Previous PageTable Of ContentsNext Page

I. Africa


General economic performance

Economic growth improved slightly in 2000 and 2001.

Economic growth in sub-Saharan Africa stood at 3 percent in 2000, a slight improvement over 1999. Despite the global economic slowdown, real GDP is expected to grow by 3.5 percent in 2001.1 Growth is estimated to have accelerated in most major economies of the region. International Monetary Fund (IMF) projections for 2002 put economic growth at 4.2 percent.

Many countries in sub-Saharan Africa continue to experience large external deficits, driven in part by weak non-fuel commodity prices and still high external debt servicing costs.

With exports accounting for more than one-third of regional GDP, the global slowdown is undermining the traded goods sector, in particular trade with the European Union (EU), which absorbs around 40 percent of the region's exports.2

However, local influences still play a dominant role in the economic prospects of most African countries. In particular, the outlook for private investment, economic diversification and longer-term growth is generally brighter in countries that have pursued sound macroeconomic and structural policies (such as Botswana, Cameroon, Mozambique, the United Republic of Tanzania and Uganda). In contrast, poor policy performance, often combined with political uncertainty and/or conflict, has marked adverse effects on prospects for sustained growth and for reductions in poverty in a number of countries.

Table 5











5.1 5 4.4 4.2 5.3 4.6

Côte d'Ivoire

6.2 5.8 1.6 -2.3 -1.5 2.8


4.2 4.7 4.4 3.7 4.0 4.0


2.1 1.6 1.3 -0.2 1.1 1.4


3.1 1.9 1.1 3.8 4.2 1.8


5.1 4.6 7.9 4.4 5 5.2

United Republic of Tanzania

3.5 3.7 3.5 5.1 4.6 4.2

South Africa

2.5 0.7 1.9 3.1 2.2 2.3

Sub-Saharan Africa2

3.7 2.6 2.5 3.0 3.5 4.2

1 Projections.

2 Including South Africa.

Source: IMF.

Undoubtedly, in recent years, different sectors of the economy have played an increasing role in sub-Saharan economic growth. Since the 1980s, industrial growth has fallen behind GDP growth and there appears to be a shift towards a higher dependency on growth in sectors such as agriculture and services.

While African countries have in the past experienced surges of investment and growth, they have often not been able to establish a virtuous circle of investment, savings and exports. Both domestic savings and investment ratios dropped significantly in the 1980s and recovered in the latter part of the 1990s. Investment in the 1990s in sub-Saharan Africa reached 18.2 percent of GDP,3 an increase of 1.2 percentage points compared with the 1980s. On the other hand, savings amounted to 14.5 percent of GDP in the 1990s, only a 0.6 percent increase over the 1980s.4

The events of 11 September and their aftermath have negatively affected the outlook for developing countries in sub-Saharan Africa. The consequent further weakening of global economic prospects has pushed down prices of most commodities, many of which were already at depressed levels. World oil prices declined to around $18 per barrel by late November 2001, from over $25 prior to the attacks.5 These trends have weakened the outlook for many of the poorest countries in the region, causing a substantial revision of prospects for the year 2002.

2000 was a year of weak agricultural performance, and only a modest recovery was expected for 2001.

Agricultural performance

Agricultural performance in sub-Saharan Africa weakened substantially in 2000. Overall agricultural production decreased by 0.3 percent in 2000 after increasing by 3.7 and 1.9 percent in 1998 and 1999, respectively. Crop production fell by 1 percent and food production contracted by 0.3 percent. Cereal production fell by 3.2 percent, the second consecutive drop. Roots and tubers output rose by a mere 0.5 percent, down from the 5.5 and 4.2 percent growth achieved in 1998 and 1999, respectively. Livestock production increased by 1.4 percent, which marks a slowdown over the previous two years. The preliminary estimates for 2001 point to another year of disappointing agricultural performance in the region, with agricultural output expanding by less than 1 percent and with crop and livestock production expected to rise by only 0.9 and 0.5 percent, respectively.

