Sedentism and child health among rendille pastoralists of Northern Kenya

Soc. Sci. Med. Vol. 43, No. 4, pp. 503-515, 1996

Pergamon

0277-9536(95)00428-9

Copyright © 1996 ElsevierScienceLtd Printed in Great Britain.All rights reserved 0277-9636/96 $15.00+ 0.00

SEDENTISM A N D CHILD HEALTH AMONG RENDILLE PASTORALISTS OF NORTHERN KENYA M A R T H A A. N A T H A N , l ELLIOT M. F R A T K I N 2. and ERIC ABELLA ROTH 3 ~Holyoke Health Center, 30 Center Street, Holyoke, MA 01040, U.S.A., 2Department of Anthropology, Smith College, Northampton, MA 01063, U.S.A. and 3Department of Anthropology, University of Victoria, Victoria, British Columbia, Canada V8W 3P5 Abstract--Many nomadic pastoralists of Africa are settling near towns and famine-relief centers in response to drought-induced livestock loss, loss of pasture land, increased involvement in market economies and political turmoil including civil war. The present study uses measurements of child health, particularly morbidity, dietary and growth patterns, to evaluate the consequences of sedentism for three Rendille communities of northern Kenya. A nutritional and health survey utilizing interviews, anthropometric measurements, physical examinations and hemoglobin measurements was conducted for 105 mothers and their 174 children under six years of age in three Rendille communities, one fully nomadic and two sedentary, in July 1990, a year of above average rainfall, and again in June 1992, a drought year. Results indicate that while the nomadic Rendille community of Lewognso shares similar morbidity patterns with its sedentary counterparts and had similar numbers of malnourished children during the wet year, the sedentary communities had significantly more malnutrition among children under six during the dry year. Moreover, the children in the settled town of Korr had significantly higher levels of anemia. Differences in malnutrition are attributed to distinctive dietary regimes: during the drought, nomadic children consumed three times as much milk as the sedentary children, while settled children's diets concentrated on starches, fat and sugar. This study suggests that the pastoral nomadic diet, particularly one dependent on camels' milk, offers children better resistance to the pressures of drought and supports findings that the subsistence base of mixed-species pastoralism is superior to sedentary alternatives with respect to child health. Copyright © 1996 Elsevier Science Ltd Key words--Africa, child health, nutrition, pastoralism, drought

INTRODUCTION The settling of formerly pastoralist (livestockkeeping) populations is occurring at a rapid rate throughout northern and eastern Africa. While human and livestock populations grew in Africa throughout the 1950s and 1960s in response to both good rainfall and improved health services, they have suffered since the late 1960s due to ecological, social and political disruptions. The Sahelian countries (e.g. Mall, Niger, northern Nigeria) experienced drought-induced famine in 1968-1973, while the Horn of Africa (Somalia, Ethiopia, Sudan) underwent prolonged famine in 1982-1984 and 1990-1992 associated with both drought and protracted civil wars [1]. In the past fifteen years, pastoralists in northern Kenya have lost over 50% of their cattle, camels, goats and sheep, the main source of their food and income [2, 3]. As a consequence, many individuals moved towards famine relief centers and burgeoning towns in search of temporary relief from these disasters. However, an increasing number of impoverished individuals have been unable to return to their formerly pastoral livelihood [4]. Today many pastoralists migrate and *Author for correspondence.

settle in response to political insecurity, pressures of human population growth, encroachment on pastoral lands by agricultural populations, expansion of national game parks limiting pastoral use, environmental degradation, or the attraction of famine relief, health and education opportunities, and wage jobs in the small towns [2-10]. Many international development agencies and non-government organizations (NGOs) have encouraged the settling of nomadic pastoralists, often with the active cooperation of national African governments and with httle input from pastoralists. The nomadic pastoral lifestyle has been characterized in some development writings as 'primitive and irrational', environmentally harmful, and detrimental to national economy [11-13]. The World Bank and United States Agency for International Development (USAID) have emphasized the benefits of commercial and private ranching over subsistence livestock herding on communal grazing resources [14], while the N G O ' s World Vision and the Catholic Relief Services have encouraged Rendille pastoralists to settle in towns to take advantage of educational, health care and religious institutions [15]. Although development agencies and national governments have encouraged alternative food production strategies such as fishing, agriculture and 503

