Diverse blood exposures associated with incident HIV infection in Calabar, Nigeria.

Few types of blood exposures have been assessed in relation to incident HIV infection in sub-Saharan Africa, despite evidence that penile-vaginal sex cannot account for the epidemic in the region. To investigate correlates of incident HIV infection in Calabar, Nigeria, we surveyed clients at voluntary HIV counselling and testing centres. Participating clients who tested multiple times were generally similar to those testing only once in terms of demographic characteristics, sexual and blood exposures and HIV prevalence. Blood exposures were common. Serial testers had a 10% annual incidence of HIV infection. Seroconverters and seronegative serial testers were similar on most demographic characteristics and sexual exposures. However, seroconverters were more likely than seronegatives to report blood exposures during the test interval, both for most specific exposures as well as summary measures of blood exposures. In particular, seroconverters were substantially more likely to report one of a set of blood exposures that cannot be explained as a consequence of unprotected vaginal sex or of health care for symptoms of HIV infection (adjusted odds ratio = 6.6, 95% confidence interval = 1.2-38). The study design we used is an inexpensive approach for describing the local epidemiology of HIV transmission and can also serve as the foundation for more definitive investigations that employ contact tracing and sequencing of HIV DNA.

Horizontally-acquired HIV infection in Kenyan and Swazi children.

Despite many reports of HIV-infected African children who have HIV-uninfected mothers, little is known about the extent and modes of horizontal HIV transmission in African children. We estimated the extent of horizontal HIV transmission in Swazi children by comparing child and mother HIV statuses in the 2006-2007 Swaziland Demographic and Health Survey (DHS). To identify correlates of horizontal HIV transmission, we conducted a case-control study of Kenyan children with horizontally acquired HIV infections and their uninfected siblings. Of 50 HIV-positive Swazi children in the DHS, 11 (weighted percent = 20, 95% confidence interval 11-33%) had HIV-negative mothers. These 11 children represented 0.6% of all Swazi children aged 2-12 who lived with their mothers. In the Kenyan study, children with horizontally acquired HIV infections had more kinds of blood exposures than their uninfected siblings. In particular, punctures related to health care for suspected malaria (phlebotomy, injection and infusion), injections while hospitalized and dental surgery (especially by informal providers) were more common in infected children. Horizontal HIV transmission appears to be common in some sub-Saharan African countries, and blood exposures seem to be the most likely routes of transmission. Rigorous surveillance and investigation of horizontally acquired HIV infection in children are urgently needed, along with universal public education about risks of specific blood exposures and ways to avoid them.

Evaluation of a patient referral contact tracing programme for hepatitis B and C virus infection in drug injectors.

Effective contact tracing for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection could enhance disease control, especially in populations with low HBV vaccination rates and high prevalence of untreated HCV infection. We evaluated a low-cost approach to HBV/HCV contact tracing in injection drug users (IDUs). Index cases (n=26) were IDUs who seroconverted to HBV and/or HCV during a prospective cohort study in Seattle. Interviewers elicited index cases' recent injection partners and administered recall cues and other techniques to boost recall. Index cases received vouchers for free hepatitis testing, which they were to give to locatable partners. Persons redeeming vouchers also received small monetary incentives. Most (26/40) seroconverters participated in the paid contact interviews. Index cases reported many partners (mean=17), and in the aggregate, index cases indicated they could refer more than one third of their elicited partners for testing. Overall, only 17 persons were ultimately referred and just eight of these were confirmed as partners sought for referral. The supplementary elicitation techniques, and especially the recall cues, increased reporting of injection partners substantially. The injection network constructed from reported partnerships was mostly connected and cyclic. Successful contact tracing in IDUs likely requires active involvement by public health staff to locate and notify exposed injection partners.

Evaluation of interviewing techniques to enhance recall of sexual and drug injection partners.