In western Africa, agricultural production stagnated in 2000 after robust growth of 6 and 3 percent in 1998 and 1999, respectively. Several countries, in particular Benin, the Gambia and Liberia, saw agricultural production expand strongly. However, Burkina Faso, Mali, the Niger, Sierra Leone and Togo all experienced marked falls in overall net output. Crop production fell by about 0.3 percent. Cereal output was down by 3.5 percent in 2000. In the Sahelian countries, in particular, cereal production fell by 12.7 percent. Production of roots and tubers rose by 2 percent, a much lower rate of growth than in the two previous years. Nevertheless, a number of countries, including Benin, Côte d'Ivoire, Liberia, the Niger and Senegal, saw large increases in cassava production. Livestock production grew by 27.4 and 8.4 percent in Côte d'Ivoire and Ghana but aggregate output rose by only 2 percent.

Preliminary estimates for 2001 suggest that agricultural production will increase by only 0.5 percent. However, prospects for cereal production in the Sahelian countries are good following a favourable rainy season, and record harvests are forecast for Burkina Faso, the Gambia and the Niger.

In central Africa, agricultural output fell by 1 percent in 2000 after contracting by 1.7 percent in 1999. Crop and livestock production fell by 4.1 and 0.7 percent, respectively, both contracting for the second year in a row. Cameroon and the Central African Republic recorded overall output gains of 2.4 and 3.7 percent, respectively, largely attributable to strong expansions of cereal output, while Chad and the Democratic Republic of the Congo saw output fall by 7.6 and 3 percent, respectively.

Table 6





Roots and






3.9 4.4 5.8 2.4 2.6 3.7


0.5 0.2 -4.2 2.0 1.4 0.3


3.7 4.1 4.1 5.5 2.6 3.9


1.9 1.8 -0.6 4.2 2.5 2.5


-0.3 -1.0 -3.2 0.5 1.4 -0.3


0.8 0.9 2.4 0.7 0.5 0.6

1 Excluding South Africa.

2 Preliminary.

Source: FAOSTAT.

Estimates for 2001 suggest a further small contraction in agricultural output in the region. A moderate expansion of agricultural output is forecast for Cameroon and Chad. In the Congo, the food supply situation has yet to recover and continuing civil strife points to another reduced cereal harvest.

Eastern Africa also saw poor agricultural performance in 2000, with output falling by 0.5 percent after growing by only 1.1 and 1.5 percent in 1998 and 1999, respectively. In particular, Burundi, Eritrea and Mozambique saw large output falls. On the other hand, Rwanda and Zimbabwe recorded strong growth in overall output. Crop output fell by 1 percent, with particularly large contractions recorded in Eritrea, Kenya and Mozambique. Favourable harvests in Rwanda, Somalia and Zimbabwe were offset by large falls in output in Burundi, Eritrea, Kenya, Madagascar, Mozambique and the United Republic of Tanzania, leading to a fall in cereal production of 3.5 percent in 2000. Roots and tubers output increased by only 0.5 percent after increasing by 6.7 and 8.2 percent in 1998 and 1999, respectively. Livestock production rose by only 0.5 percent. Drought in the pastoral areas in Ethiopia, northern Kenya and Somalia led to the deaths of an estimated 3 million head of cattle.66 In Mozambique, flooding caused the death or serious injury of around 350 000 head of cattle.

Estimates for 2001 indicate that agricultural production has grown only by about 1.3 percent, with crop and livestock output growing by 1.6 and 0.8 percent, respectively. In Somalia, cereal output grew by almost 54 percent in 2000 but prospects for the 2001 food situation are a cause for serious concern. In Eritrea, the food situation remains tight as a result of the war with Ethiopia and the drought in 2000. The 2000 cereal crop was sharply reduced as a result of the displacement of hundreds of thousands of farmers from agriculturally rich regions that normally account for more than 70 percent of cereal production, and the prospects for 2001 cereal production are not favourable. In the Sudan, the overflow of the Nile in the northern regions has displaced tens of thousands of people, destroyed crops and aggravated the already precarious food supply situation. Despite this, overall prospects for coarse grains in 2001 are favourable. Better prospects are also forecast for Uganda due to improved pasture conditions and water availability for livestock in the Kotido and Moroto districts.

In southern Africa (excluding South Africa), agricultural production fell by 3.3 percent in 2000 after increasing by 14.2 percent in 1999. Crop and livestock production fell by 3 and 3.9 percent, respectively. However, cereal production grew by 6.8 percent, with particularly good crops reported for Botswana and Namibia. In South Africa, agricultural output rose by 3.4 percent in 2000 after a 6.5 percent gain in 1999. Crop production rose by 5.2 percent, with cereal output rising by 37.1 percent after three years of declining output.

