Search PubMed⌕ Search

Biomedical subjects

J G McNeil

Publications and source records attributed to J G McNeil.

At least 37 records · Page 2Linked to original sources
PubMed1994

Two antigenically distinct subtypes of human immunodeficiency virus type 1: viral genotype predicts neutralization serotype.

At least five distinct genetic subtypes (genotypes) of human immunodeficiency virus type 1 (HIV-1) have been identified by DNA sequencing. Current vaccine candidates are based on virus strains from North America and Europe that represent only one subtype. The extent to which distinct genotypes of HIV-1 correspond to antigenically distinguishable serotypes is largely unknown and may be critically important to vaccine design. Cross-neuralization studies were done with viruses and plasma from two different genotypes. Based on neutralization susceptibility, 10 primary HIV-1 isolates from Thailand and the United States were classified into one of two antigenic subtypes that correlated with viral genotype. The existence of serotypes of HIV-1 suggests that a broadly effective vaccine may have to include strains from multiple subtypes. Neutralization of these primary HIV-1 isolates differed substantially from results with laboratory strains. Future neutralization studies using primary isolates and multiple genotypes may be important for assessment of HIV-1 antigenic diversity.

Antigenic Variation↗
PubMed1994

Incidence of HIV-1 infection among young men in Thailand.

Royal Thai Army (RTA) enlistees were tested for HIV-1 seropositivity prospectively in order to explore their feasibility as a cohort in an HIV-1 preventive vaccine efficacy trial. The 17,615 seronegative enlistees, virtually all 21-year-old men, contributed 10,409 person-years (p-y) of follow-up. Cohorts were enlisted in November 1991 and May 1992 from northern Thailand and Bangkok. The follow-up rate was 50%, with loss to follow-up significantly associated with location of the base, marital status, and educational level. Seroincidence was 0.5/100 p-y for recruits stationed in Bangkok, 1.0/100 p-y in the lower north, and 3.2/100 p-y in the upper north. In a multiple regression model, the young man's birthplace was strongly associated with risk of infection, suggesting that transmission occurred during leave as well as during duty. Incidence rates were significantly lower in those who were married at the time of enlistment and in those with > or = 10 years of education. The seroincidence rates among recruits stationed in the upper north support vaccine trial feasibility, but follow-up rates need to be improved.

Adult↗
PubMed1992

Broad and persistent effects of benzathine penicillin G in the prevention of febrile, acute respiratory disease.

After an outbreak of acute rheumatic fever at a US Army training installation, a benzathine penicillin G prophylaxis program was instituted. Surveillance data were analyzed to measure rates of febrile, acute respiratory disease (ARD) among trainees before and after prophylaxis was begun. Annual admissions for ARD decreased from 1927 to 690 (-64.2%) after benzathine penicillin G prophylaxis was begun. Admissions with throat cultures positive for Streptococcus pyogenes fell from 595 to 63 (-89.4%), a reduction that accounted only for a minority (43%) of the total 1237 "prevented" admissions. Temporal changes in disease rates at other installations where drug was not administered were also analyzed. Only a small decrease in the number of annual ARD admissions (-6.3%) was observed at other training installations. These findings support a hypothesis that benzathine penicillin G has a broad effect in the prevention of ARD that extends beyond the simple elimination of group A streptococcal infection.

Acute Disease↗
PubMed1992

Predictors of HIV-1 disease progression in early- and late-stage patients: the U.S. Army Natural History Cohort. Military Medical Consortium for Applied Retrovirology.

