OMEGA Diagnostics has increased first half profits by 32 per cent but hit further problems with the Visitect HIV-testing kit for which it has high hopes.

The chairman of the company, David Evans, told investors: "We share your frustration with the inevitable delay that is occurring with Visitect® CD4 since the last trading update."

Alva-based Omega believes the test could help revolutionise the care of people with HIV in developing countries by providing a quick method of finding out if their white-blood-cell counts have fallen to levels where retroviral drug treatment is needed.

In the update issued in October, the company said it did not expect to receive any revenues from the Visitect CD4 test in the current year after recording "sub-optimal performance" in an evaluation of the product in Kenya.

The company said then it did not expect to be able to start further laboratory work in Kenya until late January 2015.

Announcing that underlying pre-tax profits increased to £0.56 million in the six months to September, from £0.43m last time, Omega said subsequent batches of manufactured product had yielded variable results when tested on patient blood samples.

The AIM-listed company has decided to adopt a new approach with the aim of commercialising the technology, which was developed by Australia's Burnet Institute, within the shortest timeframe.

This includes bringing control of the outsourced manufacturing process back in-house on a temporary basis. Omega will also look afresh at how the test is manufactured by the Burnet Institute and how that process could be scaled up.

The company said it could not predict when Visitect would be ready for commercial launch.

However, Mr Evans said: "Despite the setback, we continue to receive feedback from the HIV/Global Health arena that convinces us that the market opportunity and outlook for CD4 remains undiminished."

The company said the trading performance of its core business had proved resilient overall in the face of certain headwinds, including some raw material supply delays.

Turnover increased to £5.7m in the first half, from £5.6m.

Noting the core business is generating cash, finance director Kieron Harbinson highlighted strong growth in the food intolerance testing division. This grew revenues to £3.5m from £2.7m last time.

Omega employs 45 staff in Alva out of a global total of 155.

Following the update in October house broker finnCap reduced its estimate for adjusted profit before tax for the current year by 20 per cent, to £1.2m. Omega made £1.1m in the year to March.