Neonatal anthropometric indicators of infant growth and mortality in Burkina Faso.

OBJECTIVE: Most evidence supporting screening for undernutrition is for children aged 6-59 months. However, the highest risk of mortality and highest incidence of wasting occurs in the first 6 months of life. We evaluated relationships between neonatal anthropometric indicators, including birthweight, weight-for-age Z-score (WAZ), weight-for-length Z-score (WLZ), length-for-age Z-score (LAZ), and mid-upper arm circumference (MUAC) and mortality and growth at 6 months of age among infants in Burkina Faso. DESIGN: Data arose from a randomized controlled trial evaluating neonatal azithromycin administration for prevention of child mortality. We evaluated relationships between baseline anthropometric measures and mortality, wasting (WLZ < -2), stunting (LAZ < -2), and underweight (WAZ < -2) at 6 months of age was estimated using logistic regression models adjusted for the child's age and sex. SETTING: Five regions of Burkina Faso. PARTICIPANTS: Infants aged 8 to 27 days followed until 6 months of age. RESULTS: Of 21,832 infants enrolled in the trial, 7.9% were low birthweight (<2500 g), 13.3% were wasted, 7.7% were stunted, and 7.4% were underweight at enrollment. All anthropometric deficits were associated with mortality by 6 months of age, with WAZ the strongest predictor (WAZ < -2 to ≥ -3 at enrollment versus WAZ ≥ -2: adjusted odds ratio, aOR, 3.91, 95% confidence interval, CI, 2.21 to 6.56). Low WAZ was also associated with wasting, stunting, and underweight at 6 months. CONCLUSIONS: Interventions for identifying infants at highest risk of mortality and growth failure should consider WAZ as part of their screening protocol.

Associations between Antenatal Care Visit Attendance and Infant Mortality and Growth.

This study examines the association between antenatal care (ANC) attendance and infant mortality and growth outcomes. The study used data from the Nouveux-nés et Azithromycine: une Innovation dans le Traitement des Enfants (NAITRE) trial conducted in Burkina Faso. This analysis included 21,795 neonates aged 8 to 27 days who were enrolled in the trial and had ANC data available. Infants were followed until 6 months of age. The analysis adjusted for potential confounders including infant's sex, maternal age, education, urbanicity, geographic region, season (dry versus rainy), pregnancy type (singleton versus multiple), number of previous pregnancies, if the infant was breastfed, and if the facility had an onsite physician to account for level of care. We used logistic and linear regression models to evaluate the association between ANC visits and all-cause infant mortality and infant growth measurements at 6 months. There was no significant association between ANC visits and 6-month mortality. Higher ANC attendance was associated with improved growth outcomes in infants at 6 months of age. After adjusting for potential confounders, each additional ANC visit was associated with a 0.03 kg increase in mean weight, 0.07 cm increase in mean length, 0.04 SD increase in mean mid-upper-arm circumference, 0.04 SD increase in mean height-for-age, 0.04 SD mean weight-for-age, and 0.02 SD mean weight-for-length Z-scores. These mean differences were statistically significant (except for weight-for-length Z-scores) but may not be clinically meaningful. Further research is warranted to explore the relationship between ANC attendance and longer-term health outcomes among infants.

Mass Azithromycin Distribution to Prevent Child Mortality in Burkina Faso: The CHAT Randomized Clinical Trial.