504

Martha A. Nathan

commercial ranching in pastoral regions, economic anthropologists and range ecologists have stressed that pastoralism, the mobile herding of domestic cattle, camels, goats and sheep for subsistence and trade products, is the best adapted, and in some cases the only, food production system possible in very arid environments [16-19]. It is not clear to what extent the sedentarization process benefits pastoralists. In some situations, pastoralists are able to settle in peri-urban environments with their livestock and participate in marketing activities including dairying, which directly benefits women and children [10, 20]. More often, towns attract poor and stockless pastoralists who seek incomes as wage-laborers or who take up farming. While settled populations do have better access to water, education, employment, the market economy, and grains obtained in trade [6, 10, 21, 22], they may be more exposed to intestinal parasites, waterborne diseases and epidemics, including measles and malaria [23]. Children in particular may face nutritional changes associated with loss of livestock resources, particularly daily supplies of milk. The effects of sedentarization on the health and nutrition of pastoralists are complex and largely unknown. The South Turkana Ecosystem Project (STEP) reported that nomadic Turkana children had more protein intake than settled schoolchildren, but the settled children were taller and heavier [24]. However, in the same population STEP also found that body weight and cross-sectional areas of arm muscle and fat were less in the settled than the nomadic adults, suggesting poorer nutritional status among settled Turkana farmers [25]. The director of the human biology studies of the STEP Project, Michael A. Little, reported in a review article that no studies of health and adaptability of pastoral populations had been conducted before, during and after a permanent settlement [26]. Our project among Rendille pastoralists in Marsabit District, located to the east of Turkana in northern Kenya, attempts to clarify this issue. In the summers of 1990 and 1992 we performed health and nutritional evaluations of women and children from three different Rendille communities, one nomadic and two sedentary, to determine the impact of settlement on maternal and child health and nutrition. This was the initiation of a larger, more intensive three-year longitudinal study currently undertaken by the authors of this complex issue of pastoral sedentarization among pastoralists in northern Kenya.

DIET, NUTRITION AND HEALTH AMONG PASTORALISTS

African pastoralism is a particular food-producing strategy especially adapted to arid regions. Herding domestic animals (particularly cattle, camels, goats and sheep) enables humans to convert scarce and patchy grazing resources into a steady supply of

et al.

protein, calories and other nutrients in the form of milk, meat and blood. Animals and animal products (milk, butter, meat, hides and wool) are also traded for grains, sugar and other commodities [8, 27]. Pastoralism is not a monolithic category but exhibits a wide variety of diets, social organization and economic production among pastoral groups. Agropastoralist groups such as cattle-keeping Gourma Fulani of West Africa or camel-keeping Baggara of Sudan obtain only 25% of their diet from milk; the rest of their nutrients come from millet and garden vegetables [28-30]. In contrast, East African herders, including cattle and small stock (goats and sheep) keeping Maasai, cattle, camel and small stock-keeping Turkana, and camel and small stock-keeping Rendille, obtain nearly all of their caloric intake from milk, meat and blood during certain times of the year, supplementing their diet with grains only during extreme dry periods [6, 31, 32]. Milk, meat and blood contain animal protein, fat and iron, and supply more than 200% of the recommended daily intake (RDI) of protein among Maasai and 400% among Turkana [31, 32]. However, total energy or caloric intake per gram milk is typically low, and Maasai and Turkana energy intake range between 55-75% of RDIs for men and women [31, 33]. One liter of milk contains only one fifth of the calories of an equivalent market value of maize. While one liter of milk yields 700 kcal and 38 grams of complete animal protein, one kilogram of maize offers 3560 kcal/kg and 95 grams essential amino-acid deficient vegetable protein [34]. Therefore, nutrition for most African pastoralists is based on milk-product consumption (high in complete protein) supplemented and thereby complemented by grain (high in calories) which is obtained from trade or agro-pastoral production [6, 35]. Vitamin and mineral deficiencies are rare but encountered during dry seasons when milk production is low. Hilderbrand found night blindness, probably due to vitamin A deficiency, among Fulani of Mall at the end of the dry season when milk yields are lowest [36]. Iron deficiencies were reported among Kenyan Turkana and Somali nomads, particularly among women and children who consume large quantities of milk but have less access to meat and blood than men [37, 38]. Twenty five percent of Maasai women and children studied by Nestel and Geissler were anemic, suggesting iron deficiency [39]. Seasonality exerts a considerable influence on the nutritional status of most pastoral populations, because pastoralist populations exploit environments with marked seasonal variation in rainfall and the availability of grazing resources. While milk production and calving are typically bountiful during the one or two brief rainy seasons each year, vegetation quickly dries and diminishes in protein content. Animals lose condition during the dry season and milk output decreases sharply. An East African Zebu cow which produces 1-2 liters of milk daily in the wet

