Geneva - The three cases of patients with swine flu who have shown resistance to anti-viral drugs were not unexpected, a senior World Health Organization official said Tuesday.

Kieji Fukuda, the WHO's chief of health security, said they were "sporadic cases" and that the phenomenon was not widespread. It was "not unexpected" to see some incidents like this with drug treatment, he noted.

All three patients, in Denmark, Hong Kong and Japan, were believed to have made full recoveries.

There were about 98,000 cases of the virus confirmed, with 440 deaths, in 137 countries and territories.

The WHO would issue within the next few days new guidelines for member states on how to monitor the virus, given that it was widespread and counting each case was no longer needed.

Rather, the organization would likely recommend that only countries with few or no cases keep tabs on every instance, but otherwise to focus on possible mutations, other changes and severity.

Fukuda said that he was not recommending any alterations to the types of treatments given to people with the new A(H1N1) 09 virus, as it is scientifically known, which has been mostly responsive to anti- viral treatment.

In the southern hemisphere, which is going through its seasonal flu period, some countries were more affected than others. In Chile, the majority of flu cases were of the new virus while in South Africa most cases were seasonal and other countries fell at points in between.

The WHO was convening Tuesday a group of experts on immunizations and their recommendations would be passed on to the director-general of the UN's health agency before being made public.

An immunization could be ready by the autumn, experts have said.(dpa)