Importance: Repeated mass distribution of azithromycin has been shown to reduce childhood mortality by 14% in sub-Saharan Africa. However, the estimated effect varied by location, suggesting that the intervention may not be effective in different geographical areas, time periods, or conditions. Objective: To evaluate the efficacy of twice-yearly azithromycin to reduce mortality in children in the presence of seasonal malaria chemoprevention. Design, Setting, and Participants: This cluster randomized placebo-controlled trial evaluating the efficacy of single-dose azithromycin for prevention of all-cause childhood mortality included 341 communities in the Nouna district in rural northwestern Burkina Faso. Participants were children aged 1 to 59 months living in the study communities. Interventions: Communities were randomized in a 1:1 ratio to receive oral azithromycin or placebo distribution. Children aged 1 to 59 months were offered single-dose treatment twice yearly for 3 years (6 distributions) from August 2019 to February 2023. Main Outcomes and Measures: The primary outcome was all-cause childhood mortality, measured during a twice-yearly enumerative census. Results: A total of 34 399 children (mean [SD] age, 25.2 [18] months) in the azithromycin group and 33 847 children (mean [SD] age, 25.6 [18] months) in the placebo group were included. A mean (SD) of 90.1% (16.0%) of the censused children received the scheduled study drug in the azithromycin group and 89.8% (17.1%) received the scheduled study drug in the placebo group. In the azithromycin group, 498 deaths were recorded over 60 592 person-years (8.2 deaths/1000 person-years). In the placebo group, 588 deaths were recorded over 58 547 person-years (10.0 deaths/1000 person-years). The incidence rate ratio for mortality was 0.82 (95% CI, 0.67-1.02; P = .07) in the azithromycin group compared with the placebo group. The incidence rate ratio was 0.99 (95% CI, 0.72-1.36) in those aged 1 to 11 months, 0.92 (95% CI, 0.67-1.27) in those aged 12 to 23 months, and 0.73 (95% CI, 0.57-0.94) in those aged 24 to 59 months. Conclusions and Relevance: Mortality in children (aged 1-59 months) was lower with biannual mass azithromycin distribution in a setting in which seasonal malaria chemoprevention was also being distributed, but the difference was not statistically significant. The study may have been underpowered to detect a clinically relevant difference. Trial Registration: ClinicalTrials.gov Identifier: NCT03676764.

Azithromycin during Routine Well-Infant Visits to Prevent Death.

BACKGROUND: Mass distribution of azithromycin to children 1 to 59 months of age has been shown to reduce childhood all-cause mortality in some sub-Saharan African regions, with the largest reduction seen among infants younger than 12 months of age. Whether the administration of azithromycin at routine health care visits for infants would be effective in preventing death is unclear. METHODS: We conducted a randomized, placebo-controlled trial of a single dose of azithromycin (20 mg per kilogram of body weight) as compared with placebo, administered during infancy (5 to 12 weeks of age). The primary end point was death before 6 months of age. Infants were recruited at routine vaccination or other well-child visits in clinics and through community outreach in three regions of Burkina Faso. Vital status was assessed at 6 months of age. RESULTS: Of the 32,877 infants enrolled from September 2019 through October 2022, a total of 16,416 infants were randomly assigned to azithromycin and 16,461 to placebo. Eighty-two infants in the azithromycin group and 75 infants in the placebo group died before 6 months of age (hazard ratio, 1.09; 95% confidence interval [CI], 0.80 to 1.49; P = 0.58); the absolute difference in mortality was 0.04 percentage points (95% CI, -0.10 to 0.21). There was no evidence of an effect of azithromycin on mortality in any of the prespecified subgroups, including subgroups defined according to age, sex, and baseline weight, and no evidence of a difference between the two trial groups in the incidence of adverse events. CONCLUSIONS: In this trial conducted in Burkina Faso, we found that administration of azithromycin to infants through the existing health care system did not prevent death. (Funded by the Bill and Melinda Gates Foundation; CHAT ClinicalTrials.gov number, NCT03676764.).

Single-dose azithromycin for infant growth in Burkina Faso: Prespecified secondary anthropometric outcomes from a randomized controlled trial.

