Addressing the unmet mental health needs of people living with HIV: a scoping review of interventions in sub-Saharan Africa

Some mental health interventions have addressed mental health among people living with HIV (PLWH) using a variety of approaches, but little is known about the details of such interventions in sub-Saharan Africa (SSA), a region that bears the largest burden of HIV in the world. The present study describes mental health interventions for PLWH in SSA regardless of the date and language of publication. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) reporting guidelines, we identified 54 peer-reviewed articles on interventions addressing adverse mental health conditions among PLWH in SSA. The studies were conducted in 11 different countries, with the highest number of studies in South Africa (33.3%), Uganda (18.5%), Kenya (9.26%), and Nigeria (7.41%). While only one study was conducted before the year 2000, there was a gradual increase in the number of studies in the subsequent years. The studies were mostly conducted in hospital settings (55.5%), were non-pharmacologic (88.9%), and interventions were mostly cognitive behavioural therapy (CBT) and counselling. Task shifting was the primary implementation strategy used in four studies. Interventions addressing the mental health needs of PLWH that incorporates the unique challenges and opportunities in SSA is highly recommended.

HIV incidence among non-migrating persons following a household migration event: a population-based, longitudinal study in Uganda

Background

The impact of migration on HIV risk among non-migrating household members is poorly understood. We measured HIV incidence among non-migrants living in households with and without migrants in Uganda.

Methods

We used four survey rounds of data collected from July 2011-May 2018 from non-migrant participants aged 15-49 years in the Rakai Community Cohort Study, an open, population-based cohort. Non-migrants were individuals with no evidence of migration between surveys or at the prior survey. The primary exposure, household migration, was assessed using census data and defined as ≥1 household member migrating in or out of the house from another community between surveys (∼18 months). Incident HIV cases tested positive following a negative result at the preceding visit. Incidence rate ratios (IRR) with 95% confidence intervals were estimated using Poisson regression with generalized estimating equations and robust standard errors. Analyses were stratified by gender, migration into or out of the household, and the relationship between non-migrants and migrants (i.e., any household migration, spouse, child).

Findings

Overall, 11,318 non-migrants (5,674 women) were followed for 37,320 person-years. 28% (6,059/21,370) of non-migrant person-visits had recent migration into or out of the household, and 240 HIV incident cases were identified in non-migrating household members. Overall, non-migrants in migrant households were not at greater risk of acquiring HIV. However, HIV incidence among men was significantly higher when the spouse had recently migrated in (adjIRR:2·12;95%CI:1·05-4·27) or out (adjIRR:4·01;95%CI:2·16-7·44) compared to men with no spousal migration. Women with in- and out-migrant spouses also had higher HIV incidence, but results were not statistically significant.

Interpretation

HIV incidence is higher among non-migrating persons with migrant spouses, especially men. Targeted HIV testing and prevention interventions such as pre-exposure prophylaxis could be considered for those with migrant spouses.

Funding

National Institutes of Health, US Centers for Disease Control and Prevention.

Research in context

We searched PubMed for studies focused on HIV acquisition, prevalence or sexual behaviors among non-migrants who lived with migrants in sub-Saharan Africa (SSA) using search terms such as "HIV", "Emigration and Immigration", "family", "spouses", "household", "parents", and "children". Despite high levels of migration and an established association with HIV risk in SSA, there is limited data on the broader societal impacts of migration on HIV acquisition risk among non-migrant populations directly impacted by it.There has been only one published study that has previously evaluated impact of migration on HIV incidence among non-migrating persons in sub-Saharan Africa. This study, which exclusively assessed spousal migration, was conducted in Tanzania more than two decades earlier prior to HIV treatment availability and found that non-migrant men with long-term mobile partners were more than four times as likely to acquire HIV compared to men who had partners that were residents. To the best of our knowledge, this is the first study to examine the effect of non-spousal migration, including any household migration and child migration, on HIV incidence among non-migrants.

Added value of this study

In this study, we used data from the Rakai Community Cohort Study (RCCS), a population-based HIV surveillance cohort to measure the impact of migration on HIV incidence for non-migrant household members. The RCCS captures HIV incident events through regular, repeat HIV testing of participants and migration events through household censuses. Our study adds to the current literature by examining the general effect of migration in the household on HIV incidence in addition to child, and spousal migration. Using data from over 11,000 non-migrant individuals, we found that spousal, but not other types of household migration, substantially increased HIV risk among non-migrants, especially among men. Taken together, our results suggest that spousal migration may be associated with an increased risk of HIV acquisition in the period surrounding and immediately after spousal migration.

