Tanya Welz - Academia.edu (original) (raw)
Papers by Tanya Welz
Introduction to Human Immunodeficiency Virus
Improvement in screening for sexually transmitted infections in HIV-positive patients following implementation of a nurse-led clinic
International Journal of Std & Aids, Jun 1, 2007
The objective of this study was to assess changes in the uptake of sexually transmitted infection... more The objective of this study was to assess changes in the uptake of sexually transmitted infection (STI) screening resulting from implementation of a specific STI clinic for HIV-positive patients. An audit of STI screening in HIV-positive patients was undertaken before and after the establishment of the clinic. Significant increases in the number of patients having a sexual health discussion and annual health screen were seen. High rates of positive results were found in all patient groups. National guidelines recommend regular STI screening for all HIV-positive patients. A specific clinic for HIV-positive patients is feasible and acceptable and may result in an increase in uptake of STI screening.
AIDS, Jul 31, 2010
Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associate... more Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associated with severe vitamin D deficiency (VDD) in HIV-infected individuals and to explore the effects of severe VDD and antiretroviral drug exposure on serum alkaline phosphatase (ALP) as surrogate marker of bone turnover. Design: Cross-sectional survey of vitamin D status among HIV-infected patients attending for routine clinical care at a large London HIV clinic. Methods: Severe VDD was defined as 25(OH)D levels of less than 10 mg/l (<25 nmol/l). Multivariate logistic regression analysis was used to identify factors associated with severe VDD and upper quartile ALP levels. Results: Vitamin D levels were measured in 1077 patients and found to be suboptimal in 91%. One-third of patients had severe VDD. Black ethnicity, sampling in winter, nadir CD4 cell count less than 200 cells/ml, and exposure to combination antiretroviral therapy were associated with severe VDD. In analyses restricted to patients on combination antiretroviral therapy, current efavirenz use was significantly associated with severe VDD [adjusted odds ratio 2.0 (95% confidence interval 1.5-2.7)]. Current tenofovir [adjusted odds ratio 3.5 (95% confidence interval 2.3-5.2)] and efavirenz use [adjusted odds ratio 1.6 (95% confidence interval 1.02-2.4)], but not severe VDD [odds ratio 1.1 (0.8-1.5)], were associated with increased bone turnover (upper quartile ALP). Conclusion: Efavirenz was associated with severe VDD, a condition associated with multiple adverse health outcomes, and efavirenz and tenofovir with increased ALP. The clinical significance of these findings requires further investigation, given the widespread use of efavirenz and tenofovir in first-line combination antiretroviral therapy.
Dried blood spot technology for CD4+ T-cell counting
The Lancet, Mar 1, 2004
... The ELISA TRAx test kit they used, which was developed by a now-defunct company, is no longer... more ... The ELISA TRAx test kit they used, which was developed by a now-defunct company, is no longer commercially available, making it difficult to reproduce their results. ... Helper T-lymphocyte count: TRAx CD4 test kit versus conventional flow cytometry. ...
Sexual behaviour, condom use and rates of sexually transmitted infections in HIV clinic attendees in South East London
International Journal of Std & Aids, Nov 1, 2009
The aim of this study was to examine sexual behaviour, condom use and rates of sexually transmitt... more The aim of this study was to examine sexual behaviour, condom use and rates of sexually transmitted infections (STIs) among attendees at a dedicated on-site STI clinic at a South London HIV centre. Data were prospectively collected by using a nurse-completed questionnaire. Ninety-eight percent of women reported one or no sexual partners in the preceding three months, whereas 57% of men who have sex with men (MSM) reported two or more partners. Only 28% of women, 53% of heterosexual men and 29% of MSM always used a condom for vaginal or anal intercourse. Positive STI diagnoses were found in 17.5% of women, 20% of heterosexual men and 49% of MSM. Twenty percent of patients who reported always using a condom and 38% of MSM reporting no sexual activity in the preceding three months had an STI. These results highlight the need for safe sex promotion and STI screening in HIV-infected patients regardless of self-reported sexual activity.
