|Photo credit: R Dwivedi/CNS|
Two billion people — one-third of humanity — carry a latent TB infection. The vast majority of those infected latently live their whole lives without becoming sick with TB or spreading the infection. The body’s immune defenses seal the invading TB germs within a tiny capsule at the infection site, thus preventing them from multiplying. When the body’s immunity is compromised, like through HIV, the capsule containing the TB germs weakens and breaks.
The germs spill out and multiply. The person becomes sick with TB, transmitting the germs to others through a telltale cough. TB--an airborne illness that spreads through a simple cough--causes roughly one in every five deaths among people living with HIV (PLHIV). Still TB is a neglected part of the AIDS political and policy agenda. More than 1 million PLHIV are in immediate need of treatment for TB. It is essential that integrated TB and HIV services be scaled up within health systems.
To attack HIV and AIDS put an end to TB said Archbishop Desmond Tutu.
The burden of paediatric TB is not as well documented as that of adult disease, partly because of the difficulty of confirming TB diagnosis in children, which is further compounded by HIV co-infection. According to Ebele F Ugochukwu of the Neonatology/Retrovirology/Infectious Diseases Unit, Department of Paediatrics, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria, “In Africa children have been estimated to account for 20-40% of the TB case load. Children infected with MTB have a high risk of progression to active disease, with the younger children being at higher risk. Infected children represent a reservoir of future adult disease. The incidence of childhood TB has increased in developing countries-- partly due to the coexisting burden of HIV disease, which is most pronounced in Sub-Saharan Africa.”
“The clinical symptoms in both diseases are similar, and the radiological changes may be non-specific. Treatment of both conditions in children is a challenge due to drug interactions and problems with adherence. There are but few stable syrup formulations of anti tuberculosis and antiretroviral drugs in children, and hence division of tablets gives rise to unpredictable dosing and emergence of resistance. To reduce the morbidity and mortality of TB and HIV, existing childhood TB programmes must be strengthened, and antiretroviral drug therapy (ART) and prevention of mother-to-child transmission programmes scaled up. HIV prevalence in the adult population must also be reduced. An increased emphasis on childhood TB, with early diagnosis and treatment, must be a priority”, he posited.
Ebele added that the pattern of childhood HIV and TB co-infection mirror these epidemics in the adult population. The number of children co-infected with HIV and TB is rising, and so is the incidence of congenital and neonatal TB. He submitted that the emergence of multi-drug resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) has occurred within the context of a high prevalence of HIV and TB.
According to Gabriele Poggensee, Nigeria Field Epidemiology and Laboratory Training Programme, Abuja, Nigeria, the current prevalence of HIV in Nigeria is 4.1% with over 3.5 million infected and an estimated 1.5 million in need of ART. Epidemiological and implementation studies are necessary for monitoring and evaluation of interventions. Gabriele Poggensee said that the spread of HIV has fuelled the TB epidemic. TB is a major cause of death among people living with HIV and accounts for about 22% of HIV-related deaths globally. In 2012, 1.1 million of the 8.8 million incident cases of TB worldwide were in PLHIV. Also, HIV is one of the main reasons for failure to meet TB control targets in high HIV settings.
On what needs to be done more for TB-HIV collaborative action in the 22 high burden countries to reduce TB related deaths in PLHIV, Dr Anthony D Harries, Senior Advisor, International Union Against Tuberculosis and Lung Disease (The Union) stresses upon:
- Better and more formal collaboration between the TB and HIV/AIDS Programmes
- More attention paid to the Three Is of reducing the TB burden in PLHIV, especially infection control in health facilities and isoniazid preventive therapy (IPT)
- More widespread coverage of ART and earlier start of ART, as ART has been clearly shown to reduce the risk of TB in PLHIV
- 100% HIV testing of TB patients and ensuring that all HIV-infected TB patients are started as soon as possible on cotrimoxazole preventive therapy and ART
The emphasis placed by DOTS (Directly Observed Therapy, Short course) on detection of smear-positive cases does not address the situation in children, the vast majority of whom have smear-negative disease, says Brent A. J., Anderson S. T., Kampmann B. in their Childhood tuberculosis: out of sight, out of mind? Trans R Soc Trop Med Hyg 2008; 102(3-4): 217-8.