BACKGROUND: Antibiotic use during early infancy has been linked to childhood obesity in high-income countries. We evaluated whether a single oral dose of azithromycin administered during infant-well visits led to changes in infant growth outcomes at 6 months of age in a setting with a high prevalence of undernutrition in rural Burkina Faso. METHODS AND FINDINGS: Infants were enrolled from September 25, 2019, until October 22, 2022, in a randomized controlled trial designed to evaluate the efficacy of a single oral dose of azithromycin (20 mg/kg) compared to placebo when administered during well-child visits for prevention of infant mortality. The trial found no evidence of a difference in the primary endpoint. This paper presents prespecified secondary anthropometric endpoints including weight gain (g/day), height change (mm/day), weight-for-age Z-score (WAZ), weight-for-length Z-score (WLZ), length-for-age Z-score (LAZ), and mid-upper arm circumference (MUAC). Infants were eligible for the trial if they were between 5 and 12 weeks of age, able to orally feed, and their families were planning to remain in the study area for the duration of the study. Anthropometric measurements were collected at enrollment (5 to 12 weeks of age) and 6 months of age. Among 32,877 infants enrolled in the trial, 27,298 (83%) were followed and had valid anthropometric measurements at 6 months of age. We found no evidence of a difference in weight gain (mean difference 0.03 g/day, 95% confidence interval (CI) -0.12 to 0.18), height change (mean difference 0.004 mm/day, 95% CI -0.05 to 0.06), WAZ (mean difference -0.004 SD, 95% CI -0.03 to 0.02), WLZ (mean difference 0.001 SD, 95% CI -0.03 to 0.03), LAZ (mean difference -0.005 SD, 95% CI -0.03 to 0.02), or MUAC (mean difference 0.01 cm, 95% CI -0.01 to 0.04). The primary limitation of the trial was that measurements were only collected at enrollment and 6 months of age, precluding assessment of shorter-term or long-term changes in growth. CONCLUSIONS: Single-dose azithromycin does not appear to affect weight and height outcomes when administered during early infancy. TRIAL REGISTRATION: ClinicalTrials.gov NCT03676764.

Infant mortality and growth failure after oral azithromycin among low birthweight and underweight neonates: A subgroup analysis of a randomized controlled trial.

BACKGROUND: Low birthweight (birthweight <2500 grams, g) and underweight (weight-for-age Z-score, WAZ, < -2) infants have higher risk of poor outcomes compared to their well-nourished peers. We evaluated the role of azithromycin for reducing mortality and improving growth outcomes in low birthweight and/or underweight infants. METHODS: Infants aged 8-27 days of age weighing ≥2500 g at enrollment in Burkina Faso were randomized 1:1 to a single, oral dose of azithromycin (20 mg/kg) or matching placebo. We evaluated mortality and anthropometric outcomes in four subgroups: 1) both low birthweight and underweight at enrollment; 2) low birthweight-only; 3) underweight-only; 4) neither low birthweight nor underweight. FINDINGS: Of 21,832 enrolled infants, 21,320 (98%) had birthweight measurements and included in this analysis. Of these, 747 (3%) were both low birthweight and underweight, 972 (5%) were low birthweight-only, 825 (4%) were underweight-only, and 18,776 (88%) were neither low birthweight nor underweight. Infants who were both low birthweight and underweight receiving azithromycin had lower odds of underweight at 6 months compared to placebo (OR 0.65, 95% CI 0.44 to 0.95), but the treatment group by subgroup interaction was not statistically significant (P = 0.06). We did not find evidence of a difference between groups for other outcomes in any subgroup. INTERPRETATION: Azithromycin may have some growth-promoting benefits for the highest risk infants, but we were unable to demonstrate a difference in most outcomes in low birthweight and underweight infants. As a secondary analysis of a trial, this study was underpowered for rare outcomes such as mortality. TRIAL REGISTRATION: ClinicalTrials.gov NCT03682653.

Neonatal Azithromycin Administration and Growth during Infancy: A Randomized Controlled Trial.