Projections for 2001 suggest a further fall in agricultural output of about 0.5 percent. A combination of prolonged dry spells, severe floods and disruption of farming activities is expected to lead to production shortfalls in the region. Preliminary estimates for 2001 indicate a reduction in cereal output of more than 8 percent over the previous year. South African net agricultural output is also projected to fall by 5.7 percent with crop production down by 10.5 percent.



The need to focus on women farmers' productivity, which can be an effective engine for social change, has become increasingly clear in sub-Saharan Africa. Women have a significant role in farming and post-harvest activities in most countries in the region. Nevertheless, a complex set of rights and obligations reflecting social and religious norms prevail within rural communities; these dictate the division of labour between men and women and act as constraints to women farmers. An understanding of women farmers' role, its importance and these constraints is a prerequisite to devising policies to improve productivity and socio-economic development.

In sub-Saharan Africa women contribute most of the labour for food production.

The role and importance of women farmers

In sub-Saharan Africa women contribute between 60 and 80 percent of the labour for food production, both for household consumption and for sale.7 Moreover, agriculture is becoming a predominantly female sector as a consequence of faster male out-migration.8 Women now constitute the majority of smallholder farmers, providing most of the labour and managing a large part of the farming activities on a daily basis.9

Traditionally, the roles of men and women in farming differ in Africa. Men clear the land and women undertake most of the remaining farming activities, particularly weeding and processing. Since the colonial period, men have been most active in cash crop production, while women have been mainly concerned with food and horticultural crops, small livestock and agroprocessing. Women's activities have tended to be homestead-based, for biological and cultural reasons. Men and women have also been responsible for their own inputs and have controlled the output. In sub-Saharan Africa, men traditionally owned land, but plots of land have been cultivated or managed jointly or separately by men and women.

Box 4


Cassava is the most widely cultivated tuber in sub-Saharan Africa and the second most important food staple in terms of per capita food energy consumed1. Because of its tolerance to extreme ecological stress conditions and poor soils, cassava plays a major role in reducing food insecurity and rural poverty.

Cassava production in the region has grown sharply over the last two decades. Between 1980 and 2001, total output rose from 48 to almost 94 million tonnes, while the area under cultivation rose from 7 to 10 million hectares. Today, sub-Saharan Africa accounts for more than half of global cassava production.




Area harvested










(Million tonnes)

(Million ha)


Nigeria 11 34 1 3 9.6 10.8
Democratic Republic of the Congo 13 16 2 1 7.0 14.5
Ghana 2 8 0.2 0.6 8.1 12.1
United Republic of Tanzania 5 6 0.4 0.9 10.7 6.8
Mozambique 4 5 0.9 0.9 4.1 5.8
Uganda 2 5 0.3 0.4 6.9 13.0
Angola 1 3 0.3 0.5 3.4 6.0
Sub-Saharan Africa 48 94 7 10 6.9 9.1
World 124 176 14 16 9.1 10.7
Source: FAOSTAT.

Although cassava is generally considered as a traditional subsistence crop, the recent introduction of new varieties (such as the TMS2 varieties of the International Institute of Tropical Agriculture) has transformed its status from that of a low-yielding famine-reserve crop to a high-yielding cash crop. With the aid of mechanical graters to prepare gari (roasted granules, a value-added product), cassava is increasingly being produced and processed as a cash crop for urban consumption.

This trend is partly attributable to the fact that cassava has multiple uses. As a food, it can be used for baking, cereals and snacks, soups, beverage emulsifiers, powdered non-dairy creamers and confections. Cassava starch is also used in various industrial sectors, such as paper manufacturing, cosmetics and pharmaceutics.

Cassava as a "woman's crop" is becoming more evident. Women undertake most processing activities, such as peeling, washing and transporting to grating and milling sites, where cassava meal and grated cassava are stacked in sacks and placed in traditional processors for the starch to drain off. Nowadays, it is mostly women and young girls who undertake the roasting and sieving of gari.

