Malaria kills more than one million people a year worldwide but was wiped out in the UAE in 2007. But as Jonathan Gornall reports, the price of freedom from disease is eternal vigilance.
Keeping the country malaria-free is an ongoing battle
It was the smallest of headlines, tucked away deep inside one of the world's least-known journals. But the six words on page 30 of the World Health Organization's Weekly Epidemiological Record on January 26, 2007, celebrated a remarkable achievement in the global fight against one of the world's most persistent diseases: "United Arab Emirates certified malaria-free".
For the men and women of the Central Malaria Control Department, the Ministry of Health and the various municipal departments who had fought a coordinated fight for 30 years to see this moment come to pass, it was a moment to savour.
The scale of that achievement was emphasised this week with the publication of a study, funded by the Bill and Melinda Gates Foundation, claiming that the number of deaths worldwide from malaria could be almost twice the 655,000 estimated for 2010 by the World Health Organization (WHO). Far from dying out, in other words, malaria remains a serious and entrenched threat. Even in Abu Dhabi, more than 2,000 cases were reported last year, nearly double that of 2010. The figures, released last month, can be attributed to a more thorough electronic monitoring system. More importantly, all of the cases were contracted in other countries.
Five years ago, the UAE was the first formerly endemic country since Singapore and Australia in the 1980s to be certified by the WHO as malaria-free, and the story of how the UAE successfully battled the disease is held up by the WHO as an example to other countries.
The certification, reported the WHO, was granted only to countries "that have successfully maintained their malaria-free status for a period of at least three years" and was given in "recognition of a considerable operational achievement".
It was in recognition of that achievement that the WHO conducted the final review of its field manual for malaria elimination during a workshop in Dubai in June 2007. Included in the manual "as an example of the organisation and operations involved in securing a malaria-free status", was the UAE's plan of action, while the finalised eight steps that had to be taken by any country seeking certification that it had eradicated malaria were drawn up "on the basis of the experience with certification of malaria elimination in the United Arab Emirates".
It was a long, uphill struggle, as UAE experts related in a presentation in May 2004 in a presentation at the Fourth Inter-country Meeting of National Malaria Programme Managers, held at Isfahan, Iran. Malaria had been "a major public health problem" in the Emirates up to and throughout the 1960s, with hot spots including the east coast, Ras Al Khaimah, Al Ain and the central plateau. The main culprits were two particular species of mosquito - Anopheles stephensi and Anopheles culicifacies - "breeding mainly in deep wells, shallow wells, basins, drums and irrigation channels". Three species of the malaria parasite Plasmodium were at work: vivax, malariae and - the most dangerous type - falciparum.
In the 1970s, international efforts to eradicate malaria worldwide were abandoned as impractical, but a few countries pressed ahead, determined to at least rid their own territory of malaria transmission. The UAE was one of them.
Some form of malaria controls were introduced in 1970, said the report, "but activities lacked regularity and organisational structure". In 1975, the responsibility for malaria control was transferred to individual health districts, but this "did not improve the situation and failed to prevent major malaria outbreaks in 1975-1977".
Faced with this "critical situation", the Government set up a Central Malaria Control Department, under the control of the Ministry of Health and with its headquarters in Sharjah. It started work in 1979, with immediate positive results: the number of cases in the country fell from 22,791 in 1978 to 11,599 in 1979.
It was a painstaking, systematic battle, and all about "vector control" - clamping down on the mosquitoes themselves, chiefly by destroying them at breeding sites while they were still in the larval stage, and by spraying insecticides in homes and communities at the centre of outbreaks. In addition, a chain of laboratories was set up to make sure that throughout the country cases of malaria were promptly detected, diagnosed and treated with the correct medicine, preventing the spread of the disease from one victim to another by the bite of a successive, previously uninfected mosquito.
In Dubai, responsibility for the surveillance and treatment of malaria cases fell to Dubai Health Authority (DHA), but it "really has been a concerted effort of the DHA, Ministry of Health UAE and Dubai Municipality, not to mention the efforts of the residents of the UAE", said Dr Fatma Alattar, head of the authority's preventive services centre. It was a concerted effort, mirrored in and coordinated with other emirates, that paid off right across the nation.
By 1968, the malaria infection rate in the UAE as a whole had been anything between 32 and 60 per cent of the population, with infants particularly vulnerable. By 1980, the transmission of the disease had been largely interrupted and the incidence rate had fallen to eight cases per thousand population. By 1985, incidence was down to 1.6 per thousand, and in 1990 the number of cases among Emiratis had fallen to 375 - down from 2,436, a decade earlier.
The very last "home-grown" malaria case, recorded in Masfout village, was detected in July 1997, since when there have been no more reported cases of locally transmitted malaria.
"This," Dr Abdulaziz Masad Al Muthanna, the director of the UAE's Central Malaria Control Department, told delegates at a meeting of malaria programme managers in Lahore in 2003, had been achieved "by hard work and systematic planning, along with valuable cooperation of other partners, such as municipalities, hospitals and clinics".
