromised,” the scientists write. “Considered together with the success of HAART (highly active antiretroviral therapy) against HIV, it would be prudent to reassess the suitability of single-drug, pre-pandemic stockpiles and to develop effective drug combination treatments.”Bill Hall, a spokesman for the US Department of Health and Human Services (HHS) in Washington, DC, called the Nature report interesting but said it would not prompt a change in the agency’s antiviral stockpiling strategy.”We have known about selected instances of resistance to oseltamivir for some time, but so far, the number of reported instances of such resistance has been extremely limited,” Hall told CIDRAP News by e-mail. “The instances of Tamiflu-resistant viruses are not correlated strongly with intensity of Tamiflu use in a given population or environment. It’s also important to remember that any Tamiflu resistance that may exist in currently circulating viruses is in no way predictive of potential resistance in a yet-to-emerge virus with pandemic potential.”So, this article is interesting from a scientific perspective, but given the limited instances in which resistance has been documented, our public health approach to our stockpiling strategy remains unchanged.”Collins PJ, Haire LF, Lin YP, et al. Crystal structures of oseltamivir-resistant influenza virus neuraminidase mutants. Nature 2008 (online publication May 14) [Abstract]http://www.nature.com/nature/journal/vaop/ncurrent/full/nature06956.htmlSee also: Apr 25 CIDRAP News story “IOM: US likely to need bigger antiviral stockpile”Mar 19 CIDRAP News story “Researchers warn of resistant flu, foodborne microbes”Jan 29 CIDRAP News story “Europeans find Tamiflu resistance in seasonal flu virus”
A doctor vaccinates a patient in a municipal vaccination centre in Nice, southeastern France, September 9,2009. Four vaccination centres will be opened by Nice’s municipality in case of contagion of H1N1 influenza virus contagion. REUTERS/Eric Gaillard (FRANCE HEALTH) Miami-Dade County Public Schools has partnered with Healthy Schools LLC to offer no-cost, in-school tetanus, diphtheria, and whooping cough – also called pertussis – (Tdap) vaccinations to sixth-grade students. The booster is required by Florida law before a child enters 7th grade.The Tdap booster will be administered by nurses from Healthy Schools at clinics set up at middle schools and K-8 centers between Wednesday, May 15 and Friday, May 31, 2019.Parents should contact their child’s school for specific dates and times of the clinics. A consent form was sent home with each 6th-grade student. Parents or guardians should complete the paper form and return it to the school any day before the clinic day scheduled for their child’s school. Children will not be vaccinated without the completed consent form, which will be available in English and Spanish.Parents/guardians who would like an additional copy of the paper consent form can obtain one by accessing Dadeschools.net. If you require additional languages, please contact your child’s school.
AddThis Sharing ButtonsShare to FacebookFacebookShare to TwitterTwitterShare to MoreAddThisAlpena, Mich. — Summer is here. That means some undesirable bugs are back and doctors are calling them a public health concern. After seeing a handful of new cases Switzer Veterinary Clinic is helping us keep those annoying ticks out of our pets’ hair.Our dogs love to run and jump through the open fields. They’re so close to the ground, they’re just a magnet for ticks.“If you talk to people who’ve lived here a long time,” said veterinarian Daniele Knight, “we’ve never seen ticks until five years ago.”The tiny bugs are good at playing hide–and–seek. “There is a higher risk in a wooded area but we also find them in town as well.”Dr. Knight says Alpena County saw more tick sightings than ever before,”so that’s raised a lot of concern for ourselves as well as the dog.”One out 60 dogs test positive. Knight said, “that’s a lot.”Ticks lead to diseases we don’t want our pets to have so the best way to remove them is to use a tick removing device.“If you remove a tick from yourself or your dog, you do not want to crush it with your fingers, because you can actually get the bacteria on yourself and get infected,” said the doctor.Search behind the ears, neck and legs. Doctors at Switzer use blood from heart warming tests to check for three different tick diseases.“You want to be on a good quality, veterinary recommended flee and tick preventive every single month,” said Dr. Knight.We don’t want our furry pals running back to us with any parasitic friends. AddThis Sharing ButtonsShare to FacebookFacebookShare to TwitterTwitterShare to MoreAddThis Tags: Dogs, Health, pets, Switzer, TicksContinue ReadingPrevious Law enforcement teams up with Special Olympics for fundraiserNext Onaway’s Moran Iron Works receives $500,000 Michigan grant for new equipment
Kenichi Yatsuhashi began life as Hearts of Oak coach with a hard fought 1-0 victory over New Edubiase at home.The tie was settled with a late Samuel Yaboah strike to give Hearts of Oak all three points on the dayHearts started with Mustapha Essuman, Richard Akrofi, Ibrahim Samudeen, and Kennedy Appiah but it was another debutant, Sam Yeboah, who came from the bench to bring smiles to the thousands of Hearts fans gathered at the Stadium.Hearts did most of the probing in the game but were left susceptible to the speed and counter of their opponents from Bekwai.Dreams FC opened their Premier league campaign with an impressive 1-0 away to fellow entrants Ebusua Dwarfs at the Robert Mensah Stadium.Johnson Owusu got the decisive goal on the nick of halftime to silence the noisy Cape Coast fans Dwarfs’ attempt to restore parity proved futile as Mozart Adjetey thwarted their efforts with series of top class saves.The brightest chance fell to striker Bright Lukman when he came one-on-one with Adjetey but he only managed to flufr his lines.Fellow debutants, Techiman City FC also fetched h a narrow 1-0 win over regional rivals Berekum Chelsea at Nana Ameyaw Park in Techiman.Ex-Chelsea attacker Issaka Ibrahim left it late to score the only goal of the game on his debut to send the home fans into wild jubilation.The Nana Ameyaw Park saw a large crowd on the day who trooped to watch Techiman City’s first Premier League game since 1986.The downside to this game was a horrific injury for Berekum Chelsea attacker Ashiwome Fumador who was taken off the pitch injured after an awkward landing. Striker Maxwell Baako scored a brace to power Wa All Stars to a commanding 3-0 win over visiting Sekondi Hasaacas at the Wa Park in the Ghana Premier League on Sunday.Maxwell Baako opened the scoring for All Stars in the 17th minute before Richard Arthur increased the tally for the on the 33rd minute mark.Baako returned from the break to score his brace to round off a comfortable victory for the Wa side.Ashantigold began their title defence with a 2-1 win over Medeama in ObuasiNuhu Fuseini and Alhassan Nuhu scored in between Bernard Ofori’s goal from the spot to hand the Miners a sweet revenge over Medeama.Alhassan Nuhu opened the scoring in the 36th minute before former teammate Bernard Ofori restored parity for Medeama through the spot kick.Nuhu Fuseini proved the winner when he scored a scorcher in the opening minutes of the second half.Bechem United defeated Liberty 2-0 at the Nana Gyeabour Park in Bechem.Yaw Arnol and Francis Afriyie scored to fetch the Bechem side an opening matchday victory.Afriyie applied a perfect technique to connect a free kick home midway through the first-half befor Arnol collected a ball from 25 yards to score a clinical effort. Inter Allies produced an effective display to see off title favourites Aduan 2-0 at the Tema Patk.Ropapa Mensah opened the scoring in the 19th minute before Ghana youth midfielder Isaac Twum scored a spectacular goal five minutes before the break.Aduana continue to struggle at Tema falling to a similar scoreline in last season’s league.–Follow Kweku on Twitter: @nana_odum. Get more updates on Facebook/Twitter with the #JoySports hashtag