Offer baseline resistance tests to newly diagnosed UK immigrants, warn Brighton clinicians

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The case of a Zimbabwean man who was treated with Combivir/efavirenz for his newly-diagnosed HIV infection in Brighton, but who was already resistant to nucleoside analogues due to undisclosed Combivir treatment prior to arriving in the UK, highlights the need to provide baseline resistance tests to newly-diagnosed immigrants, argue two clinicians from Brighton and Sussex University Hospitals in the latest issue of the Journal of Sexually Transmitted Infections.

The 47-year-old man was admitted to the Royal Sussex County Hospital in August 2001 with pneumonia, and recovered after antibiotic treatment. After reporting that he had twice received TB treatment, and testing positive for HIV with a baseline CD4 count of 20 cells/mm3 and a viral load of 134,000 copies/ml, he was started on Combivir (AZT/3TC) and efavirenz, and had a good initial viral load reduction to 1230 copies/ml within two weeks.

However, at six weeks his viral load rebounded to 71,000 despite his claiming 100% adherence, and he was admitted to the local respite unit for directly observed therapy (DOT). However, after two weeks of DOT, his viral load had increased to 240,000 copies/ml.

Glossary

resistance testing

Laboratory testing to determine if an individual’s HIV strain is resistant to anti-HIV drugs. 

directly observed therapy (DOT)

When a health care professional watches as a person takes each dose of a medication, to verify that all doses are taken as prescribed.

nucleoside

A precursor to a building block of DNA or RNA. Nucleosides must be chemically changed into nucleotides before they can be used to make DNA or RNA. 

genotypic resistance testing

In HIV, genotypic resistance tests are assays that identify mutations of the virus that can confer antiretroviral drug resistance. Resistance testing can be used to guide selection of an HIV regimen when initiating or changing antiretroviral therapy (ART). 

drug resistance

A drug-resistant HIV strain is one which is less susceptible to the effects of one or more anti-HIV drugs because of an accumulation of HIV mutations in its genotype. Resistance can be the result of a poor adherence to treatment or of transmission of an already resistant virus.

A genotypic resistance test revealed the following mutations: K65R, D67N, K70R, K103N, M184V, G190A, T215F, K219Q, suggesting extensive resistance to nucleoside analogues and to all non-nucleosides.

The man continued to maintain that he had not undergone HIV testing or treatment in Zimbabwe, but identified Combivir tablets as part of his previous anti-TB regime. Genotypic resistance testing of his archived baseline plasma sample confirmed that he had carried resistance mutations to AZT/3TC prior to beginning HAART in the UK.

Four weeks after beginning a salvage regimen of ddI/tenofovir/Kaletra/Invirase the man’s viral load dropped to 1350 copies/ml.

The authors write that “it remains uncertain whether in this case the individual had been aware of his HIV status. It is possible that antiretroviral medications may have been included as part of an unorthodox anti-tuberculosis regimen, given the high co-infection rate in Zimbabwe, without the individual having been informed. Alternatively, the individual may have been unwilling to disclose his status for fear of rejection of his legal claim to stay in the United Kingdom or for other sociocultural reasons.”

Current BHIVA guidelines only recommend resistance testing prior to suspected transmitted drug resistance, and the authors “strongly suggest” that “baseline resistance testing should be routinely considered”. They also recommend that closer questioning of UK immigrants with a ‘new’ HIV diagnosis should take place regarding previous testing and treatment.

Further information on this website

BMJ exposes serious weaknesses in case for compulsory HIV/TB tests for UK immigrants - news story

Labour warned to think again on compulsory HIV tests for immigrants - news story

UK government announces plans to restrict NHS care for non-UK nationals - news story

NHS & non-UK nationals - fact sheet

References

Natarajan UR, et al. Unexpected resistance in an African immigrant: lessons for the unwary. Sex Transm Infect 80:151–156, 2004.