There have been tremendous advances in improving human health over the past century, from the advent of antibiotics to the eradication of diseases like smallpox. However, rising populations, climate change and the emergence of drug-resistant diseases are increasing the health burdens of many countries and are likely to place an increasing strain on resources.
The annual WHO ranking of the top ten causes of death reflects the increase in lifespans globally, with ischaemic heart disease, stroke and COPD taking the top three places. But the presence of diarrhoeal diseases and tuberculosis in ninth and tenth place highlights the disparities.
Despite technological advances worldwide, access to basic necessities such as healthcare and sanitation remains a serious problem for many.
Professor Rob Hope, of Oxford’s School of Geography and the Environment and the Smith School of Enterprise and the Environment, has been leading work in Africa and Asia to design and test performance-based models to improve the reliability and financial sustainability of rural water infrastructure for communities, schools and health clinics.
Rural water infrastructure breaks regularly and takes weeks or months to repair. Professional maintenance service models have improved repair times from weeks to days with water users paying a share of the costs. User payments are providing a platform to design new funding models to reward service delivery monitored over time rather than increasing access by building new infrastructure.
‘Progress to achieve and maintain drinking water for everyone, every day requires rethinking the design and funding of current policy and practice,’ Professor Hope said. ‘We have evidence that professional maintenance models can unlock user payments at scale and attract matched funding. However, progress on reliable and affordable water must be complemented by ensuring water quality too.’
Early and accurate detection is likely to play an increasing role in combating disease in the future, especially if we are to be able to stay ahead of the curve when spotting fast- spreading outbreaks of diseases such as Ebola and Zika.
In response, collaboration with Professor Katrina Charles, also of Oxford’s School of Geography and the Environment, is allowing measurement of the quality of the water, to ensure these systems are providing reliable and safe water.
‘Communities have access to a range of water sources – from hand pumps, dams and rain,’ says Professor Charles. ‘They choose their water based on taste, affordability, availability and convenience. Our research will identify the health risks from these different sources and ways to ensure communities have useful access to safe water.’
The Malaria Atlas Project (MAP) at the University of Oxford’s Big Data Institute has created the most comprehensive picture to date of the burden of Plasmodium vivax and Plasmodium falciparum parasites, which cause the majority of the world’s malaria cases. Crucially, their work charts the change in distribution of the parasites over time from 2000 to 2017, revealing areas of progress and regions where the burden of malaria is still high or increasing.
Dr Katherine Battle, Director of Malaria Mapping for Elimination at MAP, said: ‘Despite the global health burden of P. vivax malaria there has been little work to quantify it. Our research aimed to produce robust measures of burden with associated uncertainty, and generate maps at a fine local geographic scale to allow decision- makers to target interventions where the need is greatest.
‘Challenges with both the diagnosis and treatment of P. vivax malaria make it a difficult parasite to target, so up-to-date assessments of trends and the global distribution of burden are essential to optimise control and elimination strategies.’
MAP’s latest research showed that P. vivax dropped from 24.5 million cases in 2000 to 14.3 million cases in 2017, a drop of around 42%, confirming that current strategies to combat the disease are working successfully. But the study also revealed that in some places progress has plateaued or gone into reverse in recent years.
It is unlikely that we will be able to end the HIV pandemic without a vaccine
Some big data studies have revealed less encouraging news about diseases that, while less lethal than in the past, still place an enormous strain on healthcare systems.
Researchers at Oxford have compiled one of the most comprehensive studies of HIV around the world to create a map of the spread of subtypes of the virus across the world. The study, which included 400,000 samples from 116 countries over 26 years, showed which strains are dominant in which country and region, and where new strains are emerging.
Dr Joris Hemelaar of the University of Oxford’s Nuffield Department of Women’s & Reproductive Health, who led the research, said: ‘It is unlikely that we will be able to end the HIV pandemic without a vaccine, but one of the challenges is the huge global genetic diversity of HIV-1 [the most common type of HIV in humans globally].
‘Different HIV strains can differ by around 25%, whereas the yearly change in influenza is only a few percent, but necessitates a new flu vaccine every year.
‘HIV vaccine immunogen sequences have to match, as closely as possible, the viral sequences circulating in the target population, which is why as much information as possible on the regional spreads of each subtype is vital for vaccine researchers.
‘The analysis showed that subtype C causes the greatest number of global HIV infections (46.6%) and that subtype C is the dominant strain of HIV in southern Africa, where HIV prevalence is highest. A trial with a subtype C-specific HIV vaccine is currently under way in South Africa, the country with the largest HIV epidemic, offering hope of protecting people from HIV.’
As with malaria, the researchers stress the importance of keeping HIV tests up to date to ensure that when the virus changes new strains don’t slip under the radar and go undetected in blood donor screening, surveillance, and clinical diagnosis and management. ‘Early diagnosis and treatment are key to stopping the spread of HIV and being able to offer effective treatment,’ Hemelaar adds.
Early and accurate detection is likely to play an increasing role in combating disease in the future, especially if we are to be able to stay ahead of the curve when spotting fast-spreading outbreaks of diseases such as Ebola and Zika.
In 2018 a new clinical research and response network for epidemic infections was launched in sub-Saharan Africa. The African coaLition for Epidemic Research, Response and Training (ALERRT) aims to reduce the health and socioeconomic impact of disease outbreaks in sub-Saharan Africa.
ALERRT involves 21 leading African and European partner organisations, and has established a network of centres and clinics stretching across sub-Saharan Africa to conduct research on epidemic-prone infectious diseases which will respond quickly to outbreaks.
Professor Peter Horby, from Oxford’s Centre for Tropical Medicine and Global Health, whose team coordinates the network, said: ‘People who are suffering from epidemic infectious disease deserve to benefit from the fruits of clinical research as much as any other patient, and the broader benefits of such clinical research are even greater in the context of outbreaks.
‘We want to deliver the evidence that is needed to improve patient care, including the evaluation of new diagnostics and treatment, but also the evidence to improve the control of outbreaks.
‘Through ALERRT, we will see the creation of a sustainable clinical and laboratory research network, with the operational readiness to rapidly implement clinical and laboratory research in support of outbreak control efforts.’
A second way to tackle the issue of epidemic infectious diseases is to work on prevention. Vaccines are a powerful weapon against many diseases, and are especially effective once enough of the population has received them to create herd immunity.
Despite being rare in Western countries, typhoid is still a major cause of fever in children in low- and middle-income countries and is responsible for nearly 11 million cases and more than 116,000 deaths a year worldwide.
The Typhoid Vaccine Acceleration Consortium (TyVAC), which is co-led by researchers from the University of Oxford, has been carrying out a large field study in Nepal of a new vaccine against typhoid, involving 20,000 children and infants.
Andrew Pollard, Professor of Paediatric Infection and Immunity at Oxford University’s Department of Paediatrics, who has been leading the trial in Nepal, said: ‘Vaccination will play an important part in helping to control this serious disease.
‘This vaccine has the potential to significantly reduce the burden of typhoid in high-risk populations that lack clean water and proper sanitation.’
