Adama Marra

Non-specific effects of vaccination on child survival? A prospective study in Senegal

Objectives  Several studies have shown an association between vaccination and child mortality in developing countries. The present paper examines this issue using data from a Senegalese rural area which has been monitored from 1983 to the present.

Reduction in risk-taking behaviors among MSM in Senegal between 2004 and 2007 and prevalence of HIV and other STIs. ELIHoS Project, ANRS 12139

Abstract An epidemiological survey conducted in Senegal in 2004 among men having sex with men (MSM) revealed high HIV prevalence and a high rate of risky behaviors within this population. Consequently, several prevention campaigns targeting MSM were implemented. A second survey was carried out in 2007 to assess the impact of these measures. This paper aims to examine trends in HIV and STI prevalence and in sexual behaviors between 2004 and 2007. The two surveys were conducted in four urban sites among 440 and 501 MSM – recruited using the snowball sampling method – in 2004 and 2007, respectively. A similar methodology was applied for both surveys. This consisted of a closed-ended questionnaire concerning socio-demographic, behavioral, and biomedical information plus a clinical examination including urine and blood tests to detect STIs and HIV infection. Between 2004 and 2007, the frequency of different sexual practices reported by MSM remained stable, but condom use for each type of sexual practice rose. The percentage of men who reported consistent condom use during previous-month anal sex has increased by about 35% (p<0.01). The percentage of men who reported consistent condom use during previous-month non-commercial sex with women has increased by 14% (p<0.01). HIV prevalence remained stable from 22.4% [95% CI: 18.6–26.8] in 2004 to 21.8% [95% CI: 18.3–25.7] in 2007 (adjusted OR = 1.05, p=0.8). Gonorrhea prevalence decreased from 5.5% [95% CI: 3.6–8.3] in 2004 to 2.6% [95% CI: 1.5–4.5] in 2007 (adjusted OR=0.5, p=0.07). The prevention campaigns, STI and HIV care and support programs conducted in Senegal among MSM have been followed by a reduction of risk-taking behaviors and STI prevalence among this population. Specific targeting of this group within HIV/STI prevention programs seems to be effective in decreasing sexual infections.

New malaria-control policies and child mortality in Senegal: reaching millennium development goal 4.

BACKGROUND The Demographic Surveillance System established in 1962 in Niakhar, Senegal, is the oldest in Africa. Here, we analyze trends in overall child mortality, malaria, and other causes of death in Niakhar from the beginning of data collection to 2010. METHODS After an initial census, demographic data were updated yearly from 1963 through 2010. From 1984, causes of death were determined by the verbal autopsy technique. RESULTS During 1963-2010, infant and under-5 mortality rates decreased from 223‰ to 18‰ and from 485‰ to 41‰, respectively. The decrease was progressive during the entire observation period, except during 1990-2000, when a plateau and then an increase was observed. Malaria-attributable mortality in under-5 children decreased from 13.5‰ deaths per 1000 children per year during 1992-1999 to 2.2‰ deaths per 1000 children per year in 2010. During this period, all-cause mortality among children aged <5 years decreased by 80%. CONCLUSIONS Inadequate treatment for chloroquine-resistant malaria and an epidemic of meningitis during the 1990s were the 2 factors that interrupted a continuous decrease in child mortality. Direct and indirect effects of new malaria-control policies, introduced in 2003 and completed during 2006-2008, are likely to have been the key cause of the recent dramatic decrease in child mortality.

Men Who Have Sex with Men (MSM) and Factors Associated with Not Using a Condom at Last Sexual Intercourse with a Man and with a Woman in Senegal

