Lill Trogstad1, Inger Johanne Bakken2, Nina Gunnes3, Sara Ghaderi4, Camilla Stoltenberg5, Per Magnus6, Siri E Håberg7. 1. Norwegian Institute of Public Health, Norway. Electronic address: lill.trogstad@fhi.no. 2. Norwegian Institute of Public Health, Norway. Electronic address: inger.johanne.bakken@fhi.no. 3. Norwegian Institute of Public Health, Norway. Electronic address: nina.gunnes@fhi.no. 4. Norwegian Institute of Public Health, Norway. Electronic address: sara.ghaderi@fhi.no. 5. Norwegian Institute of Public Health, Norway; University of Bergen, Bergen, Norway. Electronic address: camilla.stoltenberg@fhi.no. 6. Norwegian Institute of Public Health, Norway; University of Oslo, Oslo, Norway. Electronic address: per.magnus@fhi.no. 7. Norwegian Institute of Public Health, Norway. Electronic address: siri.haberg@fhi.no.
Abstract
BACKGROUND: Associations between influenza infection and sleep disorders are poorly studied. We investigated if pandemic influenza infection or vaccination with Pandemrix in 2009/2010 was associated with narcolepsy or hypersomnia in children and young adults. METHODS: We followed the Norwegian population under age 30 from January 2008 through December 2012 by linking national health registry data. Narcolepsy diagnoses were validated using hospital records. Risks of narcolepsy or hypersomnia were estimated as adjusted hazard ratios (HRs) in Cox regression models with influenza infection and vaccination as time-dependent exposures. RESULTS: Among the 1,638,526 persons under age 30 in Norway in 2009, 3.6% received a physician diagnosis of influenza during the pandemic, while 41.9% were vaccinated against pandemic influenza. Between October 1st 2009 and December 31st 2012, 72 persons had onset of narcolepsy and 305 were diagnosed with hypersomnia. The risk of a sleep disorder was associated with infection during the first six months, adjusted HR 3.31 with 95% confidence interval [CI], 1.01-10.79 for narcolepsy and adjusted HR 3.13 (95% CI, 1.12-8.76) for hypersomnia. The risk of narcolepsy was strongly associated with vaccination during the first six months adjusted HR 17.21 (95% CI, 6.28-47.14), while the adjusted HR for hypersomnia was 1.54 (95% CI, 0.81-2.93). CONCLUSIONS: The study confirms an increased HR of narcolepsy following pandemic vaccination. Slightly increased HRs of narcolepsy and hypersomnia are also seen after influenza infection. However, the role of infection should be viewed with caution due to underreporting of influenza.
BACKGROUND: Associations between influenza infection and sleep disorders are poorly studied. We investigated if pandemic influenza infection or vaccination with Pandemrix in 2009/2010 was associated with narcolepsy or hypersomnia in children and young adults. METHODS: We followed the Norwegian population under age 30 from January 2008 through December 2012 by linking national health registry data. Narcolepsy diagnoses were validated using hospital records. Risks of narcolepsy or hypersomnia were estimated as adjusted hazard ratios (HRs) in Cox regression models with influenza infection and vaccination as time-dependent exposures. RESULTS: Among the 1,638,526 persons under age 30 in Norway in 2009, 3.6% received a physician diagnosis of influenza during the pandemic, while 41.9% were vaccinated against pandemic influenza. Between October 1st 2009 and December 31st 2012, 72 persons had onset of narcolepsy and 305 were diagnosed with hypersomnia. The risk of a sleep disorder was associated with infection during the first six months, adjusted HR 3.31 with 95% confidence interval [CI], 1.01-10.79 for narcolepsy and adjusted HR 3.13 (95% CI, 1.12-8.76) for hypersomnia. The risk of narcolepsy was strongly associated with vaccination during the first six months adjusted HR 17.21 (95% CI, 6.28-47.14), while the adjusted HR for hypersomnia was 1.54 (95% CI, 0.81-2.93). CONCLUSIONS: The study confirms an increased HR of narcolepsy following pandemic vaccination. Slightly increased HRs of narcolepsy and hypersomnia are also seen after influenza infection. However, the role of infection should be viewed with caution due to underreporting of influenza.
Authors: Daniel A Salmon; Paul Henri Lambert; Hanna M Nohynek; Julianne Gee; Umesh D Parashar; Jacqueline E Tate; Annelies Wilder-Smith; Kenneth Y Hartigan-Go; Peter G Smith; Patrick Louis F Zuber Journal: BMJ Glob Health Date: 2021-05
Authors: Anna Hayman Robertson; Milada Mahic; Miloje Savic; Gro Tunheim; Olav Hungnes; Lill Trogstad; Walter Ian Lipkin; Siri Mjaaland Journal: Influenza Other Respir Viruses Date: 2020-01-19 Impact factor: 4.380