Generally termed as an infectious disease, tuberculosis (TB) is caused by a bacterium called “Mycobacterium tuberculosis” that spreads through cough or sneeze droplets passed into the air from an infected person. This bacterium, when directly inhaled, multiplies in the lungs causing severe chest pain and persistent coughing, which can bring up blood.
Early and accurate diagnosis and Medical Coding is crucial for controlling the spread of TB. The good news is that an international team of researchers from Kenya Medical Research Institute (Kemri) and the international community has discovered a new test that promises early detection and treatment of TB.
Diagnosing the symptoms of TB in children in its premature stage is tricky. Often, the disease is recognized in its last stages, only when a child is critically ill and when the disease has spread from the lungs to the brain or other organs, increasing the risk of death. This incessant war against TB now seems to have come to an end after the discovery of the new genetic signature which offers an efficient way of diagnosing the disease early in children.
A Simple and Rapid Test for Early Diagnosis of Tuberculosis
The findings of the international team of researchers were published on 30 April 2014 in the ‘New England Journal of Medicine’. According to the research, a distinctive genetic ‘signature’ found in the blood of children with tuberculosis (TB) offers promise for improved diagnosis of the disease. As per the study, the disease can now be identified in about 80 percent of cases by just looking at 51 specific genes in the blood of children with TB. The researchers expect that the findings can be used to develop an improved, affordable, and quick diagnostic test.
Researchers claim that in most cases, the symptoms of TB in children are similar to many other childhood diseases and the standard tests applied on adults are not effective on children. Though the disease is treatable, thousands of children still die every year due to delayed diagnosis.
The study surveyed around 2800 children with TB symptoms admitted in hospitals in Kenya, South Africa and Malawi. A thorough examination of the blood samples of these children was done using ribonucleic acid (RNA) expression microarrays. The technique verifies all genes in the human genome (over 30,000 genes) and identifies those genes which are activated or suppressed in each child’s blood.
Researchers used the samples taken from South African and Malawian patients to see discover a “signature” of TB, that is which genes were activated or suppressed in those affected by the disease. It was found that found that TB could be identified from other diseases by examining just 51 genes from over 30 000 in the human genome and checking whether they were activated or suppressed. The researchers used this information to assign a single TB risk score for each child. When tested in the Kenyan children, the TB risk score accurately diagnosed over 80 per cent of those with TB. On the other hand, a negative result accurately ruled out a diagnosis of TB. It was found that TB could be distinguished from healthy children with latent TB infection with a 42 gene signature.
Importance of Early Diagnosis
Accurate and precise testing for TB in children will help in early diagnosis of the disease and help contain its spread to the brain and other organs. This in turn, will improve outcomes and reduce treatment costs. Physicians also have to be appropriately reimbursed for the treatment they provide. Claims for TB diagnosis are submitted using ICD-9 medical codes such as
- 010 Primary tuberculosis infection
- 011 Pulmonary tuberculosis
- 012 Other respiratory tuberculosis
- 013 Tuberculosis of meninges and central nervous system
- 014 Tuberculosis of intestines peritoneum and mesenteric glands
- 015 Tuberculosis of bones and joints
- 016 Tuberculosis of genitourinary system
- 017 Tuberculosis of other organs
- 018 Miliary tuberculosis
According to World Health Organization (WHO) reports, more than 70,000 children worldwide die from TB each year due to late diagnosis and spread of the infection throughout the body. In addition to helping contain the spread of the disease, early diagnosis is also crucial to prevent unnecessary TB treatment given to thousands of children who in reality, suffer from other diseases.
Researchers emphasize that collaboration from biotechnology experts and industrial partners is required to convert the new findings of the international research team on TB diagnosis into accurate, simple and cheap tests that can be applied in hospitals, healthcare clinics and other resource-poor regions of the world where TB is prevalent.