Some nations could see HIV, tuberculosis (TB), and malaria deaths increase over the next five because of disruption to health services caused by coronavirus, a new study suggests.

Researchers estimate that in some low and middle-income countries (LMICs) affected by these diseases, the impact of Covid-19 disruption on years of life lost could be of a similar scale to the direct impact of the pandemic itself.

Maintaining core services for HIV, TB, and malaria could largely mitigate the broader health impact of Covid-19, researchers say.

This includes ensuring access to antiretroviral therapy (Art), timely TB diagnosis and treatment, and early resumption of the distribution of long-lasting insecticide-treated nets (LLINs) and anti-malarial treatment.

However, in the study published in Lancet Global Health, the authors caution that predicting the true impact of the ongoing pandemic and its response on other diseases is very difficult.

They highlight that their modelling study aims to quantify the potential scale of the impact of Covid-19, and to guide how it could be minimised, rather than provide precise estimates.

Malaria deaths worldwide have fallen by half since 2000, but progress has stalled as mosquitoes and parasites gain resistance to treatment.

Around 94% of deaths occur in sub-Saharan Africa where malaria claimed an estimated 380,000 lives in 2018.

Similarly, global HIV/Aids deaths have halved in a decade driven by the availability of Art.

In 2019, around 690,000 people died from the disease worldwide, the vast majority in LMICs.

An estimated 49 million lives were saved through TB diagnosis and treatment between 2000 and 2015, but the disease still claimed the lives of 1.8 million people in 2018.

Professor Timothy Hallett from Imperial College London – who co-led the research, said: “The Covid-19 pandemic and actions taken in response to it could undo the some of the advances made against major diseases such as HIV, TB, and malaria over the past two decades, compounding the burden caused by the pandemic directly.

“In countries with a high malaria burden and large HIV and TB epidemics, even short-term disruptions could have devastating consequences for the millions of people who depend on programmes to control and treat these diseases.

“However, the knock-on impact of the pandemic could be largely avoided by maintaining core services and continuing preventative measures.”

In the study, researchers assumed a basic reproductive number (R) – the average number of people each individual with the virus is likely to infect – of three to develop four different policy response scenarios to the Covid-19 pandemic.

These included no action, mitigation – which represents a 45% reduction in R for six months using interventions such as physical distancing, suppression-lift – a 75% reduction in R for two months, or suppression – a 75% reduction in R for one year.

Then they used transmission models of HIV, TB, and malaria to estimate the additional impact on health that could be caused in different settings.

The findings suggest the impact of the pandemic varies according to which interventions cause long disruptions to activities, and how successfully those measures reduce Covid-19 transmission, and avoid the health system being overwhelmed.

The greatest impact on HIV is projected to be from interruption to the supply and administering of Art, which may occur during times of high health system demand.

In the worst case scenario, parts of southern Africa could see up to 10% more deaths due to HIV over the next five years than would occur without coronavirus disruptions.

For TB, the greatest impact is predicted to be from reductions in timely diagnosis and treatment of new cases.

In the worst case scenario, assuming suppression in countries with a very high burden typical in southern Africa, TB deaths could rise by as much as 20% over the next five years.

The model predicts that the greatest impact on malaria burden could result from interruption of planned net campaigns, which usually take place every three years.

In the worst case, with Covid-19 disruptions coinciding with the malaria transmission season and planned LLIN distribution, malaria deaths could increase by 36% over the next five years.

The authors note several limitations, including that the scenarios modelled are not exhaustive but reflect the trade-offs between disruption due to coronavirus interventions and periods of high health system demand.

They also note that they did not consider how long-term global changes such as a global recession might affect disease programmes.