Sedentism and child health season furnishes less than 250 cc of milk in the dry season [40]. Nutritional assessments among pastoralists have focused on seasonal changes in diet and anthropometry. Previous studies among Turkana have found that while food intake based on dairy production is energy-sufficient (well above RDI) immediately following a rainy season, protein and other nutrient intakes fall well below RDIs at the end of the dry season despite increased consumption of grains and blood [26]. The Turkana and Mali studies of pastoralist diets also show that children and adults suffer decreases in body fat, and childhood growth is temporarily inhibited at the end of the long dry season [28, 41-431. In addition to seasonal stresses, there also exists considerable variation in nutritional status based on sex and age differences. In general, pastoralist women have more access to milk than men have, owing to their primary role in milking tasks and caring for nursing livestock [41,44, 45]. Tuareg women consume 1.5 times as much milk as men do [29]. However, men and boys consume more meat and blood than do women and girls in Turkana and Maasai, as they probably do in most pastoralist societies [32, 41]. Furthermore, because the commercial livestock economy is dominated by men, women are less likely to receive cash to purchase grains for their households unless they sell dairy products themselves [10,46]. Pastoral populations face many of the same health problems as agriculturalists in Africa including high infant and child mortality from infectious diseases, particularly malaria, measles, diarrhea and respiratory illness [23]. Pastoralists are less prone to waterborne diseases (cholera, hepatitis), and studies show that Kenyan Turkana and Mali Tuareg have lower internal parasite loads than agriculturalists [23, 33]. The most comprehensive work on morbidity and mortality among pastoralists was compiled by Hill in Mali and compared health of nomadic and settled Tuareg (Tamasheq) camel keepers, Fulani (Fulbe) cattle keepers, and Sonrai and Bambara agricultural populations [23]. Malaria was found in up to 35% of all groups surveyed, with rates twice as high in Gourma Tamasheq as Gourma Fulani [47]. Among Fulani infants and children diarrhea, malaria, and conjunctivitis were the most frequent disorders [36]. Hill found 25% infant mortality in all groups surveyed in Mali [23]. Little is known about the health effects of sedentarization on pastoralists. Brainard found that nomadic Turkana suffered substantially higher infant mortality than settled Turkana agriculturalists [48], and Murray et al. noted increased iron-deficiency but overall decreased morbidity among pastoralist Turkana when compared with settled fish-eating Turkana [37]. Hilderbrand et al. showed environmental and economic effects on Fulani and Kel Tamasheq infant mortality [49]. They did not evaluate consequences of the settling process.

505

As part of Hill's health study in Mali, Chabasse et al. compared the health and nutritional status of

pastoral and sedentary populations, obtaining medical examinations and serological tests of 1995 nomadic Tamasheq (Tuareg), Fulani agropastoralists and Sonrai agriculturalists [47]. This study showed the nomadic groups had higher rates of tuberculosis, brucellosis, syphilis and trachoma, and higher child mortality (children five and under) than the agricultural groups. The authors attributed the differences to a greater isolation from health care services. The settled agricultural populations, however, had higher rates of bilharzia, intestinal helminths and other parasites, and higher malaria and anemia rates, which the authors attributed to their proximity to riverine locations. THE STUDY POPULATION Until quite recently Rendille subsisted exclusively by camel, cattle and small stock pastoralism in the Kalsut Desert of Marsabit District, northern Kenya. Marsabit is Kenya's largest but least populated district, receiving an average of 500 mm of annual rainfall (and less than 250 mm in the Chalbi and Kaisut Deserts). The majority of the District's 110,000 people are livestock pastoralists including Rendille (25,000), Gabra (30,000), Boran (30,000) and Ariaal (7000); an estimated 15,000 people live in or near the district's towns practicing agriculture or engaging in trade, manufacture or wage-labor [50]. In 1990, we began a longitudinal study of nomadic and sedentary Rendille communities comparing women and their children under six years for diet, nutritional status, morbidity and anemia. Unlike Hill's study which compared different cultural groups as well as different economic strategies, we look at different economic strategies practiced by members of the same ethnic group, which enables us to hold certain cultural practices constant: marriage patterns, inheritance rights, residence, language and religious beliefs. Three Rendille communities were selected for their distinct ecological settings and economic specializations: (1) Lewogoso is a nomadic camel, cattle, and small stock-keeping settlement of approximately 250 people. This community has been extensively studied by social anthropologist Fratkin and forms a control community to compare the sedentary villages [6, 44]. Nomadic Lewogoso members live along the base of the Ndoto Mountains in Western Marsabit District, subsisting largely on their milk camels and trade of cattle, goats and sheep. (2) Ngurunit is a sedentary agro-pastoral community of approximately 800 people located in a forested valley in the Ndoto Mountains in western

506

Martha A. Nathan et al.

Marsabit District. The community is made up of poor Dorrobo (foraging) populations as well as sedentary and generally poor Rendille and Ariaal (Samburu-speaking Rendille) who keep small numbers of camels, cattle and small stock. There are two Christian missions here: the Catholic Church runs a primary school and the African Inland Church (AIC) operates a small dispensary. There are also a half dozen shops owned by Somali and Rendille traders who buy livestock and sell maize meal, sugar, tea and other commodities. (3) Korr is a new town in the windblown Kaisut Desert, located 40kin east of Ngnrunit and 120 km west of the district capital on Marsabit Mountain. Korr did not exist, except as a dry season watering hole, before the droughts of the 1970s when the Catholic Diocese of Marsabit established a church and famine-relief center there. Today Korr has about 800 town residents and a large peri-urban population of several thousand Rendille living within a 15 km radius. Many of Korr's residents depend on famine-relief foods; others earn a living from running shops or buying and selling livestock. Korr has been extensively surveyed by Roth [22, 52, 53]. The three Rendille communities, nomadic Lewogoso and Korr and Ngurunit towns, were visited in July 1990 and again in late June 1992. Rainfall data collected by the Kenyan Agricultural Research Institute show that in 1990 rainfall was above average in Marsabit District while 1992 was a drought year, characterized by well below average levels for both the long spring rains and the shorter winter rains (see Fig. 2). Although our sampling during both years occurred in the same month, negating seasonality analysis, we can compare 'wet' and 'dry' years, particularly at the height of the summer dry season, the most difficult phase of East African pastoral annual cycle. At this time lack of rains translates into decreased animal forage, leading to lower volumes and decreased protein and fat content of animal milk [54], resulting in lower nutritional intake for humans [32, 42, 49]. Possessing data for all three communities at this time in two years with distinctive rainfall levels permits assessment of the performance of nomadic vs sedentary Rendille pastoral communities at this critical time of the year. MATERIALS AND METHODS