BACKGROUND: People with multiple sex partners forget a significant proportion of their partners, and drug injectors forget a large proportion of the persons with whom they inject drugs. This incomplete reporting poses a problem for partner notification and social network research on infectious disease. GOAL: To evaluate supplementary interviewing techniques to enhance recall of sex and injection partners. STUDY DESIGN: One hundred thirty-nine persons at high risk for HIV participated in a randomized trial of interviewing techniques. After participants freely recalled their partners, interviewers administered one of five techniques to elicit partners who might have been forgotten. Four experimental techniques involved cues (locations, role relationships, personal timeline, and partners recalled prior to cues) developed from memory research. Alphabetic cues served as a control technique. To assess the cumulative effects of the techniques, all five techniques were administered to another 19 participants. RESULTS: In the randomized trial, the techniques varied moderately in effectiveness and time efficiency. When administered as a set, the five techniques increased the number of sex and injection partners elicited by 40% and 123%, respectively, on average. The techniques were most effective with individuals who recalled many partners before the cues and/or sensed they might be forgetting partners. The available evidence indicates cue-elicited partners are as valid as partners recalled before the cues. On epidemiologically significant variables, cue-elicited partners also are similar to partners recalled before the cues. CONCLUSION: The supplementary techniques counteract forgetting appreciably and may promote more effective partner notification and more complete description of risk networks.

Prostitution and the sex discrepancy in reported number of sexual partners.

One of the most reliable and perplexing findings from surveys of sexual behavior is that men report substantially more sexual partners than women do. We use data from national sex surveys and studies of prostitutes and their clients in the United States to examine sampling bias as an explanation for this disparity. We find that prostitute women are underrepresented in the national surveys. Once their undersampling and very high numbers of sexual partners are factored in, the discrepancy disappears. Prostitution's role in the discrepancy is not readily apparent because men are reluctant to acknowledge that their reported partners include prostitutes.

Forgetting as a cause of incomplete reporting of sexual and drug injection partners.

BACKGROUND AND OBJECTIVES: Partner notification and social network studies of infectious disease often involve interviewing people to elicit their sexual and/or drug injection partners. Incomplete reporting of partners in these contexts would significantly hamper efforts to understand and control the spread of sexually transmitted diseases, HIV, and other infections. There are many reasons why individuals might not name their partners in interviews. This study provides a comprehensive assessment of forgetting as a cause of incomplete reporting of sexual and injection partners. STUDY DESIGN: One hundred fifty-six persons in Seattle, Washington, at presumed high risk for HIV recalled their sexual and/or injection partners in two interviews separated by 1 week or 3 months. RESULTS: Repeated, nonspecific prompting elicited, on average, 10% of all partners recalled in an interview. Subjects displayed substantial forgetting of partners across partner types, recall periods, and four independent measurement approaches, with up to 72% of partners forgotten. The number of partners recalled and subjective assessment of forgetting are moderate to good predictors of the number of partners forgotten. Recalled and forgotten partners do not differ dramatically on any of several partner variables. CONCLUSIONS: Forgetting is a primary factor in the incomplete reporting of sexual and injection partners. Interviewers should prompt repeatedly to maximize recall of partners. Reinterviewing is currently the best method available for identifying partners as completely as possible and should be focused on individuals who report many partners and/or sense they have other partners they cannot recall.

Drug use predictors of partner violence in opiate-dependent women.

This paper examines the use of specific drugs as longitudinal predictors of violence between domestic partners in a sample of women in methadone treatment for opiate addiction. Crack cocaine use, use of other forms of cocaine, and tranquilizer use are each modestly to moderately positively associated with partner violence victimization. Women who were heavy users of these drugs were more likely to be hit, slapped, or shoved by their partners than light users or nonusers of these drugs. Three possible explanations of these associations are considered.

A meta-analysis of predictors of continued drug use during and after treatment for opiate addiction.

AIMS: Many people treated for opiate addiction continue to use drugs during and after treatment. It may be possible to improve outcomes by addressing patient characteristics that predict continued drug use. This review uses meta-analytic techniques to identify risk factors for continued drug use in patients treated for opiate abuse. DESIGN AND MEASUREMENTS: A thorough search of the published literature yielded 69 studies that reported information on the bivariate association between one or more independent variables and continued use of illicit drugs during and after treatment for opiate addiction. FINDINGS: Most of the patient variables summarized have weak longitudinal relationships with continued drug use, although several variables display moderate longitudinal associations. Ten variables show statistically significant and longitudinally predictive relationships (average r > 0.1) with continued use, including: high level of pretreatment opiate/drug use, prior treatment for opiate addiction, no prior abstinence from opiates, abstinence from/light use of alcohol, depression, high stress, unemployment/employment problems, association with substance abusing peers, short length of treatment, and leaving treatment prior to completion. Several other variables may be potentially longitudinally predictive. CONCLUSIONS: To prevent relapse, treatment interventions should address multiple variables because no single variable strongly predicts continued drug use.