Observational studies have linked early-life antibiotic exposure to increased risk of obesity in children in high income settings. We evaluated whether neonatal antibiotic exposure led to changes in infant growth at 6 months of age in Burkina Faso. Neonates aged 8 to 27 days of age who weighed at least 2,500 g at the time of enrollment were randomized in a 1:1 fashion to a single oral 20-mg/kg dose of azithromycin or equivalent volume of placebo from April 2019 through December 2020. Weight, length, and mid-upper-arm circumference (MUAC) were measured at baseline and 6 months of age. Growth outcomes, including weight gain in grams per day, length change in millimeters per day, and changes in weight-for-age Z-score (WAZ), weight-for-length Z-score (WLZ), length-for-age Z-score (LAZ), and MUAC were compared among neonates randomized to azithromycin compared with placebo. Among 21,832 neonates enrolled in the trial, median age at enrollment was 11 days, and 50% were female. We found no evidence of a difference in weight gain (mean difference -0.009 g/day, 95% confidence interval [CI]: -0.16 to 0.14, P = 0.90), length change (mean difference 0.003 mm/day, 95% CI: -0.002 to 0.007, P = 0.23), or WAZ (mean difference -0.005 SD, 95% CI: -0.03 to 0.02, P = 0.72), WLZ (mean difference -0.01 SD, 95% CI: -0.05 to 0.02, P = 0.39), LAZ (mean difference 0.01, 95% CI: -0.02 to 0.04, P = 0.47), or MUAC (mean difference 0.01 cm, 95% CI: -0.02 to 0.04, P = 0.49). These results do not suggest that azithromycin has growth-promoting properties in infants when administered during the neonatal period. Trial registration: ClinicalTrials.gov NCT03682653.

Influence of maternal age on birth and infant outcomes at 6 months: a cohort study with quantitative bias analysis.

BACKGROUND: Maternal age is increasingly recognized as a predictor of birth outcomes. Given the importance of birth and growth outcomes for children's development, wellbeing and survival, this study examined the effect of maternal age on infant birth and growth outcomes at 6 months and mortality. Additionally, we conducted quantitative bias analysis (QBA) to estimate the role of selection bias and unmeasured confounding on the effect of maternal age on infant mortality. METHODS: We used data from randomized-controlled trials (RCTs) of 21 555 neonates in Burkina Faso conducted in 2019-2020. Newborns of mothers aged 13-19 years (adolescents) and 20-40 years (adults) were enrolled in the study 8-27 days after birth and followed for 6 months. Measurements of child's anthropometric measures were collected at baseline and 6 months. We used multivariable linear regression to compare child anthropometric measures at birth and 6 months, and logistic regression models to obtain the odds ratio (OR) of all-cause mortality. Using multidimensional deterministic analysis, we assessed scenarios in which the difference in selection probability of adolescent and adult mothers with infant mortality at 6 months increased from 0% to 5%, 10%, 15% and 20% if babies born to adolescent mothers more often died during the first week or were of lower weight and hence were not eligible to be included in the original RCT. Using probabilistic bias analysis, we assessed the role of unmeasured confounding by socio-economic status (SES). RESULTS: Babies born to adolescent mothers on average had lower weight at birth, lower anthropometric measures at baseline, similar growth outcomes from enrolment to 6 months and higher odds of all-cause mortality by 6 months (adjusted OR = 2.17, 95% CI 1.35 to 3.47) compared with those born to adult mothers. In QBA, we found that differential selection of adolescent and adult mothers could bias the observed effect (OR = 2.24, 95% CI 1.41 to 3.57) towards the null [bias-corrected OR range: 2.37 (95% CI 1.49 to 3.77) to 2.84 (95% CI 1.79 to 4.52)], whereas unmeasured confounding by SES could bias the observed effect away from the null (bias-corrected OR: 2.06, 95% CI 1.31 to 2.64). CONCLUSIONS: Our findings suggest that delaying the first birth from adolescence to adulthood may improve birth outcomes and reduce mortality of neonates. Babies born to younger mothers, who are smaller at birth, may experience catch-up growth, reducing some of the anthropometric disparities by 6 months of age.