Child health was assessed in the three different communities by measuring morbidity, dietary and growth patterns for a study population of children under six years of age. From each of the three communities 35 women of childbearing age (approximately 16-45 years) were interviewed by Rendille male and female assistants in 1990. Their children under 6 years formed the orig-

inal study population (60 children from Lewognso, 60 children from Ngurunit and 54 children from Korr). The second survey was conducted by the same field assistants reinterviewing all the same women still available in the area. Children who had grown older than six years of age were eliminated and new births to those women were added. In all, 93 women from the original study were located (29 from Lewognso with 59 children, 31 women from Ngurunit with 59 children and 33 women from Korr with 66 children). Children's ages were determined by referral to their immunization records when possible, and when those were unavailable, by reference to a historic events calendar developed and used in previous Rendille studies in consultation with Rendille field assistants [55-57]. Breastfeeding patterns were similar for all three groups, as was age of weaning, with no children over 24 months still breast-fed and only one child under 18 months of age fully weaned. Women were asked about their pregnancy and child-bearing history, and previous child and infant mortality. Mothers were questioned how many days in the previous month they and each of their study children suffered respiratory, fever and diarrheal diseases.

To reconstruct child dietary patterns a detailed 24-hour dietary recall was performed for mothers and the study children. Each mother was asked to name foods consumed the previous day by themselves and their children. These were recorded separately for morning, afternoon and evening meals, and counted servings of milk, meat, maize-based starch (including cooked maize-meal, termed posho, porridge made with milk or whole maize), fat, tea, sugar, fruit (e.g. mango, papaya, bananas) or green vegetables, including local kale (in kiswahili, sukumu wiki). Frequency of servings was reported rather than actual amounts consumed (e.g. calories or volume) which were not possible to observe or otherwise measure. An important exception to this was the estimation of the amount of milk consumed based on standard metal cups widely used in the area, such that 'one small cup' was listed as one cup, 'one large cup' as 1.5 cups and milk served with tea or porridge estimated at 0.25 cups. This scheme introduced standardization to the most important Rendille food source. Finally, families were identified as 'poor' or 'sufficient' according to the number and type of animals available to each woman and/or the amount of money spent on food per week. Households were classified as 'sufficient' if they owned more than 4.5 Tropical Livestock Units (TLUs) per capita (where 1 TLU = 1 250 kg cow, 0.8 camel, or l0 gnats/sheep the minimum per capita level necessary for subsistence off livestock products in an arid environment), or if they earned incomes above $50 per month [6]. Otherwise they were considered 'poor'. The highest proportion of children from 'poor' households were from Ngurunit town (53%), followed by Korr town (28%) and the nomadic Lewogoso settlement (20%). The

Sedentism and child health

507

s S / ,/ ,/

•

-_.,. Ka~io"" ~',, "

I

RENDILLE

KORR

~-Oe~ s

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",,

K a i s u t D e s • r t

~,V£p

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.::.',N

o !

25

.SO I

ETHIOPIA )MALIA

KENYA

Elevation in meters 200

1000

1500

2000

3000

Primary Roads Secondary R o a d s

Tracks Seasonal Rivers TJ

DEASYGEOGRAPHIC5

Fig. 1. Map of Rendille study sites, northern Kenya.

differences reflect the large number of impoverished people without any livestock living near Ngurunit town. Famine relief was available to all three communities to varying degrees. Maize and beans constituted the bulk of this food aid, distributed by local

missions. As this food was available to all study communities--less to the nomadic community because of distance to distribution p o i n t s - - ' p o o r ' did not necessarily reflect lack of access to food. Mothers and children were weighed using a C M S hanging scale for children under two years of age,

Martha A. Nathan et al.

