Biomedical subjects

Neil A Martinson

Publications and source records attributed to Neil A Martinson.

5 recordsLinked to original sources

PubMed2007

Selection and persistence of viral resistance in HIV-infected children after exposure to single-dose nevirapine.

BACKGROUND: Single-dose nevirapine (sd-NVP) is the mainstay of prevention of mother-to-child transmission programs in developing countries. Exposure to sd-NVP selects for resistance mutations, however. We longitudinally assessed these mutations in HIV-1-infected infants from Soweto and Durban, South Africa. METHODS: We prospectively followed 465 infants who received sd-NVP after enrolling their mothers when pregnant. If HIV infected, their virus was genotyped, using the ViroSeq HIV-1 Genotyping System, to detect resistant mutations. Those with resistance were genotyped at 6 months and then every 6 months out to 18 months if resistance was detected at the previous visit. RESULTS: Of 53 HIV-infected infants, 24 (45.3%) had detectable resistance at their first visit, when the most frequent mutations were Y181C (75%), K103N (25%), and Y188C (12%). Of those whose visit was before 12 weeks of age, 2 of 42 infants shared identical resistance mutations with their mothers. By 18 months of age, 11 of 24 infants with resistance had died and 1 still had the Y181C mutation. CONCLUSIONS: Resistant mutations were selected in half of the infants exposed to sd-NVP, but fewer were detected over time and, unlike the case in their mothers, Y181C dominated initially and persists. Transient resistance mutations may have a negative impact on highly active antiretroviral therapy in infants and children.

Adult↗

PubMed2006

Linking the global positioning system (GPS) to a personal digital assistant (PDA) to support tuberculosis control in South Africa: a pilot study.

BACKGROUND: Tuberculosis (TB) is the leading clinical manifestation of HIV infection and caseloads continue to increase in high HIV prevalence settings. TB treatment is prolonged and treatment interruption has serious individual and public health consequences. We assessed the feasibility of using a handheld computing device programmed with customised software and linked to a GPS receiver, to assist TB control programmes to trace patients who interrupt treatment in areas without useful street maps. In this proof of concept study, we compared the time taken to re-find a home comparing given residential addresses with a customised personalised digital assistant linked to a global positioning system (PDA/GPS) device. Additionally, we assessed the feasibility of using aerial photographs to locate homes. RESULTS: The study took place in two communities in Greater Johannesburg, South Africa: Wheillers Farm, a relatively sparsely populated informal settlement, and a portion of Alexandra, an urban township with densely populated informal settlements. Ten participants in each community were asked to locate their homes on aerial photographs. Nine from Wheillers Farm and six from Alexandra were able to identify their homes. The total time taken by a research assistant, unfamiliar with the area, to locate 10 homes in each community using the given addresses was compared with the total time taken by a community volunteer with half an hour of training to locate the same homes using the device. Time taken to locate the ten households was reduced by 20% and 50% in each community respectively using the PDA/GPS device. CONCLUSION: In this pilot study we show that it is feasible to use a simple PDA/GPS device to locate the homes of patients. We found that in densely populated informal settlements, GPS technology is more accurate than aerial photos in identifying homes and more efficient than addresses provided by participants. Research assessing issues of, confidentiality and cost effectiveness would have to be undertaken before implementing PDA/GPS - based technology for this application. However, this PDA/GPS device could be used to reduce part of the burden on TB control programs.

Anti-Retroviral Agents↗

PubMed2006

High rates of HIV in surgical patients in Soweto, South Africa: impact on resource utilisation and recommendations for HIV testing.

