Pursuing herd immunity in Tanzania with data on lockdown

Sweden is being vilified for pursuing herd immunity against Covid-19 at the relatively high cost of lives. The UK tried it for a while until the rising number of deaths – both real and projected – forced the government to introduce a lockdown.

We seem to be pursuing a strategy of herd immunity. And we are doing it in data darkness.

Tanzania’s approach has been different. Rather than putting people on lockdown, we have put data on lockdown. People are more or less free, even encouraged to roam, while observing largely voluntary protective behaviours: mask-wearing, hand washing and social distancing. Data, meanwhile, is under tighter control than ever before.

No data has been released on the numbers of Covid-19 cases or deaths since April 29, 2020. The number of tests reported as having been carried out is just 652, compared to over 100,000 in neighbouring Uganda, 95,000 in Kenya and 75,000 in Rwanda by June 5, 2020.

Tanzania’s president Magufuli has spoken of the fear-inducing effects of data and the harm that this can do, and has cast doubt on the reliability of testing done at the national laboratory. Night burials have stopped (or been stopped) and quarantine locations and hospitals are empty (or have been emptied).

On May 27, the Medical Association of Tanzania noted a significant reduction in Covid-19 cases, but did not provide any data to support their assertion. When the data is on lockdown, such statements can be neither verified nor contradicted.

We seem to be pursuing a strategy of herd immunity. And we are doing it in data darkness.

Expectations and experience

Government has little control over the virulence of Covid-19 in its jurisdiction. But it can control how that virulence is communicated to the public and how citizens perceive the situation. Government can shape perceptions of reality much more than they can influence the facts. In Tanzania’s case it has done so by suppressing the data.

Citizens’ understanding of the virus shapes their expectations and actions. If their perceived reality is better than expected, people lose their fear of Covid-19, faith and trust in the official story is strengthened and they change their behaviour accordingly: let us go to the beach and have a party!

However if citizens’ experience of the outbreak is worse than expected – growing infection numbers, more deaths – people will lose faith in the official story. An erosion of trust is a serious risk for a government looking for re-election in October, as is the case for president Magufuli’s administration.

Data leakages

Data from neighbouring countries help to shed some light on the extent of Covid-19 in Tanzania. Ugandan authorities show that at least 45 Tanzanian truck drivers having tested positive in Uganda and repatriated between April 23 and May 25. Similar stories from the borders with Kenya and Zambia have been reported.

More scientifically, modelling done by the MRC Centre for Global Infectious Disease Analysis at Imperial College London was published on May 26, 2020. Using official death data – from when Tanzania was still reporting such data – as a starting point, the model estimated the true number of infections in Tanzania during the 4 weeks between April 29 and May 26, 2020 to be 24,869. If true, Tanzania would have replaced South Africa (with 23,615 cases) as Africa’s coronavirus epicentre.

The model’s estimates of daily deaths make for less alarming reading, suggesting that “if current levels of interventions are maintained”, by June 8, coronavirus related deaths would fall somewhere between four and 27 fatalities per day. That is a small fraction of the average number of daily deaths experienced in pre-Covid19 Tanzania of 1,011.

Or to put it differently, a few extra deaths – reported as “pneumonia”, for example – can easily be shrugged off by government, and then also by citizens, as nothing unusual.

If, and it is a big if, the outbreak in Tanzania really takes hold, however, similar models estimate as many as 200,000 fatalities from an unmitigated outbreak. That would be much harder to hide.

On trust and transparency

The numbers may well turn out lower – I really hope so – and the government may retain control of the narrative. But if the models prove to be anything close to accurate, the cost will be huge. People will die unnecessarily. And public trust will be seriously damaged.

Hiding the truth may be a short-term win for the government, but one that could have devastating consequences in future. Transparency – even when the news is bad – would build trust that at least the government has the common interest at heart and is doing its best to protect lives.

The future is unknown. Everyone hopes that the worst outcomes suggested by epidemiologists are avoided. But locking down data while encouraging people to move around as normal won’t make this easy.