Effect of Neonatal Azithromycin on All-Cause and Cause-Specific Infant Mortality: A Randomized Controlled Trial.

Mass azithromycin distribution reduces all-cause childhood mortality in some high-mortality settings in sub-Saharan Africa. Although the greatest benefits have been shown in children 1 to 5 months old living in areas with high mortality rates, no evidence of a benefit was found of neonatal azithromycin in a low-mortality setting on mortality at 6 months. We conducted a 1:1 randomized, placebo-controlled trial evaluating the effect of a single oral 20-mg/kg dose of azithromycin or matching placebo administered during the neonatal period on all-cause and cause-specific infant mortality at 12 months of age in five regions of Burkina Faso. Neonates were eligible if they were between the ages of 8 and 27 days and weighed at least 2,500 g at enrollment. Cause of death was determined via the WHO 2016 verbal autopsy tool. We compared all-cause and cause-specific mortality using binomial regression. Of 21,832 infants enrolled in the study, 116 died by 12 months of age. There was no significant difference in all-cause mortality between the azithromycin and placebo groups (azithromycin: 52 deaths, 0.5%; placebo, 64 deaths, 0.7%; hazard ratio, 0.81; 95% CI, 0.56-1.17; P = 0.30). There was no evidence of a difference in the distribution of causes of death (P = 0.40) and no significant difference in any specific cause of death between groups. Mortality rates were low at 12 months of age, and there was no evidence of an effect of neonatal azithromycin on all-cause or cause-specific mortality.

High seroprevalence of SARS-CoV-2 in Burkina-Faso, Ghana and Madagascar in 2021: a population-based study.

BACKGROUND: The current COVID-19 pandemic affects the entire world population and has serious health, economic and social consequences. Assessing the prevalence of COVID-19 through population-based serological surveys is essential to monitor the progression of the epidemic, especially in African countries where the extent of SARS-CoV-2 spread remains unclear. METHODS: A two-stage cluster population-based SARS-CoV-2 seroprevalence survey was conducted in Bobo-Dioulasso and in Ouagadougou, Burkina Faso, Fianarantsoa, Madagascar and Kumasi, Ghana between February and June 2021. IgG seropositivity was determined in 2,163 households with a specificity improved SARS-CoV-2 Enzyme-linked Immunosorbent Assay. Population seroprevalence was evaluated using a Bayesian logistic regression model that accounted for test performance and age, sex and neighbourhood of the participants. RESULTS: Seroprevalence adjusted for test performance and population characteristics were 55.7% [95% Credible Interval (CrI) 49·0; 62·8] in Bobo-Dioulasso, 37·4% [95% CrI 31·3; 43·5] in Ouagadougou, 41·5% [95% CrI 36·5; 47·2] in Fianarantsoa, and 41·2% [95% CrI 34·5; 49·0] in Kumasi. Within the study population, less than 6% of participants performed a test for acute SARS-CoV-2 infection since the onset of the pandemic. CONCLUSIONS: High exposure to SARS-CoV-2 was found in the surveyed regions albeit below the herd immunity threshold and with a low rate of previous testing for acute infections. Despite the high seroprevalence in our study population, the duration of protection from naturally acquired immunity remains unclear and new virus variants continue to emerge. This highlights the importance of vaccine deployment and continued preventive measures to protect the population at risk.

Neonatal azithromycin administration for prevention of infant mortality.