HIV-infected individuals in both early and late stages of HIV disease were evaluated over 2 years to assess temporal trends and determinants of disease progression. The Walter Reed (WR) staging system was used to categorize patients into an early-stage cohort (WR Stages 1 and 2, N = 1183) and a late-stage cohort (WR Stage 5, N = 260) based on the initial clinical evaluation. Progression was defined as the occurrence of Stage 5 disease or beyond for the early cohort and Stage 6 disease or beyond for the late cohort. The cumulative incidence of progression was 15.7% (137 events) for the early-stage cohort, and 53.7% (85 events) for the late-stage cohort. Baseline CD4+ T lymphocyte (T4) count was the most significant marker of progression: 26% of WR Stage 1 or 2 patients with T4 lymphocytes below 500/mm3 progressed, compared with 12% with T4 lymphocytes at or above 500/mm3. In late-stage individuals, 83% with T4 lymphocytes under 200/mm3 progressed, compared with 27% with T4 lymphocytes at or above 200/mm3. Older age was associated with progression in both early- and late-stage groups. Differences in the rates of disease progression were not significant between blacks and whites or between men and women. Two-year rates of progression among the late-stage patients dropped from 78 to 47% between 1986 and 1988. This contrasted with progression rates in the early-stage cohort, which remained stable: 18% for those entering follow-up in 1986 and 17% for those entering follow-up in 1988. These data indicate a significant slowing of HIV disease progression rates and mortality rates among individuals with late-stage disease that is temporally associated with the increased availability and use of therapies. With control of T4 lymphocyte count, age, and calendar time, neither gender nor race was significantly associated with progression in either early- or late-stage patients.

Adolescent↗
PubMed1992

A brief review of the epidemiology of HIV in the U.S. Army.

The Department of Defense has conducted extensive HIV testing for over 5 years. We summarize the epidemiology of the HIV infection in the total Army. While screening of civilian applicants effectively ensures seronegativity of enlistees, there are approximately 220 new HIV infections each year among active duty soldiers. High-risk demographic groups in the Army include single soldiers, males, those age 25-35, blacks, and Hispanics (including black and Hispanic females). While preventive efforts in the Army should reflect the higher risk experienced by these groups, all soldiers should be made aware of their susceptibility as the epidemic evolves to include more women and heterosexual men.

AIDS Serodiagnosis↗
PubMed1991

Trends of HIV seroconversion among young adults in the US Army, 1985 to 1989. US Army Retrovirus Research Group.

Because soldiers in the US Army are recurrently tested for the presence of antibody to the human immunodeficiency virus (HIV), HIV seroconversion rates can be directly measured. From November 1985 through October 1989, 429 HIV seroconversions were detected among 718,780 soldiers who contributed 1,088,447 person-years of follow-up time (HIV seroconversion rate, 0.39 per 1000 person-years). Period-specific seroconversion rates declined significantly from 0.49 per 1000 person-years (November 1985 through October 1987) to 0.33 per 1000 person-years (November 1987 through October 1988) to 0.29 per 1000 person-years (November 1988 through October 1989). The HIV seroconversion risk among active-duty soldiers was significantly associated with race/ethnic group, age, gender, and marital status. Based on these trends, we estimate that approximately 220 soldiers (95% confidence interval, 160 to 297 soldiers) were infected with HIV during 1989 and 1990, with potentially fewer in future years.

Adolescent↗
PubMed1991

Inpatient psychiatric morbidity of HIV-infected soldiers.

To determine differences in inpatient psychiatric morbidity, a total of 573 soldiers seropositive for the human immunodeficiency virus (HIV) were matched with 2,266 seronegative soldiers by age, sex, race, marital status, military rank, length of active service, military occupation, and date of HIV test. An HIV-infected individual was seven times more likely to be hospitalized than an uninfected individual. The rate of total hospitalizations was 16 times higher for the HIV-infected soldiers. The median length of hospital stay was six days for the infected soldiers and four days for the control group. The incidence of psychosis, organic mental disorders, and adjustment disorder in the HIV-infected group was significantly higher.

AIDS Dementia Complex↗
PubMed1991

Inpatient morbidity among HIV-infected male soldiers prior to their diagnosis of HIV infection.

