Bat lung epithelial cells show variable species-specific susceptibility to human and avian influenza viruses

The recent identification of two novel influenza-like viruses in bats, H17N10 and H18N11 virus, and the discovery of serologically positive Eidolon helvum bats in Ghana for avian H9 virus prompted my hypothesis that, in addition to the large repertoire of zoonotic viruses hosted, bats may serve as asymptomatic reservoir species to conventional influenza A viruses found in birds and mammals. To begin to test this hypothesis, the susceptibility of three bat cell lines, derived from lung epithelial cells of Eidolon helvum, Carollia perspicillata and Tadarida brasiliensis (TB1-Lu), to low pathogenicity avian viruses (H2N3 [A/mallard duck/England/7277/06] virus and H6N1 virus [A/turkey/England/198/09] virus), and human viruses (USSR H1N1 virus [A/USSR/77] and pandemic H1N1 2009 virus [A/California/07/2009]) was determined. All three species of bat epithelial cells were found to be more robust and resistant to influenza virus infections than permissive MDCK cells. Infected bat cells produced lower levels of viral RNA and viral progeny, and were more viable than correspondingly treated MDCK cells. Interestingly, bat cells were more susceptible and replication permissive to avian than human influenza viruses. Among the bat cells, TB1-Lu cells were the least susceptible to influenza virus infection and that appears to be related to a lack of sialic acid α2,6-Gal receptors, mammalian virus-preferred host receptors, which were present in the other two bat species. The innate mechanisms underlying resistance to influenza virus infection in bats remains to be determined, however, inhibition of the JAK/STAT pathway was found not to affect virus production from infected bat cells suggesting that JAK/STAT signalling may not have a major role in influenza virus resistance in bat cells. Modulation of NF-κB signalling was found to affect virus production suggesting that tight regulation of NF-κB may be key in controlling the pro-inflammatory response to influenza infection in bat cells and warrants further investigation

An exploratory study identifying a possible response shift phenomena of the Glasgow Hearing Aid Benefit Profile (GHABP)

A then-test technique was used to investigate the possibility of a response shift in the Glasgow hearing aid benefit profile (GHABP). Following completion of part 1 of the GHABP, 16 adults were invited for hearing-aid follow up appointments. In accordance with then-test technique, participants were asked to think back to before they had their hearing-aids fitted and the GHABP part 1 was completed again to re-establish the disability and handicap scores. These scores were then compared with the initial GHABP part I scores. Paired T testing and Wilcoxon Rank tests were carried out to investigate the statistical significance of the response shift effect. Statistically significant differences were seen between initial and retrospective GHABP (disability) scores using t test. No significant differences could be seen between the initial and retrospective handicap scores. Results suggest participants may have demonstrated a possible response shift phenomenon with the disability construct of the GHABP questionnaire, related to a possible re-calibration effect or a denial of disability effect. This exploratory study suggests that the GHABP questionnaire may be subject to a response shift phenomena. We suggest that further more robust studies are completed to verify this and recommend that this could have psychological impact on participants when explaining the results of the outcome measure and may affect hearing aid use. There is also potential for this phenomenon to affect global GHABP scores specifically when demonstrating to stakeholders the overall success of an audiology service

An analysis of hearing aid use: data logging as an adjunct with the Glasgow Hearing Benefit Profile Questionnaire