Background Men who have sex with other men (MSM) are a vulnerable population in Africa that has been insufficiently explored. Given the high rate of bisexuality among MSM (73% in the past year), it is important to understand their risk-taking behaviors regarding both men and women. Methodology/Principal Findings A socio-behavioral survey was carried out in 2007 among 501 MSM recruited using the snowball sampling method. We explore in this article why a condom was not used during last sexual intercourse with a man and with a woman, taking into account the respondents characteristics, type of relationship and the context of the sexual act. In the survey, 489 men reported that they had had sexual intercourse at least once with another man during the previous year, and 358 with a man and with a woman. The main risk factors for not using a condom at last sexual intercourse with another man were having sex in a public place (aOR = 6.26 [95%CI: 2.71–14.46]), non-participation in an MSM prevention program (aOR = 3.47 [95%CI: 2.12–5.69]), a 19 years old or younger partner (aOR = 2.6 [95%CI: 1.23–4.53]), being 24 years or younger (aOR = 2.07 [95%CI: 1.20–3.58]) or being 35 years or over (aOR = 3.08 [95%CI:1.11–8.53]) and being unemployed (aOR = 0.36 [95%CI: 0.10–1.25]). The last sexual intercourse with the respondents wife was hardly ever protected (2%). With women, the other factors were a 15 years or younger partner (aOR = 6.45 [95%CI: 2.56–16.28]), being educated (primary: aOR = 0.45 [95%CI: 0.21–0.95], secondary or higher: aOR = 0.26 [95%CI: 0.11–0.62]), being a student (aOR = 2.20 [95%CI: 1.07–4.54]) or unemployed (aOR = 3.72 [95%CI: 1.31–10.61]) and having participated in a MSM prevention program (aOR = 0.57 [95%CI: 0.34–0.93]). Conclusion Having participated in a prevention program specifically targeting MSM constitutes a major prevention factor. However, these programs targeting MSM must address their heterosexual practices and the specific risks involved.

Early breastfeeding cessation in rural Senegal: causes modes and consequences.

OBJECTIVES We studied reasons for cessation of breastfeeding before the age of 15 months, replacement feeding modes, and child mortality in West Africa. METHODS Data were gathered for 12208 children born between 1987 and 1997 in a rural area of Senegal. Interviews were conducted with caregivers of early-weaned children, and child mortality risks were assessed. RESULTS Fewer than 1% of children had been weaned early. The main reasons for early weaning were maternal death and new pregnancy (in 41% and 27% of cases, respectively). Twenty percent of children had been relactated by a wet nurse, and 16% had received formula. Many early-weaned children died before the age of 2 years (26%), particularly those weaned early as a result of the mothers death (hazard ratio = 5.1; 95% confidence interval [CI] = 1.74, 15.0). Girls had a lower hazard ratio than boys (0.16; 95% CI=0.05, 0.41). CONCLUSIONS Our results showed that early cessation of breastfeeding was rare but that associated mortality was high, especially when the mother had died.

Evolution of malaria mortality and morbidity after the emergence of chloroquine resistance in Niakhar, Senegal

BackgroundRecently, it has been assumed that resistance of Plasmodium to chloroquine increased malaria mortality. The study aimed to assess the impact of chemoresistance on mortality attributable to malaria in a rural area of Senegal, since the emergence of resistance in 1992, whilst chloroquine was used as first-line treatment of malaria, until the change in national anti-malarial policy in 2003.MethodsThe retrospective study took place in the demographic surveillance site (DSS) of Niakhar. Data about malaria morbidity were obtained from health records of three health care facilities, where diagnosis of malaria was based on clinical signs. Source of data concerning malaria mortality were verbal autopsies performed by trained fieldworkers and examined by physicians who identified the probable cause of death.ResultsFrom 1992 to 2004, clinical malaria morbidity represented 39% of total morbidity in health centres. Mean malaria mortality was 2.4‰ and 10.4‰ among total population and children younger than five years, respectively, and was highest in the 1992-1995 period. It tended to decline from 1992 to 2003 (Trend test, total population p = 0.03, children 0-4 years p = 0.12 - children 1-4 years p = 0.04- children 5-9 years p = 0.01).ConclusionContrary to what has been observed until 1995, mortality attributable to malaria did not continue to increase dramatically in spite of the growing resistance to chloroquine and its use as first-line treatment until 2003. Malaria morbidity and mortality followed parallel trends and rather fluctuated accordingly to rainfall.

Seasonal variations and trends in weight and arm circumference of non-pregnant rural Senegalese women, 1990–1997

