The effect of ethanol upon early development in mice and rats. XXIV. The effect of acute ethanol intoxication upon implantation in mice

The primary mode of human immunodeficiency virus (HIV) transmission worldwide is by exposure to the virus at vaginal, rectal, and oral mucosal surfaces. To understand HIV/simian immunodeficiency virus (SIV) transmission events at mucosal portals of entry, we used the SIV-macaque model to determine if mucosal surfaces function as barriers and select for particular viral genotypes. Rhesus macaques were inoculated intravaginally, intracolonically, intrarectally, or orally with the complex primary viral isolate SIV/DeltaB670. Peripheral blood mononuclear cells, collected within the first two weeks postinoculation, were cloned and sequenced from all infected macaques. In the majority of the animals analyzed, multiple genotypes were identified, independent of the route of infection. These findings suggest that the mucosal barrier may play a minor role in the genotypic selection observed during sexual transmission of HIV and emphasize the need to evaluate the viral diversity present within the mucosal secretions of chronically infected individuals.     

Pediatric acquired immunodeficiency syndrome. Barriers to recognizing the role of child sexual abuse

The only reportable exposure categories for human immunodeficiency virus (HIV) infection of children are vertical transmission from an HIV-infected mother or receipt of infected blood or blood products. Although sexual transmission of HIV among adults is the subject of intense concern, sexual transmission of HIV to children during child sexual abuse has received almost no investigative attention. This review discusses factors contributing to the exclusion of sexual transmission of HIV to children from studies of the epidemiology of HIV infection. Difficulties occur in screening and confirming abuse in nonselected populations of children, perceived and real barriers exist to the evaluation for HIV of sexually abused children, and problems occur in the assessment for child sexual abuse of HIV-infected children. Impediments to the understanding of the relationship between sexual abuse and HIV infection in sexually abused, HIV-infected children are considered, and measures that can allow these barriers to be overcome are discussed.     

Adherence-related behavior in adolescents with asthma: results from focus group interviews

OBJECTIVE: To describe the factors that contribute to vertical transmission of human immunodeficiency virus (HIV) and review means of decreasing the risk of transmission. STUDY DESIGN: Medline search of the international English-language literature pertaining to HIV in pregnancy from 1989 to the present. Special emphasis was placed on articles published in the last three years related to vertical transmission as well as to antepartum, intrapartum and postpartum management to reduce transmission. RESULTS: High levels of maternal viral load and more advanced maternal disease are associated with a greater risk of vertical transmission of HIV. Antepartum and intrapartum maternal treatment with zidovudine and postpartum neonatal zidovudine treatment decreases the risk of transmission by two-thirds, at least in patients with earlier stages of the disease. Breast-feeding is a source of postpartum HIV transmission and may double the total transmission rate. CONCLUSION: Zidovudine should be used in pregnancy to decrease the viral load and reduce transmission of HIV to the fetus. Other antiviral agents should be used during pregnancy if indicated, although current information is lacking about their effects on the fetus and any potential benefits in decreasing vertical transmission of HIV. Breast-feeding should be avoided.     

Why is HIV rarely transmitted by oral secretions? Saliva can disrupt orally shed, infected leukocytes

BACKGROUND: Oral transmission of human immunodeficiency virus (HIV) by the millions of HIV-infected individuals is a rare event, even when infected blood and exudate is present. Saliva of viremic individuals usually contains only noninfectious components of HIV indicating virus breakdown. OBJECTIVE: To determine whether unknown HIV inhibitory mechanisms may explain the almost complete absence of infectious HIV in the saliva. METHODS: Since most of the infectious HIV that is shed mucosally by asymptomatic individuals is found in, produced by, and transmitted by infected mononuclear leukocytes, we determined whether saliva, which is hypotonic, may disrupt these infected cells, thereby preventing virus multiplication and cell-to-cell transmission of HIV. Specifically, we measured (1) whether mononuclear leukocytes were lysed by saliva and (2) whether the lysis by saliva inhibits the multiplication of HIV and other viruses in infected leukocytes and other cells. RESULTS: Saliva rapidly disrupted 90% or more of blood mononuclear leukocytes and other cultured cells. Concomitantly, there was a 10000-fold or higher inhibition of the multiplication of HIV and surrogate viruses. Further experiments indicated that the cell disruption is due to the hypotonicity of saliva: CONCLUSIONS: Hypotonic disruption may be a major mechanism by which saliva kills infected mononuclear leukocytes and prevents their attachment to mucosal epithelial cells and production of infectious HIV, thereby preventing transmission. Implications for the known oral HIV transmission by milk and seminal fluid, as well as potential oral transmission to contacts and health care workers, are considered. This effective salivary defense may be applicable medically to interdict vaginal, rectal, and oral transmission of HIV by infected cells in seminal fluid or milk by the use of anticellular substances.     