Background: Biannual mass azithromycin administration reduces all-cause childhood mortality in some sub-Saharan African settings, with the largest effects in children aged 1-5 months. Azithromycin has not been distributed to children <1 month due to risk of infantile hypertrophic pyloric stenosis (IHPS). Methods: This 1:1 placebo-controlled trial, randomized neonates aged 8-27 days to a single oral dose of azithromycin (20 mg/kg) or equivalent volume of placebo in 5 regions of Burkina Faso during 2019 and 2020. The primary outcome was all-cause mortality at 6 months of age. Infants were evaluated at 21 days after treatment and at 3 and 6 months of age for vital status; family and provider surveillance for IHPS continued throughout. Results: Of 21,832 enrolled neonates, 10,898 were allocated to azithromycin and 10,934 to placebo. At 6 months of age, 92 infants had died, 42 (0.44%) in the azithromycin group and 50 (0.52%) in the placebo group (hazard ratio 0.85, 95% confidence interval 0.56 to 1.28, P=0.46). A single IHPS case was detected, which was in the azithromycin arm. Serious adverse events, including death and hospitalization within 28 days of treatment, occurred in 0.27% of infants in the azithromycin group and 0.14% in the placebo group, for an absolute risk difference 0.14 percentage points, 95% confidence interval 0.01 to 0.26. Conclusions: Overall mortality was lower than anticipated when the trial was designed, thus limiting its power. The available data do not support the routine use of azithromycin for prevention of mortality in neonates in sub-Saharan African settings similar to the one in which this trial was conducted. Trial registration: ClinicalTrials.gov NCT03682653.

Antenatal care attendance and risk of low birthweight in Burkina Faso: a cross-sectional study.

BACKGROUND: Low birthweight is a major contributor to infant mortality. We evaluated the association between antenatal care (ANC) attendance and low birthweight among newborns in 5 regions of Burkina Faso. METHODS: We utilized data from the baseline assessment of a randomized controlled trial evaluating azithromycin distribution during the neonatal period for prevention of infant mortality. Neonates were eligible for the trial if the weighed at least 2500 g at enrollment and were 8-27 days of age. Data on ANC attendance and birthweight was extracted from each child's carnet de santé, a government-issued health card on which pregnancy and birth-related data are recorded. We used linear and logistic regression models adjusting for potentially confounding variables to evaluate the relationship between ANC attendance (as total number of visits and ≥ 4 antenatal care visits) and birthweight (continuously and categorized into < 2500 g versus ≥2500 g). RESULTS: Data from 21,223 births were included in the analysis. The median number of ANC visits was 4 (interquartile range 3 to 5) and 69% of mothers attended at least 4 visits. Mean birthweight was 2998 g (standard deviation 423) and 8.1% of infants were low birthweight (< 2500 g). Birthweight was 63 g (95% CI 46 to 81 g, P < 0.001) higher in newborns born to mothers who had attended ≥4 ANC visits versus < 4 visits. The odds of low birthweight among infants born to mothers with ≥4 ANC visits was 0.71 (95% CI 0.63 to 0.79, P < 0.001) times the odds of low birthweight among infants born to mothers who attended < 4 ANC visits. CONCLUSIONS: We observed a statistically significant association between ANC attendance and birthweight, although absolute differences were small. Improving access to ANC for all women may help improve birth outcomes. TRIAL REGISTRATION: The parent trial is registered at clinicaltrials.gov: NCT03682653 ; first registered 24 September 2018.

Immune Reconstitution During the First Year of Antiretroviral Therapy of HIV-1-Infected Adults in Rural Burkina Faso.

There are no data on the outcome of highly active antiretroviral therapy (HAART) in HIV-infected adults in rural Burkina Faso. We therefore assessed CD4(+) T-cell counts and HIV-1 plasma viral load (VL), the proportion of naive T-cells (co-expressing CCR7 and CD45RA) and T-cell activation (expression of CD95 or CD38) in 61 previously untreated adult patients from Nouna, Burkina Faso, at baseline and 2 weeks, 1, 3, 6, 9 and 12 months after starting therapy. Median CD4(+) T-cell counts increased from 174 (10(th)-90(th) percentile: 33-314) cells/µl at baseline to 300 (114- 505) cells/µl after 3 months and 360 (169-562) cells/µl after 12 months of HAART. Median VL decreased from 5.8 (4.6- 6.6) log10 copies/ml at baseline to 1.6 (1.6-2.3) log10 copies/ml after 12 months. Early CD4(+) T-cell recovery was accompanied by a reduction of the expression levels of CD95 and CD38 on T-cells. Out of 42 patients with complete virological follow-up under HAART, 19 (45%) achieved concordant good immunological (gain of ≥100 CD4(+) T-cells/µl above baseline) and virological (undetectable VL) responses after 12 months of treatment (intention-to-treat analysis). Neither a decreased expression of the T-cell activation markers CD38 and CD95, nor an increase in the percentage of naive T-cells reliably predicted good virological treatment responses in patients with good CD4(+) T-cell reconstitution. Repeated measurement of CD4(+) T-cell counts during HAART remains the most important parameter for immunologic monitoring. Substitution of repeated VL testing by determination of T-cell activation levels (e.g., CD38 expression on CD8(+) T-cells) should be applied with caution.