Introduction: There is significant variability in the ways in which hearing aid use is reported. In part, this is because there is no agreed method of reporting hearing aid use. A recent review by Perez and Edmonds (2012) concluded that a dual-stage approach using data-logging and self-reported outcome measures is preferable to an approach that uses one method alone. A dual-stage approach may provide a comprehensive understanding of hearing aid use and help further develop a detailed understanding of some of the problems associated with non-use or under-use. Objective: This study aimed to compare the relationship of self-reported hearing aid use using the Glasgow Hearing Aid Benefit Profile questionnaire (GHABP; Gatehouse, 1999) to hearing aid data-logging information, and to establish whether the GHABP can be used to accurately measure hearing aid use. Methods: This was an observational cohort study conducted in Wales, United Kingdom. A total of 119 participants were recruited at their hearing aid follow-up appointments. The length of time between hearing aid fitting and follow-up was variable. With participants’ consent, data were collected using the Glasgow Hearing Aid Benefit Profile part 2 questionnaire and data-logging information stored in the hearing aid. Correlational analyses were used to assess the relationships between the two measures of hearing aid use. Results: Mean data-logging use was 5.87 hours per day (SD=5.15) and the mean GHABP use was 67.34% (SD=32.98). Both “use” variables failed a Shapiro Wilks test of normality. There was a strong positive Pearson rho correlation between data-logging use and GHABP use (rs, = .645, p<0.01). Analysis of the GHABP questionnaire revealed that 53 participants stated that they used their hearing aids between 81% and 100% of the time. There were some low levels of use when examining data-logging in the context of variable GHABP results. Conclusions: In participants who present higher GHABP use scores with lower levels of data-logging use, some plausible reasons include: I) Inadvertent overestimation of their use by patients (recall error), 2) The GHABP questionnaire may not be sufficiently sensitive or structured in such a way to effectively measure use. For example, “listening in a quiet environment” is not captured in a GHABP question, or 3) The reporting of use as a percentage may not be an appropriate measure of use. For this reason, in keeping with Perez and Edmonds (2012), both self-reported measures of use and data-logging should be used together and audiologists are reminded to consider both measures with some level of caution

Bat lung epithelial cells show greater host species-specific innate resistance than MDCK cells to human and avian influenza viruses

Background With the recent discovery of novel H17N10 and H18N11 influenza viral RNA in bats and report on high frequency of avian H9 seroconversion in a species of free ranging bats, an important issue to address is the extent bats are susceptible to conventional avian and human influenza A viruses. Method To this end, three bat species (Eidolon helvum, Carollia perspicillata and Tadarida brasiliensis) of lung epithelial cells were separately infected with two avian and two human influenza viruses to determine their relative host innate immune resistance to infection. Results All three species of bat cells were more resistant than positive control Madin-Darby canine kidney (MDCK) cells to all four influenza viruses. TB1-Lu cells lacked sialic acid α2,6-Gal receptors and were most resistant among the three bat species. Interestingly, avian viruses were relatively more replication permissive in all three bat species of cells than with the use of human viruses which suggest that bats could potentially play a role in the ecology of avian influenza viruses. Chemical inhibition of the JAK-STAT pathway in bat cells had no effect on virus production suggesting that type I interferon signalling is not a major factor in resisting influenza virus infection. Conclusion Although all three species of bat cells are relatively more resistant to influenza virus infection than control MDCK cells, they are more permissive to avian than human viruses which suggest that bats could have a contributory role in the ecology of avian influenza viruses

Bat lung epithelial cells show variable species-specific susceptibility to human and avian influenza viruses

The recent identification of two novel influenza-like viruses in bats, H17N10 and H18N11 virus, and the discovery of serologically positive Eidolon helvum bats in Ghana for avian H9 virus prompted my hypothesis that, in addition to the large repertoire of zoonotic viruses hosted, bats may serve as asymptomatic reservoir species to conventional influenza A viruses found in birds and mammals. To begin to test this hypothesis, the susceptibility of three bat cell lines, derived from lung epithelial cells of Eidolon helvum, Carollia perspicillata and Tadarida brasiliensis (TB1-Lu), to low pathogenicity avian viruses (H2N3 [A/mallard duck/England/7277/06] virus and H6N1 virus [A/turkey/England/198/09] virus), and human viruses (USSR H1N1 virus [A/USSR/77] and pandemic H1N1 2009 virus [A/California/07/2009]) was determined. All three species of bat epithelial cells were found to be more robust and resistant to influenza virus infections than permissive MDCK cells. Infected bat cells produced lower levels of viral RNA and viral progeny, and were more viable than correspondingly treated MDCK cells. Interestingly, bat cells were more susceptible and replication permissive to avian than human influenza viruses. Among the bat cells, TB1-Lu cells were the least susceptible to influenza virus infection and that appears to be related to a lack of sialic acid α2,6-Gal receptors, mammalian virus-preferred host receptors, which were present in the other two bat species. The innate mechanisms underlying resistance to influenza virus infection in bats remains to be determined, however, inhibition of the JAK/STAT pathway was found not to affect virus production from infected bat cells suggesting that JAK/STAT signalling may not have a major role in influenza virus resistance in bat cells. Modulation of NF-κB signalling was found to affect virus production suggesting that tight regulation of NF-κB may be key in controlling the pro-inflammatory response to influenza infection in bat cells and warrants further investigation