A recent study3 shows that women's labour is becoming increasingly significant in production also. Men still play central roles in land preparation and ploughing but women provide the bulk of the labour for weeding, harvesting, transporting and processing. The later stages of transportation, processing and marketing are also handled mainly by women.

The recent rise in commercial cassava production will accord even greater importance to the role of women, as it is in the post-harvest activities that women's labour predominates (see Figure).

Ghanaian women peeling cassava roots
Cassava constitutes an important part of the diet of many poor people in Africa.

- FAO/18293/P. CENINI

There are some exceptions, however. For example, grating and pressing are handled largely by men in Ghana and Nigeria, where these tasks have been mechanized.4 In Nigeria, men and women have a equal share in processing. This may be explained by the fact that women's access to resources is limited. The study found that men own twice as many food-processing machines as women, although the services the machines provide are available to both men and women.

In addition, women still lack decision-making power in many instances. When large proportions of the products are intended for sale, household decisions are mostly taken by the male head, who usually dictates how the cash earned will be used. Women are allowed to control only small cassava sales, the proceeds of which are used to buy necessities for the family such as soap, matches and salt.

Cassava continues to gain importance in many sub-Saharan countries, both as a food staple and a cash crop. Women's labour inputs for production, harvesting, transport and processing are very substantial and increasing. Targeted policies with regard to credit, gender-sensitive extension services and technological and institutional changes geared towards women would further advance productivity in this sector. The empowerment of women is the key to success in the cassava economy.

1 Cassava provides 286 kilocalories (kcal)/person/day out of a total of 2 198 kcal/person/day.
2 Tropical Manioc Selection varieties.
3 The Collaborative Study of Cassava in Africa (COSCA) undertaken by the International Institute of Tropical Agriculture from 1989 to 1997, based on data drawn from 281 villages in six African countries (F.I. Nweke, D.S.C. Spencer and J.K. Lynam. 2002. The cassava transformation: Africa's best-kept secret. East Lansing, USA, Michigan State University Press).
4 Ibid.

These farming patterns are changing over time. Many countries have seen an increasing trend in female-headed households. By the mid-1980s women headed an average of 31 percent of all rural households - a much greater proportion than in other regions. There is much variation within this trend, however, ranging from a proportion of 10 percent in Burkina Faso and the Niger in the early 1990s to 46 percent in Botswana and 72 percent in Lesotho in the late 1980s.10

The traditional roles of men and women farmers are changing.

Moreover, population pressure and off-farm employment opportunities for men have led to an increasing proportion of women becoming de facto farm managers. In such households, women's autonomy and authority vary over time. In some cases, male migrants return to work on the farm during the peak agricultural season. Men are often absent from the rural labour force when in their twenties and thirties, and women exceed men in the age group 20-44. For example, in Kenya, about 86 percent of farmers are women, 44 percent of whom work in their own right and 42 percent of whom represent their husbands in their absence.11 As a result, a higher proportion of women than men are engaged in most phases of the production cycle for food, cash crops and livestock - in addition to their household work and small income-earning activities.

Women are also engaged on a more regular basis than men in all farm activities and phases of the production cycle. They provide most of the labour and manage many farms on a daily basis. As Table 7 suggests, women work much longer hours than men and spend more time on farming activities, even though the figures are far from being homogenous.

Table 7











Burkina Faso

7.0 8.3 1.7 6.0


4.3 6.2 3.8 6.1


7.0 9.0 1.5 5.0


6.4 7.6 0.8 4.6

Source: K.A. Saito, H. Mekonnen and D. Spurling. 1994. Raising productivity of women farmers in sub-Saharan Africa. World Bank Discussion Paper 230. Washington, DC.

Gender differentials in agricultural productivity and constraints facing women farmers

While men and women generally face the same external constraints, they have an unequal access to human-controlled factors. They have different endowments, such as land rights and education, and different access to technologies, labour, capital, support services and credit. This disparity results in differentials in productivity to the detriment of women.

Female productivity in agriculture is lower than that of men.

A number of studies have examined the relative productivity of men and women in farming in sub-Saharan Africa. Often, but not always, findings indicate that women farmers have lower productivity for reasons of poor access to resources. Figure 21 also reflects the weaker productivity of women farmers: the average production per farmer12 tends to be lower in countries in which women represent the larger share of agricultural labour force than men.