508

°

!1

100

E E

10

0.1

dul

AUg

Sop

Oct

Nov

Dec

Jan

Feb

Mar

Apt

May

Jun

Month -"o--1989/90 --4,- 1991/92

Fig. 2. Rainfall 1990 and 1992, Korr town. and a SECA digital scale for mothers and children over two. Heights were measured using a Shorr measuring board [58]. Triceps skinfolds thicknesses were measured with a Holtain calliper following Frisancho [59], and mid-arm circumferences were obtained via a Roche disposable tape. For the 1990 survey hemoglobin values were determined as the average of two samples taken by Hemocue analysis of finger stick pricks.

with respect to days ill with respiratory infections. These findings are surprising in light of differing health resources available to the communities. The sedentary communities of Korr and Ngurunit possess health clinics; in contrast, the mobile community of Lewogoso is located between 15 and 50 km from health clinics in Ngurunit or Korr town. Though access to a clinic was not reflected in differing morbidity patterns, immunization rates for Korr and Ngurunit towns children were far higher

RESULTS

Morbidity

Morbidity data were gathered by asking mothers: (1) the number of days each child in the household was ill in the past month and (2) the category of disease, e.g. diarrhea, fever and/or respiratory infections ('colds' or 'cough'). Results, recorded by community for each study year and representing mean values, are presented in Table 1 and Fig. 3. Analysis of these data by pair-wise Student's t-test revealed no significant differences between days ill for the 1990 wet season, suggesting that the nomadic community exhibited similar childhood morbidity as its sedentary counterparts. Likewise, the same approach showed only one significant t-value (P < 0.01) in the 1992 season, and this was between the sedentary towns, Korr and Ngurunit,

Table 1. Days ill in past month, mean values 1990 and 1992 by community 1990 Lewogoso (N

Diarrhea

Fever

Respiratory

1.08

3.51

3.90

I. 14

5.40

4.96

= 59)

Ngurunit town

(N ~ 57) Korr town 0,68 4.53 (N ffi53) All pairwise t-testsnon significant,P > 0.05

1992 Lawognso

4.58

0.82

0.79

1.93

0.83

0.52

1.95

1.51

1.92

2.61

(N = 67) Ngurunit town (N = 63) Korr town (N =

61)

Fever, Korr vs Ngurunit, t-test P < 0.01, all other paired t-tests non-significant at 0.05 level.

Sedentism and child health

Diarrhea

Fever

5

5

4.5

4.5

4

4

3.5

3.5

3

S

2.5

2.5

2

2

1.5

1.5

1

1

0.5

0.5

0

0

I!

Respiratory

C:D Z

go

509

O~ Z

92

Fig. 3. Morbidity by location, 1990 and 1992. than for nomadic Lewogoso. In 1992 children over 12 months of age in Kerr had 100% BCG, DPT and OPV immunization protection, while in Lewogoso percentage immunized were, respectively, 6, 0 and 2. Measles immunization rates were more nearly equal because an epidemic which struck in 1990 prompted a campaign to immunize all the children in the District before our return in 1992. While morbidity patterns between communities appear highly similar despite distinctive health care resources, Table 3 reveals marked differences between years. The most important difference is the decline in average fever and respiratory infection days in 1992. Comparing wet year figures from 1990 to those represented by the dry year of 1992 by means of the Kolmogorov Two-Sample Test [60], revealed significant differences (P < 0.01) for fevers for all three communities and for respiratory illness for Ngurunit (P < 0.05) and Kerr (P < 0.01). Hemoglobin levels obtained for children in each location in 1990 shows relative anemia in all three communities, but with significantly higher anemia at Kerr town (9.47 mg/dl) than among Ngurunit (10.83) or Lewogoso children (11.03), as shown in Table 4. Diet

Despite similar morbidity patterns among communities, analysis of 24-hour dietary recall data revealed strikingly different dietary regimes between the

nomadic Lewogoso community and sedentary Kerr and Ngurunit towns. Table 5 and Fig. 4 present children's consumption of major food items the previous day for each community in 1990 and 1992. Lewogoso children drank two to three times as much milk as their sedentary counterparts. This highly significant (P < 0.001) difference was maintained in the 1992 dry year sample, when the average amount of milk intake actually increased for Lewogoso, i.e. 1990 average = 2.32 cups, 1992 average = 3.17 cups. That the camel pastoralists of Lewogoso possess an entirely different dietary regime from the sedentary communities is evident when comparing average daily servings of sugar, starch and fat for both study years, as shown in Fig. 4. As expected, servings of starch are much higher among the sedentary communities for both wet and dry years. Tea and sugar are also more frequently consumed in the sedentary towns, particularly in Kerr. Residents of Ngurunit, the only community capable of supporting gardens, eat the most greens. The relatively high bean consumption in Kerr represents the inclusion of this food item in famine relief foods widely distributed in the community. In contrast, Lewogoso's figures for fat and meat were the lowest of all communities for both study years, reflecting nomadic pastoralists' reluctance to kill their subsistence animals for meat and the sedentary communities' tendency to purchase processed fat (ghee) through the market economy.

Martha A. Nathan

510

et al.

