Nutritional status, growth and sleep habits among Senegalese adolescent girls

OBJECTIVE

To study the relation between sleep habits, nutritional status, growth and maturation in a group of African adolescent girls. The main hypothesis to be tested was that sleep length could be an effective way to spare energy, and thus malnourished girls sleep longer than normal girls.

DESIGN

Three repeated yearly surveys (1997-1999) on a subsample of girls drawn from a larger study cohort on growth at adolescence.

SETTING

The Niakhar district in the central part of Senegal.

SUBJECT

In total, 40 girls were initially drawn. Missing girls were replaced at each round by girls having the same characteristics and belonging to the same cohort.

INTERVENTION

At each round, data on pubertal development (breast stages and occurrence of menarche), growth and nutritional status were collected. Adolescents wore an accelerometer for three or four consecutive nights and days at each round.

RESULTS

At the beginning of the survey, girls were 13.3+/-0.5 y old. They were under international reference values in weight and height. Their mean sleep duration was 8.5+/-0.9 h. Their puberty status did not influence their sleep habits; however, they slept more in March than in June, which was related to the seasonal change in daylight. There was a significant relation between body mass index and sleep habits: thinner girls slept a longer time and more quietly than the more corpulent girls.

CONCLUSION

The nutritional status of these girls influenced their sleep habits: this may have been either a direct causal relation or a consequence of a protective attitude on the part of the mothers towards the frailer girls.

[Influence of urban migration on physical activity, nutritional status and growth of Senegalese adolescents of rural origin]

In Africa, rural populations especially adolescent girls resort to urban migrations for labour in order to diversify and improve their livelihood. Their work and their living conditions may influence their health and development patterns. The aim of this study was to evaluate the influence of these migrations on physical activity, nutritional and growth status of rural Senegalese adolescent girls. In 1998, within the framework of a longitudinal study of growth during puberty (n = 406), a sub-sample (n = 80, 14.4 +/- 0.5 years) was drawn in order to estimate physical activity, during three days, quantitatively by accelerometry and qualitatively by questionnaire. One part of this sample temporarily migrated to Dakar in order to work as maids (migrants, n = 40). The other part remained in the rural community of Niakhar in order to help their families in daily domestic and agricultural tasks and/or to attend school (non-migrants, n = 40). In 1999, sexual maturation of 331 adolescent girls (15.5 +/- 0.5 years) belonging to this group was based on stages of breast development and occurrence of menarche. Their growth and nutritional status were assessed with anthropometry (height, weight, mid arm circumference, six skinfolds). Adolescents were asked about their urban migratory histories and were divided into four categories according to the duration of urban migration: no migration (NM), short (S), medium (M) and long duration (L). These adolescent girls had a very high physical activity which is far higher than that of American girls. Migrants were more active than non-migrants (p < 0.0001). In 1999, as a whole, these 331 adolescent girls were smaller, thinner and less mature than adolescent girls from industrialized countries. Midarm circumference, body mass index (BMI) and fat mass index (FMI) were significantly higher with the duration of migration (p < 0.01), after adjusting for differences in sexual maturation. Growth retardation seemed more important for the adolescent girls who never migrated and for those who have the longest duration of migration (p = 0.05). At the beginning of puberty, there were no differences in height for age indice and BMI. Urban migrations resulted in an advanced puberty and an improvement of nutritional status (higher BMI, FMI and midarm circumference) but without catch-up in growth. These findings could be explained by precarious living conditions in rural area and by higher workload in urban area.

High levels of habitual physical activity in west African adolescent girls and relationship to maturation, growth, and nutritional status: results from a 3-year prospective study

This study examines energy expenditure and physical activity levels for a sample of 40 adolescent girls of the Sereer ethnic group of rural Senegal. The girls were 13.3 +/- 0.5 years at the start of the study (June 1997) and were followed annually for the next 2 years during puberty. Data collected during each round included: 1) pubertal status (as assessed by breast development and occurrence of menarche); 2) selected anthropometric dimensions (weight, stature, arm circumference, and six skinfolds); and 3) physical activity levels quantitatively assessed using CSA accelerometers. During rounds 1 and 3, activity was also qualitatively reported by direct minute-by-minute observations. A food consumption survey was performed once during the 3(rd) round, using an individual food weighing method. Girls of this sample had high levels of energy expenditure with daily physical activity levels (PALs) ranging from 1.70 to 1.85 multiples of basal metabolic rate. Energy intakes were, on average, sufficient to meet energy and protein requirements, although micronutrient deficiencies were likely to exist. Activity levels declined with age between the 1(st) and 3(rd) rounds. Stepwise regression analyses showed that stature was negatively correlated with both total daily and day-time activity, whereas the body mass index was positively associated with this measure. Pubertal status and subcutaneous fatness were not significant predictors of activity levels. The contribution of these adolescent girls to the everyday tasks of the household was considerable. They spent more than 3 hours 30 minutes per day in domestic duties.