Objective:To describe levels, monthly variations and trends in weight and arm circumference of non-pregnant lactating women living in the Sahel, characterized by one short yearly rainy season (July–October).Methods:A mixed unbalanced cross-sectional longitudinal observational study conducted at 3, 5, 7 and 10 months postpartum among 3869 women living in the Sine area in central Senegal who had brought their infants into dispensaries for immunization from January 1990 to February 1997, and 1–5 consecutive children per woman (26 106 visits).Results:Mean weight was 55.7 kg (s.d.: 7.1), but it varied by 2.5–3.9 kg each year, from high means during the dry season (March–May) to low means at the end of the rainy season (September–November). The prevalence of underweight, overweight and obesity (body mass index (BMI)<18.5, 25–29.9 and >30 kg/m2, respectively) was 7.6% (95% confidence interval: 7.3, 7.9), 6.4% (6.1, 6.7) and 0.4% (0.3, 0.4), but varied strongly by season (P<0.0001 for all). Unlike weight, mean arm increased during the early rains, a peak season of agricultural work (+0.10 cm/month (s.d.: 0.6) from June to August vs −0.35 kg/month (s.d.: 1.1) for weight). BMI and arm circumference were positively associated with age (mean: 20.8 vs 22.2 kg/m2 and 25.3 vs 27.4 cm, at 20–24 and 40–49 years, respectively, P<0.0001 for both).Conclusions:Season was a major determinant of the anthropometric status of rural African women. Negative energy balance reduced body weight from the onset of agricultural labour, while arm circumference increased during early rains, probably due to high physical activity.

Changement de protocole dans la méthode d’autopsie verbale et mesure de la mortalité palustre en milieu rural sénégalais

In rural Senegal, three populations have been followed up since several decades and the malaria mortality trend has been observed since the mid-1980s. However, limits are associated with the verbal autopsy method used to determine causes of death, especially deaths due to malaria. A change in protocol occurred in recent years in two of these three sites with the involvement of two physicians (instead of only one) in the diagnosis. The objective is here to measure its potential impact on diagnosis of malaria deaths. Five hundred and fifteen diagnoses reported on child deaths occurred from 2000 to 2005 have been analysed. We have identified, on the basis of a multinomial logistic regression model, factors affecting the determination of malaria deaths among the characteristics of the child, the death, the illness and its symptoms, and we also took into account method factors. Factors related to the method do not play on the malaria diagnosis. This result insures the continuity of the series on malaria mortality statistics since 2000 in the two sites despite changes in the method. However, the new protocol leads to vanish possibility of having deaths among ill-defined or unknown causes. In the African context of absence of health statistics, data obtained through the verbal autopsy method in demographic surveillance system can provide accurate information in the epidemiological field, even regarding malaria.

Change of protocol in the verbal autopsy method and measure of malaria mortality in rural areas in Senegal

In rural Senegal, three populations have been followed up since several decades and the malaria mortality trend has been observed since the mid-1980s. However, limits are associated with the verbal autopsy method used to determine causes of death, especially deaths due to malaria. A change in protocol occurred in recent years in two of these three sites with the involvement of two physicians (instead of only one) in the diagnosis. The objective is here to measure its potential impact on diagnosis of malaria deaths. Five hundred and fifteen diagnoses reported on child deaths occurred from 2000 to 2005 have been analysed. We have identified, on the basis of a multinomial logistic regression model, factors affecting the determination of malaria deaths among the characteristics of the child, the death, the illness and its symptoms, and we also took into account method factors. Factors related to the method do not play on the malaria diagnosis. This result insures the continuity of the series on malaria mortality statistics since 2000 in the two sites despite changes in the method. However, the new protocol leads to vanish possibility of having deaths among ill-defined or unknown causes. In the African context of absence of health statistics, data obtained through the verbal autopsy method in demographic surveillance system can provide accurate information in the epidemiological field, even regarding malaria.

Changement de protocole dans la méthode d'autopsie verbale et mesure de la mortalité palustre en milieu rural sénégalais Change of protocol in the verbal autopsy method and measure of malaria mortality in rural areas in Senegal

In rural Senegal, three populations have been followed up since several decades and the malaria mortality trend has been observed since the mid-1980s. However, limits are associated with the verbal autopsy method used to determine causes of death, especially deaths due to malaria. A change in protocol occurred in recent years in two of these three sites with the involvement of two physicians (instead of only one) in the diagnosis. The objective is here to measure its potential impact on diagnosis of malaria deaths. Five hundred and fifteen diagnoses reported on child deaths occurred from 2000 to 2005 have been analysed. We have identified, on the basis of a multinomial logistic regression model, factors affecting the determination of malaria deaths among the characteristics of the child, the death, the illness and its symptoms, and we also took into account method factors. Factors related to the method do not play on the malaria diagnosis. This result insures the continuity of the series on malaria mortality statistics since 2000 in the two sites despite changes in the method. However, the new protocol leads to vanish possibility of having deaths among ill-defined or unknown causes. In the African context of absence of health statistics, data obtained through the verbal autopsy method in demographic surveillance system can provide accurate information in the epidemiological field, even regarding malaria.