Table 2. Immunization data, children > 12 months of age, sedentary (Korr and Lewogoso) vs nomadic (Lewogoso) communities by year

Table 4. Hemoglobin levels for children by location, 1990

Immunization

Community

Sedentary

Nomadic

X2

Ngurunit town Korr town Lewogoso nomads

1990

BCG Covered Not covered

98 0

16 43

98.4***

Paired t-tests:

DPT Covered Not covered

85 13

5 54

92.2***

82 16

5 54

84.3***

82 16

4 55

87.9***

109 2

3 46

137.2"**

80 31

49

70.6***

80 31

1 48

66.7***

105 6

35 14

16.7"**

Korr vs Ngurunit Korr vs lewogoso Ngurunit vs Lewogoso

OPV Covered Not covered

Sample size

Hemoglobin mg/dl

36 32 36

10.83 9.47 11.03

t-score

P

3.20 3.28 0.44

** ** *

* = P >0.05. ** = P < 0.01.

Measles Covered Not covered 1992

BCG Covered Not covered

DPT Covered Not covvred

0

OPV Covered Not covered

Measles Covered Not covered *** = P < 0,001.

Child growth Having delineated the morbidity and dietary profiles of each community, and recognizing the well-established synergism between nutrition, morbidity and child growth [61, 62], analysis next compared child growth status by community and year. Given the cross-sectional nature of the data and the ambiguity of age assessment to the correct month/year, our analysis focused on weight for height measurements, which indicate immediate malnutrition (wasting) rather than long-term growth failure (stunting), and which is age-independent. To do so the world Health Organization Reference Standard for sex-specific Weight by Stature indices was used [63]. Following standard procedures for Table 3. Comparison of 1990 and 1992 days ill in past month by community, mean values Locale

Diarrhea

Fever

Respiratory

1.08 0.82 10.5"

3.51 0.79 33.4***

3.90 1.92 20.8*

1.14 1.51 4.9*

5.40 1.92 40.1"**

4.96 2.61 29,3***

0.68 0.83 5.8*

4.52 0,52 35.5**

4.58 1.95 33.7**

Lewogaso 1990 1992 D-value

Ngurunit town 1990 1992 D-value

Korr town 1990 1992 D-value *ffiP >0.05. ** = P < 0.01. * * * ffi P < 0 . 0 0 1 .

field-based data [64], analysis proceeded in two steps: (1) comparison of the weight-by-height values for the total sample with the WHO reference standard and, (2) determination by community of the number and percentage of children with very low values. Neither of these steps is free of controversy. Comparison of Third World children with Western-based reference standards may be inappropriate and may exacerbate determination of critical cut-off points separating undernourished from truly malnourished children [65, 66]. For the present samples direct comparison of Rendille child growth patterns with the WHO standard revealed the great majority of cases from 1-3 SD below the median of the standard, as shown in Table 6. Because of this we followed the usual methodology of denoting the cut-off point between undernourished and malnourished as 2 SD below the reference median, demarcating the third centile level of the standard and denoting extreme thinness for

Table 5. Comparison of major dietary items for non-breastfeeding children, by community and year, noting significant pair-wise t -tests 1990

Dietary item Milk Sugar Starch Fat Beans Meat Greens

Lcwogoso (N = 38)

Ngurunit town (N ffi 40)

2.32 1.16 1.00 0.39 0.00 0.00 0.00

1.2Y'c 1.98" 1.88i 1.08b 0.73 0.45 0.03

Korr town (N = 32) 0.78 c 1.88d 1.69d 0.94d 0.50 0.44 0.00

' ffi Lewogoso vs Ngurunit t-test, P < 0.001. b = Lcwogoso vs Ngurunit t-test, P < 0.05. ¢ = Lewogoso vs Korr t-test, P < 0.001. d = Lewogoso vs Korr t-test, P < 0.01. c = Ngurunit vs Korr t-test, P < 0.05. 1992

Dietary item Milk Sugar Starch Fat Beans Meat

Greens

I.,¢wogoso (N = 54) 3.17 0.13 0.41 0.06 0.02 0.06 0.00

Ngurunit town (N = 55) 0.84* 1.33'~ 2.07' 1.07a'd 0.42" 0.11 0.07

ffi Lewogoso vs Ngurunit t-test, P < 0.001. b = Lewogoso vs Korr t-test, P < 0.001. c = Ngurunit vs Korr t-test, P < 0.001. d ffi Ngurunit vs Korr t-test, P < 0.001. '

Korr town (N = 47) 0.89 b 2.06 b 2.00 b 0.52 b 0.43 b 0.17

0.00

Sedentism and child health

511

LewogosoNomads-gO LewogosoNomads-g2

Korr Town-90 Korr Town-02

Ngurunit Town-90

lmmM

Ngurunlt Town-g2 I

0%

lO%

20%

30%

40%

[ ] Milk [ ] Starch •

50%

60%

70%

80%

Meat [ ] Beans [ ] Fat [ ] Sugar •

90%

100%

Greens

Fig. 4. Diet by location, 1990 and 1992.

stature. All children falling below this level were classified as malnourished. Since innumerable studies stress breastfeeding as a source o f additional nutrition and increased immunecompetence all breastfeeding children were removed from analysis [67, 68]. Results determined from the remaining children are shown by community and Table 6. Percent children malnourished by location, 1990 and 1992.