BACKGROUND: A natural history study of human immunodeficiency virus (HIV) disease was carried out among 1575 HIV-infected US Army men and 6220 demographically similar uninfected soldiers. Inpatient morbidity occurring up to 8 years prior to the date of HIV infection diagnosis among those men who became HIV infected was evaluated for both groups. METHODS: Incidence density rates were calculated for hospital admissions. Poisson regression was used to assess the trend in hospital admissions among those subsequently diagnosed with HIV infection. Prevalence ratios for discharge diagnoses were also calculated. RESULTS: Sixteen diagnoses/diagnosis categories occurred statistically more frequently among subsequently HIV diagnosed individuals than among those who remained uninfected. Among these were hepatitis B and abscess of anal/rectal region (6 to 8 years prior to HIV infection diagnosis); unspecified viral infection, enlarged lymph nodes, syphilis (3 to 5 years prior to HIV infection diagnosis); and diagnoses suggestive of acute retroviral syndrome (1 to 2 years prior to HIV infection diagnosis). CONCLUSIONS: Data such as these may provide useful information to HIV surveillance efforts regarding patterns of morbidity experienced prior to HIV infection as well as to health care providers regarding patients at high risk for becoming infected with HIV.

Adult↗
PubMed1991

HIV infection: military occupational sequelae.

The military experience of 573 soldiers found to be HIV seropositive and their 2,262 matched seronegative controls were compared to determine if differences exist. Examination of personnel records for study members showed an expected difference in assignment changes, with seropositives being moved significantly more often to other units in compliance with a regulation prohibiting their presence in special operations units and units located overseas. Otherwise, there was no statistically significant difference at the 0.05 level when comparing changes in education, military occupational specialty code, promotion, or demotion. Seropositive individuals were less likely to marry, but no more likely to divorce. Seropositives were more likely to be separated from active service and barred from reenlistment for medical reasons.

HIV Infections↗
PubMed1990

Tracking the spread of the HIV infection epidemic among young adults in the United States: results of the first four years of screening among civilian applicants for U.S. military service.

Because the period from infection to clinically apparent disease is long, variable, and changing as new therapies are developed and applied, AIDS data are inadequate for tracking current values of critical parameters of HIV infection epidemics: prevalence of infection, rate of acquisition of new infections (incidence rate), and direction and rate of change of infection incidence over time (acceleration). These "vital signs" of infection epidemics can be tracked using serial cross-sectional seroprevalence data, however. From October 1985 through September 1989, more than 2.3 million applicants for U.S. military service were screened for antibody to HIV. The overall seroprevalence was 1.31 per 1,000 (3,014/2,300,675). Seroprevalences were highest near urban centers of the AIDS epidemic and were independently associated with age, race/ethnicity, and gender. Based on age seroprevalence trends, it was crudely estimated that at least one of 2,000 young men and one of 7,000 young women are infected with HIV annually in the U.S. Infection incidence rates, estimated from age and temporal trends, were estimated to be highest among black males (1.40/1,000/year) and lowest among white females (0.03/1,000/year). Poisson regression analysis of seroprevalence trends suggested that infection incidence rates accelerated among black females during the first 3 years of screening. Since selection factors undoubtedly changed over the period, estimates based on these data probably underestimate actual values in the general population, particularly near urban AIDS epicenters. Nonetheless, even crude estimates of these critical values, particularly among adolescents and young adults, are useful to guide policy development, to allocate resources, and to monitor program effects.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Risk factors for prevalent human immunodeficiency virus (HIV) infection in active duty Army men who initially report no identified risk: a case-control study.

A large proportion of human immunodeficiency virus antibody (HIV-Ab) positive male soldiers are considered to be at no identified risk (NIR) because they do not disclose histories of sexual activity with other men, intravenous drug use, blood transfusions, or sexual activity with persons at known high risk for HIV infection. A case-control study involving personal interviews with 26 NIR cases and 74 controls was conducted to determine if lifestyle information that might jeopardize a soldier's military career could be obtained from an Army population and to evaluate risk factors for prevalent HIV infection. Subjects consented to a voluntary, anonymous, and confidential interview containing information on demographic characteristics, medical history, drug use, and sexual behavior. Of 26 cases interviewed, 20 (76.9%) reported behaviors defined by the Centers for Disease Control (CDC) as risk factors for HIV infection, while 11 of 74 (14.9%) controls also reported such behaviors. This proportion of reclassified NIR cases was similar to that reported from the NIR case series study conducted by the CDC. Of the six (23.1%) cases who remained at NIR, all reported at least one of the following risks: a history of sexually transmitted diseases, sexual contact with prostitutes, or sexual activity with female partners which caused bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Direct measurement of human immunodeficiency virus seroconversions in a serially tested population of young adults in the United States Army, October 1985 to October 1987. Walter Reed Retrovirus Research Group.

