As the all-out strike by the State's public health doctors entered its seventh week yesterday, health boards admitted they were finding it difficult to cope.
Mr Michael Lyons, spokesman for the health board's chief executives, said: "Clearly we are coping with great difficulty."
He said there were "significant issues" now facing health boards in the absence of the 270 public health doctors, who are on strike over pay and working conditions.
These issues, he said, included falling immunisation rates, and difficulties around the follow-up of cases of infectious diseases which they were finding "problematic".
"It's almost self-evident that we are finding things difficult. Clearly the CEOs would welcome a speedy resolution to the dispute," said Mr Lyons, who is CEO of the Eastern Regional Health Authority.
"The whole area of promoting immunisation uptake is compromised to a certain extent by their absence. If uptake falls below a particular percentage, it requires a push. That is falling behind a bit without them," he added.
The striking doctors, who are mainly women, work entirely in the public sector and have a wide range of duties, which include school visits to administer booster vaccinations, nursing home inspections, child developmental checks, and tracing contacts of those who have presented with infectious diseases such as measles, meningitis, TB and SARS.
In addition, they are involved in the health screening of asylum-seekers, which is not now being offered in several areas.
As both sides in the dispute remained deadlocked yesterday, with only informal contacts having taken place between them in the past week, doctors on the picket lines remained resolute. Mr Paul McKeown, a public health specialist with the National Disease Surveillance Centre, said he was now more determined than the first day he went on strike.
"Going without pay for six weeks is hard but the fact that we are still out here is a measure of our determination not to go back until we have a proper and safe public health system in place, one that Irish people deserve," he said.
Part of the dispute revolves around the fact that there is no structured out-of-hours public health system in the Republic. The doctors want to be rostered to work at evenings and weekends to deal with infectious disease as they occur. Up to this they have done this work without pay.
The doctors earn between €48,470 and €81,914, depending on their grade. The Irish Medical Organisation wants the most senior grades to be paid the same as hospital consultants, whose pay scale ranges from €114,718 to €142,406.
However, the Health Service Employers' Agency has said consultant status for senior public health doctors is "not a runner". Its head of industrial relations, Mr Brendan Mulligan, said this sticking point had hindered progress in resolving all the issues in dispute.
The Department of Health agreed nine years ago to review public health structures.