Jul 19, 2012
Resistance mutation may reduce flu virus fitness but not transmissibility
The H275Y neuraminidase (NA) mutation, which confers oseltamivir (Tamiflu) resistance in both the former seasonal H1N1 virus and pandemic 2009 H1N1 (pH1N1) virus, appears to reduce viral fitness slightly but not transmissibility, according to a cell- and animal-based study in the Journal of Virology yesterday. Hong Kong researchers introduced the NA gene from a pH1N1 virus and two separate seasonal H1N1 strains into the genetic background of the pH1N1 virus. They found that the H275Y mutation diminished viral infectivity in human airway epithelial cells, but only slightly. They also infected ferrets with recombinant seasonal H1N1 viruses differing by hemagglutinin and NA (some with seasonal H1N1, some with pH1N1 components) and found that direct-contact and respiratory-droplet transmission were comparable whether the virus contained the H275Y mutation or not.
Jul 18 J Virol abstract
Pakistan tribal leaders endorse Taliban ban on polio vaccination
Tribal leaders in one of Pakistan's remote and volatile areas yesterday endorsed the Taliban's ban on polio vaccination as a protest against drone strikes, Agence France-Presse (AFP) reported today. The announcement came during a gathering of elders and religious scholars in Miranshah, North Waziristan, during which health officials hoped to convince leaders to accept the polio immunization campaign. The latest 3-day event ended yesterday and was designed to reach 6.1 million Pakistani children in the north. A tribal leader claimed the drone attacks are killing many children, while polio affects only a few. Earlier in the week in Karachi gunmen fired on two World Health Organization (WHO) polio vaccine workers, though it's unclear if immunization activities were the motive. Pakistan is one of three countries in which the disease is endemic, and a few months ago global health officials vowed to redouble efforts to eradicate the disease from its final footholds, which also include Afghanistan and Nigeria. Efforts to improve vaccination in those areas have been hampered by suspicions about the vaccinators as well as religious objections that have since been turned back by many Islam scholars.
Jul 19 AFP story
Jul 17 CIDRAP News story "Threats, attacks hurt Pakistan's polio vaccination push"
In other polio vaccine developments, global health groups have enlisted a popular Pakistani cricket star to push the polio vaccination message, according to a Jul 8 Radio Free Europe report. The player Shahid Afridi is from they Khyber tribal district, one of the tribal areas where several polio cases have been reported this year.
Jul 8 Radio Free Europe report
Genotyping helped trace TB outbreak among Florida homeless people
The investigation of a tuberculosis (TB) outbreak among homeless people in Duval County (Jacksonville), Fla., demonstrates the value of genotyping in recognizing TB case clusters and the continuing need for TB control measures among the homeless, according to the Centers for Disease Control and Prevention (CDC). Although Florida's TB burden has declined in recent years, the percentage of TB cases with the same genotype increased from 2008 to 2011, says an article today in Morbidity and Mortality Weekly Report (MMWR). In an investigation in February and March, Florida and CDC officials identified 99 cases from 2004 to the present that had matching TB genotypes, epidemiologic links, or common social risk factors. Thirteen of the 99 cases were fatal. Ninety-six patients were US-born, and 78 had a history of homelessness, incarceration, or substance abuse. Investigators identified one particular homeless shelter and an outpatient mental health facility as sites of concern for transmission over the past 2 years. In response to the outbreak, the Duval County Health Department screened about 2,300 people for TB and intends to screen another 2,100, the report says.
Jul 20 MMWR article
Related Jul 9 CIDRAP News item about the outbreak