Although women are less productive in farming, the general consensus is that they are no less efficient than men in their use of resources.13 Rather, a lack of complementary inputs leads to a lower labour productivity for female farmers.

Evidence from Burkina Faso shows that, compared to males from the same household, female cultivators of the same crops in the same year achieved yields 30 percent below average.14 One reason for this differential was the lower level of male and child labour used on plots controlled by women. Additionally, virtually all fertilizer was concentrated on male-controlled plots. It was estimated that a reallocation of the variable factors of production from male- to female-controlled plots in the same household would raise household output by between 10 and 20 percent. An important conclusion of the findings was that households generally do not act as a single individual and that appropriate modelling of the complexity of the household decision-making process is needed in order to provide better policy guidance.

Lower female productivity seems to derive from unequal access to resources and education.

For a sample of Kenyan farmers, it was found that the gross value of output per hectare from male-managed plots was 8 percent above that of female-managed plots.15 It was estimated that if women were to use the same resources as men their productivity would increase by about 22 percent. The study also concluded that educating women is more likely to increase the use of new technologies than educating men.

Other research in Kenya indicates that increasing women's levels of physical and human capital (to that of men's in the sample) would increase yields by between 7 and 9 percent.16 The impact of schooling on farm output was also found to be greater for women than for men because men with more schooling tend to seek off-farm employment and are more likely to be successful in finding and keeping a job. Women, on the other hand, are seldom able to find off-farm work.

Many factors explain the weakness of women's productivity in agriculture. Women farmers have quantitatively and qualitatively less access to information, technology, land, inputs and credit. Policy-makers, managers, agents and participants in agricultural support services are generally males, who are not always sufficiently aware of the specific problems and needs of women farmers. As a result, information and extension services are typically geared towards male farmers, on the assumption that the message will trickle across to women. Evidence shows that, in reality, this is not the case.

Women's access to land is a particular problem.

In sub-Saharan Africa women are particularly disadvantaged compared with men because they farm smaller plots of land with more uncertain tenure.17 Women's access to land is limited by legal and institutional factors such as legal discriminations against their ownership and inheritance of land. Although legislative changes now permit women to own property, in many countries in the region traditions and customs continue to prevent women from having effective ownership.

In Wadi Kutum, the Sudan, for example, a titling scheme registered most of the land owned by women in men's names, but women did not even protest because, customarily, they do not conduct relations with the state, which has long been considered as men's domain.18 Without secure title to land, women are often denied membership of cooperatives and other rural organizations. Lack of ownership title also means a lack of collateral and hence access to credit. Many developing countries have legally affirmed women's basic right to own land but actual female control of land is rarely observed.

Women typically receive less than 10 percent of the credit awarded to smallholders and only 1 percent of the total amount of credit directed to agriculture in Kenya, Malawi, Sierra Leone, Zambia and Zimbabwe.19 In sub-Saharan Africa, more women than men are too poor to buy inputs such as fertilizer, and they are not generally considered as creditworthy by classical financial institutions.

Training and extension services, and in particular the use of female field extension workers, have been identified as a potentially important factor in raising female productivity.20 However, in a glaring example of "gender blindness", only 7 percent of agricultural extension services in Africa were directed to women farmers in 1988 and only about 11 percent of all extension personnel were women.21

Conclusion and policy implications

Women's labour productivity appears to be lower than men's in sub-Saharan Africa. This does not mean that women's potential productivity is low, nor that women's role in agriculture can be neglected. On the contrary, evidence shows that the apparent low productivity of women is a result of the social and economic constraints they face.

To improve women farmers' productivity in the region, much change is required. Less discriminatory laws and policies must replace legislation and customs that constrain women's access to factors of production such as land, credit, inputs, information and technology. The interventions must be situation-specific. Actions must be technically relevant and be suited to the sociocultural and religious precepts of the farming community and the resources of the community.

Yet no quick solutions are likely to guarantee remarkable results, because the success of many of the required remedies depends on changes in attitude on the part of women themselves. Finding ways to increase women farmers' awareness of the gender-related inequities they face and the resulting inefficiencies and to give greater empowerment to women in their public choices are some of the most important challenges currently faced by agriculture in sub-Saharan Africa.