The invention of the modern uroflowmeter by Willard M. Drake, Jr at Jefferson Medical College

OBJECTIVES: As a means of enhancing public health efforts to control sexual transmission of human immunodeficiency virus (HIV), methods were developed to report on risk behavior in a manner that is comparable and widely interpretable. METHODS: An elementary sexual behavior risk index (the vaginal episode equivalent index) that is in accord with some of the essential knowledge about sexual transmission of HIV is described, and a multivariate ordinal risk (MOR) method that can be used to improve such risk indices is introduced. RESULTS: An example shows that these approaches are applicable to observational studies of seroconversion. CONCLUSIONS: The MOR represents a powerful new tool to develop valid comparable measures of sexual risk behavior and, thereby, to advance HIV prevention research.     

Incidence of human immunodeficiency virus antibody in a prenatal population at a community hospital

Prenatal human immunodeficiency virus (HIV) screening may reduce vertical HIV transmission. We screened 4,419 prenatal sera and found 38 repeatedly reactive specimens with an HIV-1-HIV-2 enzyme-linked immunosorbent assay. Western blot analysis confirmed four of these specimens as positive for HIV-1 antibodies. Screening detects previously unidentified HIV infections, but false-positive results may also occur.     

Passive immunization of newborn rhesus macaques prevents oral simian immunodeficiency virus infection

To determine if passively acquired antiviral antibodies modulate virus transmission and disease progression in human pediatric AIDS, the potential of pre- and postexposure passive immunization with hyperimmune serum to prevent oral simian immunodeficiency virus (SIV) infection or disease progression in newborn rhesus macaques was tested. Untreated neonates became infected after oral SIV inoculation and had high viremia, and most animals developed fatal AIDS within 3 months. In contrast, SIV hyperimmune serum given subcutaneously prior to oral SIV inoculation protected 6 newborns against infection. When this SIV hyperimmune serum was given to 3 newborns 3 weeks after oral SIV inoculation, viremia was not reduced, and all 3 infants died within 3 months of age due to AIDS and immune-complex disease. These results suggest that passively acquired antihuman immunodeficiency virus (HIV) IgG may decrease perinatal HIV transmission. However, anti-HIV IgG may not impart therapeutic benefit to infants with established HIV infection.     

Increased transmission of vertical hepatitis C virus (HCV) infection to human immunodeficiency virus (HIV)-infected infants of HIV- and HCV-coinfected women

The transmission of perinatal hepatitis C virus (HCV) infection was studied retrospectively in 62 infants born to 54 HCV- and human immunodeficiency virus (HIV)-coinfected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by nested RNA polymerase chain reaction. The overall rate of vertical HCV transmission was 16.4% (9/62). Most HCV-infected children did not develop antibodies to HCV. The rate of HCV infection was higher among HIV-infected infants (40%) than among HIV-uninfected infants (7.5%; odds ratio, 8.2; P = .009). This difference in transmission was not related to differences in maternal HCV load, as measured by branched DNA assay, or mode of delivery. Why HIV-infected infants of HCV- and HIV-coinfected women have significantly higher rates of perinatal HCV transmission remains to be elucidated. The rate of HCV transmission in HIV-uninfected infants of HCV- and HIV-coinfected women is similar to that reported for infants born to HIV-seronegative mothers.     

