Tag: flu

Barts-MS rose-tinted-odometer  ★★★

Not walking my talk. Having not taken up the NHS offer of the seasonal flu vaccine and having just spent the last 3 days bed-bound with severe flu I found the following research paper very timely. 

Using the Norwegian registries these investigators show that pwMS are much more susceptible to the complications of influenza, i.e. pwMS are much more likely to require emergency hospital admission as a result of influenza infection. Reasons for this are three-fold. Firstly, people with advanced MS may not have as strong gag and cough reflexes with a higher chance of aspiration of their secretions with secondary pneumonia. They may also have weakened respiratory muscles that increase their chances of getting a segmental collapse of their lungs and secondary pneumonia. Secondly, many pwMS are on immunosuppressive medications which blunt their immune response to the influenza virus making the virus more virulent and likely to affect multiple organ systems. Finally, on average pwMS have reduced resilience to infections independent of being on immunosuppressive medication, this probably relates to deconditioning, temperature-related conduction-block in response to fever and the fact that many pwMS are disabled. In summary, pwMS handled infections less well than the general population and are more likely to get complications. 

Disappointing is the observation that pandemic vaccination did not influence the risk of hospitalization in this study. I suspect this was because the pandemic vaccine used in this study epoch was not effective. 

Even if you don’t need hospitalisation having influenzae is very unpleasant and make your MS symptoms much worse. There have been some studies that have shown that not all patients recover back to their baseline when they get worsening of their MS symptoms in response to an infection. The latter observation would imply that the infection triggered an MS relapse. Avoiding infections is, therefore, one of our aims as part of the holistic management of MS.

As I sit here and type this blog post I am still incredibly tired with brain fog and many persistent symptoms that will take a week or more to clear. The physical symptoms are one thing, what about the social impact? I just spent the three days of the festive season in bed ignoring my family and social commitments. The bottom line is if you can avoid having flu, why wouldn’t you? It is not too late to be vaccinated. 

Ghaderi et al. Hospitalization following influenza infection and pandemic vaccination in multiple sclerosis patients: a nationwide population-based registry study from Norway. Eur J Epidemiol. 2019 Dec 23. doi: 10.1007/s10654-019-00595-2.

Patients with multiple sclerosis (MS) are at increased risk of infections and related worsening of neurological function. Influenza infection has been associated with increased risk of various neurological complications. We conducted a population-based registry study to investigate the risk of acute hospitalization of MS patients in relation to influenza infection or pandemic vaccination in Norway. The entire Norwegian population in the years 2008-2014 was defined as our study population (N = 5,219,296). Information on MS diagnosis, influenza infection and vaccination were provided by Norwegian national registries. The self-controlled case series method was used to estimate incidence rate ratios (IRRs) with 95% confidence intervals (95% CI) in defined risk periods. 6755 MS patients were identified during the study period. Average age at first registration of an MS diagnosis was 51.8 years among men and 49.9 years among females (66.9%). The IRR for emergency hospitalization among MS patients the first week after an influenza diagnosis was 3.4 (95% CI 2.4-4.8). The IRR was 5.6 (95% CI 2.7-11.3) after pandemic influenza, and 4.8 (95% CI 3.1-7.4) after seasonal influenza. Pandemic vaccination did not influence risk of hospitalization [IRR within the first week: 0.7 (95% CI 0.5-1.0)]. Among MS patients, influenza infection was associated with increased risk for acute hospitalization while no increased risk was observed after pandemic vaccination. Influenza vaccination could prevent worsening of MS-related symptoms as well as risk of hospitalization.

CoI: multiple