Map highlights diagnosis gaps for deadly CNS infections in HIV patients in Africa

A map of deadly infectious diseases known to attack the central nervous system (CNS) of people who are already suffering with HIV has unearthed diagnosis "blank spots" in Africa, according to research published today in The Lancet Global Health .

The researchers say that these new insights should help form the backbone of initiatives to provide tailored packages of care in order to drive-down the number of deaths caused by HIV.

Every year, an estimated 630,000 people in Africa die of HIV-related conditions, with around one third of these caused by bacterial, fungal and parasitic infections that attack the CNS.

Cryptococcal meningitis - due to a fungal infection of the meninges that cover the brain - has long been considered as the leading cause of deaths linked to the CNS. But the study co-designed by Dr Angela Loyse at City St George's, University of London, Dr Cecilia Kanyama at UNC Project, Lilongwe Malawi, and colleagues from The National Institute of Medical Research in Tanzania, Hôpital Central in Yaoundé, Cameroon, Lighthouse Trust in Malawi, The London School of Hygiene & Tropical Medicine and Institut Pasteur in Paris, have unveiled potential regional differences for the first time.

A total of 356 people living with HIV with suspected CNS infections were studied in five public hospitals across Malawi, Tanzania and Cameroon as part of the 'DREAMM' project.

The DREAMM project looked at the impact of revamping laboratory and clinical facilities for faster diagnosis and tailored treatment on admission to hospital, including more thorough training opportunities for frontline healthcare workers and lab technicians.

This holistic and pragmatic approach, which is tailored to resource limited settings, accurately diagnosed 75% of CNS infections (269 of the 356 study participants). The team then measured the number of people living with the four main causes of HIV-related CNS infection: cryptococcal meningitis, tuberculous meningitis, bacterial meningitis, and cerebral toxoplasmosis.

Cryptococcal meningitis was the leading cause of CNS infection overall, which was responsible for 55% of all infections. It was the most common cause in Tanzania (60% of infections) and Malawi (53%). However, cerebral toxoplasmosis - a parasitic infection of the brain - was the leading cause of CNS infection in Cameroon at 43%, despite not being prevalent in the other countries.

The second most common cause of infection were CNS-linked tuberculosis in Tanzania (29%), bacterial meningitis in Malawi (19%) and cryptococcal meningitis in Cameroon (40%).

Our data is incredibly valuable to tackle these blank spots in diagnosis and care. It tells us that unless diagnoses like cerebral toxoplasmosis are looked for and treated, then avoidable HIV-related deaths will continue.

This is a snippet of the picture across Africa. We now need more data like this to fully map-out the causes of CNS infections so that we end HIV-related deaths and meet the Sustainable Development Goals."

Dr. Angela Loyse, lead of the study and Associate Professor in Infectious Diseases at City St George's, University of London

Dr. Cecilia Kanyama, DREAMM African Principal Investigator for Malawi, based at UNC Project Malawi, Lilongwe, said:

"Within the DREAMM study, we proved that strengthening routine care in African public hospitals slashed HIV-linked meningitis deaths in half. The hope is that we can combine that work with our new prevailing insights to provide tailored packages of care that will ultimately tackle the high death rates caused by these diseases."

The research is funded by the European and Developing Countries Clinical Trials Partnership and French Agency for Research on AIDS and Viral Hepatitis.