The global target of a 50 percent reduction in tuberculosis (TB) by 2015 may already have been achieved, but TB remains a neglected disease among women and young children, say health experts.
In 1993 the World Health Organization (WHO) declared TB a global public health emergency.
“About one third of the global population is infected with TB, with an estimated three million cases that remain undetected,” said Haileyesus Getahun,coordinator of the WHO Stop TB Department.
According to WHO, in 2011, there were an estimated 8.7 million newly diagnosed TB cases, 13 percent of which were co-infected with HIV. There were an estimated 1.4 million TB-related deaths, including 430,000 deaths among people living with HIV (PLHIV).
Though seen as a “man’s disease” due to the higher infection rate among men worldwide, said Getahun, it is actually one of the top (and under-diagnosed) killers of women. In 2011 some 300,000 HIV-negative women and 200,000 women living with HIV died of TB-related causes.
“There are several social factors that contribute to women getting diagnosed later, like the stigma associated with TB. Also, in pregnant women, TB symptoms are masked,” Getahun said.
TB in expectant women increases the risk of birthing complications, including maternal death.
According to WHO, maternal TB causes a two-fold increase in vaginal bleeding, eclampsia (pregnancy-induced hypertension), pre-eclampsia, and a 10-fold increase of miscarriage.
Among newborns, maternal TB causes a two-fold increase in low birth weight and premature births (both risk factors for childhood death) and a six-fold increase of perinatal death (within the first 28 days of life).
While the exact extent of the problem is still unknown, said Getahun, recent studies from sub-Saharan Africa and India have shown that TB was a direct cause of an estimated 6-15 percent of all maternal deaths and an indirect cause of 15-34 percent.
Paediatric diagnoses, treatment lag
TB is usually signalled by coughing and sneezing when TB bacteria (spread through the air) attack the lungs and other parts of the body in the case of extra-pulmonary TB.
The disease is notably most infectious in overcrowded areas like jails and slums.
Children are especially vulnerable. An estimated 500,000 children are newly infected with TB every year after coming into contact with infected adults; some 700,000 children die annually from TB-related causes.
“The diagnosis of childhood TB is very challenging. The children are not able to produce a significant amount of sputum [mucus tested for TB bacteria] for diagnosis and TB prevention for child contacts is not practised,” said Meshack Ndirangu of the African Medical and Research Foundation, a medical NGO headquartered in Nairobi, Kenya.
But even if diagnosed correctly, treatment is still problematic.
“There are no child-friendly drugs available to treat TB. We need to crush tablets made for adults and this leads to inaccuracy. We cannot tell for certain if the children are getting the right dosage for their weight,” Ndirangu told IRIN.
Health system gaps
Current health system gaps such as the collection of data also make it difficult to effectively track and diagnose TB for all ages.
“There is a diverse set of [medical screening criterion] in adults and children. We need to standardize screening tools and referral systems at the community level,” said Ndirangu.
According to Ndirangu, globally, many medical groups lack training to integrate the data they collect with government health data.
The collection and transportation of cultures for testing in a health facility is also troublesome, especially in remote areas.
Among pregnant women, screening for the prevention of mother-to-child transmission of HIV is given more priority rather than the transmission of TB, even though co-infection is common.
An estimated 12-15 million people living with HIV worldwide are co-infected with both TB and HIV. In parts of sub-Saharan Africa, up to 70 percent of TB patients are co-infected with HIV.
According to the WHO, in 2011, there were 3.2 million people enrolled in HIV care who were screened for TB; compared to 2.3 million in 71 countries in 2010. The goal is to screen all those in HIV care for TB by 2015.
PLHIV are 50 times more likely than HIV-negative people to develop TB and 90 percent of them usually die within months without proper treatment.
The risk of developing TB is more than 10 times higher among pregnant women living with HIV than among HIV-negative pregnant women, according to UNAIDS.
“We should have TB/HIV incorporated into maternal and child health intervention programmes. When health workers screen for HIV when they conduct maternal health care visits, they can also screen for TB,” Ndirangu said.
“It only takes a few minutes to do a symptomatic diagnosis of TB. It can save the life of a woman and the life of her unborn child,” he concluded.
WHO insists prevention of TB is the best cure and has been pushing for the roll-out of isoniazid preventive treatment, infection control and intensified case finding. However, countries have been slow to roll out this three-part intervention.