Dr Horsburgh was speaking at Otago University, in Dunedin, on Thursday about research into major health care and medicine access challenges facing people living in rural parts of the Tairawhiti area.
He has been a co-investigator in a major study, led by Prof Pauline Norris, of the Otago School of Pharmacy, some findings from which were released last year.
These showed rural Maori were much less likely to receive antibiotics despite needing them more because of far higher rates of rheumatic fever.
Rheumatic fever starts with a sore throat, but can later cause permanent heart damage. It results in about 180 deaths in this country each year.
Maori in Tairawhiti, where the Otago study was carried out, have extremely high rates of rheumatic fever. Heart damage can be prevented among people in high-risk groups by taking antibiotics for sore throats.
A recent Ministry of Health-funded report said acute rheumatic fever had been "virtually eradicated from most 'developed' countries".
But rates in New Zealand had "failed to decrease since the 1980s and remain some of the highest reported in a developed country," the report said.
Dr Horsburgh, a lecturer in preventive and social medicine, highlighted problems in gaining access to medical care and prescription medicines in remote parts of Tairawhiti, where poverty and challenging roads added to problems.
The Government last year announced that a further $12 million was being provided to boost the national campaign against rheumatic fever, including in Tairawhiti.
Dr Horsburgh this week emphasised that the Otago study had not contributed to that funding boost, but had highlighted the need for more effective help to counter high rates of rheumatic fever.
Rural school clinics were being used to take swabs of children with sore throats, and if Group A streptococcus (GAS) - which could lead to rheumatic fever- was found, antibiotic treatment was given.
It was too early to know what effect the school clinic approach was having in Tairawhiti, but it was encouraging that many cases of GAS were being detected and treated, he said.
Prof Norris said that "access to medicines remains a serious problem for many people, especially in rural areas, and for Maori in particular."
