Co-infections and co-morbidities are common in sub-Saharan Africa – creating challenges but also opportunities for more coordinated care.

At a parallel session on Tuesday morning, several researchers discussed work exploring interactions between pathogens and between infections and non-communicable diseases. In the real world, infections are rarely experienced in isolation, so understanding the effects of one condition on another, as well as interactions between treatments, is of fundamental importance.  

Treating schistosomiasis in people living with HIV

Dr Roslyn Thelingwani, based at the African Institute of Biomedical Science and Technology, Harare, Zimbabwe, discussed how treatment of schistosome infections might be impaired in people living with HIV who are taking antiretroviral therapy.

Roslyn and her colleagues have examined how two commonly used antiretrovirals, efavirenz and ritonavir, affect the pharmacokinetics of praziquantel, the standard treatment for schistosomiasis. The studies explored effects on two enantiomers of praziquantel R- and S-praziquantel – the R-form is the most pharmacologically active while the S-form is responsible for the drug’s bitter taste, but the current drug formulation includes both forms.

Efavirenz was found to significantly reduce bloodstream levels of both R- and S-praziquantel, while ritonavir had a smaller impact just on S-praziquantel.

These drug–drug interactions highlight the possibility that praziquantel levels may not reach therapeutic levels in some people living with HIV on antiretroviral therapy. Roslyn suggested that more work was needed on the risk of treatment failure and potential for side effects in people living with HIV who are treated with praziquantel for schistosome infections.

Reactivation of oncogenic herpesviruses

EDCTP Senior Fellow Dr Georgia Schafer, from the International Centre for Genetic Engineering and Biotechnology (ICGEB), South Africa, discussed her recent studies on Kaposi’s sarcoma herpes virus (KSHV) – a cancer-causing virus that is particularly common in sub-Saharan Africa. KSHV causes a range of conditions while in latent (quiescent) or lytic (actively replicating) phases, including Kaposi’s sarcoma, a major cause of death in people with HIV infections.

Georgia has been examining potential interactions between KSHV and SARS-CoV-2. Working with a cohort of people living with HIV, who are particularly at risk of Kaposi’s sarcoma, she has been examining KSHV viral load over time and comparing individuals who have been vaccinated with those who have not. Intriguingly, she has found preliminary evidence that viral load may be increasing over time in those who have not been vaccinated, potentially due to recurrent SARS-CoV-2 infections.

Integrating care

By contrast, Ms Jane Kabami, who is based at the Infectious Diseases Research Collaboration, Kampala, Uganda, and is coordinating the EDCTP-funded ‘Integrating HIV/HTN’ study, presented evidence that combining HIV and high blood pressure (hypertension, HTN) care can significantly improve health outcomes.

Hypertension is a growing issue among people living with HIV in sub-Saharan Africa, due both to HIV infection and the long-term impacts of treatment. In a cluster randomised controlled trial, Jane evaluated a multicomponent integrated care model, in which hypertension screening and management was added to an HIV care model. More than 3600 people living with HIV were recruited into the trial.

The study found a greatly increased rate of screening for hypertension in the intervention arm (76% versus 22%), and hypertension control in the intervention arm increased from 33% at 12 months to 57% at 24 months. The findings suggest that the integrated care model could have a major impact on blood pressure control in people living with HIV.  

Other presenters

Dr Edith Majonga, Biomedical Research & Training Institute (Zimbabwe): Myocardial structure and function assessed by cardiac magnetic resonance in adolescents with perinatal-acquired HIV infection taking antiretroviral therapy.

Dr Andrew Peter Kyazze, Makerere University (Uganda): Latent tuberculosis infection among people with diabetes mellitus in Uganda and Tanzania

Professor Rashida Ferrand, London School of Hygiene and Tropical Medicine (UK) and Biomedical Research and Training Institute (Zimbabwe): Comorbidities in children and adolescents growing up with HIV: the need to focus beyond viral suppression.