Research Findings - Research on AIDS and Other Medical Consequences of Drug Abuse - Non-AIDS Medical Consequences of Drug Abuse

Prenatal Drug Exposure: Early Developmental Effects

Findings from the Maternal Lifestyle Study (MLS) show that prenatal cocaine effects at 1 month of age are detectable and subtle. In addition, the analyses demonstrate that the effects of other drugs (opiates, alcohol, marijuana) can also be observed in the context of a polydrug use model. The sample consisted of 658 exposed and 730 comparison infants matched on race, gender, and gestational age. Sites were located in Detroit, Memphis, Miami, and Providence. Cocaine exposure was related to lower arousal, poorer quality of movement and self-regulation, higher excitability, more hypotonia, and more nonoptimal reflexes, with most effects maintained after adjusting for covariates. Some acoustic cry characteristics, reflecting reactivity, respiratory, and neural control of the cry sound were also compromised by prenatal drug exposure (cocaine, opiates, alcohol, and marijuana). The researchers emphasize that the effects are subtle, i.e., reliable but small differences between the groups, not necessarily clinically significant deficits. However, the authors also emphasize that these subtle differences suggest neurobehavioral vulnerability that may be exacerbated by the caregiving environment, with the resulting potential to develop into deficits. In addition, there are long-term implications of the findings (e.g., cocaine may affect areas of the brain with consequences not likely to be seen until school age and beyond). Long-term follow-up is necessary for determining whether these subtle differences develop into clinically significant deficits. Lester, B.M., Tronick, E.Z., LaGasse, L, et al. The Maternal Lifestyle Study: Effects of Substance Exposure During Pregnancy on Neurodevelopmental Outcome in 1-Month-Old Infants. Pediatrics, 110, pp. 1182-1192, 2002.

Prenatal Cocaine Exposure and Child Language Functioning to 7 Years of Age

Dr. Emmalee Bandstra and colleagues at the University of Miami have reported new findings indicating a stable cocaine-specific effect on indicators of language functioning during early childhood through 7 years of age. Language functioning was assessed at ages 3, 5, and 7 years of age. The sample included 443 children (236 prenatally-exposed to cocaine, and 207 not exposed to cocaine). Longitudinal Generalized Linear Model and Generalized Estimating Equations (GLM/GEE) analyses indicated an association between prenatal cocaine exposure and deficits (i.e., about 1/5 standard deviation) in total language standard scores, after controlling statistically for gender of child; visit age; prenatal exposure to alcohol, marijuana, and tobacco; and over 20 potentially confounding medical and sociodemographic covariates. The researchers report that the link from prenatal cocaine exposure to later language deficits does not appear to be mediated by cocaine-associated deficits in birth weight, length, or head circumference. Bandstra, E.S., Morrow, C.E., Vogel, A.L., et al. Neurotoxicology and Teratology, 24, pp. 297-308, 2002.

Staphylococcus Aureus Infection in Drug Abusers

Lowy and his colleagues of Columbia University report that drug users have a higher incidence of colonization with S.aureus than does the general population and as a result are at high risk of infection, and in particular, colonization with similar bacterial isolates of S.aureus among inhalation drug users within drug-use risk networks. Their study suggests that patterns of drug use and the geographic location where drug sharing occurs are major contributors to the transfer of staphylococci and, as a result, to the high prevalence of staphylococcal colonization and perhaps disease in this population (Clinical Infectious Diseases, 35, pp. 671-677, 2002). The investigators also maintain that there is limited understanding of the epidemiology and pathogenesis of S.aureus infection in drug users, partly due the difficulty of studying disease transmission among drug users in the community, and the limitations of the investigative tools that have been used. Based on an extensive review of the literature, the authors suggest that molecular epidemiological techniques and social network methodology should be used to understand the basis of the persistence, distribution, and transmission dynamics of S. aureus among drug users. In this paper they propose a framework for investigating the transmission of pathogens in community-based settings. Lowy, F.D. and Miller, M., New Methods to Investigate Infectious Disease Transmission and Pathogenesis-Staphylococcus aureus Disease in Drug Users, The Lancet, 2, pp. 605-612, 2002.

Cocaine and TB in Drug Users

Howard and her colleagues (Montefiore/Einstein Medical College, NY) report for the first time that cocaine use is one of the risk factors for tuberculin positivity in a community-based cohort of drug users in methadone treatment. In a cohort of about 800 current and former drug users, crack cocaine and alcohol use was associated with an elevated risk of tuberculin positivity. It was more evident in those infected with HIV, drug users who worked as home health aids, elderly, those born in Puerto Rico or a foreign country, and those who had contact with someone with active tuberculosis. The investigators recommend all drug users continue to be targeted for tuberculin testing in accordance with the current CDC guidelines. Howard, A.A., Klein, R.S., Schoenbaum, E.E., and Gourevitch, M.N. Crack Cocaine Use and Other Risk Factors for Tuberculin Positivity in Drug Users, Clinical Infectious Diseases, 35, pp. 1183-1190, 2002.