Health data: There was a 62 per cent increase in the number of cases of malaria reported in the State last year.
Some 44 cases were reported, the highest number in many years, according to the Health Protection Surveillance Centre (HPSC).
The previous year, 2004, there were 27 cases reported. And in 2003 there were 21 cases notified, in 2002 there were 20, and in 2001 there were just 11 cases.
The data has been collated in a new study by three Health Protection Surveillance Centre staff and was presented at the summer scientific meeting of the faculty of public health medicine at the Royal College of Physicians of Ireland.
The study stresses that the number of cases of malaria notified may underestimate the true extent of cases as it does not correlate with data for the number of discharges from hospital with malaria as a diagnosis.
To illustrate, there were 462 discharges with malaria as a primary or secondary diagnosis over the six-year period 1999-2004 but there were only 115 cases of malaria notified to the Health Protection Surveillance Centre over the same period.
All cases notified to the centre in 2001-2005 are believed to have originated from exposure abroad.
The majority of cases notified, where full data was available, occurred among those visiting family in their country of origin - these accounted for 33 per cent of cases.
New entrants to the State accounted for 23 per cent of cases, and holidaymakers accounted for 18 per cent.
In most cases, the country of infection was reported as sub-Saharan Africa.
The majority of cases, 97 per cent, either failed to take any anti-malaria treatment or failed to comply fully with the prescribed course.
Cases that acquired their illness while visiting friends and relatives overseas rarely reported having taken anti-malaria drugs.
The authors of the study noted that individuals in regions where malaria is endemic build up an immunity to malaria that leaves rapidly while living in a malaria-free region like Ireland and may wrongly assume that they are still immune to the disease.
The majority of holiday and business travellers who acquired malaria reported taking anti-malaria tablets but almost all of these, 93 per cent, failed to comply fully with the prescribed course.
The authors conclude that education should be targeted at all travellers to countries where malaria is prevalent.
They should be advised of their risk of exposure to malaria and the steps they should take to avoid being bitten by mosquitoes, which carry the infection.
The disease can manifest itself through flu-like symptoms and can be fatal.
The authors said people should also be aware that preventive measures are not 100 per cent effective.
Therefore, they should seek treatment promptly if they suffer symptoms suggestive of malaria within a year following their return from visiting an endemic country.
People should also remember to inform their doctor of their travel history.
Worldwide each year it is estimated up to 30,000 travellers fall ill with malaria on their return from visiting countries where the disease is endemic.
Malaria accounts for around four million deaths annually.
There were two deaths from the disease in Ireland in 1999-2004.
Last month 24-year-old Queens graduate Christopher Gallagher (24) from Derry died of malaria in Thailand while on the final leg of a three-month backpacking trek in southeast Asia.
His family believe he contracted the disease, despite having taken all recommended medical precautions, while trekking through the Burmese jungles in March.