Interactions between HIV and surgical diseases are relatively poorly described in high HIV prevalence settings. We report HIV prevalence and its associations in a prospective study of adults admitted to surgical units in Soweto, South Africa. Voluntary counselling and testing (VCT) for HIV was offered to surgical inpatients. Research nurses interviewed participants at enrolment and doctors reviewed records after discharge. In HIV-infected participants, CD4 counts and viral loads were ascertained. Of 1000 participants, 537 consented to VCT, of whom 176 (32.8%, 95% CI 28.8-36.9%) tested HIV positive. A history of tuberculosis (adjusted odds ratio (AOR) 3.0, 95% CI 1.5-6.2) or sexually transmitted infection (AOR 2.7, 95% CI 1.8-4.2) was associated with HIV infection. Diagnoses of cutaneous abscesses (OR 3.4, 95% CI 1.4-8.1) and anorectal sepsis (OR 3.1, 95% CI 1.1-9.0) were associated with HIV and indicated advanced disease. There were no differences in rates of operative procedures, wound sepsis, investigations or length of stay by HIV status. Hospital-acquired pneumonia was more common in HIV-infected participants (P=0.028). In conclusion, in this high HIV prevalence setting, resource utilisation is similar between HIV-infected and uninfected patients in surgical wards where high rates of HIV in young adults support routine HIV testing. WHO clinical staging of HIV should include anal sepsis as an indicator of advanced HIV disease.

Adult↗

PubMed2006

Optimizing treatment for HIV-infected South African women exposed to single-dose nevirapine: balancing efficacy and cost.

INTRODUCTION: Nevirapine (NVP) resistance may decrease the effectiveness of viral suppression with NVP-based antiretroviral therapy (ART) in women infected with human immunodeficiency virus (HIV) with previous exposure to single-dose NVP. However, the alternative lopinavir-ritonavir-based ART regimen is more expensive. Our objectives were to project the tradeoffs regarding life expectancy, cost, and cost-effectiveness of these ART regimens for NVP-exposed, HIV-infected women in South Africa. METHODS: We developed a simulation model in which NVP-exposed, HIV-infected South African women received 1 of 5 treatment strategies: HIV care without ART, NVP-based ART, lopinavir-ritonavir-based ART, NVP-based ART followed by lopinavir-ritonavir-based ART, or lopinavir-ritonavir-based ART followed by NVP-based ART. The prevalence of NVP resistance was 39%; other data were obtained from the published literature. RESULTS: Projected life expectancy was 43.7 months for women who did not receive ART, 77.4 months for women who received a single NVP-based regimen, and 84.5 months for women who received a single lopinavir-ritonavir-based regimen. NVP resistance reduced survival time by up to 11.6 months among women who received NVP-based ART. The cost-effectiveness of NVP-based ART was $800 (US dollars) per year of life saved, compared with no ART, and the cost-effectiveness of lopinavir-ritonavir-based therapy was $4400 per year of life saved, compared with NVP-based ART. Lopinavir-ritonavir followed by NVP-based ART yielded the greatest life expectancy (105.4 months), had a cost-effectiveness of $2300 per year of life saved, and, if the efficacy of NVP-based regimens improved >6 months postpartum, further increased survival. CONCLUSIONS: NVP resistance substantially decreased the projected survival time associated with NVP-based ART, and lopinavir-ritonavir-based ART resulted in a superior survival time but at higher cost. A sequential regimen starting with lopinavir-ritonavir-based ART followed by NVP-based ART maximized projected survival and was cost effective in South Africa.

Adult↗

PubMed2006

Combining PMTCT with active case finding for tuberculosis.

Tuberculosis (TB) is the preeminent manifestation of HIV infection and has become a leading cause of maternal mortality and morbidity in high HIV-prevalence settings. Active TB in pregnant women has potentially serious consequences for fetuses and newborns. In Soweto, South Africa, there is a more than 90% uptake of voluntary counseling and HIV testing during routine antenatal care, and almost one third of pregnant women are HIV-infected. The posttest counseling session of the prevention of mother-to-child transmission program provides an opportunity to screen HIV-infected pregnant women for TB. In this study, 370 HIV-infected pregnant women were screened for symptoms of active TB by lay counselors at the posttest counseling session. If symptomatic, they were referred to nurses who investigated them further. Eight women were found to have previously undiagnosed, smear-negative, culture-confirmed TB (2160/100,000). The mean CD4 count in those with active TB compared to those without TB was 276 x 10(6) cells per liter vs 447 x 10(6) cells per liter (P = 0.051). Symptoms most associated with active TB were hemoptysis and fever. We conclude that rates of TB in HIV-infected pregnant women are high, and screening for TB during routine antenatal care should be implemented in high HIV-prevalence settings.

Adult↗