Contagiousness in treated HIV-1 infection

BACKGROUND

Effective antiretroviral treatment of HIV-1, defined as continuously undetectable virus in blood, has substantial effects on the infectiousness and spread of HIV.

AIM

This paper outlines the assessment of the Swedish Reference Group for Antiviral Therapy (RAV) and Public Health Agency of Sweden regarding contagiousness of HIV-infected persons on antiretroviral therapy (ART). Results and Conclusion: The expert group concludes that there is no risk of transmission of HIV during vaginal or anal intercourse if the HIV-infected person fulfils the criteria for effective ART. Summary: The effective antiretroviral therapy (ART) for HIV-1 infection has dramatically reduced the morbidity and mortality among people who live with HIV. ART also has a noticeable effect on the infectiousness and on the spread of the disease in society. Knowledge about this has grown gradually. For ART to be regarded effective, the level of the HIV RNA in the plasma should be repeatedly and continuously undetectable and the patient should be assessed as continually having high adherence to treatment. Based on available knowledge the Swedish Reference Group for Antiviral Therapy (RAV) and the Public Health Agency of Sweden make the following assessment: There is no risk of HIV transmission during vaginal or anal intercourse if the HIV positive person fulfils the criteria for effective treatment. This includes intercourse where a condom is not used. However, there are a number of other reasons for recommending the use of condoms, primarily to protect against the transmission of other STIs (sexually transmitted infections) and hepatitis, as well as unwanted pregnancy. The occurrence of other STIs does not affect the risk of HIV transmission in persons on effective ART. It is plausible that the risk for transmission of HIV infection between people who inject drugs and share injection equipment is reduced if the individual with HIV is on effective ART, but there are no studies that directly show this. The risk of transmission from mother to child during pregnancy, labour and delivery is very low if the mother's treatment is initiated well before delivery and if the treatment aim of undetectable virus levels is attained. This is dependent on healthcare services being aware of the mother's HIV infection at an early stage. In most contacts with health and medical care, including dental care, the risk of transmission is not significant if the patient is on effective treatment, but the risk may remain, although considerably reduced, in more advanced interventions such as surgery. When an incident with risk of transmission occurs, the patient must always inform those potentially exposed about his or her HIV infection.

Long-term follow-up of a vaccination program for infants born to HBsAg-positive mothers in Stockholm County, Sweden

We investigated the long-term antibody response to hepatitis B virus (HBV) vaccination in babies born to chronically infected mothers. They received one dose of monovalent HBV vaccination at birth and one month of age, followed by 3 doses of hexavalent vaccine including an HBV component at ages 3, 5, and 12 months, respectively, with a very high percentage of protective anti-HBs levels at 13 months. At the age of 8-12 years, 56 out of 68 children (82%) had protective levels of anti-HBs, two had signs of anti-HBc seroconversion without any history of clinical disease and none had ongoing infection. A small subgroup was retested after one booster dose, in all resulting in increase in anti-HBs from below 10 IU/L to levels corresponding to protective immunity. We conclude that this vaccination strategy is effective throughout the first decade of life in avoiding chronic infection and in maintaining a good serological response.

Low levels of microbial translocation marker LBP are associated with sustained viral response after anti-HCV treatment in HIV-1/HCV co-infected patients

BACKGROUND

Microbial translocation (MT) contributes to immune activation during HIV and HCV infections. We investigated the kinetics of MT markers during anti-HCV and anti-HIV treatments, and if baseline plasma levels of lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP) and soluble CD14 (sCD14) could predict anti-HCV treatment outcome.

METHODS

Plasma from 78 HIV-infected patients was evaluated for LPS, LBP and sCD14. The patients starting anti-HCV treatment (with ongoing antiretroviral (ART) treatment) were categorized into sustained viral responders (SVR; n = 21) or non-responders (NR; n = 15) based on treatment outcome. ART starting subjects--were categorized into chronically HCV-infected (CH; n = 24) and mono-infected (HIV; n = 18), based on the HCV infection status. Samples were collected before start (at baseline) of pegylated-interferon-alpha/ribavirin (peg-IFN/RBV) or antiretroviral-therapy and two years after treatment start (at follow up). χ2-test, non-parametric statistics and logistic regression were applied to determine the associations with treatment response and changes of the soluble markers.

