Modelling the COVID-19 pandemic

Two pieces on Bihar’s COVID-19 epidemic: Bihar’s COVID-19 Epidemic Is Not Over – but Where Is It, Exactly? (Murad Banaji, The Wire, 27/10/2020) and Does Bihar’s COVID-19 Data Seem Too Good To Be True? (Murad Banaji, The Wire, 02/11/2020). Technical notes for the first piece here.

Herd Immunity for COVID-19 – a Straightforward Explainer (Murad Banaji, The Wire, 11/10/20). What is herd immunity all about, and what is a “herd immunity approach” to COVID-19? And is it a good idea? In Q and A form.

What Early Reports From Mumbai’s Second Seroprevalence Survey Tell Us (Murad Banaji, The Wire, 06/10/20). A smaller fraction of people were found with COVID-19 antibodies compared to the last survey (early July). Was this good news, bad news – or about waning antibodies? (Accompanying calculations on the effects of waning test sensitivity.)

What Is Driving Mumbai’s COVID-19 Surge? And How Bad Is It? (Murad Banaji, The Wire, 28/09/20). Despite high COVID-19 prevalence Mumbai saw a surge in cases in September recording its highest daily figures of the epidemic so far. What drove this surge? (Accompanying technical material focussed on different levels of infection detection in slum and non-slum areas of Mumbai.)

Covid-19: Why it’s impossible to draw firm conclusions from the first national serosurvey (Murad Banaji, Scroll, 23/09/20). The first national serosurvey in India was riddled with flaws, and yet implausible narratives built on its tenuous data abound. (A detailed peer review of the first serosurvey paper in IJMR.)

Mumbai Had 13k ‘Excess’ Deaths in March-July. How Does Its COVID Story Change? (Murad Banaji, The Wire, 10/09/20). The Indian Express obtained all cause mortality data for Mumbai which showed a sharp rise in excess deaths during March-July over and above the recorded COVID-19 deaths. The city’s COVID story is gradually becoming clearer. (A more fully linked version of this piece with technical detail here.)

Are Health Experts Right To Focus on Cutting COVID-19 Deaths, Not Containment? (Murad Banaji, The Wire, 03/09/20). Some thoughts on recommendations by public health bodies that “the government’s focus should be to prevent deaths from COVID-19 and no longer on containing the infection.”

A city divided: Covid-19 reveals Mumbai’s faultlines (Murad Banaji, Scroll, 20/08/20). Mumbai’s COVID-19 story is only gradually starting to become clear. With rapid spread in the slums, and a more long drawn out epidemic in middle class areas, Mumbai has seen two interlinked epidemics; housing poverty is the key dividing line. A fully referenced version of this piece here.

What Pune’s Sero-Survey Does and Doesn’t Tell Us About Its COVID-19 Epidemic (Murad Banaji, The Wire, 18/08/20). A quick look at the serosurvey results from Pune with some astonishingly high seroprevalence values. Supporting material here.

A quick look at Ahmedabad’s serosurvey results.

What Do the Delhi and Mumbai Sero-Survey Results Tell Us About COVID-19 in India? (Murad Banaji, The Wire, 30/07/2020). A first quick analysis of seroprevalence results from two major Indian cities, and what they tell us about fatality rates and prevalence of COVID-19 in India. Supporting material for Delhi here and Mumbai here.

COVID-19: Has Delhi Passed its Peak or Is its Test Strategy Confusing the Picture? (Murad Banaji, The Wire, 22/07/2020). Delhi ramped up COVID-19 testing, and then gradually switched from sensitive RT-PCR tests, to less sensitive rapid antigen tests. This created a sharp peak and rapid descent in daily case data which hid a more ambiguous reality.

How many people in India have had Covid-19? (Murad Banaji, Scroll, 09/07/2020). The tale of the ICMR serosurvey which led to some wild claims, but whose results have never been released. Supporting documentation: Data-driven estimation of prevalence and fatality undercounting for COVID-19 in India and Analysis of ICMR’s estimates of COVID-19 prevalence and infection fatality rate.