Molecular evidence for nosocomial transmission of human immunodeficiency virus from a surgeon to one of his patients

We have investigated the molecular evidence in favor of the transmission of human immunodeficiency virus (HIV) from an HIV-infected surgeon to one of his patients. After PCR amplification, the env and gag sequences from the viral genome were cloned and sequenced. Phylogenetic analysis revealed that the viral sequences derived from the surgeon and his patient are closely related, which strongly suggests that nosocomial transmission occurred. In addition, these viral sequences belong to group M of HIV type 1 but are divergent from the reference sequences of the known subtypes.     

Causes of chronic persistent cough in adult patients: the results of a systematic management protocol

BACKGROUND AND METHODS: In Japan, 26 children who vertically acquired human immunodeficiency virus (HIV) infection had been reported as at February 1997. Little information was published about their epidemiological backgrounds and the rate of perinatal HIV transmission in Japan remains unknown. To learn the epidemiological features of perinatal HIV infection in Japan, we examined the medical records of five perinatally infected children. RESULTS: Three of five mothers were Japanese and two others were South East Asian. Four of them acquired HIV infection abroad and one became infected through her spouse who had acquired infection abroad. Therefore, HIV infection in these five cases can be regarded as an imported infectious disease. None of the five mothers noticed their HIV infection before their pregnancy. One mother was found to be HIV seropositive during her pregnancy, but the others did not notice their HIV infection until their delivery. CONCLUSIONS: To reduce the incidence of perinatally HIV-infected children it is necessary to lower the incidence of mother-to-infant HIV transmission. In Western countries they have succeeded in reducing the risk for perinatal HIV transmission with perinatal zidovudine therapy. To prescribe the preventive therapy against perinatal HIV transmission, it is essential to know if pregnant women are infected with HIV or not. Therefore, women of childbearing age should accept voluntary prenatal HIV testing. At the same time, they should be offered such programs that can enable them to receive timely counseling, besides medical treatment, if they are found to be HIV infected.     

Efficacy of zidovudine and human immunodeficiency virus (HIV) hyperimmune immunoglobulin for reducing perinatal HIV transmission from HIV-infected women with advanced disease: results of Pediatric AIDS Clinical Trials Group protocol 185

Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovudine combined with human immunodeficiency virus (HIV) hyperimmune immunoglobulin (HIVIG) infusions administered monthly during pregnancy and to the neonate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (IVIG) without HIV antibody. Subjects had baseline CD4 cell counts /=200/microL) but not with time of zidovudine initiation (5.6% vs. 4.8% if started before vs. during pregnancy; P=. 75). The Kaplan-Meier transmission rate for HIVIG recipients was 4. 1% (95% confidence interval, 1.5%-6.7%) and for IVIG recipients was 6.0% (2.8%-9.1%) (P=.36). The unexpectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HIV disease and prior zidovudine therapy, although it limited the study's ability to address whether passive immunization diminishes perinatal transmission.     

Shock. Physiological principles for resuscitation

As the epidemic of the acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa enters its second decade, much has been learned about the distribution and determinants of the disease and its causative agent, the human immunodeficiency virus (HIV). Over 6 million people, or 2.5% of the adult population, are thought to be infected with HIV. The distribution of HIV is largely determined by sexual behavior; as for other sexually transmitted diseases, the characteristics of sexual networks determine the extent and rate of spread of HIV. Female sex workers and their male clients are at high risk for HIV and have been important in initiating the epidemic in many African countries. The dynamics of HIV in the rest of the population are complex; men with multiple sexual partners are largely responsible for transmission of HIV to women in the general population. Other sexually transmitted diseases and lack of male circumcision may increase the probability of transmission of HIV during sexual intercourse and probably are partially responsible for the rapid diffusion of HIV in Africa. Interventions among high-risk groups are needed, but they must be accompanied by attempts to induce behavior change among men and women in the general population. Epidemiologic studies of the determinants of sexual behavior and sexual contact patterns, as well the design and evaluation of interventions, are urgently needed. Key areas for development are the study of behavioral exposures and outcomes, the evaluation of interventions, developing new methods for conducting interventions in resource-poor environments, and increasing the number of African scientists with the skills and resources to conduct epidemiologic studies.     