Children's weight-for-heightdistribution according to WHO standard, non-breastfeeding children Between Between Below - I and median and Above - 2 SD - 2 SD - 1 SD median N (%) N (%) N (%) N (%) 1990

Locale

I.,¢wogoso 3 (9) 31 (89) 1 (2) 0 (0) (N ffi35) Ngurunit town 4 (12) 24 (73) 5 (15) 0 (0) (N ffi33) Korr town 4 (13) 20 (65) 7 (22) 0 (0) (N ffi31) Xz ffiLcwogoso vs Ngurunit town = 0.23*. Z2= I.¢wogoso vs Korr town ffi0.51". X2ffiKorr town vs Ngurunit town = 0.01". *ffiP >0.05. Between Between Below - I and medianand Above - 2 SD - 2 SD - I SD median N (%) N (%) N (%) N (%) 1992

Locale

Lewogoso 3 (6) 40(74) II (20) (N ffi 54) Ngurunit town 12 (22) 34 (63) 8 (15) (N = 54) Korr town 11 (23) 33 (70) 3 (7) (N ffi47) ~2 ffiLewogmo vs Ngurunit town ffi 6.27***. X2= Lewogoso vs Korr town ffi6.71'**. X2 ffi Korr town vs Ngurunit town = 0.02*. * ffi P >0.05. *** = P < 0.001.

0 (0) 0 (0) 0 (0)

year in Fig. 5. These reveal significant variation in the numbers and percentages of malnourished children across years and between communities. In the first regard, the 1990 wet year sample showed comparatively low levels of childhood malnutrition relative to the dry year 1992 sample. While this was expected, given the well-known hardships associated with drought in pastoral societies, the status of the nomadic Lewogoso sample, in both the wet, and particularly the dry, year samples is surprising. In the wet 1990 sample pairwise chi-square analysis comparing community to community revealed no significant differences in the distribution of malnourished children. However, in the 1992 'dry year' data the Lewogoso sample exhibited significantly lower rates o f childhood malnutrition in comparison to either of the sedentary communities (Lewogoso vs K e r r X2 = 7.8, P < 0.01, Lewogoso vs Ngurunit town X2 ffi 6.7, P < 0.01). In fact, the percent children malnourished in the dry year in Lewogoso was actually less than in the same community in the wet year, though this comparison did not reach significance. These findings are particularly surprising in light of the previously-cited studies from nomadic pastoral communities, all of which found those societies experiencing severe nutritional stress during the dry season [31, 33, 49, 691. In these studies authors stress that the dry season brings lower volumes of milk as well as decreased milk protein and fat content, as a direct consequence of decreased forage, which in turn is caused by diminished rainfall. The end result for children is often severe nutritional shortages culminating in decreases in body fat and temporary growth inhibition [28, 29, 41--43]. Yet in Lewogoso in this study, children's milk consumption remained high, apparently more than compensating for their lower intake of starch, sugar, fat and greens compared to

512

Martha A. Nathan

et al.

LewogoloNmnads40 Lewogo6oNomads-92

Kon"Town-90 Korr Town-92

Ngur.n# Town4~ NgunmltTown-92 0

S

10

15

20

25

30

35

Percent Malnourished Fig. 5. Child malnourishment by location, 1990 and 1992.

settled children. Consequently, nomadic Lewogoso children in the 1992 dry year exhibited a far lower incidence of malnutrition than did children in the sedentary communities of Korr and Ngurunit town. S U M M A R Y AND D I S C U S S I O N

Survey data comprising dietary recall, morbidity and anthropometrics drawn at the height of the dry season for three Rendille communities, one nomadic and two sedentary, were analyzed to assess child health in two years with highly distinctive rainfall levels, a wet year represented by 1990, and a dry year, 1992. Analysis revealed that morbidity patterns were similar for all communities in each separate year. Interestingly, though, children of Lewogoso, Korr town and Ngurunit town all suffered fewer episodes of respiratory illness and fever in the month prior to our 1992 sample. We attribute these declines to more arid conditions in 1992, resulting in less standing water for malaria-beating mosquitoes and a concomitant reduction in malarial fever. Similarly drier, warmer conditions occasioning fewer home fires may lessen the incidence of childhood respiratory disease. Despite the similar morbidity pattern, dietary recall data revealed a highly distinctive dietary pattern between the sedentary communities of Korr and Ngurunit towns and the nomadic Lewognso group. The major difference between the sedentary and nomadic samples was the significantly higher amount of milk drunk by the latter. Of particular interest was the retention of milk consumption levels in Lewognso in the 1992 dry year sample. Another noteworthy difference was the sedentary communities' much higher reliance on fats, starch and meat relative to Lewogoso. Comparing the study groups via anthropometrics, specifically weight-for-height, revealed that child-

