29 Jan, 16 | by Leslie Goode, Blogmaster
A recent issue of the New Zealand Medical Journal (NZMJ) (128: vol. 1426) gives pride of place to a series of papers that reconsider the way forward for HIV prevention in New Zealand (NZ) against the background of the past thirty years. Recent contributions to STI journal by these authors analyse the behavioural surveillance data from NZ (Saxton & Hughes (STIs); Lachowsky & Summerlee (STIs); Lachowsky & Dewey (STIs)); the papers in NZMJ set these findings against a broader background (Saxton & Giola; Hughes & Saxton; Dickson & Saxton; Saxton & Ludlam).
Broadly speaking, the situation in NZ resembles, both in nature and scale, what we find in Western European countries: namely, persistent but relatively low-level epidemics concentrated in the MSM population (above all, in Auckland), and among heterosexual individuals of foreign extraction (Dickson & Saxton).
The distinctiveness of the NZ epidemics, as against those of Western Europe, lies primarily in geo-political factors: such as migration from sub-Saharan Africa, which reached a peak in 2006 before abruptly declining – or the changing demography of Auckland with its large populations of South Asians and people of Pacific origin (Dickson & Saxton: Lachowsky & Summerlee (STIs)). The main emphasis of the NZMJ papers, however, is on issues that will have a familiar ring to West European readers – such as the importance of achieving a balance between public health and clinic-based approaches to HIV control.
Overall, their account suggests some considerable degree of success on the part of health interventions – but in the face of a public health challenge that is constantly evolving and may yet prove intractable. As regards the success, some behavioural surveillance data indicate levels of condom use with casual partners of 85% (Hughes & Saxton; Saxton & Hughes (STIs)); The challenge is represented by the growing minority who do not perceive HIV as a threat on account of new treatments (Hughes & Saxton; Saxton & Ludlam). There also remain, as elsewhere, the problems of high levels of undiagnosed HIV (c. 20%) and relatively late presentation to health services (over a third of MSM at CD4=<350/mm3). A things stand, the worst kind of scenarios seen amongst gay communities in Thailand or the US would appear to have been averted. Nevertheless, the epidemics show every sign of persisting, and, given a level of diagnosis that it is marginally higher than seen hitherto, may still turn out to be on an upward trajectory.
A key focus of the NZMJ editorial (Saxton & Giola) is on the continued importance of behaviour-based interventions in a world where the momentum seems to have shifted to clinic based control involving pharmaceuticals. They highlight the danger that the medicalization of HIV prevention could lead to a disinvestment in behaviour-based interventions, which, they imply, would not be conducive to controlling the epidemic. In this regard, the authors cite Phillips & Cambiano who argue that a mere 10% reduction in condom use would, without improvements in testing levels and ART initiation, result in a doubling of HIV incidence over 15 years.