Human immunodeficiency virus and hepatitis C virus coinfection

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) share the same parenteral, sexual and vertical routes of transmission (McNair et al. 1992). This common epidemiology explains the high frequency of combined infections by hepatotropic viruses in HIV-infected patients. The aim of the present review is to clarify some important issues dealing with the reciprocal interactions between HIV and hepatitis C virus infections. The main topics include epidemiology, virological markers of HIV-infection, histopathology, natural course and treatment of hepatitis C in HIV-infected individuals.     

Lactic dehydrogenase virus infection enhances parasite egg production and inhibits eosinophil and mast cell responses in mice infected with the nematode Nippostrongylus brasiliensis

OBJECTIVE: To determine if awareness of methods to reduce vertical transmission of human immunodeficiency virus (HIV) is associated with HIV test acceptance and to clarify patients' attitudes toward routine versus elective prenatal HIV testing. METHODS: In a cross-sectional study, 247 antenatal patients were surveyed regarding HIV knowledge, self-perceived HIV risk, and willingness to learn a positive test result. This information, along with demographic and risk factor data, was related to HIV test acceptance. Patients also indicated their attitudes toward routine versus elective prenatal testing for HIV and other common prenatal screening tests. RESULTS: Seventy-two percent of antenatal patients accepted HIV testing. Test acceptance was not associated with the presence of risk factors, self-perceived HIV risk, or demographic factors, including race and ethnicity. Test acceptance was associated positively with patients' knowledge of a medical intervention to reduce vertical transmission and their willingness to learn a positive HIV test result. Only 24% of patients knew that the risk of vertical transmission could be reduced using medication. Sixty-nine percent of patients said that prenatal HIV testing should be routine, whereas 27% said that it should be done only after specific written consent. As a group, our patients viewed HIV screening no differently from screening for other infections in pregnancy. CONCLUSION: Interventions aimed at increasing HIV testing rates among pregnant women should focus on educating patients about vertical transmission reduction and promising new therapies for HIV infection. Proponents of elective testing should re-evaluate the assumption that patients view HIV testing differently from other prenatal tests for which separate written consent is not required.     

Trends in HIV incidence among young adults in the United States

CONTEXT: Behaviors that result in potential exposure to human immunodeficiency virus (HIV) usually begin in adolescence or young adulthood, but trends in HIV incidence in young people remain unclear. OBJECTIVE: To estimate trends in HIV incidence in teenagers and young adults. DESIGN AND SETTING: Back-calculation of past HIV incidence in persons born between 1960 and 1974 using US national acquired immunodeficiency syndrome (AIDS) incidence data and estimates of the distribution of times between HIV infection and AIDS. MAIN OUTCOME MEASURES: Incidence and prevalence of HIV in 1988 and 1993 in persons aged 20 and 25 years, respectively, in each of those years. RESULTS: As of January 1993, about 22000 men and 11000 women aged 18 to 22 years were living with HIV infection in the United States. Homosexual contact was the leading route of infection among young men. Heterosexual contact was the leading route of infection among young women. The HIV incidence attributed to homosexual contact or injection drug use decreased among persons aged 20 and 25 years between 1988 and 1993, but HIV incidence attributed to heterosexual contact was stable or increasing. Notably, in men aged 20 and 25 years, HIV prevalence declined by about 50% in white men but was relatively stable in black and Hispanic men. In contrast, HIV prevalence in women aged 20 and 25 years rose by 36% and 45%, respectively, because of increasing heterosexual transmission. Overall, HIV prevalence in persons aged 20 and 25 years declined by only 14% between 1988 and 1993. CONCLUSIONS: In young persons, HIV incidence in homosexual men and injection drug users was slowing by 1993; this favorable trend was offset by increasing heterosexual transmission, especially in minorities.     

