Tuberculosis (TB) is one of the top ten causes of death worldwide. People with TB can infect up to 10 to 15 people annually if they are in close contact with them. Breaking the transmission cycle is key to fighting the disease. For that to happen diagnosis needs to be stepped up. The Conversation Africa’s Health Editor Joy Wanja Muraya spoke to Dr Jane Ong'ango on strategies to find the missing TB cases in Kenya.
What is the burden of tuberculosis globally and in Kenya ?
Great progress has been made to control and eliminate TB. However it remains one of the top infectious diseases causing death. It disproportionately affects the world’s poor and is rated as one of the top 10 causes of death worldwide. In 2015 TB caused more deaths than HIV. There were an estimated 10.4 million cases across the world that year.
Global efforts to reduce illness and deaths from TB are part of the sustainable development goals and the World Health Organisation’s End TB Strategy. The objectives of these two global efforts is to eliminate TB globally by 2030 through the reduction of TB deaths by 90% and the reduction of TB incidence by 80% compared with levels in 2015.
A tuberculosis prevalence survey done in Kenya 2016 showed a prevalence rate of 558 tuberculosis cases per 100,000 population. This is double the 2015 WHO estimate of 233 cases per 100,000 population. Tuberculosis is the fourth biggest killer in Kenya after HIV/AIDS, maternal deaths and lower respiratory infections.
Based on the TB cases identified by the health system in 2015, the prevalence survey showed that every year about 40% of TB cases remain undetected in Kenya. This means that nearly half of the number of people with TB disease are undetected and not on treatment. They are considered as missing TB cases.
Who constitutes the ‘missing’ TB cases?
This is the gap between the estimated number of people who become ill with TB in a year and the number of people who were diagnosed and treated by the national TB programmes.
In 2015 the World Health Organisation estimated that there were about 4.3 million people “missing across” the world. India, Indonesia and Nigeria accounting for almost half of them.
Finding the missing cases is critical to eliminating TB because they actively contribute to transmitting the disease to others.
Where are the missing cases?
A majority (75%) of individuals who have TB usually have TB related symptoms which could include any of the following; cough of any duration, night sweats, weight loss, fatigue, fever, and shortness of breath. Among these individuals the severity of the symptoms differ, despite this all should be screened for TB at the earliest possible time from when the symptoms develop.
In addition about a quarter (25%) of individuals with TB do not have symptoms and will thus continue to spread the bacteria in the community. The missing TB cases may either have symptoms or not and could be found within three scenarios in the community which include;
- Individuals in the community with non severe symptoms, and therefore do not seek care.
- Individuals at work, school, home or clinics are presumed not to have TB and hence not screened.
- Individuals seek care for TB symptoms at health facilities, but do not get diagnosed.
What can we do to find the missing TB cases?
There is need to provide public awareness on Tuberculosis including having targeted messages for the vulnerable populations to encourage people to seek early intervention for any TB related symptom.
Health facilities should screen all persons with TB symptoms within their various departments to reduce possible chances of missing the cases. In addition to symptom screening there is need to expand use of Chest X-ray and avail GeneXpert as the first diagnostic test for all presumed TB cases.