Implications of all the available evidence

Our findings suggest that spousal migration in or out of the household is associated with greater HIV incidence. Targeted HIV testing and prevention interventions such as pre-exposure prophylaxis could be considered for men with migrant spouses.

Perceived stigma among people with TB and household contacts

BACKGROUND: TB-related stigma hampers access to diagnosis and treatment, making it important to understand the demographic and clinical characteristics associated with perceived TB stigma. TB stigma has not been studied in household contacts before, yet they comprise an important population for epidemic control, with high risk of infection.METHOD: A cross-sectional study was conducted among people with TB and household contacts in South Africa using a 12-item perceived TB stigma scale (score range: 0-36). Demographic and clinical characteristic data were collected using a close-ended questionnaire. A linear mixed-effects regression model was used to explore perceived TB stigma levels and its associated characteristics.RESULTS: The sample included 143 people with TB and 135 household contacts. The mean perceived TB stigma score among people with TB was 22.1 (95% CI 21.1-23.1) and 22.2 (95% CI 21.1-23.3) among household contacts. Being in the same household explained 24.3% variability in stigma perception. Residence in the urban study site (Soshanguve) and a positive HIV diagnosis were associated with higher perceived TB stigma score.CONCLUSIONS: People with TB and household contacts have similarly high prevalence of perceived TB stigma. Positive HIV status and urban location were associated with higher prevalence of perceived TB stigma.

Investigating linkage to care between hospitals and primary care clinics for people with TB in rural South Africa

People with tuberculosis (TB) are often lost to follow-up during treatment transition to another facility. These losses may result in substantial morbidity and mortality but are rarely recorded. We conducted a record review on adults diagnosed with TB at 11 hospitals in Limpopo, South Africa, who were subsequently transferred to a local clinic to initiate or continue treatment. We then performed in-depth record reviews at the primary care clinic to which they were referred and called participants who could not be identified as starting treatment. Between August 2017 and April 2018, we reviewed records of 778 individuals diagnosed with TB in-hospital and later referred to local clinics for treatment. Of the 778, 88 (11%) did not link to care, and an additional 43 (5.5%) died. Compared to people without cough, those with cough had higher odds of linking to care (aOR = 2.01, 95% CI: 1.26-3.25, p = 0.005) and were also linked more quickly [adjusted Time Ratio (aTR) = 0.53, 95% CI:0.36-0.79, p<0.001], as were those diagnosed microbiologically (aOR = 1.86, 95% CI: 1.16-3.06, p = 0.012; aTR = 0.58, 95% CI: 0.34-0.98, p = 0.04). People diagnosed with TB in hospitals often disengage following referral to local clinics. Interventions to identify and re-engage people who do not present to local clinics within days of referral might close an important gap in the TB treatment cascade.

Pragmatic cluster-randomized trial of home-based preventive treatment for TB in Ethiopia and South Africa (CHIP-TB)

BACKGROUND

Each year, 1 million children develop TB resulting in over 200,000 child deaths. TB preventive treatment (TPT) is highly effective in preventing TB but remains poorly implemented for household child contacts. Home-based child contact management and TPT services may improve access to care. In this study, we aim to evaluate the effectiveness and cost-effectiveness of home-based contact management with TPT initiation in two TB high-burden African countries, Ethiopia and South Africa.

METHODS

This pragmatic cluster randomized trial compares home-based versus facility-based care delivery models for contact management. Thirty-six clinics with decentralized TB services (18 in Ethiopia and 18 in South Africa) were randomized in a 1:1 ratio to conduct either home-based or facility-based contact management. The study will attempt to enroll all eligible close child contacts of infectious drug-sensitive TB index patients diagnosed and treated for TB by one of the study clinics. Child TB contact management, including contact tracing, child evaluation, and TPT initiation and follow-up, will take place in the child's home for the intervention arm and at the clinic for the control arm. The primary outcome is the cluster-level ratio of the number of household child contacts less than 15 years of age in Ethiopia and less than 5 years of age in South Africa initiated on TPT per index patient, comparing the intervention to the control arm. Secondary outcomes include child contact identification and the TB prevention continuum of care. Other implementation outcomes include acceptability, feasibility, fidelity, cost, and cost-effectiveness of the intervention.