Maternal virus load and perinatal human immunodeficiency virus type 1 subtype E transmission, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group

To determine the rate and risk factors for human immunodeficiency virus (HIV)-1 subtype E perinatal transmission, with focus on virus load, pregnant HIV-infected women and their formula-fed infants were followed prospectively in Bangkok. Of 281 infants with known outcome, 68 were infected (transmission rate, 24.2%; 95% confidence interval, 19.3%-29.6%). Transmitting mothers had a 4.3-fold higher median plasma HIV RNA level at delivery than did nontransmitters (P<.001). No transmission occurred at <2000 copies/mL. On multivariate analysis, prematurity (adjusted odds ratio [AOR], 4.5), vaginal delivery (AOR, 2.9), low NK cell percentage (AOR, 2.4), and maternal virus load were associated with transmission. As RNA quintiles increased, the AOR for transmission increased linearly from 4.5 to 24.8. Two-thirds of transmission was attributed to virus load>10,000 copies/mL. Although risk is multifactorial, high maternal virus load at delivery strongly predicts transmission. This may have important implications for interventions designed to reduce perinatal transmission.     

HIV infection in women: an escalating health concern

The proportion of women infected with the human immunodeficiency virus (HIV) continues to increase. Over one-half of women acquire the virus through heterosexual contact. The diagnoses that define the acquired immunodeficiency syndrome and the use of antiretroviral therapy are similar in men and women, except in pregnancy. However, management decisions differ significantly regarding contraceptive and gynecologic care. Besides abstinence, use of the latex condom continues to be the most effective way of preventing transmission of HIV. The management of human papillomavirus-associated disease, pelvic inflammatory disease and vaginal candidiasis is especially challenging in women with HIV infection. A positive status for the virus does not appear to affect pregnancy outcome. Each year, up to 2,000 infants are born infected with HIV. Transmission can occur by transplacental or intrapartum spread or through breast milk. Since 1994, prophylaxis with zidovudine has been shown to be an effective method of limiting transmission to infants. It is important to offer all pregnant women a test for HIV, with counseling provided both before and after the test, even if testing does not become mandatory under the law.     

Postexposure prophylaxis after nonoccupational HIV exposure: clinical, ethical, and policy considerations

In the wake of recent breakthroughs in antiviral therapies and Centers for Disease Control and Prevention (CDC) recommendations advocating occupational postexposure prophylaxis (PEP), health care workers are increasingly receiving inquiries about PEP following exposures to the human immunodeficiency virus (HIV) through sex and injection drug use. The probability of HIV transmission by certain sexual or injection drug exposures is of the same order of magnitude as percutaneous occupational exposures for which the CDC recommends PEP. In such cases, if the exposure is sporadic, it seems appropriate to extrapolate from the data on occupational PEP and recommend prophylaxis. However, for individuals with continuing or low-risk exposures, we instead recommend referrals to state-of-the-art risk reduction programs. Clinicians, using local HIV seroprevalence data and their knowledge of transmission probabilities, can help exposed patients make an informed decision regarding PEP. Because of the large number of risky encounters that will not be treated prophylactically, even after significant outreach efforts, public health interventions that emphasize PEP as part of a comprehensive HIV prevention program should be confined to cities with highest HIV prevalences.     

Long-term survival of children with human immunodeficiency virus infection in New York City: estimates from population-based surveillance data

The life expectancy of children with human immunodeficiency virus (HIV) infection acquired through mother-to-child transmission has important clinical and public health significance. Several sources of population-based surveillance data from New York City, covering 1982 through the end of 1994, were combined to estimate long-term survival of HIV-infected children and age-specific prevalence. HIV incidence among newborns was estimated by applying expected transmission rates to seroprevalence surveys of parturient women and by using back-calculation methods. HIV prevalence in childhood was based on cumulative HIV incidence and cumulative mortality, adjusting for underreporting of death and background causes of death. A modified actuarial method was developed to estimate survival of infected children. At the beginning of 1995, between 1,945 and 3,323 children less than age 13 years were estimated to be living with HIV infection acquired through mother-to-child transmission in New York City. Between 36% and 61% of these infected children were estimated to survive to age 13 years (median survival, 8.6 years to >13 years). A substantial proportion of infected children will survive to adolescence. Thus, it is important that their educational, medical, and other needs be considered. These methods may be useful in other areas in which HIV seroprevalence data among childbearing women and HIV mortality statistics are available.