Maternal herpes simplex virus type 2 coinfection increases the risk of perinatal HIV transmission: possibility to further decrease transmission?
ABSTRACT To evaluate the association between maternal herpes simplex virus type 2 seropositivity and genital herpes simplex virus type 2 shedding with perinatal HIV transmission.
Evaluation of women who participated in a 1996-1997 perinatal HIV transmission prevention trial in Thailand.
In this nonbreastfeeding population, women were randomized to zidovudine or placebo from 36 weeks gestation through delivery; maternal plasma and cervicovaginal HIV viral load and infant HIV status were determined for the original study. Stored maternal plasma and cervicovaginal samples were tested for herpes simplex virus type 2 antibodies by enzyme-linked immunoassay and for herpes simplex virus type 2 DNA by real-time PCR, respectively.
Among 307 HIV-positive women with available samples, 228 (74.3%) were herpes simplex virus type 2 seropositive and 24 (7.8%) were shedding herpes simplex virus type 2. Herpes simplex virus type 2 seropositivity was associated with overall perinatal HIV transmission [adjusted odds ratio, 2.6; 95% confidence interval, 1.0-6.7)], and herpes simplex virus type 2 shedding was associated with intrapartum transmission (adjusted odds ratio, 2.9; 95% confidence interval, 1.0-8.5) independent of plasma and cervicovaginal HIV viral load, and zidovudine treatment. Median plasma HIV viral load was higher among herpes simplex virus type 2 shedders (4.2 vs. 4.1 log(10)copies/ml; P = 0.05), and more shedders had quantifiable levels of HIV in cervicovaginal samples, compared with women not shedding herpes simplex virus type 2 (62.5 vs. 34.3%; P = 0.005).
We found an increased risk of perinatal HIV transmission among herpes simplex virus type 2 seropositive women and an increased risk of intrapartum HIV transmission among women shedding herpes simplex virus type 2. These novel findings suggest that interventions to control herpes simplex virus type 2 infection could further reduce perinatal HIV transmission.
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Conference Paper: Tolerating late memory traps in ILP processors[Show abstract] [Hide abstract]
ABSTRACT: ILP processors can execute a large number of instructions at the same time. Thus it becomes more and more difficult to support traps efficiently. On the other hand a current trend in architecture is to support various memory functions in software rather than hardware, usually by trapping the execution processor on a cache miss, TLB miss or a failed access to a local or remote memory. These late memory traps block the faulty instruction at the top of the active list, backing up the pipeline. Moreover the support for late memory traps may affect the performance of non-faulting memory instructions as well. In this paper we analyze the overhead caused by late memory traps in ILP processors and define several measures for this overhead. In order to tolerate late memory traps, we propose hardware prefetching of exception conditions and a tagged store buffer to implement deferred traps on stores. We show that, with these hardware optimizations, the overhead added by the lateness of traps is significantly reduced relative to the overhead of early traps. Because of caching effects the frequency of late memory traps usually decreases as they are taken deeper in the memory hierarchy and their overall impact on the execution time becomes negligibleComputer Architecture, 1999. Proceedings of the 26th International Symposium on; 02/1999
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ABSTRACT: Herpes simplex virus (HSV) transmitted from mother to child around the time of delivery can cause potentially fatal disease in the newborn. Women who experience their first genital HSV infection in pregnancy are at the highest risk of transmitting the virus to their newborn. Efforts to prevent vertically transmitted HSV disease can be directed in the following three ways: (i) prevent maternal genital HSV infection; (ii) prevent transmission during pregnancy and delivery; or (iii) postnatally prevent disease in an exposed newborn. Oral aciclovir and valaciclovir given prophylactically in late pregnancy have been shown to limit clinical recurrence of genital herpes, shedding of HSV at delivery and the rate of caesarean delivery for past HSV disease. However, there are insufficient data to determine the effect of oral antiviral prophylaxis in pregnancy on neonatal HSV disease. Neonatal HSV disease should always be treated with systemic antiviral therapy. There is currently no vaccine licensed to prevent genital herpes, although a number show promise in clinical trials. The role of intrapartum antiviral therapy and postnatal strategies to prevent neonatal HSV disease require further evaluation.Drugs 02/2009; 69(4):421-34. DOI:10.2165/00003495-200969040-00003 · 4.13 Impact Factor
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ABSTRACT: To determine the prevalence of sexually transmitted infections (STIs) and other reproductive tract infections (RTIs) among pregnant women in Moshi, Tanzania and to compare the occurrence of STIs/RTIs among human immunodeficiency virus (HIV)-infected and uninfected women. Pregnant women in their 3rd trimester (N = 2654) were recruited from two primary health care clinics between June 2002 and March 2004. They were interviewed, examined and genital and blood samples were collected for diagnosis of STIs/RTIs and HIV. The prevalence of HIV, active syphilis and herpes simplex virus - type 2 (HSV-2) were 6.9%, 0.9% and 33.6%, respectively, while 0.5% were positive for N gonorrhoeae, 5.0% for T vaginalis and 20.9% for bacterial vaginosis. Genital tract infections were more prevalent in HIV-seropositive than seronegative women, statistically significant for syphilis (3.3% vs 0.7%), HSV-2 (43.2% vs 32.0%), genital ulcers (4.4% vs 1.4%) and bacterial vaginosis (37.2% vs 19.6%). In comparison with published data, a declining trend for curable STIs/RTIs (syphilis, trichomoniasis and bacterial vaginosis) was noted. Rates of STIs and RTIs are still high among pregnant women in Moshi. Where resources allow, routine screening and treatment of STIs/RTIs in the antenatal care setting should be offered. Higher STIs/RTIs in HIV-seropositive women supports the expansion of HIV-counseling and testing services to all centers offering antenatal care. After identification, STIs/RTIs need to be aggressively addressed in HIV-seropositive women, both at antenatal and antiretroviral therapy care clinics.Reproductive Health 03/2009; 6:4. DOI:10.1186/1742-4755-6-4 · 1.62 Impact Factor