COVID-19 and the Liverpool influenza epidemic of 1950

Since the coronavirus pandemic struck at the beginning of 2020, it has become commonplace to make reference to the pandemic of influenza, commonly known as the Spanish flu, that devastated the world in 1918/19 with an estimated 50–100 million deaths worldwide. ¹ Less attention has been paid to other major outbreaks of influenza and to their periodicity. An understanding of this issue could throw light on those ecological aspects of aerosol-borne viruses. This could prove to be important as we emerge from the impacts of COVID-19 and anticipate what nature may have next in store for us.

One of the significant previous epidemics of influenza struck the city of Liverpool and its surrounding region in the last week of 1950 and the early weeks of 1951. As described by Dr Andrew Semple, the Deputy Medical Officer of Health for the City and Port of Liverpool, at the time, in the annual Public Health Report for 1950 ‘ … although of short duration (it) was for three consecutive weeks the cause of the highest weekly death roll, apart from aerial bombardment (during the Blitzkrieg by the German Luftwaffe in May 1941), in the city’s vital statistical records since the great cholera epidemic of 1849’. ²

The virus responsible for the outbreak was identified as ‘Virus A prime type’, which had also been associated with an outbreak on Tyneside some weeks earlier. A subsequent analysis of the ‘Great Towns’ and standard regions of England and Wales showed that taking 23rd December as the starting point in the epidemic reached its peak in week 4 in the Northern Region and Liverpool, where the death rate was twice as high as elsewhere. ³

In the case of Liverpool the first intimation of the epidemic was pressure on general practice with unusually high consultation rates beginning just after Christmas and deaths for the week ending 30th December reaching 301 compared to 229 during the same week of the previous year. In the days before computers and with influenza not being a notifiable disease, Semple and his colleagues turned to all-cause mortality based on weekly sickness absence returns from the Corporation’s own departments together with those of the Passenger Transport Department. He reported that in the week ending 6th January 1950 the total deaths at 658 exceeded that during the worst week of the pandemic of 1918/19 and that the 1950 outbreak peaked the following week with 894 deaths from all causes.

With strong resonance to the pandemic of 2020/21, the main difficulties identified by Semple in the handling of the emergency were the lack of accurate information, the pressure on general practitioners and domiciliary carers, and the difficulty of gaining admission to hospital. It is especially notable even in the age of computers of how poor the flow of information and intelligence proved to be concerning virus test results and even the numbers of COVID-19 deaths not least at weekends. It is salutary that in 1950/51 the threat posed by a respiratory virus to the residents of care homes for the elderly was clearly identified yet 70 years later we colluded in the deaths of tens of thousands of our senior citizens by failing to safeguard them against the virus.

Faced with a later significant influenza outbreak in Liverpool in 1957, the Liverpool public health team extended its triangulation of data sources to include daily sickness rates from a local football pools firm employing mostly women and a large mixed factory. Such imaginative approaches to practical action-orientated epidemiology with a provenance dating back to Liverpool’s first Medical Officer of Health, William Henry Duncan, lacked prominence in the national response to COVID-19 in 2020. ⁴ In his evidence to Edwin Chadwick’s Commission on The Sanitary Condition of the Labouring Classes in England in 1842, and in the absence of all but the most rudimentary vital statistics, Duncan collected school absence data that compared sickness absence rates between the wealthy and the less salubrious neighbourhoods, an early example of inequalities in health research.^5,6

At a meeting of the Section of Epidemiology and State Medicine of the Royal Society of Medicine to consider the 1951 influenza epidemic, a discussion led by Dr WH Bradley identified three phenomena which he argued should be considered as part of the background of any epidemic of influenza:

The periodicity and incidence of the disease in past years

The nadir of 1948

The pathology ³

Seventy years later we still understand little about the periodicity of these epidemic and pandemic waves such as to put us in a better place to anticipate and mitigate them. Of considerable interest in the light of recent experience of a much-diminished incidence of influenza resulting from the adoption of enhanced hygiene, mask wearing and social distancing over the last 12 months must be the very low incidence of influenza in 1948 that preceded the 1950/51 epidemic. This should certainly put us on our guard as to what to expect in the near future. Our catastrophic misreading of the pathology associated with the COVID-19 pandemic should surely be a warning to the hubris with which we approach nature’s imaginative repertoire; and as we face the prospect of new variants of COVID-19 travelling around the world and testing all routes and ports of entry, even to island nations, the weak state of Port Health compared with its standing in previous epidemics should alert us to how badly we have neglected this fundamental pillar of public health.