DISCUSSION

This implementation research trial will determine whether home-based contact management identifies and initiates more household child contacts on TPT than facility-based contact management.

TRIAL REGISTRATION

NCT04369326 . Registered on April 30, 2020.

Household- Versus Incentive-Based Contact Investigation for Tuberculosis in Rural South Africa: A Cluster-Randomized Trial

BACKGROUND

Household contact investigation for people newly diagnosed with tuberculosis (TB) is poorly implemented, particularly in low- and middle-income countries. Conditional cash incentives may improve uptake.

METHODS

We conducted a pragmatic, cluster-randomized, crossover trial of 2 TB contact investigation approaches (household-based and incentive-based) in 28 public primary care clinics in South Africa. Each clinic used 1 approach for 18 months, followed by a 6-month washout period, after which the opposite approach was used. Fourteen clinics were randomized to each approach. In the household-based arm, we conducted TB screening and testing of contacts at the household. In the incentive-based arm, both index patients and ≤10 of their close contacts (either within or outside the household) were given small cash incentives for presenting to study clinics for TB screening. The primary outcome was the number of people with incident TB who were diagnosed and started on treatment at study clinics.

RESULTS

From July 2016 to January 2020, we randomized 28 clinics to each study arm, and enrolled 782 index TB patients and 1882 contacts in the household-based arm and 780 index patients and 1940 contacts in the incentive-based arm. A total of 1413 individuals started on TB treatment in the household-based arm and 1510 in the incentive-based arm. The adjusted incidence rate ratio of TB treatment initiation in the incentive- versus household-based arms was 1.05 (95% confidence interval: .97-1.13).

CONCLUSIONS

Incentive-based contact investigation for TB has similar effectiveness to traditional household-based approaches and may be a viable alternative or complementary approach to household-based investigation.

Time to care-seeking for TB symptoms

BACKGROUND: Early presentation to healthcare facilities is critical for early diagnosis and treatment of TB. We studied self-reported time to care-seeking from the onset of TB symptoms among primary healthcare clinic (PHC) attendees in Limpopo Province, South Africa.METHODS: We used data from participants enrolled in a cluster-randomized trial of TB case finding in 56 PHC clinics across two health districts. We fitted log-normal accelerated failure time regression models and we present time ratios (TRs) for potential risk factors.RESULTS: We included 2,160 participants. Among the 1,757 (81%) diagnosed with active TB, the median time to care-seeking was 30 days (IQR 14-60); adults sought care later than children/adolescents (adjusted TR aTR 1.47, 95% CI 1.10-1.96). Among those not diagnosed with TB, the median was 14 days (IQR 7-60); being HIV-positive (aTR 1.57, 95% CI 1.03-2.40); having less than grade 8 education and currently smoking were associated with longer time to care-seeking. In the combined analysis, living with HIV and having underlying active TB was associated with faster care-seeking (TB status x HIV interaction: TR 0.68, 95% CI 0.48-0.96).CONCLUSION: Delay in care-seeking was associated with age, lower education and being a current smoker. TB awareness campaigns targeting these population groups may improve care-seeking behavior and reduce community TB transmission.

Racial differences in the dermatological manifestations of tuberous sclerosis complex and the potential effects on diagnosis and care

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder of non-malignant tumor growths throughout major organ systems and neurological, neuropsychiatric, renal, and pulmonary co-morbidities. Skin manifestations are readily visible, often develop early in life, and are major features that contribute to TSC diagnosis. Medical photographs of such manifestations are commonly shown as examples from White individuals creating a potential barrier to accurately identifying these features in darker skinned individuals.

Objectives

The aim of this report is to raise awareness of dermatological manifestations associated with TSC, compare their appearance by race, and consider how recognition of these features could impact diagnosis and treatment of TSC.

Design and Methods

We conducted a retrospective chart review at the TSC Center of Excellence (TSCOE) at the Kennedy Krieger Institute, which included all patients in the center from 2009 (inception) through the end of the calendar year 2015 and analyzed data from the TSC Alliance Natural History Database (NHD).

Results

Among TSCOE patients, 50% of Black patients were diagnosed before the age of 1 year, compared with 70% of White patients. NHD data corroborated this trend showing a significant difference with only 38% of Blacks as compared with 50% of Whites were diagnosed at age ⩽1 year. A significant difference was observed where White participants had higher odds of having received genetic testing in both data sets. While no differences in the total number of TSC features was observed in either data set, shagreen patches and cephalic fibrous plaques were more frequently recorded in the NHD for Black individuals.