Psychiatric disorders in spouse caregivers of care recipients with Alzheimer's disease and matched controls: a diathesis-stress model of psychopathology.

To test a diathesis-stress model of psychopathology, the authors examined the rates of current and lifetime psychiatric disorders in 82 spouse caregivers of Alzheimer's disease (AD) patients and 86 demographically matched controls. Caregivers and controls did not differ in the prevalence of disorders before the onset of care recipients' AD (or during a similar time period for the controls); caregivers experienced more depressive-anxiety disorders after the onset of patient's AD than controls. This study strongly supported the 3 key components of a diathesis-stress interaction. First, caregivers with a psychiatric history prior to the onset of patient's AD were more likely than caregivers with no history to receive a diagnosis after the onset of AD. Second, a similar relationship existed for controls. Finally, caregivers with a psychiatric history were more likely to experience a recurrence after the onset of AD than controls with a psychiatric history. These findings indicate that the diathesis of psychiatric history and the stress of caregiving interact, resulting in the observed group differences in the prevalence of psychiatric disorders.

The social structural basis of the organization of persons in memory.

This paper summarizes and discusses three studies of patterns in the recall of persons in socially bounded communities. Individual sin three different communities (a graduate academic program, a religious fellowship, and a department in a formal organization) free-listed the names of persons in their respective communities. Results indicate that the individuals in each community share a common cognitive structure of community members that is based on the community's social structure. These studies, combined with the results of other research, strongly suggest that persons are organized in memory according to social structural principles and that affiliation and dominance are the principal dimensions of social cognition. Suggestions are offered for future research to test the generality of these findings.

Disparate relationships between blood pressure and left ventricular mass in patients with and without left ventricular hypertrophy.

The relationship between casual blood pressure and left ventricular (LV) mass has been reported to be fairly weak in hypertensive patients. In this study we analyzed this relationship using noninvasive devices to monitor blood pressure for 24 hours in ambulatory patients and M-mode echocardiography to determine LV mass. Among the 33 patients with hypertension, 21 had echocardiographic LV hypertrophy (LV mass greater than 250 g). Patients with LV hypertrophy did not differ significantly from patients without hypertrophy with respect to age or casual systolic or diastolic blood pressure. The averages of whole-day systolic and diastolic blood pressures were 146 +/- 17 (SD) over 90 +/- 12 and 136 +/- 16 over 89 +/- 12 mm Hg, respectively. The relationship between whole-day average systolic blood pressure and LV mass was significantly positive (r = 0.66, p less than 0.05) in patients without hypertrophy but was not significant in patients with LV hypertrophy (r = -0.24). Similarly, the relationship between whole-day average diastolic blood pressure and LV mass was significantly positive in the former group (r = 0.64, p less than 0.05) but significantly negative in hypertensive patients with LV hypertrophy (r = -0.67, p less than 0.01). Thus, blood pressure correlates positively with LV mass only in patients without cardiac hypertrophy. In hypertensive patients with LV hypertrophy, factors additional to the high blood pressure itself must participate in the regulation of LV mass.

Transdermal continuous antihypertensive therapy.

Self-adhesive patches containing a 7-day supply of transdermal clonidine were used to treat twenty patients with mild essential hypertension. These skin patches (3.5 cm2), which were changed by the patients every week, reduced diastolic blood-pressure to less than 90 mm Hg in twelve patients. When placebo-containing patches were substituted in these twelve patients after 3 months of treatment, blood-pressure rose slowly to its pretreatment level. Side effects appeared to be milder than those experienced during conventional oral antihypertensive treatment. Plasma clonidine concentrations were lower than peak levels after oral administration. This new method for treating hypertension was convenient and well tolerated, and may increase patient compliance.