Tsetse fly and African trypanosomiasis affect 37 African countries.



Tsetse-transmitted African animal trypanosomiasis (AAT)23 infests between 9 and 10 million km2, or 37 percent of the continent, and affects 37 countries.24 Some 45 million head of cattle and many other domestic animals live within or directly at the margin of the tsetse-infested areas. According to the World Health Organization (WHO), many millions of humans are also at risk, with tens of thousands of deaths attributed each year to sleeping sickness, the human form of trypanosomiasis, and an estimated 300-500 thousand people carrying this usually fatal form of the disease.25

The disease leads to loss of productivity in animals and, without treatment, is frequently fatal. Large areas of land are today left with relatively few cattle because of the presence of the tsetse fly, and the estimated losses in agricultural output and productivity are very significant.26 However, the costs of tsetse/trypanosomiasis (T&T) control or eradication are considerable and only relatively limited evidence is available on the cost-benefit relationship of T&T control and/or eradication on a sub-Saharan scale.

The disease reduces livestock productivity.

The direct impact of trypanosomiasis

The disease directly affects livestock productivity by:

Although there are significant variations among observations, an average reduction of 20 percent in herd meat and milk output in areas of tsetse challenge is considered to be a conservative estimate.28 Overall, the cattle population is reduced by 30-50 percent because farmers keep their animals away from areas with a high tsetse challenge or trypanosomiasis risk.

Evidence based on actual farmer's practice (as opposed to controlled experiments) from a sample of livestock owners in Burkina Faso indicates that 87 percent of respondents recognized a substantial reduction in the number of cattle dying of AAT following implementation of tsetse control. Livestock owners estimated that the overall mortality rate fell from 63 percent in 1993/94 - prior to control - to 7 percent in 1996/97 - after control.29

Using data from the Programme Against African Trypanosomiasis (PAAT) Information System, it has been estimated that a 200 percent increase in cattle numbers in areas at risk might result in the theoretical case of complete and instant tsetse removal.30

The disease also has negative implications for crop-livestock production systems.

The indirect impacts of the disease

Even more significant may be the indirect impact on crop production, land use, ecosystem structure and function, and human welfare. Trypanosomiasis prevents, in many places, the development of integrated crop-livestock production systems. That means that tilling must be performed by hand and agricultural productivity is lower than if healthy animals were available to provide draught power.

Evidence from Ethiopia suggests that a team of oxen in a tsetse-infested area is only capable of cultivating 60 percent of the land that can be cultivated in a tsetse-free area.31 The disease can lead to species well suited for animal traction not being introduced into areas at risk. For example, West African zebus and horses are little used in the wetter semi-arid and drier subhumid regions of West Africa because of the risk of contracting AAT.

Box 5


The Programme Against African Trypanosomiasis (PAAT) was endorsed in 1997 by the FAO Conference. By combining the forces of FAO, WHO, the International Atomic Energy Agency (IAEA) and the Organization of African Unity (OAU)/ Interafrican Bureau for Animal Resources (IBAR), the programme seeks to:

  • ensure a harmonious, sustainable approach towards improved human health and sustainable socio-economic and agricultural development of tsetse-infested areas;
  • promote and coordinate international alliances and efforts assisting in harmonized interventions against T&T;
  • achieve integrated trypanosomiasis control in Africa.

PAAT is primarily concerned with the development and application of science-based standards for assessing the economic, social and environmental benefits and costs of T&T management. It studies and analyses the balance between human needs in terms of food security and livelihood sustenance and the preservation of natural resources and prevention of environmental degradation.

Much discussion within PAAT has focused on prioritizing tsetse interventions, integrated into the overall agricultural production scheme, in selected, well-demarcated areas. This principle has become recognized as a prerequisite for success. The integration of T&T intervention into the general process of agricultural development and production provides the opportunity to maximize the benefits for the rural poor while minimizing the negative effects on the environment. It will thus contribute to sustainable pest management in targeted farming systems, and enhance the opportunities for adoption by livestock owners and producers.

In order to deal comprehensively with the magnitude and complexity of the T&T problem within the context of national and regional action plans for poverty alleviation, multidisciplinary efforts are progressively replacing the technology-based approaches of the past.