Conclusion

We highlight a disparity in the representation of Black participants within the NHD, TSCOE, and TSC trials, in addition to differences in utilization of molecular testing and topical mechanistic target of rapamycin (mTOR) inhibitor therapy between Black and White individuals. We show a trend toward later diagnosis age in Black individuals. These differences between races warrant further study across additional clinical sites and other minority groups.

Geographic mobility and time to seeking care among people with TB in Limpopo, South Africa

SETTING: Human mobility contributes to the spread of infectious diseases. South Africa has a long history of internal labor migration and a high burden of TB.METHODS: People newly diagnosed with TB in the Vhembe and Waterberg Districts of Limpopo answered a questionnaire regarding geographic movement over the past year. Participants were classified as 'highly mobile' (spending more than 30 nights at a residence other than their primary residence in the past year, or being ≥250 km from their primary residence at the time of the interview) or 'less mobile'. We explored associations between sociodemographic characteristics and high mobility, and between mobility and time to presentation at a clinic.RESULTS: Of the 717 participants included, 185 (25.7%) were classified as 'highly mobile'. Factors associated with high mobility included living with someone outside of Limpopo Province, HIV-positive status (men only), and current smoking (men only). Highly mobile individuals had similar care-seeking behavior as less mobile individuals (adjusted time ratio 0.9, 95% CI 0.6-1.2, P = 0.304)CONCLUSION: Highly mobile people with TB in Limpopo Province were more likely to live with people from outside the province, smoke, and have HIV. These patients had similar delays in seeking care as less mobile individuals.

Determinants of infant breastfeeding practices in Nepal: a national study

Background

Optimal breastfeeding practices, reflected by early initiation and feeding of colostrum, avoidance of prelacteal feeds, and continued exclusivity or predominance of breastfeeding, are critical for assuring proper infant nutrition, growth and development.

Methods

We used data from a nationally representative survey in 21 district sites across the Mountains, Hills and Terai (southern plains) of Nepal in 2013. Determinants of early initiation of breastfeeding, feeding of colostrum, prelacteal feeding and predominant breastfeeding were explored in 1015 infants < 12 months of age. Prelacteal feeds were defined as food/drink other than breast milk given to newborns in first 3 days. Predominant breastfeeding was defined as a child < 6 months of age is mainly breastfed, not fed solid/semi-solid foods, infant formula or non-human milk, in the past 7 days. Adjusted prevalence ratios (APR) and 95% confidence intervals (CI) were estimated, using log Poisson regression models with robust variance for clustering.

Results

The prevalence of breastfeeding within an hour of birth, colostrum feeding, prelacteal feeding and predominant breastfeeding was 41.8, 83.5, 32.7 and 57.2% respectively. Compared to infants not fed prelacteal feeds, infants given prelacteal feeds were 51% less likely to be breastfed within the first hour of birth (APR 0.49; 95% CI 0.36, 0.66) and 55% less likely to be predominantly breastfed (APR 0.45; 95% CI 0.32, 0.62). Infants reported to have received colostrum were more likely to have begun breastfeeding within an hour of birth (APR 1.26; 95% CI 1.04, 1.54) compared to those who did not receive colostrum. Infants born to mothers ≥ 20 years of age were less likely than adolescent mothers to initiate breastfeeding within 1 hour of birth. Infants in the Terai were 10% less likely to have received colostrum (APR 0.90; 95% CI 0.83, 0.97) and 2.72 times more likely to have received prelacteal feeds (APR 2.72; 95% CI 1.67, 4.45) than those in the Mountains.

Conclusions

Most infants in Nepal receive colostrum but less than half initiate breastfeeding within an hour of birth and one-third are fed prelacteal feeds, which may negatively affect breastfeeding and health throughout early infancy.

Electronic supplementary material

The online version of this article (10.1186/s13006-019-0208-y) contains supplementary material, which is available to authorized users.

