VISITECT CD4: Omega’s offering for ART

HIV is a major global health challenge affecting approximately 33 million people worldwide. Five million new cases are reported every year, mainly in the developing world. It remains the primary cause of global disease burden in 12 countries including South Africa and India, where access to healthcare is often limited.

Treatment initiation

Antiretroviral therapy (ART) is a possible treatment option to help prevent the loss of immune function that occurs as the disease progresses. Determining the CD4 count is a vital component in the management and care of HIV-positive patients and is required to assess their candidacy for ART initiation. WHO guidelines (2009) recommend that once the CD4 count falls below 350 cells/µl, the patient should commence therapy and their health-during-treatment be monitored every three to six months. While 6.6 million people are receiving ART in low- and middle-income countries, this is less than half of those needing treatment (UNAIDS World AIDS day report, 2011). This equates to a growing demand for CD4 testing based on the number of individuals still in need, together with those currently on ART.

Diagnostic challenges

Availability of diagnostic testing is one of the major obstacles to timely, high-quality HIV treatment. Typically, CD4 counts are measured in laboratories using flow cytometry. Expensive and sophisticated equipment is needed, as well as highly trained personnel, a clean water supply and cold storage for reagents, necessitating the test to be carried out in centralised locations. Delays between testing and obtaining results can also lead to a significant ‘loss to follow up’ and often patients do not return to receive life-saving treatment.

In addition, the majority of non-reference laboratories and clinics in countries most affected by HIV cannot regularly monitor CD4 counts and access to testing can be difficult or even impossible in rural areas. Benchtop analysers have been developed for use in rural communities, but issues with electricity, maintenance, logistics and training are still a major concern and limit their uptake in rural areas. CD4 testing remains the bottleneck of ART initiation and without timely CD4 testing, ART initiation is hindered, often resulting in an irreversible compromise to the immune system.

Point-of-care testing

VISITECT CD4 is a ground-breaking, disposable, point-of-care test for the determination of CD4 counts in whole blood. Developed by the Burnet Institute in Melbourne, Australia, it is based on proven lateral flow technology and provides an affordable, convenient, instrument-free solution for laboratories and remote clinics worldwide, enabling ART therapy to become accessible to every HIV-infected patient. It is manufactured and marketed by Omega Diagnostics Group.

Features

• Finger-prick blood sampling
• Instrument-free testing
• Visual ‘TREAT’ or ‘NO TREAT’ result
• Results obtained in 40 minutes
• Proven lateral flow technology
• Convenient and easy-to-use
• Room temperature storage
• Affordable, low cost
• Perform multiple tests at one time

Results

Results are interpreted visually by comparing the colour intensity of the Test

(T) line with the Reference (350) line:

• T line EQUAL / WEAKER than 350 line: CD4 count is =350/µl Presumptive interpretation is ‘TREAT’
• T line STRONGER than 350 line: CD4 count is >350/µl Presumptive interpretation is ‘NO TREAT’
• C line ABSENT/BROKEN/ IRREGULAR: Interpretation is ‘INVALID’ Repeat the test

– Andrew Shepherd, Founder & CEO, Omega Diagnostics