Cost of integrated vector control with improved sanitation and road infrastructure coupled with the use of slow-release Bacillus sphaericus granules in a tropical urban setting.

A field test of integrated vector control was conducted in a tropical urban setting with a combination of a floating, slow-release, granular formulation of Bacillus sphaericus and environmental engineering measures (renovation of roads, collective water pumps, and cesspool lids). The targets were Culex quinquefasciatus and Anopheles gambiae in the two biggest towns of Burkina Faso (West Africa). Within the intervention zone, water pumping stations were improved and the surroundings drained to prevent the accumulation of stagnant water. Roads were leveled and given either simple gutters on each side or a concrete channel on one side to drain runoff water. Garbage containers were installed to provide an alternative to the drainage channels for waste disposal. Septic tanks were modified so that they could be emptied without destroying their lid. This study showed that it is possible to implement mosquito control in a tropical urban environment with teams of young people rapidly trained to apply a biological larvicide without any tools other than an iron bar to lift cesspool lids. Environmental improvements were initially costly, but demanded little subsequent expenditure. Local inhabitants' committees were mobilized to provide people with information and monitor the efficacy of the measures. Compared with what people spent individually on mosquito prevention and malaria medicine, these measures were not expensive, but many expected the community to pay for them from existing taxes, e.g., for water treatment and disposal. The necessary funding and logistics require a municipal organization with neighborhood support, if the measures are to be effective.

Cross-clade recognition of HIV-1 CAp24 by CD4+ T cells in HIV-1-infected individuals in Burkina Faso and Germany.

The presence of antigen-specific cellular immune responses may be an indicator of long-term asymptomatic HIV-1-disease. The detection of cellular immune responses to infection with different subtypes of HIV-1 may be hampered by genetic differences of immunodominant antigens such as the capsid protein CAp24. In Nouna, Burkina Faso, HIV-1 circulating recombinant forms CRF02_AG and CRF06_cpx are the 2 major strains detectable in HIV-1-infected individuals, while subtype B strains prevail in Europe and North America. Amino acid sequences of CAp24 were assessed in blood samples from 10 HIV-1-infected patients in Nouna, Burkina Faso. Production of interferon-gamma (IFN-gamma) in peripheral blood CD4(+) lymphocytes in response to recombinant HIV-1 proteins derived from clade B (including CAp24(NL4-3)) was measured using a modified flow-cytometry-based whole blood short term activation assay (FASTimmune, BDBiosciences). IFN-gamma production following stimulation with a whole length CAp24 protein derived from clade B (CAp24(NL4-3)) was additionally quantified in comparison to a CAp24 protein derived from CRF02_AG (CAp24(BD6-15)) in 16 HIV-1-infected patients in Heidelberg, Germany. Amino acid sequence identity of CAp24 obtained from patients in Nouna ranged between 86 and 89% when compared to the clade B CAp24(NL4-3) consensus sequence, between 90 and 95% when compared to the circulating recombinant form CRF06_CPX consensus sequence, and between 92 and 96% when compared to the CAp24(BD6-15) consensus sequence. Significant numbers of HIV-1-specific CD4(+) lymphocytes producing IFN-gamma were detected in 4 of 10 HIV-1-infected patients. In 7 of 16 patients in Heidelberg, recombinant CAp24(BD6-15) stimulated IFN-gamma-production in CD4(+) lymphocytes to a similar extent as the clade B-derived CAp24(NL4-3). Thus, antigen-specific CD4(+) lymphocytes from both West African and European patients infected with different strains of HIV-1 show relevant cross-clade recognition of HIV-1 CAp24 in a flow-cytometry-based whole blood short term activation assay.