TB remains an important and potentially preventable cause of childhood deaths. Young children have a high risk of progression to active disease following infection, and are much more likely to develop severe or disseminated TB. Children with latent TB infection become the reservoir of future disease in adulthood, perpetuating the epidemic, says Ebele.
The highest TB incidence and HIV prevalence are recorded in Sub-Saharan Africa, and, as a consequence, children in this region bear the greatest burden of TB/HIV co-infection. Nigeria ranks 5th among the 22 high TB burden countries which collectively bear 80% of the global burden of TB, and also takes the third position in the global populations of PLHIV.
HIV/AIDS is the major threat to TB control programmes in Africa. As HIV prevalence rises, so do the TB rates. The control of TB, therefore, partly depends upon the control of HIV transmission, says Raviglione M. C., Harries A. D., Msiska R., Wilkinson D., Nunn P. in Tuberculosis and HIV: current status in Africa. AIDS 1997; 11 Suppl B: S115-23.
The following are important issue areas requiring urgent attention--
TB among children living with HIV: Public health efforts to address HIV and TB have focused largely on adults. There are no child-friendly formulations of TB medicines for children living with HIV and it is difficult to diagnose TB among children living with HIV with the currently available technology. In October 2013, The Union and its partners released the first-ever roadmap for large-scale action against TB among children. The roadmap projects that $120 million per year would have a major positive impact on TB, including among children living with HIV.
Bureaucratic barriers to integrated TB and HIV care: One of the main barriers to care for people affected by TB-HIV is the weak coordination between TB and HIV programmes. This bureaucratic challenge means that people affected by TB-HIV often cannot access health services to treat both illnesses together. Imagine having to go to one facility to receive care for one disease, and to another facility for treatment of another disease—if care is available at all. Or, imagine receiving ART for HIV, but never being screened for TB even though it presents a big risk to your health. By the time PLHIV receive a diagnosis of TB, they are often in advanced stages of the disease.
Drug-resistant tuberculosis is a threat to PLHIV: In October 2013, the WHO labelled the global spread of MDR-TB a public health crisis. And just last month, in South Africa, activists called on the government to declare MDR-TB a public health emergency. Providing earlier MDR-TB treatment to PLHIV, and starting ART sooner can have significant benefits. A study published in the International Journal of Tuberculosis and Lung Disease in March 2014 found that initiating ART soon after individuals began MDR-TB treatment led to an 86% reduction in deaths.
More progress is needed in providing access to IPT: The WHO recommends that those PLHIV who do not have active TB receive 6 months of IPT. The purpose of IPT is to reduce the risk of the PLHIV having a latent TB infection progress to active TB disease. Research shows that IPT is safe and effective for PLHIV, and an estimated 50% of people newly diagnosed with HIV meet eligibility criteria to receive IPT. However, progress in providing IPT to PLHIV has been slow and varies by country. Globally, only 31% of people living with HIV who began ART in 2012 were also provided IPT. But in India, for example, it is uncommon for PLHIV to receive IPT, and the country does not report data on IPT access.
Speaking on the impediments which high burden countries are facing to stem the increasing incidence of MDR-TB, Dr. Harries advocates good infection control practices in health facilities and the community; early diagnosis of MDR-TB in patients who are failing first line treatment; shorter and less toxic anti-TB treatment regimens that can help patients to properly complete treatment. He also emphasizes for better control of HIV and instituting widespread ART to reduce the risk of TB in high HIV-prevalence areas.
Isaac Eranga, Citizen News Service - CNS
18 August 2014