People hospitalised with fever in Africa were most likely to be treated for malaria but, in some areas, nearly all these patients were actually ill from a different infection, a new collaborative study led by John Crump suggests.
Prof Crump, who is visiting the United States, said in an interview that, as far as he was aware, ''this study is the first in Africa to look comprehensively at causes of non-malaria fever beyond bacterial sepsis''.
''It unmasks a major mismatch between the way patients are managed and the infections that they actually have.''
Prof Crump is McKinlay Professor of Global Health at Otago University and is co-director of the university's Centre for International Health.
In a paradigm-shifting study published yesterday in the journal PLoS Neglected Tropical Diseases, more than 800 severely ill in-patients in Tanzania were studied to identify the causes of their fever.
More than half of patients, on admission, had been diagnosed clinically with malaria, but fewer than 2% had malaria when tested.
By contrast, invasive bacterial infections such as typhoid fever and animal-associated infections such as leptospirosis were common but had never been considered.
The finding that invasive bacterial infections and animal-associated diseases were major causes of fever had taken many people by surprise, he said.
Malaria had been the diagnosis of choice for fever among healthcare providers and patients in Africa for decades.
But declines in malaria since 2004, associated with control efforts and improved treatment meant ''a growing proportion of patients with fever actually have an infection other than malaria'', he said.
''The increasing use of malaria rapid diagnostic tests in Africa along with research such as ours is showing that in many areas malaria is an increasingly uncommon cause of fever.''
The research, which was supported by the US National Institutes of Health, had been eight years in the making.
Many of the causes of non-malaria fever the researchers had found to be common in northern Tanzania were rarely or never considered in the differential diagnosis by clinicians.
Benefits from the research included better data to inform improvements in management of severely ill patients with fever in Africa and increased profile of a range of neglected tropical and zoonotic infectious diseases that warrant increased research focus.
Zoonotic diseases can be passed on from animals to humans.
''The results of such work can ensure that disease diagnosis, treatment, prevention and control efforts are rationally resourced, based on what is really making people sick,'' he said.