Assessment of physical activity among rural Senegalese adolescent girls: influence of age, sexual maturation, and body composition

PURPOSE

To analyze the level of habitual physical activity and its relationship with age, maturational stage, and growth status in a group of adolescent Senegalese girls.

METHODS

Physical activity was assessed for 3 consecutive years in a sample of 40 girls of rural origin. They were 13.3 +/- 0.5 years old at the beginning of the study and belonged to a Sereer community located in the center of Senegal. Minute-by-minute movement counts using accelerometers enabled quantification of levels of physical activity. The assessment was performed during a 4-day period in the first round (1997) and during a 3-day period in 1998 and 1999. Half of the girls were not yet pubescent during the first round, and the whole sample displayed growth retardation in weight and stature, compared with the World Health Organization/National Center for Health Statistics reference.

RESULTS

Estimated levels of activity were high, ranging from 1.80 to 1.85 multiples of basal metabolic rate. There was a clear decline in the activity level during the course of study. Schoolgirls were less active than the others. Mature adolescents showed more activity during the night. A weak, but significant and positive correlation existed between body mass index and activity during the day; during the night, there was a positive correlation with fat and lean body mass.

CONCLUSION

Factors determining the activity level were intricate but greater maturity and better nutritional status appeared to be positively related to the activity level.

[Prevention of infection in a surgical environment in the regional hospitals of Senegal]

This study evaluated the attitudes and practices of the personnel with respect to the prevention of nosocomial infections in a hospital environment. We carried out a qualitative survey of all categories of personnel between July 1998 and March 1999, at the five regional hospitals in Senegal (Thiés, Kaolack, Saint-Louis, Diourbel, and Louga). Data were collected in two ways: using a questionnaire to evaluate knowledge and by observing the attitudes and practices of the personnel. Hands were rarely washed before and after each procedure and surgical washing was often performed in poor conditions. The decontamination of soiled equipment was ineffective. Reusable instruments were washed directly with bare hands or by individuals wearing used surgical gloves. The equipment used for sterilization was dilapidated and unsuitable and the norms for sterilization were seldom respected. Circulation in the region of the operating theatre was disorganized, if not anarchic. The personnel had a high risk of contamination from blood. Biomedical waste was not decontaminated: it was collected poorly and disposed of directly into the environment. None of the sites visited had a program of waste incineration. In conclusion, at the sites visited, there is a high risk of nosocomial contamination during care and the reuse of equipment, for both the staff and the patients treated.

The Dielmo project: a longitudinal study of natural malaria infection and the mechanisms of protective immunity in a community living in a holoendemic area of Senegal

The Dielmo project, initiated in 1990, consisted of long-term investigations on host-parasite relationships and the mechanisms of protective immunity in the 247 residents of a Senegalese village in which malaria is holoendemic. Anopheles gambiae s.l. and An. funestus constituted more than 98% of 11,685 anophelines collected and were present all year round. Inoculation rates of Plasmodium falciparum, P. malariae, and P. ovale averaged respectively 0.51, 0.10, and 0.04 infective bites per person per night. During a four-month period of intensive parasitologic and clinical monitoring, Plasmodium falciparum, P. malariae, and P. ovale were observed in 72.0%, 21.1% and 6.0%, respectively, of the 8,539 thick smears examined. Individual longitudinal data revealed that 98.6% of the villagers harbored trophozoites of P. falciparum at least once during the period of the study. Infections by P. malariae and P. ovale were both observed in individuals of all age groups and their cumulative prevalences reached 50.5% and 40.3%, respectively. Malaria was responsible for 162 (60.9%) of 266 febrile episodes; 159 of these attacks were due to P. falciparum, three to P. ovale, and none to P. malariae. The incidence of malaria attacks was 40 times higher in children 0-4 years of age than in adults more than 40 years old. Our findings suggest that sterile immunity and clinical protection are never fully achieved in humans continuously exposed since birth to intense transmission.

Vector Density Gradients and the Epidemiology of Urban Malaria in Dakar, Senegal

The dispersion of anopheline mosquitoes from their breeding places and its impact on malaria epidemiology has been investigated in Dakar, Senegal, where malaria is hypoendemic and almost exclusively transmitted by Anopheles arabiensis. Pyrethrum spray collections were carried out along a 910-meter area starting from a district bordering on a permanent marsh and continuing into the center of the city. According to the distance from the marsh, vector density (the number of An. arabiensis per 100 rooms) at 0-160, 160-285, 285-410, 410-535, 535-660, 660-785, and 785-910 meters was 84, 40, 5, 2, 2, 0.4, and 0, respectively, during the dry season, and 414, 229, 110, 84, 99, 69, and 21, respectively, during the rainy season. The proportion of 8-11-year-old children with negative immunofluorescent antibody test results for Plasmodium falciparum was 17%, 28%, 44%, 54%, 50%, 63%, and 73%, respectively, in these different sections. Malaria prevalence in the community was maximum in the area bordering on the marsh where it ranged from 1% to 15% (average 6%) according to age and season of the year. These findings show the epidemiologic importance of vector density gradients in Dakar. The implications for malaria control in urban areas are discussed.