Sexually Transmitted Infections, Sep 28, 2010
positivity rates in other healthcare services, such as general practices and prison clinics. Sent... more positivity rates in other healthcare services, such as general practices and prison clinics. Sentinel surveillance of HIV testing in multiple laboratories would also provide the opportunity to assess local and national trends in testing over time, both overall and in specific service types. Locally, such data may be used to investigate patterns of service use by different demographic groups and to evaluate changes in testing in response to local initiatives, such as awareness campaigns or new guidelines for healthcare professionals. We conclude that sentinel laboratory surveillance of HIV testing should be prioritised in order to monitor and improve our understanding of patterns of HIV testing in the UK and to inform local and national policy. Acknowledgements We would like to acknowledge the contribution of the laboratory staff and clinicians of the Leeds and Bradford Pathology Partnership, who carried out testing and provided data. We would also like to thank Darren Lyons for his work on data extraction and processing, and Brian Rice for his assistance with the HIV new diagnoses database. Funding The resources for this pilot study were drawn from existing staffing and funds provided by the English Department of Health. The funding body did not have any involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.
HIV Medicine, 2016
ObjectivesDolutegravir (DTG), a second‐generation integrase strand transfer inhibitor (INSTI), is... more ObjectivesDolutegravir (DTG), a second‐generation integrase strand transfer inhibitor (INSTI), is now among the most frequently used antiretroviral agents. However, recent reports have raised concerns about potential neurotoxicity.MethodsWe performed a retrospective analysis of a cohort of HIV‐infected patients who had initiated an INSTI in two large German out‐patient clinics between 2007 and 2016. We compared discontinuation rates because of adverse events (AEs) within 2 years of starting treatment with dolutegravir, raltegravir or elvitegravir/cobicistat. We also evaluated factors associated with dolutegravir discontinuation.ResultsA total of 1950 INSTI‐based therapies were initiated in 1704 patients eligible for analysis within the observation period. The estimated rates of any AE and of neuropsychiatric AEs leading to discontinuation within 12 months were 7.6% and 5.6%, respectively, for dolutegravir (n = 985), 7.6% and 0.7%, respectively, for elvitegravir (n = 287), and 3.3% a...
HIV Medicine, 2017
We thank Capetti and colleagues for their interesting comments [1] which suggest that morning dos... more We thank Capetti and colleagues for their interesting comments [1] which suggest that morning dosing may help resolve dolutegravir (DTG)-related insomnia and sleep disorders. In our retrospective study [2], we had no information on the timing of DTG administration in most of our patients. However, in our experience, patterns of adverse events leading to DTG discontinuation were heterogeneous and not limited to sleep disorders. They included dizziness, depression, headache, paraesthaesia, poor concentration and slow thinking. Although relatively rare, reversible and usually mild to moderate, these events were less frequently seen with elvitegravir or raltegravir. Since our initial publication, we have seen additional patients complaining of dizziness or cognitive problems 1-2 h after DTG intake, suggesting that peak plasma levels may be too high in these individuals. Other groups from the Netherlands [3], Italy [4,5] and France [6] have also reported unexpected adverse events with DTG. These include anxiety, irritability and depression but also headache and musculoskeletal pain. In these patients, it seems unlikely that a switch to morning dosing would resolve neuropsychiatric symptoms. Of note, Capetti and colleagues have confirmed our observations that neuropsychiatric events were more frequent in older and in female patients, suggesting a pharmacokinetic problem. Indeed, recent pharmacokinetic studies have found higher drug exposure in older patients [7,8] but also in patients treated with atazanavir or cobicistat [9,10]. We believe that there is an urgent need for more data on drug levels in these patient populations, especially in individuals who develop neuropsychiatric events. Capetti and colleagues' univariate analysis did not find a higher event rate with abacavir use. This is in contrast to our findings and those of other studies [3,4] and it is debatable whether currently available data are sufficient to exclude a drugÀdrug interaction between abacavir and DTG [11,12].
Drug Interactions in the Treatment of Malignancy in HIV-Infected Patients
Oncology Research and Treatment, 2017
The number of patients with HIV (human immunodeficiency virus) requiring treatment for malignancy... more The number of patients with HIV (human immunodeficiency virus) requiring treatment for malignancy is increasing worldwide. Concurrent treatment of HIV and malignancy is complicated by unpredictable drug-drug interactions, which can cause potentially life-threatening toxicities and ineffective treatment of either disease. This article aims to provide a practical approach to drug interactions and their management in this context to help deliver effective and safe treatment of both the malignancy and HIV.