hood malnutrition levels were comparable for all three communities in the wet year 1990. However, a major, but unexpected, finding was that while there was much more wasting among the town children in the dry year, malnutrition did not increase in the nomadic Lewogoso sample, and was significantly less than that found in the towns in 1992. These final findings were surprising since Lewogoso is the most dependent of all communities upon livestock products, and hence was assumed to be most susceptible to dry season fluctuations which reduce livestock milk production. Yet in direct contrast to expectations, the nomadic pastoral production system appears to be far more effective in dry season times than the sedentary systems sampled here, even though the latter were regularly receiving famine food relief to augment their diet. This finding is at variance with the Turkana studies which show seasonal malnutrition [26,41]. We attribute this difference to the large number of camels kept by Rendille (which may produce five times the quantity of milk of an equal number of cattle), and the larger communities within which they live, contributing to more sharing of food resources [70, 71]. These findings of similar morbidity but highly distinctive dietary patterns between the sedentary and nomadic samples point strongly to the latter as the causal agent in the different patterns of wasting. In this context, two other potentially highly significant factors, one biological, and one social, are worthy of discussion and consideration. In the first regard hemoglobin values obtained in 1990 for children at Korr were markedly lower than at other locations, with a mean value of 9.47 mg/dl compared to 10.83 at Ngurunit town and 11.03 for Lewognso nomads. Rates of anemia were high in all communities, below - 2 S D from the WHO median of

Sedentism and child health 12.5 mg/dl [72]. Ferritin levels were not obtained so distinctions between iron-deficiency and parasite-induced hemolysis cannot be made. Although there is a substantial amount of iron in camels' milk, it is also probable that there are higher rates of malaria in Korr town which would account for the differences in anemia. If the anemia is nutritional in nature, it would be added support for these initial findings of the enhanced nutritional potency of the nomadic diet. Surprisingly, economic differences do not seem to affect child health or nutritional status. Children from poor households, classified by livestock holdings and/or wage earning power, are found in all three communities, with both Korr and Ngurunit town households featuring more poor households than Lewogoso. This reflects the fact that impoverishment and sedentarization are co-related. Families often settle in or near towns because they are poor, particularly if they lack livestock. However settlement also has a positive side, featuring improved access to jobs, education, primary health care and access to famine relief foods. Yet the 1992 findings reveal that nomadic children in Lewogoso, despite the absence of famine relief foods, enjoyed far better nutritional status, where children from poor families received non-significantly different amounts of milk, as measured in cups, relative to food-sufficient children from Lewogoso (Xpoor= 2.7, Xsu~n, = 3.3, t = 0.86, P > 0.05). These results point to the sharing of milk animals and milk itself between wealthy and poorer kin in the nomadic communities, serving to negate livestock ownership differences. The most important conclusion from our study is that subsistence patterns based on traditional nomadic pastoralism (i.e. dependence on milk, meat and trade of camels, cattle, goats and sheep) provide better nutrition to Rendille children during drought periods than does town residence where people lack access to their domestic livestock. Despite the advantages of better health care and security in towns, the number of town children who were severely malnourished was over three times that of children in the nomadic community of Lewogoso during the drought year of 1992. This finding runs counter to the collective wisdom and policies promoted by international development and relief organizations which encourage the sedentarization of nomadic pastoralists, privatization of the range, and the development of private ranches to raise livestock. Our findings suggest that nomadic pastoralism based on the raising of domestic livestock primarily for milk is the most productive strategy to achieve food sufficiency in Africa's arid regions. We recommend that development agencies direct their efforts to (1) improve veterinary health of local livestock, (2) provide physical security for mobile herders and (3) improve market conditions (including the paving of roads) for the sale of a moderate number of animals.

513

Acknowledgements--The authors express their appreciation to the Office of the President, Republic of Kenya; the African Medical Research and Education Foundation (AMREF); the Institute of African Studies at the University of Nairobi; the Kenya Medical Research Institute (KEMRI); and the staff of Korr Catholic Mission and African Inland Church in Ngurunit, Marsabit District for their cooperation in this project. We also thank our research assistants Larian and AnnaMarie Aliayaro, Patrick Ngoley, Frances and Jane Omare and Kevin Smith; Penn State University faculty members John Beard, Anne Buchanan, James Wood and Helen Wright for their assistance, and to two anonymous reviewers at Social Science and Medicine for their thoughtful suggestions. Funding for this project was provided by grants from the Geisinger Research Foundation, the Mellon Foundation, Penn State University, and the University of Victoria; current research is funded by the National Science Foundation Grant No. 5BR-9400145. Versions ofthis paper were presented the 1991 Meeting of the American Public Health Association in Atlanta, Georgia, the 13th International Congress of Anthropological and Ethnological Sciences in Mexico City (July 1993), and the 1994 Annual Meeting of the Society for Ethnobiology in Victoria, British Columbia.

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