The worst culprits were so-called ESBL-forming intestinal bacteria, which include certain strains of E. coli, according to the report by the Institute for Infectious Disease Control (Smittskyddsinstitutet, SMI).
A total of 3,754 cases of ESBL were reported in 2009. Comparing the second half of last year with the same period in 2008, the number of cases rose 27 percent, the report revealed.
"This is a worrying development, among other reasons because there is a serious lack of new antibiotics that can be used against these gram-negative bacteria. Treatment options are few," said Barbro Olsson Liljequist, chief microbiologist at SMI.
ESBL, while harmless in most people, can cause ailments including pneumonia or urinary tract or blood infections. People who are frail, in intensive care or otherwise in hospital for an extended period are among those in the risk groups.
The more antibiotics are used, the greater the risk becomes for the emergence and spread of resistant bacteria. Antibiotic use continues to vary widely between different counties in Sweden.
So far in 2010, seven major ESBL outbreaks have occurred in the health care system. Another study shows that one in four Swedish tourists who returned from holidays abroad brought home ESBL bacteria that they did not have before they left.
"There is no evidence to suggest that we have stopped the ESBL outbreaks," said Otto Cars, director of Strama, a Swedish anti-superbug programme. "They continue and we must take it seriously."
Worse, for the third consecutive year, the report noted cases in Sweden of multiresistant ESBL-producing bacteria that are immune to carbapenems. Carbapenems are one of the few groups of antibiotics that remain active against this type of bacteria.
In 2009, three cases of carbapenem resistance were reported. In each case, the patient had received medical care in southern Europe. Thirteen cases of carbapenem resistance have been reported to date in Sweden.
One bright spot in the report is that prescriptions for antibiotics in outpatient care declined sharply by 7.4 percent in 2009. The largest decrease was for children up to the age of six, with prescriptions dropping 17.2 percent.
"It is positive that consumption declined in 2009," said Cars. "The increase in resistant bacteria underlines the importance of not using antibiotics unnecessarily. In addition, we must invest more on hygiene routines and there must be capacity in the health care system to cope with the increased resistance - for example, with access to single rooms."
An analysis done by the National Board of Health and Welfare (Socialstyrelsen) shows that it is common for children to receive repeated courses of antibiotics. Every 10th prescription of respiratory antibiotics for children up to the age of six years is followed by a new course within 14 days. There may be several factors behind this, such as problems with the children taking the medication in the manner intended.
Cars stressed that the use of antibiotics must be reduced even further. He believes that hospital care for those who are infected will result in enormous bills in the future.
"I am convinced that it will cost about 1 billion kronor [$126.13 million] in Sweden," he said.
Cars believes that every county should have an emergency plan to quickly halt the spread of an outbreak. No such requirement currently exists for counties.