Population-based and ANC sentinel-surveillance age-specific HIV prevalence estimates
<b>Copyright information:</b>Taken from "Population and antenatal-based HIV prev... more <b>Copyright information:</b>Taken from "Population and antenatal-based HIV prevalence estimates in a high contracepting female population in rural South Africa"http://www.biomedcentral.com/1471-2458/7/160BMC Public Health 2007;7():160-160.Published online 18 Jul 2007PMCID:PMC1948890.
The HIV pandemic is one of the greatest threats to human health in history. r Seventy per cent of... more The HIV pandemic is one of the greatest threats to human health in history. r Seventy per cent of worldwide deaths from AIDS occur in sub-Saharan Africa. r Without treatment for HIV, worsening immunocompromise leads to the development of opportunistic infections and certain cancers. r Factors associated with more rapid HIV disease progression include older age, poor nutrition and co-infection with tuberculosis and hepatitis C. r Preventative strategies, such as behaviour change, screening of blood products, postexposure prophylaxis and treatment of HIV during pregnancy, help decrease rates of HIV transmission. r Improved access to treatment worldwide has reduced the annual number of HIVassociated deaths and may also reduce the number of new HIV infections globally.
AIDS, 2010
Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associate... more Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associated with severe vitamin D deficiency (VDD) in HIV-infected individuals and to explore the effects of severe VDD and antiretroviral drug exposure on serum alkaline phosphatase (ALP) as surrogate marker of bone turnover. Design: Cross-sectional survey of vitamin D status among HIV-infected patients attending for routine clinical care at a large London HIV clinic. Methods: Severe VDD was defined as 25(OH)D levels of less than 10 mg/l (<25 nmol/l). Multivariate logistic regression analysis was used to identify factors associated with severe VDD and upper quartile ALP levels. Results: Vitamin D levels were measured in 1077 patients and found to be suboptimal in 91%. One-third of patients had severe VDD. Black ethnicity, sampling in winter, nadir CD4 cell count less than 200 cells/ml, and exposure to combination antiretroviral therapy were associated with severe VDD. In analyses restricted to patients on combination antiretroviral therapy, current efavirenz use was significantly associated with severe VDD [adjusted odds ratio 2.0 (95% confidence interval 1.5-2.7)]. Current tenofovir [adjusted odds ratio 3.5 (95% confidence interval 2.3-5.2)] and efavirenz use [adjusted odds ratio 1.6 (95% confidence interval 1.02-2.4)], but not severe VDD [odds ratio 1.1 (0.8-1.5)], were associated with increased bone turnover (upper quartile ALP). Efavirenz was associated with severe VDD, a condition associated with multiple adverse health outcomes, and efavirenz and tenofovir with increased ALP. The clinical significance of these findings requires further investigation, given the widespread use of efavirenz and tenofovir in first-line combination antiretroviral therapy.
Sexually Transmitted Infections, 2006
To evaluate the effectiveness of interventions to prevent mother-to-child transmission of HIV at ... more To evaluate the effectiveness of interventions to prevent mother-to-child transmission of HIV at a large teaching hospital in South East London, and to assess reasons for the small numbers of transmissions that continue to occur. Design: A database of all pregnant women diagnosed as HIV positive between 1993 and 2005 was reviewed, with detailed (retrospective) case-note review of all mother-infant pairs where HIV transmission occurred. Setting: King's College Hospital, London, UK, a teaching hospital serving an ethnically diverse and socially deprived population. Results: 296 pregnancies to 274 women were recorded. 9 of 296 (3.0%) women were lost to follow-up before the end of the pregnancy. Of 287 pregnancies followed up until after delivery, 6 (2.1%) resulted in HIV infection in the infant. More recently, between 2000 and 2004, this transmission rate was even lower, at 3 in 231 (1.3%). Each of these six women had complications, including late presentation to services and defaulting follow-up appointments, which were likely to increase the risk of HIV transmission. Four of the six transmissions occurred in utero. Conclusion: The overall transmission rate of 2% attests to the efforts of the multidisciplinary care team in managing this population which is often hard to reach. Clearly, good systems are needed to trace those women who default. Further data are needed regarding in utero transmissions.
Drug Interactions in the Treatment of Malignancy in HIV-Infected Patients
Oncology Research and Treatment
Do nevirapine and efavirenz affect vitamin D homeostasis similarly?
Aids, Mar 1, 2011
Surveillance of HIV testing: where should we go next?
