|Millions of African children are orphaned as a result of Aids, but tuberculosis is also a threat [EPA]
When the Themba Lethu HIV/Aids Clinic opened at Johannesburg's Helen Joseph Hospital in 2005, the focus was on saving lives by getting people on antiretroviral therapy (ART) as quickly as possible.
But as the numbers taking ART started to climb, doctors began noticing a second, hidden epidemic: tuberculosis (TB).
Patients being treated for Aids were still dying of tuberculosis in large numbers.
Worse, the raging HIV/Aids epidemic seemed to have masked the growing tuberculosis problem.
Once on the wane, tuberculosis is again resurgent, especially in countries facing major HIV/Aids epidemics.
In 2006, it killed an estimated 1.7 million people, according to the UN. An estimated two million died of HIV/Aids, but for many the immediate cause was tuberculosis; TB is the number one killer for people with Aids.
Unlike Aids, TB - once known as the white plague - is a curable disease, but proper treatment is complicated and requires at least a six-month course of antibiotics.
However, HIV attacks the immune system, making people more susceptible to infections like TB, and as a result, there are high-levels of co-infection.
At Helen Joseph Hospital, for example, more than 90 per cent of patients admitted to hospital wards for TB were also HIV-positive.
Of all patients diagnosed with TB, 65 per cent are also HIV-positive.
As South Africa focused on combating HIV/Aids, its tuberculosis rates quietly soared. The country now has one of the worst epidemics in the world.
By 2006, the TB incidence rate in South Africa - the number of new cases each year - had become the second highest in the world, a staggering 940 cases per 100,000, according to the World Health Organisation (WHO).
Only neighbouring Swaziland, another Aids-stricken country with a population of just over a million, has a higher rate.
'HIV driving TB'
|Most of the children at this Johannesburg orphanage lost their parents to Aids [EPA]
Though the two epidemics are feeding off each other, little effort has been made to co-ordinate treatment of the two diseases.
"TB is the step-child of HIV," says Dr Johnson Mahlangu, who runs the TB focal point at Helen Joseph.
"HIV is really driving the TB epidemic, but health systems are not geared up to manage the two diseases together."
HIV/Aids are often treated at specialised clinics, like Themba Lethu, many of which receive funding and support from international donors and local non-governmental organisations.
Primary health care providers usually treat tuberculosis. As a result, patients infected with both must go to two separate clinics and see two separate sets of health care providers.
"The two just aren't talking to each other," says Mahlangu, who works for Right to Care, a non-governmental organisation.
At Helen Joseph, with support from Right to Care, and the US president's Emergency Fund for Aids Relief, doctors are taking an innovative approach to integrating care for the two diseases.
A year ago, Right to Care opened the new TB focal point next door to the Themba Lethu clinic. Patients at Helen Joseph who are being treated for one disease are now tested for the other. And care for patients who test positive for both can now be co-ordinated.
Both clinics have also been outfitted with a special ventilation system and UV lights that help kill the infectious mycobacterium that cause TB.
"One of the biggest challenges is that if you have patients who are HIV-positive and you mix them with TB patients, you're going to really increase the risk of infection," says Mahlangu.
Tuberculosis is spread through the air, especially in confined spaces.
The TB unit has also succeeded in dramatically increasing the number of patients who follow through with treatment.
Before the focal point opened, 50 per cent of patients diagnosed with TB at Helen Joseph disappeared from the health system before receiving treatment. Now, each is tracked to ensure they enrol in and complete TB treatment.
However, though the South African government says it is committed to integrating TB and HIV treatment around the country, Helen Joseph remains a rare model.
Norah Mahlangu (no relation to the doctor), a 27-year-old mother from the township of Soweto, was diagnosed with HIV in 2004.
The virus stripped away her body's defences, but it was tuberculosis that nearly killed her.
Before she could start antiretroviral therapy, she needed treatment for her TB. She nearly did not make it through.
Norah was lucky. She had help from Susan Moloto, a nurse at Soweto Hospice who understood the relationship between the two diseases and helped her access treatment.
Now her TB has cleared up and she has started taking antiretroviral drugs.
Soweto Hospice even gives her extra food, an essential but often overlooked part of her treatment. Both the antibiotics taken for tuberculosis and antiretroviral drugs can make patients feel sick if taken on an empty stomach.
No one in Norah's house has a job - something that is not uncommon in South Africa, especially in the poor communities hardest hit by tuberculosis.
"She completed the whole TB treatment, which is very hard," says Moloto. "Now she's better."
|Susan Moloto, left, a nurse at Soweto
Hospice, visits Norah at her home
In South Africa, as in many of the African countries were HIV/Aids is widespread and tuberculosis resurgent, completion rates for tuberculosis treatment have fallen in recent years.
Only about 70 per cent of people successfully finish their treatment. The rest die or stop taking their drugs. Many more are never even identified as being infected.
The poor quality of TB treatment costs lives but is also causing the rise of dangerous new strains of drug resistant tuberculosis.
Doctors are increasingly worried about multidrug-resistant tuberculosis (MDR-TB), which is resistant to the two most powerful drugs used to treat the disease.
Globally there were half a million new cases of MDR-TB last year, about five per cent of all new tuberculosis cases. But HIV-positive people are twice as likely to be infected with resistant strains, and are more likely to die if they are.
Even more alarming for many health care professionals is the recent emergence in South Africa's KwaZulu-Natal province of a deadly strain of tuberculosis that is virtually untreatable with known drugs.
Struggling to diagnose
South Africa is struggling to even properly diagnose MDR-TB.
At Helen Joseph, for example, tests for TB are returned from the laboratory in less than 24 hours. But it can take up to two months to determine whether someone is infected with MDR-TB.
By then, the patient is often dead or has disappeared. They have also had months to spread the resistant strain to other people.
Dr. Louisa Ferreira, who runs the paediatric ward at Soweto Hospice, says she is seeing an increasing number of MDR-TB cases in her own small ward and in local hospitals.
For now, TB is still in the shadow of HIV/Aids, but she and others say the threat it poses is enormous.
She said: "It may be bigger than HIV."