Interactive Malaria Education Intervention and Its Effect on Community Participant Knowledge: The Malaria Awareness Program in Vhembe District, Limpopo, South Africa

Malaria is preventable and treatable, yet remains the most prevalent parasitic endemic disease in Africa. This article analyzes prospective observational data from the Malaria Awareness Program (MAP), an interactive malaria education initiative led by home-based care workers to improve participant knowledge of malaria as a precursor to increased uptake of malaria control interventions in the Vhembe District, Limpopo, South Africa. Between 2012 and 2016, 1,330 individuals participated in MAP. MAP's effectiveness was measured through pre- and post-participation surveys assessing knowledge in malaria transmission, symptoms, prevention, and treatment. The primary analysis assessed differences in knowledge between individuals who completed MAP ( n = 499) and individuals who did not complete MAP ( n = 399). The adjusted odds of correct malaria knowledge score versus partially correct or incorrect score among MAP completers was 3.3 and 2.8 times greater for transmission and prevention, respectively ( p values<.001). A subanalysis assessed knowledge improvement among participants who completed both pre- and post-MAP intervention surveys ( n = 266). There was a 21.4% and 10.5% increase in the proportion of participants who cited correct malaria transmission and prevention methods, respectively. Future research should assess behavioral changes toward malaria prevention and treatment as a result of an intervention and examine incidence changes in the region.

Comparing longitudinal CD4 responses to cART among non-perinatally HIV-infected youth versus adults: Results from the HIVRN Cohort

BACKGROUND

Youth have residual thymic tissue and potentially greater capacity for immune reconstitution than adults after initiation of combination antiretroviral therapy (cART). However, youth face behavioral and psychosocial challenges that may make them more likely than adults to delay ART initiation and less likely to attain similar CD4 outcomes after initiating cART. This study compared CD4 outcomes over time following cART initiation between ART-naïve non-perinatally HIV-infected (nPHIV) youth (13-24 years-old) and adults (≥25-44 years-old).

METHODS

Retrospective analysis of ART-naïve nPHIV individuals 13-44 years-old, who initiated their first cART between 2008 and 2011 at clinical sites in the HIV Research Network. A linear mixed model was used to assess the association between CD4 levels after cART initiation and age (13-24, 25-34, 35-44 years), accounting for random variation within participants and between sites, and adjusting for key variables including gender, race/ethnicity, viral load, gaps in care (defined as > 365 days between CD4 tests), and CD4 levels prior to cART initiation (baseline CD4).

RESULTS

Among 2,595 individuals (435 youth; 2,160 adults), the median follow-up after cART initiation was 179 weeks (IQR 92-249). Baseline CD4 was higher for youth (320 cells/mm3) than for ages 25-34 (293) or 35-44 (258). At 239 weeks after cART initiation, median unadjusted CD4 was higher for youth than adults (576 vs. 539 and 476 cells/mm3, respectively), but this difference was not significant when baseline CD4 was controlled. Compared to those with baseline CD4 ≤200 cells/mm3, individuals with baseline CD4 of 201-500 and >500 cells/mm3 had greater predicted CD4 levels: 390, 607, and 831, respectively. Additionally, having no gaps in care and higher viral load were associated with better CD4 outcomes.

CONCLUSIONS

Despite having residual thymic tissue, youth attain similar, not superior, CD4 gains as adults. Early ART initiation with minimal delay is as essential to optimizing outcomes for youth as it is for their adult counterparts.

Advanced-stage hepatocellular carcinoma with portal vein thrombosis: conventional versus drug-eluting beads transcatheter arterial chemoembolization

OBJECTIVES

Our study sought to compare the overall survival in patients with hepatocellular carcinoma (HCC) and portal venous thrombosis (PVT), treated with either conventional trans-arterial chemoembolization (cTACE) or drug-eluting beads (DEB) TACE.

METHODS

This retrospective analysis included a total of 133 patients, treated without cross-over and compared head-to-head by means or propensity score weighting. Mortality was compared using survival analysis upon propensity score weighting. Adverse events and liver toxicity grade ≥3 were recorded and reported for each TACE. In order to compare with historical sorafenib studies, a sub-group analysis was performed and included patients who fulfilled the SHARP inclusion criteria.

RESULTS

The median overall survival (MOS) of the entire cohort was 4.53 months (95 % CI, 3.63-6.03). MOS was similar across treatment arms, no significant difference between cTACE (N = 95) and DEB-TACE (N = 38) was observed (MOS of 5.0 vs. 3.33 months, respectively; p = 0.157). The most common adverse events after cTACE and DEB- TACE, respectively, were as follows: post-embolization syndrome [N = 57 (30.0 %) and N = 38 (61.3 %)], diarrhea [N = 3 (1.6 %) and N = 3 (4.8 %)], and encephalopathy [N = 11 (5.8 %) and N = 2 (3.2 %)].