Why case fatality rate itself is almost never the story – but is often made to be. (Murad Banaji, The Wire, 27/06/2020). Case fatality rate (CFR) is perhaps the most misused of all statistics in discussions about COVID-19. A quick summary of what CFR does not tell us, how CFR is misused, and how CFR could still provide some useful hints about the trajectory of COVID-19 if analysed carefully.

Maharashtra’s missing COVID-19 deaths: an update. (Murad Banaji, The Wire, 18/06/2020) + details of the simulations here. It was acknowledged by the state government that a number of COVID-19 deaths had not been added to the official toll, vindicating an earlier piece; but even after the update, the data suggests that a lot of COVID-19 deaths in Maharashtra are missing.

How will the Covid-19 pandemic end? (Murad Banaji, Scroll, 12/06/2020) + Supplementary material: How do COVID-19 epidemics end? On the various possible futures of COVID-19 epidemics and the dangers of being simplistic about them. Modelling and data analysis.

Missing COVID-19 deaths in Russia – how many? (Murad Banaji, 06/06/2020). I wanted to see if modelling supported claims of fatality underreporting in Russia and, if so, gave any indication of the scale.

COVID-19 in Delhi and Mumbai – brief notes and comparisons. (Murad Banaji, 03/06/2020). Delhi and Mumbai are the two major epicentres of the pandemic in India. What are the similarities and differences in their COVID-19 data stories?

A brief analysis of Madhya Pradesh’s COVID-19 data. (Murad Banaji, 02/06/2020). Does the data suggest that there are missing COVID-19 fatalities in Madhya Pradesh?

A brief analysis of West Bengal’s COVID-19 data. (Murad Banaji, 01/06/2020). The story of missing fatalities, a correction, and a case fatality rate which declined, rose, and declined again…

The Similarities and Differences in COVID-19 Data From Delhi and Tamil Nadu. (Murad Banaji, The Wire, 29/05/2020) + Supplementary material: Notes on the evolution of COVID-19 in Delhi and Tamil Nadu. These two regions have superficially similar COVID-19 data-sets, but quite different COVID-19 trajectories.

What effects has the lockdown had on the evolution of Covid-19 in India? (Murad Banaji, Scroll.in, 27th May 2020) + Supplementary material: Notes on lockdown and its effects on the evolution of COVID-19 in India.

The Delhi COVID-19 epidemic so far: missing fatalities (Murad Banaji, 18th May 2020). A brief model-based exploration to study the trajectory of the COVID-19 outbreak in Delhi, and see whether there is evidence in the data for claims that COVID-19 deaths are being underreported in Delhi.

Brief notes on the London COVID-19 epidemic so far (Murad Banaji, 16th May 2020). These notes respond to modelling described in an Evening Standard article from May 15th which appears to provide support for lifting the lockdown in London.

The Tricky Issue With Knowing How Many Are Dying From COVID-19 in India (Murad Banaji, The Wire, 15/05/2020) + Supplementary material: Notes on the COVID-19 epidemic in Maharashtra, a change in protocol, and “missing” fatalities. I’ve added an update on Mumbai’s COVID-19 data anomaly here (June 14th).

Brief notes on the German COVID-19 epidemic so far (Murad Banaji, 09/05/2020).

Individual based modelling of the COVID-19 pandemic (Latest description of the modelling, Murad Banaji, 02/05/2020). This is the latest version of this document and supercedes previous documents – it may not, however, be completely up-to-date. The accompanying code is at https://github.com/muradbanaji/COVIDSIM/

The Problem With Spinning Simple Stories Based on India’s COVID-19 Numbers (Murad Banaji, The Wire, 22/04/2020)

Modelling the COVID-19 pandemic – how it can be done and why we should be cautious. A summary for the non-mathematician of different methodologies, and why COVID presents particular challenges. (Murad Banaji, 03/04/2020)