Sexually Transmitted Infections, Oct 1, 2010
... Tanya Welz. Correspondence to Dr Tanya Welz, Department of HIV/Genitourinary medicine, Caldec... more ... Tanya Welz. Correspondence to Dr Tanya Welz, Department of HIV/Genitourinary medicine, Caldecot Clinic, Kings College Hospital NHS Trust, Caldecot Road, London SE5 9RS, UK ... BMJ 2006;332:3324. [Abstract/FREE Full text]. ↵: Gauthier A,; Breuer J,; Carrington D,; et al. . ...
Mwaba and colleagues are exploring the resurrection of a flawed design that would offer an inferi... more Mwaba and colleagues are exploring the resurrection of a flawed design that would offer an inferior testing option and the danger of clinical misinterpretation. As Mwaba and colleagues say, we should all focus on developing not-for-profit, simple, lowtech, quality assured methods for improved management of HIV-infected patients. However, the lack of evidence presented to support dried blood-spot technology and the achievements of the new CD4 counting methods 5 suggest that progress is more likely to come from flow cytometry and analytical image systems that properly discriminate between lymphocytes and monocytes. 2,5
Introduction to Human Immunodeficiency Virus
Pribram/Nutrition and HIV, 2010
Tropical Medicine and International Health, 2005
Many countries in Africa are planning to provide highly active antiretroviral therapy (HAART) to ... more Many countries in Africa are planning to provide highly active antiretroviral therapy (HAART) to millions of people with acquired immune deficiency syndrome. This will be a highly complex therapy programme. Physician-based models of care adapted from industrialized countries will not succeed in providing treatment to the majority of those who need it in resource-constrained settings. A high priority is to identify care models for Africa that will increase coverage of HAART safely and effectively: key issues are (i) whether nursing staff or non-clinically qualified staff can take the major role in the treatment programme and reduce the workload of physicians, (ii) whether treatment and monitoring can be delivered through peripheral health centres or through home visits and achieve better adherence and be more cost-effective than delivery at hospitals and (iii) which clinical algorithms used by nursing or non-clinically qualified staff will be effective for screening, diagnosing and managing treatment-related side-effects and medical problems being incurred. Many current ART support programmes are making little or no investment in research, but answering important questions on delivery of HAART will be essential if HAART programmes are to be successful in African nations with a high burden of human immunodeficiency virus infection.
Introduction to Human Immunodeficiency Virus
Improvement in screening for sexually transmitted infections in HIV-positive patients following implementation of a nurse-led clinic
International Journal of Std & Aids, Jun 1, 2007
The objective of this study was to assess changes in the uptake of sexually transmitted infection... more The objective of this study was to assess changes in the uptake of sexually transmitted infection (STI) screening resulting from implementation of a specific STI clinic for HIV-positive patients. An audit of STI screening in HIV-positive patients was undertaken before and after the establishment of the clinic. Significant increases in the number of patients having a sexual health discussion and annual health screen were seen. High rates of positive results were found in all patient groups. National guidelines recommend regular STI screening for all HIV-positive patients. A specific clinic for HIV-positive patients is feasible and acceptable and may result in an increase in uptake of STI screening.
AIDS, Jul 31, 2010
Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associate... more Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associated with severe vitamin D deficiency (VDD) in HIV-infected individuals and to explore the effects of severe VDD and antiretroviral drug exposure on serum alkaline phosphatase (ALP) as surrogate marker of bone turnover. Design: Cross-sectional survey of vitamin D status among HIV-infected patients attending for routine clinical care at a large London HIV clinic. Methods: Severe VDD was defined as 25(OH)D levels of less than 10 mg/l (<25 nmol/l). Multivariate logistic regression analysis was used to identify factors associated with severe VDD and upper quartile ALP levels. Results: Vitamin D levels were measured in 1077 patients and found to be suboptimal in 91%. One-third of patients had severe VDD. Black ethnicity, sampling in winter, nadir CD4 cell count less than 200 cells/ml, and exposure to combination antiretroviral therapy were associated with severe VDD. In analyses restricted to patients on combination antiretroviral therapy, current efavirenz use was significantly associated with severe VDD [adjusted odds ratio 2.0 (95% confidence interval 1.5-2.7)]. Current tenofovir [adjusted odds ratio 3.5 (95% confidence interval 2.3-5.2)] and efavirenz use [adjusted odds ratio 1.6 (95% confidence interval 1.02-2.4)], but not severe VDD [odds ratio 1.1 (0.8-1.5)], were associated with increased bone turnover (upper quartile ALP). Conclusion: Efavirenz was associated with severe VDD, a condition associated with multiple adverse health outcomes, and efavirenz and tenofovir with increased ALP. The clinical significance of these findings requires further investigation, given the widespread use of efavirenz and tenofovir in first-line combination antiretroviral therapy.