CONCLUSION

Our retrospective study could not reveal a difference in toxicity and efficiency between cTACE and DEB-TACE for treatment of advanced stage HCC with PVT.

KEY POINTS

• Conventional TACE (cTACE) and drug-eluting-beads TACE (DEB-TACE) demonstrated equal safety profiles. • Survival rates after TACE are similar to patients treated with sorafenib. • Child-Pugh class and tumor burden are reliable predictors of survival.

The Use of Indwelling Tunneled Pleural Catheters for Recurrent Pleural Effusions in Patients With Hematologic Malignancies: A Multicenter Study

BACKGROUND

Malignant pleural effusion is a common complication of advanced malignancies. Indwelling tunneled pleural catheter (IPC) placement provides effective palliation but can be associated with complications, including infection. In particular, hematologic malignancy and the associated immunosuppressive treatment regimens may increase infectious complications. This study aimed to review outcomes in patients with hematologic malignancy undergoing IPC placement.

METHODS

A retrospective multicenter study of IPCs placed in patients with hematologic malignancy from January 2009 to December 2013 was performed. Inclusion criteria were recurrent, symptomatic pleural effusion and an underlying diagnosis of hematologic malignancy. Records were reviewed for patient demographics, operative reports, and pathology, cytology, and microbiology reports.

RESULTS

Ninety-one patients (mean ± SD age, 65.4 ± 15.4 years) were identified from eight institutions. The mean × SD in situ dwell time of all catheters was 89.9 ± 127.1 days (total, 8,160 catheter-days). Seven infectious complications were identified, all of the pleural space. All patients were admitted to the hospital for treatment, with four requiring additional pleural procedures. Two patients died of septic shock related to pleural infection.

CONCLUSIONS

We present, to our knowledge, the largest study examining clinical outcomes related to IPC placement in patients with hematologic malignancy. An overall 7.7% infection risk and 2.2% mortality were identified, similar to previously reported studies, despite the significant immunosuppression and pancytopenia often present in this population. IPC placement appears to remain a reasonable clinical option for patients with recurrent pleural effusions related to hematologic malignancy.

A variance components factor model for genetic association studies: a Bayesian analysis

Studies of gene-trait associations for complex diseases often involve multiple traits that may vary by genotype groups or patterns. Such traits are usually manifestations of lower-dimensional latent factors or disease syndromes. We illustrate the use of a variance components factor (VCF) model to model the association between multiple traits and genotype groups as well as any other existing patient-level covariates. This model characterizes the correlations between traits as underlying latent factors that can be used in clinical decision-making. We apply it within the Bayesian framework and provide a straightforward implementation using the WinBUGS software. The VCF model is illustrated with simulated data and an example that comprises changes in plasma lipid measurements of patients who were treated with statins to lower low-density lipoprotein cholesterol, and polymorphisms from the apolipoprotein-E gene. The simulation shows that this model clearly characterizes existing multiple trait manifestations across genotype groups where individuals' group assignments are fully observed or can be deduced from the observed data. It also allows one to investigate covariate by genotype group interactions that may explain the variability in the traits. The flexibility to characterize such multiple trait manifestations makes the VCF model more desirable than the univariate variance components model, which is applied to each trait separately. The Bayesian framework offers a flexible approach that allows one to incorporate prior information.

Design sequences for sensory studies: achieving balance for carry-over and position effects

In sequences of human sensory assessments, the response toa stimulus may be influenced by previous stimuli. When investigating this phenomenon experimentally with several types or levels of stimulus, it is useful to have treatment sequences which are balanced for first-order carry-over effects. The requirement of balance for each experimental participant leads us to consider sequences of n symbols comprising an initial symbol followed by n ;blocks' each containing a permutation of the symbols. These sequences are designed to include all n (2) ordered pairs of symbols once each, and to have treatment and sequence position effects which are approximately or thogonal. Such sequences were suggested by Finney and Outhwaite (1956), who were able to find examples for particular values of n. We describe and illustrate acomputer algorithm for systematically enumerating the sequences for those values of n for which they exist. Criteria are proposed for choosing between the sequences according to the nearness to orthogonality of their treatment and position effects.