Effectiveness of second-line therapy

Better drugs and improved care means that second-line anti-HIV therapy now has a good chance of offering long-term control of viral load.

Researchers pooled information obtained from 22 cohort studies from around the world.

This analysis showed that soon after potent antiretroviral therapy became available in 1996 – 97 the incidence of virological failure during second-line therapy was 114 cases per 100 person years. This fell to 42 cases per 100 person years in 2000 – 2001. By 2004 – 2005, the rate of second-line treatment failure had fallen to just 15 cases per 100 person years.

But despite these advances in controlling viral load with second-line anti-HIV therapy, the researchers found that the risk of death for patients whose second-line treatment failed remained unaltered between 1996 – 2005.

Anti-HIV therapy working well in developing countries

Studies conducted in resource-limited countries show that anti-HIV therapy is improving the immune systems of treated patients and leading to significant falls in mortality.

The studies showed that antiretroviral treatment programmes have high levels of patient retention – over 90% after twelve months in a Rwandan study.

Antiretroviral-treated patients in the Rwandan study had good improvements in their CD4 cell counts, and a separate study in KwaZulu Natal showed that mortality in patients receiving anti-HIV treatment fell by over 20%.

And analysis of studies conducted in Africa, South America and South East Asia showed that patients who received anti-HIV treatment were experiencing increases in their CD4 cell counts up to five years after starting therapy.

Once daily Kaletra tablets as safe and effective as twice daily doses

The tablet formulation of the protease inhibitor Kaletra (lopinavir/ritonavir) works as well when dosed once daily as twice daily.

After a year patients taking once daily Kaletra(lopinavir 800mg/ritonavir 200mg) tablets were just as likely to have an undetectable viral load as the patients who took the tablets twice daily (two doses of lopinavir 400mg/ritonavir 100mg). Kaletra was taken with Truvada(tenofovir and FTC).

Patients taking Kaletra tablets once and twice a day had similar increases in their CD4 cell counts. Taking the drug once a day did not increase the risk of side-effects, including diarrhoea.

Lymphomas

A study has looked at the risk factors for lymphomas in patients taking anti-HIV treatment.

German researchers found two main risk factors: having a detectable viral load, which increased the risk of Burkitt or Burkitt-like lymphomas; and having a CD4 cell count below 200 cells/mm³ increased the risk of non-Hodgkin’s lymphoma.

It is therefore very important that patients receive treatment with the aim of suppressing viral load to the lowest possible levels, said the researcher who conducted the study.

Drug resistant tuberculosis

Poor infection control, rather than non-adherence to treatment, is often the underlying cause of new cases of drug resistant tuberculosis in South Africa.

Drug resistant tuberculosis is a growing problem around the world, and cases of the infection are now emerging that have resistance to second-line drugs – extensively drug resistant TB (XDR-TB).

Researchers wanted to see why patients were getting drug resistant TB. They therefore conducted a study including patients with a previous history of tuberculosis who were then diagnosed with either multi-drug resistant tuberculosis (MDR-TB) or XDR-TB.

A total of 17 patients were included in the study, most of whom were HIV-positive.

Tests showed that every patient had been reinfected with a drug resistant strain of tuberculosis.

Reinfection with drug resistant tuberculosis had serious consequences – 15 of the patients died within two weeks of the infection being diagnosed.

Good infection control is essential to the control of drug resistant tuberculosis, the researchers emphasise.

Infants acquiring drug resistant HIV

Babies who are infected with HIV by their mother are often acquiring drug resistant strains of the virus, a study has shown. And this resistant virus is often acquired during breastfeeding because levels of anti-HIV drugs in breastmilk are too low to prevent transmission.

Treatment to prevent mother-to-child transmission

Treating HIV-infected mothers with tenofovir and FTC (emtricitabine) for a week after labour in addition to single-dose nevirapine during labour is safe and helps prevent the transmission of nevirapine-resistant virus to babies.

A study presented to CROI included 38 HIV-positive mothers in Africa and Asia. All the women received AZT from the 28^th week of pregnancy to prevent mother-to-child transmission. During labour they also received a single dose of nevirapine as well as tenofovir and FTC. They then received a week of treatment with tenofovir and FTC. Their infants received nevirapine at birth and AZT for the first week of life.

This treatment produced big drops in the mothers’ viral load. None of the infants were infected with drug-resistant virus.

About a quarter of the women experienced side-effects, and adverse events were observed in a similar proportion of infants. But it is likely that many of these were unrelated to the use of anti-HIV drugs.

Children infected with HIV from pre-chewed food

Three children in the US have been infected with HIV after been given pre-chewed food. The food had blood on it from the mouth of the adult caregiver.

HIV-positive caregivers are being warned not to give pre-chewed food to children.

In resource-limited countries pre-chewing of food is common because of a lack of prepared baby food, so pre-chewing may pose a greater risk where there is a high prevalence of HIV and oral health is poor.

Herpes and HIV transmission

Providing anti-herpes treatment to women lowers HIV viral load in both blood and vaginal secretions, a study conducted in Peru shows.

The study involved 20 women who were infected with both HIV and genital herpes (HSV-2). Half the women were given the anti-herpes drug valaciclovir to take every day, the other ten women were given a placebo.

Results showed that valaciclovir reduced HIV viral load in both the blood and in vaginal fluids. It also reduced the shedding of HSV-2.

And a study conducted amongst gay men in the US showed that HIV-positive gay men with HSV-2 were 16 times more likely to pass on HIV to their partner if their partner did not have genital herpes. Suppressing HSV-2 in HIV-positive men could, therefore, reduce the risk of HIV transmission.

These studies come after trials showed that providing anti-herpes treatment did not reduce HIV infections in men or women.  

Serodiscordant relationships: men more likely to be HIV-positive than women, and condom use low

An HIV testing study in Uganda has found that 2% of couples living together involve one partner who is HIV-positive and one who is HIV-negative (often called a serodiscordant relationship).

The study was looking at home-based voluntary counselling and testing (VCT). Trained counsellors visit people at their homes and offer HIV tests. It seems to be a successful way of increasing levels of HIV testing.

In serodiscordant relationships, men were more likely to be infected with than women (55% vs. 33%).

Condom use in these relations was very low, with 94% saying they never used them, meaning that there was a high risk of the uninfected partner acquiring HIV.