Dried blood spot technology for CD4+ T-cell counting
The Lancet, Mar 1, 2004
... The ELISA TRAx test kit they used, which was developed by a now-defunct company, is no longer... more ... The ELISA TRAx test kit they used, which was developed by a now-defunct company, is no longer commercially available, making it difficult to reproduce their results. ... Helper T-lymphocyte count: TRAx CD4 test kit versus conventional flow cytometry. ...
Sexual behaviour, condom use and rates of sexually transmitted infections in HIV clinic attendees in South East London
International Journal of Std & Aids, Nov 1, 2009
The aim of this study was to examine sexual behaviour, condom use and rates of sexually transmitt... more The aim of this study was to examine sexual behaviour, condom use and rates of sexually transmitted infections (STIs) among attendees at a dedicated on-site STI clinic at a South London HIV centre. Data were prospectively collected by using a nurse-completed questionnaire. Ninety-eight percent of women reported one or no sexual partners in the preceding three months, whereas 57% of men who have sex with men (MSM) reported two or more partners. Only 28% of women, 53% of heterosexual men and 29% of MSM always used a condom for vaginal or anal intercourse. Positive STI diagnoses were found in 17.5% of women, 20% of heterosexual men and 49% of MSM. Twenty percent of patients who reported always using a condom and 38% of MSM reporting no sexual activity in the preceding three months had an STI. These results highlight the need for safe sex promotion and STI screening in HIV-infected patients regardless of self-reported sexual activity.
Sexually Transmitted Infections, Sep 28, 2010
positivity rates in other healthcare services, such as general practices and prison clinics. Sent... more positivity rates in other healthcare services, such as general practices and prison clinics. Sentinel surveillance of HIV testing in multiple laboratories would also provide the opportunity to assess local and national trends in testing over time, both overall and in specific service types. Locally, such data may be used to investigate patterns of service use by different demographic groups and to evaluate changes in testing in response to local initiatives, such as awareness campaigns or new guidelines for healthcare professionals. We conclude that sentinel laboratory surveillance of HIV testing should be prioritised in order to monitor and improve our understanding of patterns of HIV testing in the UK and to inform local and national policy. Acknowledgements We would like to acknowledge the contribution of the laboratory staff and clinicians of the Leeds and Bradford Pathology Partnership, who carried out testing and provided data. We would also like to thank Darren Lyons for his work on data extraction and processing, and Brian Rice for his assistance with the HIV new diagnoses database. Funding The resources for this pilot study were drawn from existing staffing and funds provided by the English Department of Health. The funding body did not have any involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.
HIV Medicine, 2016
ObjectivesDolutegravir (DTG), a second‐generation integrase strand transfer inhibitor (INSTI), is... more ObjectivesDolutegravir (DTG), a second‐generation integrase strand transfer inhibitor (INSTI), is now among the most frequently used antiretroviral agents. However, recent reports have raised concerns about potential neurotoxicity.MethodsWe performed a retrospective analysis of a cohort of HIV‐infected patients who had initiated an INSTI in two large German out‐patient clinics between 2007 and 2016. We compared discontinuation rates because of adverse events (AEs) within 2 years of starting treatment with dolutegravir, raltegravir or elvitegravir/cobicistat. We also evaluated factors associated with dolutegravir discontinuation.ResultsA total of 1950 INSTI‐based therapies were initiated in 1704 patients eligible for analysis within the observation period. The estimated rates of any AE and of neuropsychiatric AEs leading to discontinuation within 12 months were 7.6% and 5.6%, respectively, for dolutegravir (n = 985), 7.6% and 0.7%, respectively, for elvitegravir (n = 287), and 3.3% a...
