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Biomedical subjects

M L Newell

Publications and source records attributed to M L Newell.

At least 91 records · Page 5Linked to original sources
PubMed1994

Vertical transmission of HIV infection.

Transmission of HIV infection from mother to child may occur before, during or after delivery. Estimates of the rate of vertical transmission range from 15-20% in Europe to 25-35% in Africa. Mother-to-child transmission is associated with progression of disease in the mother, severe prematurity and breastfeeding. The association with mode of delivery needs further investigation. Attention is now being given to intervention to reduce mother-to-child transmission of HIV infection.

Africa↗
PubMed1994

Longitudinal follow-up studies.

A longitudinal study should be undertaken only when there is a clear reason to justify this and a reasonable chance of achieving the objectives. A multidisciplinary approach is often required, and continuity of staff and long-term collaboration with colleagues are important for their success. A longitudinal approach is required to estimate the prevalence of an infection in pregnancy and the rate of vertical transmission and to clarify the natural history in infected children. An example of cytomegalovirus infection is given; the parallels with HIV are obvious.

Adult↗
PubMed1993

Screening for HIV infection in pregnancy.

Antenatal HIV screening policies throughout the British Isles were surveyed and results linked to data on HIV-infected pregnant women notified through the Royal College of Obstetricians and Gynaecologists. Units offering HIV testing to all pregnant women were compared with those offering it only to women considered to be at risk, and in both situations fewer than 50% of infected women were identified as HIV infected for the first time in antenatal clinics. Based on laboratory reports of HIV infection in women of childbearing age, paediatric reports of children born to HIV positive women and unlinked anonymous neonatal screening programmes, there was evidence of under-recognition of HIV infection in pregnancy, particularly in England and Wales.

AIDS Serodiagnosis↗
PubMed1993

Estimating the rate of mother-to-child transmission of HIV. Report of a workshop on methodological issues Ghent (Belgium), 17-20 February 1992. The Working Group on Mother-to-Child Transmission of HIV.

PURPOSE: In the last 8 years, numerous cohort studies have been conducted to estimate the rate of mother-to-child transmission (MTCT) of HIV. Many of these have faced problems in data collection and analysis, making it difficult to compare transmission rates between studies. This workshop on methodological aspects of the study of MTCT of HIV-1 was held in Ghent (Belgium) in February 1992. STUDY SELECTION AND DATA EXTRACTION: Fourteen teams of investigators participated, representing studies from Central (five) and Eastern Africa (three), Europe (two), Haiti (one) and the United States (three). A critical evaluation of the projects was carried out, under four headings: (1) enrollment and follow-up procedures, (2) diagnostic criteria and case definitions, (3) measurement and comparison of MTCT rates and (4) determinants of transmission. RESULTS OF DATA ANALYSIS: Reported transmission rates ranged from 13 to 32% in industrialized countries and from 25 to 48% in developing countries. However, no direct comparisons could be made because methods of calculation differed from study to study. Based on this review, a common methodology was developed. Agreement was reached on definitions of HIV-related signs/symptoms, paediatric AIDS and HIV-related deaths. A classification system of children born to HIV-1-infected mothers according to their probable HIV infection status during the first 15 months of life, allowed the elaboration of a direct method of computation of the transmission rate and of an indirect method for studies with a comparison group of children born to HIV-seronegative mothers. This standardized approach was subsequently applied to selected data sets. CONCLUSIONS: The methodology can now be applied to all studies with sufficient follow-up and comparisons made between transmission rates. This step is essential for assessing determinants of transmission and for the development of a common approach for the evaluation of interventions aimed at reducing or interrupting MTCT of HIV.

Adult↗
PubMed1992

Risk of human immunodeficiency virus type 1 transmission through breastfeeding.

Detection of human immunodeficiency virus type 1 (HIV-1) in breast milk by culture and polymerase chain reaction does not necessarily mean that breastfeeding is a route of transmission, although evidence from several case-reports points in that direction. We undertook a systematic review of published studies meeting criteria that allowed determination of quantitative risk of transmission via breastfeeding. Based on four studies in which mothers acquired HIV-1 postnatally, the estimated risk of transmission is 29% (95% Cl 16-42%). Analysis of five studies showed that when the mother was infected prenatally, the additional risk of transmission through breastfeeding, over and above transmission in utero or during delivery, is 14% (95% Cl 7-22%). Where there are safe alternatives to breastfeeding, universal named testing of pregnant women would provide an opportunity to advise more infected women not to breastfeed and might thereby reduce the number of vertically infected children. Since breastfeeding protects against infant deaths from infectious diseases, breastfeeding is still recommended where infectious diseases are a common cause of death in childhood, despite the additional risk of HIV transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1992

HIV infection: the issues for women and children.

HIV is now a worldwide pandemic, affecting some ten million adults and one million children--the overwhelming majority from sub-Saharan Africa. In Africa equal numbers of men and women are infected: in Europe just ten per cent of all cases of Aids are among women and two per cent among children.

Adult↗