A simple tummy bug to some but fatal to 500,000 impoverished children each year
It’s a short sharp shock to the system from which almost every child on the planet will have suffered before they reach the age of five.
But while in the developed world rotavirus infection leads to little more than an unpleasant but easily treated bout of gastroenteritis, in the developing world it remains one of the great silent killers, claiming the bulk of the half a million lives lost each year to the disease worldwide and hospitalising millions more.
The news this month that Dubai has begun vaccinating against rotavirus as part of its federal immunisation programme, following Abu Dhabi’s lead last year, has been welcomed by experts in the field.
It was “a landmark decision for the country”, said Dr Anita Jain, who as India Editor for the British Medical Journal has been overseeing its extensive coverage of developments and debates surrounding the often controversial introduction of the rotavirus vaccine in countries around the world.
For countries such as the UAE, where gastroenteritis is easily managed and the potentially fatal consequences of the dehydration caused by diarrhoea and vomiting easily avoided by quick and effective hydration, the main benefit of introducing population-wide immunisation is to reduce the cost to the healthcare system of treating the disease.
But in countries where treatment is neither as effective nor as readily available as in the UAE, it is deaths, not costs, that the World Health Organisation is anxious to reduce.
Everywhere in the world, both adults and children suffer commonly from gastroenteritis, inflammation of the stomach and bowel usually caused by viral or bacterial infection, encouraged by poor hygiene and spread easily by touch, close proximity and even the sharing of bath and swimming pool water.
In adults, the bug most commonly responsible for gastroenteritis is the highly contagious novovirus, which can be caught anywhere but usually hits the headlines when an outbreak tears through the passengers on a cruise ship.
Only this week, in fact, the Centers for Disease Control and Prevention (CDC) in the US confirmed it was a strain of novovirus that had laid low 700 passengers and crew on Royal Caribbean’s Explorer of the Seas earlier this month, scuttling a winter cruise to the sun and forcing them to disembark in chilly New Jersey.
Though children can also catch the novovirus, they are usually more susceptible to the rotavirus. The good news is that, while there is no cure, it is a generally self-treating condition and the unpleasant symptoms – diarrhoea, fever and stomach cramps– will disappear within a few days.
Children are, however, much more susceptible to rapid dehydration than adults, and especially so in hot countries where clean drinking water is hard to come by. Small wonder, then, as research has shown, that 82 per cent of the half a million child deaths caused by the rotavirus each year take place in the world’s poorest countries – and that the World Health Organisation (WHO) is signing up countries to a global immunisation programme.
As ever, prevention is better than cure, but the battle to develop a safe rotavirus vaccine has not been easily won and controversy continues to surround immunisation.
The ability to protect against rotavirus was developed only relatively recently. Indeed, the terrible scale of the impact of the disease was not fully understood until the publication of a groundbreaking paper by the WHO in 1985, which estimated that rotavirus was responsible for 20 per cent of all deaths caused by diarrhoea in children under five in developing countries.
It was known that the incidence rate of rotavirus was similar in industrialised and developing countries, which implied that improvements to water supplies, sanitation or hygiene were not the sole answer. What was needed to control the spread of rotavirus, the authors from the London School of Hygiene and Tropical Medicine concluded, was “the development, trial, and widespread use of an effective vaccine”.
The first vaccine was developed in America and licensed for routine immunisation in August 1998. But within nine months it was suspended and then withdrawn from manufacture after it was found to be causing intussusception. This is a dangerous condition in which part of the bowel “telescopes”, or turns in on itself, causing vomiting, lethargy, acute pain and dehydration. If left untreated – usually by air enema or, in the worst cases, surgery– it is fatal.
Research continued and there are now two rotavirus vaccines,Rotarix and RotaTeq, which have successfully undergone large trials and are recommended for use by the World Health Organisation.
WHO wants to see rotavirus vaccines introduced into every country’s national immunisation program, but of January this year only 53 mostly well-off countries had done so. These countries, says WHO, have seen “rapid and remarkable reductions of severe and fatal diarrhoea in young children” and the vaccines are “saving lives and improving health”.
The organisation recommends that the first dose of either drug should be administered between the ages of six and 15 weeks, and that the second and final dose be given no later than 32 weeks.
The drugs cannot, however, get the job done entirely on their own. WHO says the vaccines “should be part of a comprehensive strategy to control diarrhoeal diseases” - a strategy that should include improvements in hygiene and sanitation, zinc supplementation and community-based administration of oral rehydration solution, and the absence many such factors can complicate the impact of immunisation in countries that need it the most.
WHO figures show that more than 98,000 children died from rotavirus gastroenteritis in India in 2008 alone, rising more recently to in excess of 110,000, according to the nation’s Million Death Study. Nevertheless, experts remain divided over whether the country’s plan to introduce a vaccine into its national childhood immunisation is a good idea.
In a recent head-to-head debate in the British Medical Journal, Umesh Parashar, an epidemiologist at the CDC in Atlanta, Georgia, argued that immunisation, using locally developed vaccines costing no more than US$7 a dose, would be highly cost-effective in India.
Hospital admissions and clinic visits by children for rotavirus were costing the country US$65 million a year - a vast sum in a country where health spending was a mere US$54 a head.
And, even if the vaccine were effective in only 50 per cent of cases, it would still prevent 44,000 deaths and 290,000 hospital admissions among Indian children every year.
However, Jacob Puliyel, a consultant paediatrician at St Stephen’s Hospital in Old Delhi, and Professor Joseph Mathew of the Advanced Paediatric Centre at Chandigarh’s Institute of Medical Education and research, disagreed.
The WHO programme to immunise all the world’s children with the rotavirus vaccine was “ based on mistaken assumption”, they said. Furthermore, in India itself “careful evaluation of available evidence does not support the launch of the programme”. It would not, they said, be cost-effective and would “divert funds from more life saving interventions and could cause harm”.
Such debates, experts believe, are best resolved by widespread field trials of the vaccines – on-the-ground experience in a range of settings that can be translated into information that can be usefully applied elsewhere in the world.
One such example is a recent study carried out into the effectiveness of the vaccine programme introduced in Belgium. The new data, the first of its kind from Europe, offered “robust evidence of the effectiveness of the vaccine in a real-life setting”, wrote Manish Patel, a CDC epidemiologist, in a recent editorial in the British Medical Journal.
“Undeniably,” he concluded, “efforts to control rotavirus have produced remarkable dividends [and] these early successes should be a springboard to progress. Improving affordability, maintaining the momentum of vaccine introductions and evaluations, and searching for ways to improve efficacy will be crucial if the rotavirus problem is to be resolved globally.”
And that’s where pioneering programmes such as those now under way in Dubai and Abu Dhabi come in, says Dr Anita Jain.
“Lessons that the UAE can provide, and I hope is a part of the programme, is to evaluate factors such as feasibility of implementing the programme, costs, and long-term benefits,” she said.
“This would add to the body of evidence as other countries consider introducing the vaccine and there may be potential for researchers in the two countries to collaborate over studying the vaccine effectiveness further and development of locally effective vaccines.”
Published: February 16, 2014 04:00 AM