Assessment of mother-to-child HIV-1 and HIV-2 transmission: an AIDS reference laboratory collaborative study.

OBJECTIVE: A prospective study was carried out to assess HIV-1 and HIV-2 mother-to-child transmission (MTCT) rates in Portugal between 1999 and 2005 by analysing the proportion of diagnosed infected children born to HIV-positive mothers. MATERIALS AND METHODS: Serial blood samples were collected from 1315 children at risk of HIV-1 infection, 131 children at risk of HIV-2 infection and six children at risk of both HIV-1 and HIV-2 infections attending 25 Health Institutions. HIV proviral DNA was detected by nested polymerase chain reaction (PCR) and statistical analysis was performed using spss. RESULTS: DNA PCR using HIV-1 and HIV-2 long terminal repeat (LTR) primers amplified 92.5% and 75% of maternal HIV infections, respectively. Overall, MTCT occurred in 3.4% [95% confidence interval (CI) 2.5-4.6%] of HIV-1 and 1.5% (95% CI 0.2-5.4%) of HIV-2 mother-child pairs. A significant decrease in HIV-1 MTCT was observed with time, from 7.0% (95% CI 2.6-14.6%) in 1999 to 0.5% (95% CI 0.0-2.5%) in 2005. HIV MTCT was associated with an absence of antiretroviral therapy in infected pregnant women (P<0.0001). Of the 48 infected children (46 with HIV-1 and two with HIV-2), the schedule of blood sample collection was followed for only 26 children. In 14 (53.8%) of those 26 children the infections were diagnosed in the first sample collected before they were 48 h old, suggesting in utero transmission. Despite the national recommendations for antenatal HIV testing, a high overall proportion (22.2% for HIV-1 and 44.3% for HIV-2) of mothers did not access any MTCT prevention measures, mostly because of late diagnosis in pregnancy. A small but significant proportion of HIV-2 infection was found in mothers with no identifiable link with West Africa. CONCLUSION: HIV-2 transmission rates are low (1.5% in this study), and this may have led to a lower uptake of interventions, but in the absence of interventions transmission does occur. HIV-1 transmission was also associated with a lack of intervention, mostly as a result of late presentation. Use of primers restricted to a single sequence led to false-negative maternal results in a significant proportion of cases. In part this may have been attributable to very low HIV DNA loads as well as primer template mismatches. HIV infection was not documented in children born to mothers with negative HIV DNA PCR results.

Activity-based costing via an information system: an application created for a breast imaging center.

Activity-based costing (ABC) is a process that enables the estimation of the cost of producing a product or service. More accurate than traditional charge-based approaches, it emphasizes analysis of processes, and more specific identification of both direct and indirect costs. This accuracy is essential in today's healthcare environment, in which managed care organizations necessitate responsible and accountable costing. However, to be successfully utilized, it requires time, effort, expertise, and support. Data collection can be tedious and expensive. By integrating ABC with information management (IM) and systems (IS), organizations can take advantage of the process orientation of both, extend and improve ABC, and decrease resource utilization for ABC projects. In our case study, we have examined the process of a multidisciplinary breast center. We have mapped the constituent activities and established cost drivers. This information has been structured and included in our information system database for subsequent analysis.

The question of parallax-effect on radiographic assessment of short trachea in infants and children.

Disproportionately short trachea, can be recognized in AP chest radiographs of infants and older children taken during quiet respiration and showing an evaluable air tracheobronchogram, by the thoracic vertebral level of the carina (normally at T4 in neonates and infants, and at T5 in children two years of age or older). To establish the extent to which a parallax-effect of differing angles of X-ray beam relative to the patient can influence the radiologic assessment of carinal level, we measured the tracheal-vertebral distance at the carina in 29 lateral radiographs of neonates, infants and children, prepared diagrams of the loci of carinal beam intercept of the vertebral column for different angles of beam to body, from tracings of lateral radiographs of two 2-week-old infants, one with trachea of normal length and one with short trachea; of a nine-year-old child with short trachea, and of a ten-year-old with normal trachea, and made radiographs of a postmortem tracheobronchogram of a two-day-old infant at different beam angles. We conclude that tube-body angles of the order of 10-15 degrees from vertical at 27 inches (68.6 cm) or at 40 inches (101.6 cm) FFD do not significantly affect the apparent thoracic vertebral level of the carina in AP chest radiographs, and that a beam angle of 20 degrees or more from vertical is necessary to change the apparent level of tracheal bifurcation by one vertebral body, depending on the patient's age and on whether the patient's position relative to the X-ray beam is lordotic or anti-lordotic.(ABSTRACT TRUNCATED AT 250 WORDS)