Indeed, between 2000 and 2016, the number of adults aged 50 years and older living with HIV in sub-Saharan Africa doubled. At present, their HIV prevalence is exceeding that of younger adults.

By 2040, one-quarter of people living with HIV in Africa will be aged 50 years and older; tailored awareness and treatment campaigns are pressing.

Dr Luicer Olubayo, a researcher at the Sydney Brenner Institute for Molecular Bioscience (SBIMB) at Wits University and the first author of a study published in The Lancet Healthy Longevity journal, which investigated HIV in older people in Kenya and South Africa, noted that perceptions on who acquires HIV are limited. "We often think of HIV as a disease of younger people. It doesn't help that intervention campaigns are mainly targeted at the youth."

Moreover, older adults are less likely to believe that they can get HIV. This misconception is pervasive and has consequences for reaching global targets to achieve UNAIDS' 95-95-95 targets by 2030 (95% of people living with HIV know their status, 95% of people who know their status are on treatment, and 95% have a suppressed viral load).

"While HIV prevalence among individuals over 50 years of age is similar to or even exceeds that of younger adults, HIV surveys focus on younger individuals, leaving considerable gaps in understanding HIV prevalence, incidence and treatment outcomes in older populations," says Associate Professor F. Xavier Gómez-Olivé, at the MRC/Wits-Agincourt Research Unit.

Stigma remains a barrier to treatment

The uptake of HIV testing among older adults is poor, which delays diagnosis and limits access to care. This is, indeed, one of the signifiers of the pervasiveness of stigma surrounding the disease.

"We know that there is significant social stigma related to HIV infection. This is why understanding HIV-related stigma in older adults remains crucial as a way to inform interventions to support older people's mental health and overall well-being," says Olubayo.

Interventions could focus on repeated testing, the use of pre-exposure prophylaxis (PrEP), and campaigns to increase awareness and reduce infections among the elderly.

"HIV can be managed alongside other chronic conditions, too, since HIV is managed as a long-term illness," says Gómez-Olivé.

Non-communicable diseases, such as hypertension, diabetes, and obesity, have dramatically increased in sub-Saharan Africa, particularly among older people. HIV treatment and intervention can be included in the healthcare ecosystem of long-term illnesses.

Apart from stigma, a complex interplay of factors shapes HIV risk

The study shows that age, education, gender, and where people live all affect their risk of HIV. Even though more people now have access to HIV treatment, older adults -- especially in rural areas -- still face significant challenges in preventing HIV, such as low education levels and gender inequality.

Widowed women had the highest HIV rate (30.8%). This may be due to losing a partner to HIV, stigma, and a greater risk of unsafe behaviours like transactional sex and limited power to negotiate condom use. People without formal education and those with low income also had higher rates of HIV infection.

The benefit of longitudinal data to make decisions

An important added value of this study is the provision of longitudinal insights into the HIV epidemic among older adults in sub-Saharan Africa. "Our study is beneficial in that older populations are under-represented, and not much is known about them over time. What changes are occurring? We have to answer these kinds of questions. With longitudinal data, we can look at the effectiveness of antiretroviral therapy coverage in older people," says Gómez-Olivé.

The study used data collected in urban Kenya and in urban and rural sites across South Africa during two data collection waves: 2013-2016 and 2019-2022.

Throughout a decade of research, the team has been gaining a deeper understanding of this ageing HIV epidemic. Numerous important insights about HIV in older populations have been achieved, and research gaps are being covered.

Data for the study were drawn from the Africa Wits-INDEPTH Partnership for Genomic Research (AWI-Gen) from adults aged 40 years and older. AWI-Gen is a multicentre, longitudinal cohort study conducted at six research centres in four sub-Saharan African countries (South Africa, Kenya, Burkina Faso, and Ghana) to investigate various health determinants.

Aging starts at the cellular level. As we get older, aged or "senescent" cells accumulate in our body. Not only have these cells lost much of their original function, but they continue to emit compounds which trigger inflammation. There is a growing body of evidence for how they play a part in aging-related conditions like arterial hardening, Alzheimer's disease, and type 2 diabetes.

To understand and treat such ailments, scientists need to come to grips with how senescent cells affect our physiology. Naturally, this starts with identifying which of our cells are senescent, and which are not. Unfortunately, existing methods rely on selective "labeling," e.g. the attachment of a fluorescent molecule to specific compounds known to be present in aged cells. Not only is this time-consuming and complex, but the process itself can change the properties of the very thing scientists want to study.

To get around this issue, a team led by Assistant Professor Ippei Yagi from Tokyo Metropolitan University has come up with an entirely different approach to identifying senescent cells. Instead of chemical labels, they put cells under an alternating electric field. This causes a slight rearrangement of charge, where one end of the cell is more positively charged than the other. When the electric field is not uniform over space, the cell migrates; in the case of an alternating field, the cell wanders backwards and forwards between the electrodes. As the frequency of the field is changed, the motion of the cell changes significantly at a value known as the cutoff frequency. The method, known as frequency-modulated dielectrophoresis (FM-DEP), aims to characterize cell type by measuring this value.

The team focused their efforts on human dermal fibroblasts, an important part of connective tissue in the skin. When they tested senescent cells against younger ones, they found that there was a marked difference in their cutoff frequencies. These changes come about from changes in the fatty (lipid) molecules which make up the membrane of the cells. Importantly, FM-DEP is rapid, easy to apply, and label-free.

The new method is not only a convenient tool for research into aging, but may see application to regenerative medicine, and drug screening. The team hope to apply FM-DEP to other cell types as well, as a versatile new approach to cell identification.

This work was supported by JSPS KAKENHI Grant Numbers JP23K28453 and JP23KK0260.

For more than a decade, ticagrelor (Brilinta in the US and Brilique in Europe) has been recommended for patients with acute coronary syndrome -- a range of conditions related to sudden reduced blood flow to the heart.

Last December, an investigation by The BMJ found serious data integrity problems in the landmark clinical trial (PLATO) that was used to gain worldwide approval for ticagrelor, calling into question the drug's advantage over cheaper rivals.

Now, as generic versions of the drug prepare to launch this year, The BMJ has expanded its investigation, looking at two key platelet studies that AstraZeneca claimed explained ticagrelor's ability to treat acute coronary syndrome successfully.

It finds that the "primary endpoint" results (the trial's key measurement) for both clinical trials were inaccurately reported in the leading cardiology journal Circulation, and reveals that more than 60 of 282 readings from platelet machines used in the trials were not present in US Food and Drug Administration (FDA) datasets.

What's more, one active trial investigator never became a study author, while one author told The BMJ he was not involved in the trial, and most investigators, including the principal investigator, were unreachable or declined to be interviewed.

Victor Serebruany, an adjunct faculty member at Johns Hopkins University and ticagrelor's most renowned critic, told The BMJ that "there are episodes of skyrocketing rebound and profound platelet inhibition after ticagrelor making patients prone to thrombosis or bleeding. If doctors had known what happened in these trials, they would never have started using ticagrelor."

Circulation and AstraZeneca did not respond to a request for comment.

Serebruany added: "It's been obvious for years that there is something wrong with the data. That the FDA's leadership could look past all these problems -- on top of the many problems their own reviewers identified and are now being discovered by The BMJ -- is unconscionable. We all need to know how and why that happened."