El valor del dominio de Lenguas extranjeras y sus efectos en la situación y formación profesional de los docentes

There has been a significant increase in the rate of influenza notifications in the ACT, during 2005–2015, most notably in the years following the 2009 pandemic (2010–2015). Nationally, increases in influenza notifications have been observed across similar time periods.11, 35, 39 The test rate in the ACT also appears to have increased, however without data available for all years from all laboratories, it is difficult to accurately ascertain the magnitude or significance of this increase. In contrast, the percentage of positive tests did not show any trend over time, despite variation between years. In 2009 and 2012 both positivity and testing rate peaked. This is consistent with a peaks in hospitalisations for influenza observation nationally during these years.11 The 2009 pandemic year also saw the notification incidence rate peak. In 2007, the positivity was also elevated, which is

consistent with a peak in influenza death rates observed nationally in this year.11 _The

incidence of notifications did not express remarkable peaks in 2007 or 2012, despite peaks in positivity and evidence of more severe influenza outcomes.11 _{Whilst the apparent}

concordance between positivity and years with observed higher severe influenza outcomes observed in this analysis does not alone support an association. The findings highlight that notifications alone are likely unable to show the full epidemiological story of influenza in a given year.

Compulsory notification of confirmed influenza means notification data is biased by the number of tests conducted, making it difficult to estimate trends in true disease burden if increased testing occurs. The rise in notification rates in the ACT, in particular during 2013–2015, needs to be interpreted carefully as test rates during this time period also appear to have increased. Despite data only available from one laboratory for these years, the test rate was higher than all other non-pandemic years with the exception of 2012, where positivity peaked. The increased incidence rate of notifications for these periods may therefore reflect increased case ascertainment, rather than increased disease burden in the population. This finding is in keeping with reports from syndromic surveillance systems, which during the 2015 influenza season, reported slightly lower community ILI peaks in Flutracking and ASPREN surveillance data, compared to 2012 and 2014.21, 23 _Community

ILI peaks in 2012 and 2014 reported by Flutracking, and ASPREN systems are consistent with peaks in the positive test rate we observed in the ACT. In this analysis, test data for the years 2013–2015 are reported by one laboratory only. This is the only laboratory that provides positivity data for influenza surveillance reporting in the ACT. As data for 2013–

2015, and seasonal surveillance reporting are currently available from only one laboratory, the possibility of selection bias makes it difficult to interpret positivity trends for these years where we have seen the largest increase with confidence.

Overall, the notification incidence rate was highest amongst 0-4 year olds and those age ≥80 years. Although notification counts were highest in those age 20–49 years, this most likely reflects the population distribution of the ACT, where the median age is 34.5 years at the last census year, 2011.40 _{The age group specific distribution of tests was similar to notifications,}

however the proportion of positive tests was lowest in these age groups and peaked in children aged 10–14. The higher proportion of positive tests observed in older children and young adults (5–29 years), in particular the 10–14 year age group, may suggest case ascertainment is low in these ages. Conversely, the low proportion of positive tests in the 0–4 year and ≥80 age groups may reflect high case ascertainment in these age groups and a high willingness to test by clinicians.

High testing frequency may be partly related to outbreaks of non-influenza respiratory infection which are also particularly prevalent in the young and the elderly.41-43 _{High prevalence of non-}

influenza respiratory illness would therefore drive increased testing and lower positivity, attributing to trends observed in the ACT test data. The collection of samples for PCR assays that detect multiple respiratory pathogens for ILI presentations in these age groups for example has recently been proposed to explain similar epidemiologic phenomena in a review of national hospitalisation data.11 It has also been suggested however, that for this effect to have an effect on the interpretation of notification trends, such bias would need to be continual, strong and neglected in analysis to pose the same threat of misinterpretation as not considering the proportion of positive tests.19

Both ACT-based pathology laboratories offer specimens be submitted for a respiratory virus panel of assays for their PCR testing.44-47 _{The proportion of positive tests conducted for}

children and the elderly, and the proportion of tests for PCR were both greater at Laboratory A. This may reflect that Laboratory A is the only provider that serves the public hospitals in the ACT. Here we hypothesize that hospitals are more likely visited by high risk age groups (young and elderly) and the use of PCR panel testing hospital settings may drive down positivity in the presence of other circulating respiratory viruses. Future research of case

positivity trends. In addition, there were also significant differences between the two laboratories by sex, with a significantly greater proportion of both tests conducted for females at Laboratory B. The differences in distribution of age and sex between the two laboratories analysed, suggests that selection bias may influence the generalisation of positivity trends in reporting.

PCR was added to the Medicare Benefit Schedule (MBS) in 2005, and funding for PCR was boosted following the 2009 pandemic.28 _{Increased influenza testing activity in Australia has}

been previously attributed to increased accessibility to, and frequency of, PCR testing.29, 48

In the ACT, the use of PCR testing has increased significantly over time and has

contributed to the predominant proportion of notifications for influenza in the ACT since 2009. Although the rate of PCR notifications was 1.6 times greater than serology

notifications, this analysis found no statistically significant difference in the positivity between the two diagnostic methods, despite PCR as a diagnostic test having greater

sensitivity and specificity.49 Further, despite a higher proportion of serology tests conducted at Laboratory B the incidence rate for positive tests at Laboratory B was also higher.

Serology notifications and testing results should be interpreted with caution. Previous comparisons of PCR and serology sensitivity and specificity in detecting influenza from ILI in the community setting identify serology as slow, insensitive and difficult to interpret, especially at low titres and out of season.49 Poor specificity of serology as a marker of recent influenza infection may report non-acute or recently recovered cases and mask the relative impact of PCR on test positivity. A recent study of general practice sentinel surveillance of ILI has demonstrated the proportion of patients with ILI correlated to influenza test positivity in primary care patients.48 _{Assuming that Laboratory B, being a}

private laboratory, primarily services general practice, a similar study in the ACT would be of benefit in answering some of the issues in surveillance and positive test interpretation identified above.