Kenya, Uganda VCTs turning in thousands of false HIV-positives

Hundreds — or even thousands — of Kenyans and Ugandans may have been told that they are infected with HIV when they are not, thanks to faulty rapid, 15-minute tests administered at VCT centres.

Many others may have wrongly been declared negative, clearing them for unprotected sex, when they actually are HIV-positive.

That is the worrying conclusion of a study involving 6,255 people carried out in Uganda and Kenya, which bluntly says that the misuse of rapid tests at most VCT centres makes them fraught with error and that they cannot by themselves alone determine whether one is HIV-positive or not.

The three HIV rapid tests which were evaluated in the study, the findings of which appear in a recent issue of the East African Medical Journal, were Determine by Abbott Laboratories, Uni-Gold by Trinity Biotech of Ireland and Capillus, also by Trinity Biotech.

The tests are widely used in poor countries because they are cheap. Each HIV screening with the tests costs about one dollar, compared with about $40 using the much more reliable PCR test, which is considered the gold standard.

The East African Medical Journal is published by the Kenya Medical Association.

In Kenya, according to Dr Peter Cherutich, Assistant Director of Medical Services at the Ministry of Health and head of HIV prevention at NASCOP, the National Aids/STI Control Council, the three most used rapid tests are Determine, Bioline from SD Bioline of South Korea and Uni-Gold. The first two are usually used as first-line tests while Uni-Gold is confirmatory.

The risk of HIV misdiagnosis using the rapid tests rises substantially when they are used once, without the benefit of a confirmatory test. This practice is thought to be rampant, especially at VCT sites outside medical facilities, which are usually manned by non-medical staff.

In Kenya, according to Dr Cherutich, the requirement for one to work at a VCT site is a secondary education and three weeks’ training in the administration of the tests.

Results from the Kenya-Ugandan study, which involved men aged between 18 and 60 seeking VCT services from a rural village in Masaka and the Kakira sugar plantation, both in Uganda, as well as a coastal village in Kilifi, and the Nairobi slum of Kangemi, confirm that there are important issues of quality assurance and dependability of results obtained using the rapid tests.

When used as a single test in Masaka, for example, Determine was able to correctly identify only 45.70 per cent of those infected with HIV as carrying the virus.

This means that out of every 100 HIV-positive people, 54 could actually have walked out of the VCT centre thinking they were HIV-negative, when in actual fact they were not, if they were not advised to take a confirmatory test.

In Kakira, the same test only captured 65.71 per cent of the infections, while the Capillus test captured 86.62 per cent of infections at the same location.

When two different tests were administered on all 6,255 subjects, a total of 131 people had “discrepant results” — where one was positive and the other negative.

Using a third confirmatory test, 27 of the subjects were finally confirmed to be carrying the virus, meaning that without such controls and using just one test, 104 people could have been told they were HIV-positive when they were not.