Socio-economic factors affect disease spread

Maori and Pacific people are at highest risk of an increasing rate of Staphylococcus aureus disease in New Zealand.

Staphylococcus aureus is a major disease most commonly associated with skin and soft tissue infections, but can also cause serious invasive infections such as osteomyelitis and necrotizing pneumonia.

The disease occurs in both community and healthcare settings among a variety of demographic groups.

In a study of baseline trends of S.aureus infections in the Auckland population, there were notable differences in disease burden with the incidence highest among Maori and Pacific peoples.

The research described the incidence, trends and patient characteristics of S.aureus infections in patients presenting to Auckland City Hospital over 11 years and compared the demographics of infections of both MSSA and MRSA strains.

"We found notable demographic differences between community and healthcare-associated S.aureus infections, as well as differences in the comparative epidemiology of MSSA and MRSA," says lead researcher, Dr Debbie Williamson.

The data provided broad and comprehensive representations of the trends and burden of S.aureus in the Auckland area.

"There was a significant increase in the incidence of hospitalisations for skin infections – in keeping with other recent studies in New Zealand, " says Dr Williamson. "This further highlights a concerning national trend."

Although reasons for this increase were unclear, suggested contributing factors include delayed access to healthcare, increases in household crowding and declining socio-economic circumstances for specific population groups, she says.

"We found that in our setting, the vast majority (88 percent) of S. aureus infections were caused by MSSA and the incidence of MSSA increased significantly over the study period," says Dr Williamson. "This was in contrast to the incidence of MSRA which remained stable, and so decreased in comparison to MSSA.

"Our work provides valuable baseline data on the epidemiology and trends of S.aureus in New Zealand," she says."The significant increase in community associated S.aureus infections is of public health importance."