HIV Medicine, 2017
We thank Capetti and colleagues for their interesting comments [1] which suggest that morning dos... more We thank Capetti and colleagues for their interesting comments [1] which suggest that morning dosing may help resolve dolutegravir (DTG)-related insomnia and sleep disorders. In our retrospective study [2], we had no information on the timing of DTG administration in most of our patients. However, in our experience, patterns of adverse events leading to DTG discontinuation were heterogeneous and not limited to sleep disorders. They included dizziness, depression, headache, paraesthaesia, poor concentration and slow thinking. Although relatively rare, reversible and usually mild to moderate, these events were less frequently seen with elvitegravir or raltegravir. Since our initial publication, we have seen additional patients complaining of dizziness or cognitive problems 1-2 h after DTG intake, suggesting that peak plasma levels may be too high in these individuals. Other groups from the Netherlands [3], Italy [4,5] and France [6] have also reported unexpected adverse events with DTG. These include anxiety, irritability and depression but also headache and musculoskeletal pain. In these patients, it seems unlikely that a switch to morning dosing would resolve neuropsychiatric symptoms. Of note, Capetti and colleagues have confirmed our observations that neuropsychiatric events were more frequent in older and in female patients, suggesting a pharmacokinetic problem. Indeed, recent pharmacokinetic studies have found higher drug exposure in older patients [7,8] but also in patients treated with atazanavir or cobicistat [9,10]. We believe that there is an urgent need for more data on drug levels in these patient populations, especially in individuals who develop neuropsychiatric events. Capetti and colleagues' univariate analysis did not find a higher event rate with abacavir use. This is in contrast to our findings and those of other studies [3,4] and it is debatable whether currently available data are sufficient to exclude a drugÀdrug interaction between abacavir and DTG [11,12].
Drug Interactions in the Treatment of Malignancy in HIV-Infected Patients
Oncology Research and Treatment, 2017
The number of patients with HIV (human immunodeficiency virus) requiring treatment for malignancy... more The number of patients with HIV (human immunodeficiency virus) requiring treatment for malignancy is increasing worldwide. Concurrent treatment of HIV and malignancy is complicated by unpredictable drug-drug interactions, which can cause potentially life-threatening toxicities and ineffective treatment of either disease. This article aims to provide a practical approach to drug interactions and their management in this context to help deliver effective and safe treatment of both the malignancy and HIV.
Population-based and ANC sentinel-surveillance age-specific HIV prevalence estimates
<b>Copyright information:</b>Taken from "Population and antenatal-based HIV prev... more <b>Copyright information:</b>Taken from "Population and antenatal-based HIV prevalence estimates in a high contracepting female population in rural South Africa"http://www.biomedcentral.com/1471-2458/7/160BMC Public Health 2007;7():160-160.Published online 18 Jul 2007PMCID:PMC1948890.
The HIV pandemic is one of the greatest threats to human health in history. r Seventy per cent of... more The HIV pandemic is one of the greatest threats to human health in history. r Seventy per cent of worldwide deaths from AIDS occur in sub-Saharan Africa. r Without treatment for HIV, worsening immunocompromise leads to the development of opportunistic infections and certain cancers. r Factors associated with more rapid HIV disease progression include older age, poor nutrition and co-infection with tuberculosis and hepatitis C. r Preventative strategies, such as behaviour change, screening of blood products, postexposure prophylaxis and treatment of HIV during pregnancy, help decrease rates of HIV transmission. r Improved access to treatment worldwide has reduced the annual number of HIVassociated deaths and may also reduce the number of new HIV infections globally.
AIDS, 2010
Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associate... more Objective(s): To identify factors (including exposure to specific antiretroviral drugs) associated with severe vitamin D deficiency (VDD) in HIV-infected individuals and to explore the effects of severe VDD and antiretroviral drug exposure on serum alkaline phosphatase (ALP) as surrogate marker of bone turnover. Design: Cross-sectional survey of vitamin D status among HIV-infected patients attending for routine clinical care at a large London HIV clinic. Methods: Severe VDD was defined as 25(OH)D levels of less than 10 mg/l (<25 nmol/l). Multivariate logistic regression analysis was used to identify factors associated with severe VDD and upper quartile ALP levels. Results: Vitamin D levels were measured in 1077 patients and found to be suboptimal in 91%. One-third of patients had severe VDD. Black ethnicity, sampling in winter, nadir CD4 cell count less than 200 cells/ml, and exposure to combination antiretroviral therapy were associated with severe VDD. In analyses restricted to patients on combination antiretroviral therapy, current efavirenz use was significantly associated with severe VDD [adjusted odds ratio 2.0 (95% confidence interval 1.5-2.7)]. Current tenofovir [adjusted odds ratio 3.5 (95% confidence interval 2.3-5.2)] and efavirenz use [adjusted odds ratio 1.6 (95% confidence interval 1.02-2.4)], but not severe VDD [odds ratio 1.1 (0.8-1.5)], were associated with increased bone turnover (upper quartile ALP). Efavirenz was associated with severe VDD, a condition associated with multiple adverse health outcomes, and efavirenz and tenofovir with increased ALP. The clinical significance of these findings requires further investigation, given the widespread use of efavirenz and tenofovir in first-line combination antiretroviral therapy.
