Existing test for heart conditions modified to suit low income settings
Scientists in Uganda have modified an international test for diagnosing acute rheumatic fever, a heart disease to enable primary health care workers to diagnose this condition in settings where there are no doctors or heart specialists. Dr. Emmy Okello, head of the division of cardiovascular medicine at the Uganda Heart Institute, describes how they have modified this test, the Jones criteria. Dr. Okello is one of the scientists funded through the Training Health Researchers into Vocational Excellence in East Africa (THRiVE), a research capacity building consortium.
The current Jones criteria for the diagnosis of acute rheumatic fever is based on a set of clinical signs and symptoms supported by laboratory tests that have to be met before someone is diagnosed with rheumatic fever, the condition that leads to rheumatic heart disease. Due to differences in disease presentation, some patients do not fully meet the Jones criteria and are then missed during the early phase of disease, only to show up later with advanced disease. The team has expanded the Jones criteria by adding additional tests that are locally available, and have developed this into a clinical decision tool that will capture most patients with acute rheumatic fever and easily followed and used by the health worker.
Developing a modified tool
This tool is in the final stages of development in a two-year prospective study of acute rheumatic fever in Lira, Northern Uganda. We then plan to test and validate it in another region of the country.
Currently, over 90% of acute rheumatic fever cases are missed and the patients then present later with advanced heart valve disease that either requires expensive heart surgery that is not widely available or most end up dying prematurely. If successful, this tool will improve capture and early diagnosis of acute rheumatic fever. This offers a huge opportunity to intervene with monthly injection of benzathine penicillin, a cheap (<1$) and widely available treatment.
An undiagnosed disease. A continent that lacks capacity
Rheumatic heart disease - the long term consequence of rheumatic fever -currently affects 39 million people with about 365,000 deaths annually. 70% of these are estimated to come from sub-Saharan Africa. In Uganda, about 3 out of 100 children have been documented to have the early form of disease but in the hospitals, most patients with the condition present late with advanced disease that leads to death in 2 out of 10 patients. This is attributed to gaps in early disease diagnosis and weakness in the public health care system that misses the early stages of the disease.
The worldwide scarcity of medical doctors affects the African continent most where there are only a few specialists. Heart specialists are even fewer with only about 2,000 available to the over 1.2 billion population in Africa. Most of these live and practice in South Africa and the Maghreb countries, leaving an even fewer number for sub-Saharan Africa. Interventions that promote task shifting to less specialised personnel do contribute to better access to health care.
Preventing progression of the disease
One arm of the study is studying genetics of patients diagnosed with rheumatic fever to understand how the body responds to infection with Group A streptococcus- the bacteria that triggers rheumatic fever- that eventually leads to rheumatic heart disease. This knowledge will hopefully aid in development of treatment modalities that prevent progression of acute rheumatic fever to end stage valve disease.