Long-term BP monitoring in the evaluation of antihypertensive therapy.

Noninvasive BP monitoring was performed in hypertensive patients before and during placebo therapy and before and during therapy with the long-acting peripheral alpha-adrenergic receptor antagonist, terazosin hydrochloride. Placebo therapy did not result in significant changes in casual BP or in averages of whole-day, daytime, or nighttime BPs. Short-term therapy with terazosin did not induce significant changes in casual supine or daytime BPs. However, whole-day BP monitoring disclosed that nighttime BPs were lower during shortterm therapy. Moreover, the circadian pattern of BP was shifted downward during terazosin therapy. Long-term therapy with terazosin resulted in significant changes in BP. All BP values were lowered significantly. The differences in the circadian BP pattern between placebo and long-term terazosin therapy show that in these patients BP was lowered throughout the 24 hours of the day. The results of the study emphasize the usefulness of 24-hour BP monitoring in the evaluation of the effectiveness of long-acting antihypertensive agents.

A representative value for whole-day BP monitoring.

Shorter-term alternatives to 24-hour monitoring of BP were analyzed in six hypertensive patients. Average BPs during the 24-hour period were lower than averages during a two-hour morning period or those based on either three readings or a single reading taken at 8 AM. The systolic and diastolic BP two-hour averages correlated more strongly with the 24-hour averages than did the three-reading or single-reading alternatives. Thus, the average of serial BP readings obtained during a two-hour morning period is a consistent predictor of the whole-day BP and represents it more closely than the conventionally used single reading.

A vasodilator that avoids renin stimulation and fluid retention: antihypertensive treatment with trimazosin.

Trimazosin was given for periods of at least 6 mo to 25 patients with mild to moderate essential hypertension. In doses of 300 to 900 mg dialy trimazosin alone led to blood pressure control (supine diastolic blood pressure less than 90 mm Hg with a fall of at least 10 mm Hg) in 16 patients (64%). Despite the decrements in blood pressure there were no changes in body weight or creatinine clearance. There was also no changes in plasma renin activity or urinary aldosterone excretion rate. Although patients with high control renin values appeared to have greater blood pressure decreases than those with low renin values, responsiveness to treatment was not associated with consistent effects of trimazosin on the renin-angiotensin system. Trimazosin induced a small decrease in plasma total cholesterol concentration. In seven patients whose blood pressures were not controlled by trimazosin alone, the addition of polythiazide led to decreased blood pressure and in five control of pressure was achieved. Thus, trimazosin is an effective antihypertensive when given by itself or in combination with a diuretic. Its mechanism of action has not been established, but its ability to induce vasodilation without concomitant sodium retention or stimulation of the renin axis may be an important factor in its effectiveness.

Centrally acting antihypertensive agents: a comparison of lofexidine with clonidine.

Lofexidine, a new centrally acting antihypertensive agent, was compared in a double-blind study with clonidine in the treatment of mild (standing diastolic blood pressure 95-104 mm Hg) or moderate (105-129 mm Hg) essential hypertension. In dialy dosages of 0.2 or 0.4 mg, monotherapy with lofexidine produced significant decreases in blood pressure and heart rate that were not different from those with clonidine. Blood pressure and heart rate were not different from those with clonidine. Blood pressure control (supine and standing diastolic pressure less than 90 mm Hg) occurred in seven of eight mild hypertensives treated with lofexidine and in seven of ten treated with clonidine. In moderate hypertension, three of 11 and seven of ten, ten of the 14 responders to clonidine required dosages of 0.4 mg daily or less. The maximum dosage tested was 1.6 mg daily. Concomitant hydrochlorothiazide therapy was given to eight of the lofexidine responders and 12 of the clonidine responders. For both drugs, drowsiness and dry mouth were the chief complaints. Neither agent changed standard clinical biochemistries except for decreased potassium and increased bicarbonate concentrations due to concurrent diuretic therapy. Lofexidine to have clinical characteristics similar to those of clonidine. Each of these agents is best used in lower doses, which are frequently effective and less likely to produce symptomatic complaints.