Sexually Transmitted Infections, 2006
To evaluate the effectiveness of interventions to prevent mother-to-child transmission of HIV at ... more To evaluate the effectiveness of interventions to prevent mother-to-child transmission of HIV at a large teaching hospital in South East London, and to assess reasons for the small numbers of transmissions that continue to occur. Design: A database of all pregnant women diagnosed as HIV positive between 1993 and 2005 was reviewed, with detailed (retrospective) case-note review of all mother-infant pairs where HIV transmission occurred. Setting: King's College Hospital, London, UK, a teaching hospital serving an ethnically diverse and socially deprived population. Results: 296 pregnancies to 274 women were recorded. 9 of 296 (3.0%) women were lost to follow-up before the end of the pregnancy. Of 287 pregnancies followed up until after delivery, 6 (2.1%) resulted in HIV infection in the infant. More recently, between 2000 and 2004, this transmission rate was even lower, at 3 in 231 (1.3%). Each of these six women had complications, including late presentation to services and defaulting follow-up appointments, which were likely to increase the risk of HIV transmission. Four of the six transmissions occurred in utero. Conclusion: The overall transmission rate of 2% attests to the efforts of the multidisciplinary care team in managing this population which is often hard to reach. Clearly, good systems are needed to trace those women who default. Further data are needed regarding in utero transmissions.
Drug Interactions in the Treatment of Malignancy in HIV-Infected Patients
Oncology Research and Treatment
Do nevirapine and efavirenz affect vitamin D homeostasis similarly?
Aids, Mar 1, 2011
Surveillance of HIV testing: where should we go next?
Sexually Transmitted Infections, Oct 1, 2010
... Tanya Welz. Correspondence to Dr Tanya Welz, Department of HIV/Genitourinary medicine, Caldec... more ... Tanya Welz. Correspondence to Dr Tanya Welz, Department of HIV/Genitourinary medicine, Caldecot Clinic, Kings College Hospital NHS Trust, Caldecot Road, London SE5 9RS, UK ... BMJ 2006;332:3324. [Abstract/FREE Full text]. ↵: Gauthier A,; Breuer J,; Carrington D,; et al. . ...
Mwaba and colleagues are exploring the resurrection of a flawed design that would offer an inferi... more Mwaba and colleagues are exploring the resurrection of a flawed design that would offer an inferior testing option and the danger of clinical misinterpretation. As Mwaba and colleagues say, we should all focus on developing not-for-profit, simple, lowtech, quality assured methods for improved management of HIV-infected patients. However, the lack of evidence presented to support dried blood-spot technology and the achievements of the new CD4 counting methods 5 suggest that progress is more likely to come from flow cytometry and analytical image systems that properly discriminate between lymphocytes and monocytes. 2,5
Introduction to Human Immunodeficiency Virus
Pribram/Nutrition and HIV, 2010
Tropical Medicine and International Health, 2005
Many countries in Africa are planning to provide highly active antiretroviral therapy (HAART) to ... more Many countries in Africa are planning to provide highly active antiretroviral therapy (HAART) to millions of people with acquired immune deficiency syndrome. This will be a highly complex therapy programme. Physician-based models of care adapted from industrialized countries will not succeed in providing treatment to the majority of those who need it in resource-constrained settings. A high priority is to identify care models for Africa that will increase coverage of HAART safely and effectively: key issues are (i) whether nursing staff or non-clinically qualified staff can take the major role in the treatment programme and reduce the workload of physicians, (ii) whether treatment and monitoring can be delivered through peripheral health centres or through home visits and achieve better adherence and be more cost-effective than delivery at hospitals and (iii) which clinical algorithms used by nursing or non-clinically qualified staff will be effective for screening, diagnosing and managing treatment-related side-effects and medical problems being incurred. Many current ART support programmes are making little or no investment in research, but answering important questions on delivery of HAART will be essential if HAART programmes are to be successful in African nations with a high burden of human immunodeficiency virus infection.