RESULTS

Plasma levels of LPS and sCD14 were elevated in all subjects before antiviral-treatment but remained unchanged at follow-up. Elevated levels of LBP were present in patients with HIV and HIV/HCV co-infection and were reduced by ART. Additionally, higher levels of LBP were present at baseline in NR vs. SVR. Higher levels of LBP at baseline were associated with non-response to peg-IFN/RBV treatment in both bivariate (OR: 0.19 95% CI: 0.06-0.31, p = 0.004) and multivariate analysis (OR: 1.43, 95% CI: 1.1-1.86, p = 0.07).

CONCLUSION

In HIV/HCV co-infected patients high baseline LBP levels are associated with non-response to peg-IFN/RBV therapy. Plasma LBP (decreased by ART) may be a more relevant MT marker than LPS and sCD14.

Occasional spontaneous clearance of chronic hepatitis C virus in HIV-infected individuals

The IL28B genotype has been found to have a strong influence on spontaneous clearance of acute HCV both in HCV mono- and HIV/ the HCV co-infected patients. Spontaneous clearance of chronic HCV without HCV treatment is rare. Here, we report on three chronic HCV cases co-infected with HIV with spontaneous clearance of their HCV infection, all with the IL28B CC genotype. These cases were derived from a surveillance of the total HIV/HCV co-infected cohort in Sweden (n =4 66). The estimated frequency of spontaneous clearance of chronic HCV infection in our cohort was calculated to be 0.6-4.7%. Our cases lend some support to the initiation of ART prior to HCV treatment in HIV/HCV co-infected patients. Furthermore, HCV-RNA testing should be recommended immediately before initiation of HCV treatment, to find the subset of HIV/HCV co-infected patients with IL28B CC that may have cleared their chronic infection spontaneously.

HCV RNA decline in chronic HCV genotype 2 and 3 during standard of care treatment according to IL28B polymorphism

The IL28 gene is highly associated with sustained viral response (SVR) in patients infected with genotype 1 after standard of care (SOC) treatment with peg-IFN and ribavirin. It is also associated with a steeper first phase HCV RNA decline during treatment. In genotype 2 and 3 infections, these correlations are less obvious. We studied the IL28B association to rapid viral response (RVR), SVR, first and second phase HCV RNA decline during treatment in 100 HCV mono-infected and 13 HCV/HIV co-infected patients. We found a significantly higher mean baseline HCV RNA level in IL28B SNP CC than non-CC mono-infected patients, 6.99 vs 6.30 log(10) IU/mL (P = 0.02), and a significantly larger median 1st phase decline in patients with CC than non-CC genotype, 2.03 vs 1.37 log(10) IU/mL, respectively. The overall SVR rate in HCV mono-infected patients was 87% vs 77% in HCV/HIV co-infected patients, with no correlation to IL28B SNP. In mono-infected patients with RVR, the SVR rate was high and independent of IL28B genotype. In mono-infected patients who failed to achieve RVR who had IL28B CC and non-CC genotype, 64% and 67% achieved SVR, respectively. In genotype 2 and 3 infected patients, the 1st phase HCV RNA decline was steeper in patients with IL28B CC vs non-CC genotype during SOC treatment. This did not translate into a higher frequency of RVR or SVR. Hence, the clinical relevance of pretreatment analysis of IL28B polymorphisms in genotype 2 and 3 infected patients can be questioned in patients with expected high SVR rate.

Hepatitis B seroprevalence in persons attending youth clinics in Stockholm, Sweden in 2008

Sweden is a low endemicity country for hepatitis B virus (HBV). The previously reported prevalence of chronic HBV is <1% and of overall markers <5%. HBV is not included in the universal childhood vaccination programme. Instead, selected high-risk groups are targeted. Our aim was to examine the HBV seroprevalence in youth clinic clients in Stockholm and identify if this population might be a new target group for vaccination. In total, 515 clients aged 18–22 years were recruited. They completed a risk-assessment questionnaire and 464 (90%) had a serum specimen tested for HBV serology. Chronic HBV was found in 0.6% and 0.9% had previously been infected with HBV. A seroprevalence of 1.8% HBV markers was found among non-vaccinated persons. This is lower than reported from other countries and not different from the general population in Sweden. However, in persons originating from HBV endemic countries ( n = 123), the prevalence was higher, 6.5%. Only 14% were vaccinated and the majority hence susceptible to HBV. The target groups are not reached by the present vaccination strategy. Youth clinics are ideal settings for catch-up vaccination.