Impact of slow-release Bacillus sphaericus granules on mosquito populations followed in a tropical urban environment.

A floating, slow-release, granular formulation of Bacillus sphaericus (Neide) was used to control mosquito larvae in two suburban areas of two tropical cities: Ouagadougou and Bobo-Dioulasso, Burkina Faso. A circular area of 2 km2, diameter 1,600 m, was treated in each city using a similar, smaller area 1 km away as an untreated control. Mosquito captures were made in houses in four concentric circles, from the periphery to the center; each circle was 50 m in width. Mosquitoes were captured in CDC light traps or from human landings. More than 95% of the mosquitoes were Culex quinquefasciatus (Say) (Diptera: Culicidae). The human landing catches provided twice as many mosquitoes as did the CDC traps/night/house. The treatments resulted in important reductions relative to the control area and to preintervention captures. The reduction was more prominent in the inner circle (up to 90%) than in the outer circle (50-70%), presumably because of the impact of immigrating mosquitoes from nontreated breeding sites around the intervention area. This effect was more pronounced for light trap catches than from human landings. The impact of treatment was also measured as the mean ratio of mosquito density in the two outer circles to that of the two inner circles. This ratio was approximately 1:1 before the intervention and reached 1:0.43 during the intervention. This comparison does not depend on the assumption that, in the absence of intervention, the mosquito population development in the two areas would have been identical, but does depend on the homogeneity of the intervention area. The study showed that it is possible to organize mosquito control in a tropical, urban environment by forming and rapidly training teams of young people to carry out the mosquito control mostly using a biopesticide that can be applied without any tools except an iron bar to lift lids on some cesspits.

Seroprevalence of six different viruses among pregnant women and blood donors in rural and urban Burkina Faso: A comparative analysis.

A seroprevalence study was carried out of six different human pathogenic viruses, namely human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell leukemia virus (HTLV), human herpesvirus type 8 (HHV-8), and dengue virus among pregnant women and blood donors from rural (Nouna) and urban (Ouagadougou) Burkina Faso, West Africa. A total of 683 samples from blood donors (n = 191) and pregnant women (n = 492) were collected from both sites and screened for the different virus infection markers resulting in the following prevalence values for Nouna or Ouagadougou, respectively: HIV 3.6/4.6, anti-HBV core (anti-HBc) 69.6/76.4, HBV surface antigen (HBsAg)14.3/17.3, HCV 2.2/1.5, HTLV 1.4/0.5, HHV-8 11.5/13.5, dengue virus 26.3/36.5. Individuals aged > or =25 years were more likely to be infected with HIV than those below 24 years (P < 0.05). Infection with HIV increased the likelihood of co-infection with other viruses, such as HHV-8, HBV and HTLV. Co-infection studies involving five viruses (HBV-HBsAg, HHV-8, HIV, HCV, and HTLV) showed that 4.8% (33/683) of the studied population were dually infected, with HBsAg+ HHV-8 (13/33), HBsAg+HIV (8/33) and HIV+HHV-8 (8/33) being the most common co-infections. Of the population studied 0.6% (4/683) was triply infected, the most common infection being with HBV+HIV+HHV-8 (3/4). There was no difference in the prevalence of HIV, anti-HBc, HBsAg, HCV, HTLV, and HHV-8 either among blood donors or pregnant women in urban or rural setting, while dengue virus prevalence was relatively lower in rural (26.3%) than in urban (36.5%) Burkina Faso.