Frankly, he said, "we have taken pride in acknowledging this accomplishment", which was celebrated on the first UAE National Malaria-Free Day, on December 28, 2002.
But although the UAE is itself clear of malaria, to the satisfaction of an exhaustive audit by the WHO, it must remain constantly on its guard, as Dr Al Muthanna acknowledged. The UAE faced challenges in remaining clear because of its success as a tourism centre, shopping destination and trading centre, "attracting a great number of people from all over the world all around the year".
The key was "early correct diagnosis and prompt effective, safe treatment ... the first technical element in the UAE strategy to prevent reintroduction of malaria". For that reason, malaria diagnosis and treatment remains free of charge, while the effectiveness of antimalarial drugs, which may only be issued through a government organisation, is constantly monitored and travellers heading to infected countries are offered free health education and free prophylactic drugs at clinics throughout the Emirates.
"We cannot afford to sit back and relax after achieving such a huge goal," says Dr Alattar. "Surveillance is an ongoing, continuous process and can never be stopped in this regard until malaria is eradicated worldwide."
And, as the WHO points out, the UAE is surrounded by countries still plagued by high incidences of malaria - including Pakistan and Yemen - and others with limited problems, such as Saudi Arabia, Iraq and Iran. Four other countries in the WHO's Eastern Mediterranean region - Egypt, Morocco, Oman and Syria - are in the phase of preventing reintroduction of malaria, but in the case of Egypt and Syria it is not yet clear how the upheavals of the Arab Spring may have disrupted their malaria programmes.
Malaria does continue to be found in the UAE, brought into the country by infected expatriate workers or residents returning from malarial countries, and containing these cases is vital to prevent the reintroduction of locally transmitted malaria. The disease is spread by one non-infected mosquito ingesting the blood of an infected carrier, and then biting, and infecting, another human host.
The number of cases has fluctuated over the years since eradication, "largely reflecting importation of malaria cases from abroad", but the need for constant vigilance was highlighted last month when Abu Dhabi - Health Authority (Haad) announced that the 2,000 cases identified in the emirate in the first nine months alone of 2011 was double the number for the whole of 2010.
"We do have a very good electronic reporting system," says Dr Ahmed Abdulla, a specialist in tropical diseases who is head of the Communicable Diseases Section at Haad and who receives a personal notification every time a case of malaria is identified. To make sure it is an imported case, the department conducts a rigorous epidemiological investigation, looking at the patient's travel history, the date they entered the country, the species of parasite involved and the timing of the first symptoms.
The problem against which the section is now battling, he says, is relapse: "This is very important and one of the challenges we are having now."
The malaria parasites can lie low in the liver for months, or even years, and this is why it is essential to finish the free 14-day course of treatment. Some sufferers never start it, perhaps because they think that malaria is one of the deportable diseases, which it is not, and they are afraid to go to the public hospital or screening and prevention centres, says Dr Abdulla.
"That is why public awareness is an important part. It is important to tell people that this is a treatable disease and not a deportable disease and this treatment is for your own safety."
The scale of the operation to monitor and control malaria in the UAE is impressive, involving more than 100 laboratories at hospitals and health centres in detection, diagnosis and treatment, and a further 37 private laboratories in detection of cases, while the Central Malaria Control Department runs dedicated malaria clinics in all the previous hot spots.
It is a labour-intensive operation: in 2003 alone, 42,600 blood samples were examined for malaria parasites, of which 1,796 cases (4.2 per cent) were positive for malaria. The recorded cases were found among people from 39 nationalities, though the vast majority - 87.5 per cent - were from the Indian subcontinent, predominantly Pakistan.
Another vital line of attack is to deprive mosquitoes of their breeding grounds, and to destroy their larvae. The key to preventing mosquitoes breeding, in fact, is to intervene at the larval stage, and across the UAE entomology teams systematically check suspected breeding places and treat them with larvicides. Again, this is a labour-intensive activity. In 2003, for example, almost 130,000 sites were checked, of which just 1,565 came up positive.
This vital work continues today in each emirate - while malaria thrives elsewhere in the region, the battle against the disease will never be over. In Abu Dhabi, Haad's Communicable Diseases Section makes daily random visits to known mosquito breeding sites and, if they find larvae, the Centre of Waste Management dispatches private contractors to treat the area with larvicides - or even fish that eat the larvae.
"We are moving towards implementing biological controls," says Dr Abdulla. "We are very concerned about the environment and instructing the service providers to cultivate fish in most of the places and we have intensified our efforts during the last two or three months."
Travellers, he says, must play their part. "Malaria was endemic in the UAE for a long time and a lot of effort has gone in to eliminating it. Unfortunately, most of the expats when they go for their annual vacations in malaria endemic countries, in Asia or Africa, they do not take their malaria prophylactics, which is why they come back with malaria; also nationals and Europeans who travel in the region. My advice to anyone who travels to any endemic country is please make sure you take your malaria prophylactics."
The UAE's achievement, says Dr Abdulla, is an enormous one, "and we do have a great challenge not to jeopardise this situation with any introduction of malaria. We don't want to see any setback; we don't want to see a single case of malaria that has been locally transmitted."