A new report from independent market analyst, Datamonitor's, reveals that the rate of Hepatitis B (HBV) co-infection in HIV infected individuals is increasing among the seven major markets (Japan, US, France, Italy, UK, Germany, Spain), with an average incidence of 7 per cent.

The advent of Highly Active Antiretroviral Therapy (HAART) has led toincreased longevity in those infected with HIV and shared epidemiological risk increases the likelihood of these individuals contracting HBV. Although HBV has little impact on HIV disease progression, HIV renders HBV more aggressive and frequent, with co-infected individuals eight times more likely to die of liver damage-related mortality.

Datamonitor reveals that inadequate diagnosis of concurrent disease states, lack of effective HBV treatment and HAART hepatoxicity all have a great impact on the effective management of this niche population. Datamonitor recommends that development of HBV antivirals, preferably with dual HIV and HBV efficacy, would address the obvious gap in treating this co-morbid population, providing an additional opportunity for companies to capitalize on the HIV mono-infected market.

HIV chronicity induced by effective HAART regimes raises co-morbid HBV rates

Long-term usage of HAART for the management of HIV has decreased mortality among the HIV-infected population, although this has consequently led to an increasing prevalence of chronic co-infections such as Hepatitis B (HBV) and Hepatitis C (HCV). HBV is 50 to 100 times more infectious than HIV (WHO Hepatitis B guidelines, 2003) and indeed, the likelihood of HIV-infected individuals contracting HBV is 3-6 times greater than non-infected individuals (Bodsworth, 1991). Disease progression of HIV is usually unaltered by co-infection with HBV; although HBV is more frequent and aggressive among the HIV-infected population, resulting in increased incidence of liver damage-related mortality. With increasing access to HAART therapy in both the developed and developing world, Datamonitor believes there is likely to be a concurrent increase in the incidence of HIV/HBV co-infection in the short-to-medium term, although this rate is unlikely to exceed the growth rate observed in HIV mono-infection.

One of Datamonitor's key findings was the lack of awareness and recognition of this co-infected state by both physicians and patients. Early diagnosis of the co-morbid population is affected by physicians' ignorance mainly due to the scarcity of comprehensive treatment guidelines. Datamonitor also found that, within different markets, co-morbid patients were presenting and receiving treatment through a variety of routes within their respective healthcare systems; an additional issue with negative implications for patients' effective management. Datamonitor warns that concurrent early diagnosis of both HIV and HBV disease states is essential to increasing the life span of this co-morbid population. Confirming the presence of both viruses ensures optimum treatment from the onset, thus improving patient prognosis at later stages.

HBV co-infection acts as an additional economic burden to an already expensive HIV HAART regimen (approximately $10,000 per patient in the US). It is therefore more cost-effective to vaccinate the HIV/HBV co-infected population, rather than manage HBV infection with expensive antiviral and immunomodulator therapies. Although HBV vaccines have reduced efficacy in HIV-infected patients, they could still diminish co-infection prevalence.

Based on key opinion leader findings, Datamonitor suggests several actionable points, the first being that the majority of those co-infected with HIV/HBV, i.e. HIV-infected high-risk groups such as intravenous drug users (IVDUs)), be further targeted for diagnosis, vaccination and treatment to minimize infection. This could also be extended to new immigrants in Western regions. Although immigration of HBV infected individuals from endemic countries was thought to have little impact on the general population, it is likely to affect those same high-risk groups. Western markets, such as the UK, with a high degree of immigration from sub-Saharan Africa should therefore reconsider their HBV vaccination guidelines. They should also be aware of the 'relapse' in the male homosexual population with regard to the transmission of parenteral viruses, although this is thought to be relatively rare for HBV.