08 May 2009
SA's unsung killer
By David Furlonger
Cystic fibrosis, traditionally regarded as a "white" disease in SA, is proving to be no respecter of colour. Instead of the few dozen patients formerly believed to suffer from the inherited chronic disease, doctors now believe numbers could run into thousands - most of them undiagnosed.
Indeed, some researchers believe thousands of black South Africans may have died from cystic fibrosis complications without the symptoms being recognised.
"Children who died after being diagnosed with malnutrition, lung infections or diarrhoea may well have been displaying the symptoms of cystic fibrosis," says Professor Michele Ramsay, head of the molecular genetics laboratory in the department of human genetics at the SA national health laboratory service.
Cystic fibrosis is caused by a defective gene that causes the body to produce a thick, sticky mucus that clogs the lungs and pancreas. Common results are life-threatening lung infections and an inability to break down and absorb food. Typically, patients suffer from persistent coughing, shortness of breath, poor growth and weight gain despite a healthy appetite, and difficulty in performing bowel movements.
Prof Michele Ramsay - Symptoms unrecognised
Life expectancy among cystic fibrosis sufferers has improved in recent years but it is still a terminal illness. In the 1950s, most children diagnosed with the disease died before they reached primary-school age. As recently as the 1980s, they were lucky to reach their late teens. Today, thanks to improved research and treatment, many cystic fibrosis patients can expect to live into their 30s and 40s.
However, doctors say there is still no cure for cystic fibrosis. International gene therapy research has raised hopes that a cure will be found but Ramsay says success is still some way off. A number of drugs have enjoyed some success but they are generally suitable only for patients with specific mutations of the disease. Some specialists say the best hope for long-term survival is a double-lung transplant. The procedure has enjoyed some success in SA but is very expensive.
Cystic fibrosis is passed on to sufferers from parents, both of whom must carry the defective gene. Carriers are generally unaware of their status. According to specialist cystic fibrosis doctors Professor Mervyn Mer and Cathy Baird, about 4% of white South Africans are carriers, 2% of coloureds and 1% of blacks. Only when two carriers procreate is full-blown cystic fibrosis passed on. There is a one in four chance of their children being infected.
In an article in the SA Respiratory Journal, Mer and Baird write that the presence of cystic fibrosis is far greater than generally recognised. "It translates into an incidence of cystic fibrosis in every 2 800 white children, one in every 10 000 coloured babies and at least one in every 32 000 black babies born in SA." Another study, however, suggests one in 4 624 black babies could suffer from cystic fibrosis.
Even when infected, sufferers do not automatically display standard symptoms. In some patients, the disease becomes evident soon after birth; with others it takes some years. Unnoticed, complications may include diabetes, chronic sinusitis, osteoporosis, abnormal liver function and even male infertility, says Mer.
The problem in SA is that cystic fibrosis is a little-known disease. In countries like the UK, Australia and the US, awareness and corporate sponsorship are huge, raising millions of dollars for research every year. For some multinationals, cystic fibrosis is their flagship charity. International performers like Celine Dion lend their name to awareness of the disease. Fraser, the two-year-old son of British prime minister Gordon Brown, suffers from cystic fibrosis.
In SA, by contrast, "we are severely challenged in critical mass regarding expertise and finances", says Ramsay. "There are so many things to study here in SA that it's difficult to pursue every research direction."
One reason is undoubtedly that it is seen as a white disease. "That idea has been debunked by scientists but the impression persists among many in the public," says Ramsay. "It's a disease that occurs in every shade of our rainbow nation."
Baird says her interaction with doctors and clinics confirms the prevalence of cystic fibrosis in black communities is higher than previously suspected. Mer says: "There are hundreds, possibly thousands, of black people out there unaware they could have cystic fibrosis."
The sooner the disease is identified, the better the sufferer's quality of life may be. "The individual's health and life expectancy is strongly correlated with whether a diagnosis is made, when it is made and the clinical management and treatment following diagnosis," says Ramsay. "For this reason it is vital that an accurate diagnosis is made as early as possible and that appropriate treatment is initiated and sustained."
Excessively salty skin is a tell-tale sign of cystic fibrosis. Traditional folklore in parts of northern Europe tells of mothers licking newborn babies' foreheads to gauge their chances of survival, says Baird - suggesting forms of the disease have been around for centuries. Ramsay says there are even biblical references to the practice.
Baird says the "gold standard" in detecting cystic fibrosis is a simple sweat test, which is inexpensive and non-invasive. The problem, says Ramsay, is that most rural clinics and their staff lack expertise and facilities.
"Developing countries are challenged on several fronts with regard to diagnostic testing," she says. "Populations tend to be spread sparsely over large geographic distances and the health and laboratory infrastructures tend to be poor. The sweat test is often not available. When it is, it is inadequately performed by staff who lack the appropriate education and skills. This affects both sweat collection and the quality of the biochemical testing. To perform DNA analysis requires laboratories with sophisticated equipment and scientists with the knowledge and skill to perform and interpret the tests."
New drugs, improved treatment and intensive physiotherapy all help combat the effects of cystic fibrosis. But for SA sufferers, as in the rest of the world, living with the disease means regular hospital stays, gradually reduced lung function and the awareness that life is likely to be shorter than for most people. In SA, it is also a lonely disease. Lack of public awareness means sufferers get little understanding beyond their immediate families.
Nevertheless, there are many examples of sufferers living lives to the full. Around the world, cystic fibrosis sufferers have excelled in all kinds of endeavours, including business, the arts and even sport. In SA, Paul Dolman, a cystic fibrosis patient with 40% lung capacity, is a regular Comrades Marathon finisher and motivational speaker. Others find different ways to beat the odds, such as climbing Mount Kilimanjaro.
Mer says: "There are some extraordinary people out there living with cystic fibrosis. They recognise that, in the long term, they are unlikely to beat the disease, but at the same time, they are not willing to let it beat them."