Direct measurement of the incidence of infection with the human immunodeficiency virus (HIV)--the rate of new HIV infection--is vital if we are to understand better the dynamics of the current epidemic of HIV infection. Because soldiers are periodically and routinely screened for antibody to HIV, it is possible to measure the incidence of HIV infection directly in this large, demographically well-characterized population of young adults. To determine the incidence of HIV infection in this population, we examined test results reported by the U.S. Army's routine antibody-screening programs. During the first two years of the screening programs, the observed incidence of HIV infection was approximately 0.77 per 1000 persons per year. This rate was higher than expected on the basis of previously published estimates of seroprevalence in the Army (approximately 1.50 per 1000). On the basis of this annual incidence, and assuming it to be stable, we estimate that approximately 600 soldiers will become infected with HIV each year. The observed rate in the Army may be lower than the incidence of HIV infection in the corresponding demographic groups within the general U.S. population.

AIDS Serodiagnosis↗
PubMed1989

A cluster of blister-associated toxic shock syndrome in male military trainees and a study of staphylococcal carriage patterns.

In March-April 1985, toxic shock syndrome (TSS) developed in three male military trainees at one base secondary to infected blisters acquired while marching during basic combat training. One trainee died. Staphylococcus aureus was isolated from the blisters in all three patients, and the two strains available for testing both produced toxic shock syndrome toxin-1 (TSST-1). A culture survey identified carriage of S. aureus in 44% (145/333) of the trainees; carriage rates did not differ between the company with two ill trainees and a control company. Carriage was more frequent in the nose than foot (41% versus 9%, p less than 0.0001). White trainees were more likely to carry S. aureus than black trainees (47% versus 28%, p = 0.013), although the same proportion of strains was positive for TSST-1 in both races. The two strains obtained from the patients had similar but not identical phage typing patterns, but had identical antibiograms, and neither strain carried any plasmids. Based upon phage typing of the TSST-1 positive S. aureus strains isolated in the study, widespread carriage of the case strain(s) in other trainees was not found nor was clustering noted by barrack room. It is possible that differences in carriage rates may partially explain the low rate of TSS in blacks.

Adult↗
PubMed1989

Evidence for spread of the human immunodeficiency virus epidemic into low prevalence areas of the United States.

Reports of an increased proportion of AIDS cases occurring in small and medium-sized cities suggest that the HIV epidemic may be spreading into locations that were previously characterized by their low HIV antibody prevalences. Studying the question of the geographic spread of the HIV infection epidemic (rather than the AIDS epidemic) has been difficult largely because most serial seroprevalence data have been gathered from cohorts of high risk individuals (e.g., homosexual/bisexual cohorts) in New York City, San Francisco, and other geographically circumscribed areas. The U.S. military applicant HIV screening data were used in the current report to examine rates and 24 month temporal trends in geographic areas characterized by their HIV endemicities. The data examined concern the seven most populous states and four hyperendemic metropolitan areas located within those states (New York City, Miami, Houston, and San Francisco). In the nonepidemic regions, seroprevalence rates increased among black and white applicants. In the four epidemic urban areas, only young black applicants had higher HIV seroprevalence rates during the second 12 month period. Six of the seven nonepidemic regions had positive HIV seroprevalence trends, and these trends were significant in Florida, California, Texas, Illinois, and Ohio. The increases in these regions were greater for young blacks (30% excess for year 2 vs. year 1) compared to young whites (12% excess for year 2 vs. year 1). These data provide evidence of birth year specific increases in seroprevalence over time occurring in presumed low HIV prevalence areas. These increases cannot be due to, but are observed in spite of, biases associated with increasing self-selection over time.

Acquired Immunodeficiency Syndrome↗