The low use of draught animal power in sub-Saharan Africa, even within trypano-free areas, means that additional measures, such as training, credit and infrastructure, are needed to obtain the full benefit of tsetse control.

Table 8


Total cattle stocks

cattle at risk

Cattle not kept owing
to tsetse infestation



Sub-Saharan Africa

196 196

45 343

90 743

1 Based on 1997 data.

Source: FAOSTAT; PAAT; M. Gilbert, C. Jenner, J. Pender, D. Rogers, J. Slingenbergh and W. Wint. 1999. The development and use of the Programme Against African Trypanosomiasis Information System. Paper prepared for the International Scientific Council for Trypanosomiasis Research and Control (ISCTRC) Conference, 27 September to 1 October 1999. Mombasa, Kenya.

Further adverse effects of trypanosomiasis include less-efficient nutrient recycling, less diversification of income and less access to credit. Moreover, substantial (tenfold) increases in milk production can result from the introduction of dairy cows that are trypano-intolerant.32

Cost-benefit ratios for tsetse control

The relationship between the cost of T&T control/eradication and its resulting benefits depends on a number of factors. For example, in areas of low-challenge trypanosomiasis control through trypanocides is possibly more profitable than through other techniques.33 The appropriate type of T&T control (see Box 6) depends on the type of farming landscape, topography, the degree of tsetse challenge, the type of insecticide used, the scale of the operation and the time frame envisaged; it therefore follows that a multitude of different approaches are required in sub-Saharan Africa. Consequently, any effort to assess the cost-benefit ratio of T&T control is a complex undertaking.

Setting up a trap to catch tsetse flies
This trapping technique, in comparison with other catching methods, is appealing for its cheapness, flexibility and environmental compatibility.


A study of cost-benefit ratios for a number of techniques, time periods and degrees of tsetse challenge, using data from Burkina Faso, suggests that at low levels of challenge trypanosomiasis control through trypanocides is the most profitable option unless the time period is very long. A comparison of the use of traps versus insecticide shows that the latter technique produces higher cost-benefit ratios only when the time period is long and the interest rate used for discounting future benefits is low. The sterile insect technique (SIT) is profitable only when applied to areas of relatively high tsetse challenge and over a long time horizon (15 years). Even under such assumptions, SIT does not compare favourably with the trap and insecticide methods.34

A further study estimated, on the basis of available evidence for a wide range of techniques and making some simplifying assumptions, cost-benefit ratios of regionwide tsetse control.35 These estimates, which should be taken as approximations only, range from 1:1.4 to 1:2.6 when considering a 20-year period. The full extent of the benefits is expected to be obtained at the end of the 20 years, when the cost-benefit ratio is estimated to rise to 1:5.

Studies have shown the favourable cost-benefit ratios of tsetse control.


Tsetse control or eradication thus appears to be desirable and feasible in certain sets of circumstances, where the conditions are conducive and long-term agricultural benefits can be secured. Many different methods have been, and are being, applied, including drug therapy, trypanotolerance, vector control or eradication and SIT. However, controversy remains within the scientific community with regard to appropriate products and methods and whether they would be effective in the long run.

It is perhaps relevant here to consider the campaign to eradicate Chagas disease (American trypanosomiasis) from South America. The so-called Southern Cone Initiative against Chagas disease is one of the largest disease-control programmes ever mounted, covering an area of over 6 million km2 with a time frame of ten years. The aim is to eliminate transmission of the causative agent Trypanosoma cruzi in Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay. Formally launched in 1991, the programme has achieved remarkable success, with transmission interrupted in Uruguay in 1997. Interruption of transmission is expected for the other countries within the next few years. More recently, the Andean and Central American Initiatives have started with the same aim.

This suggests that concerted action on the part of the affected countries and international organizations is indispensable to the eradication of this disease. It is in this spirit that PAAT (see Box 5) is seeking to combine the forces of FAO, WHO, the International Atomic Energy Agency (IAEA) and the Organization of African Unity (OAU)/Interafrican Bureau for Animal Resources (IBAR) to promote integrated trypanosomiasis control within the broader goal of enhancing food security, sustainable agriculture and rural development.

More recently, the OAU Heads of State and Government Summit of July 2000 endorsed the Pan African Tsetse and Trypanosomosis Eradication Campaign (PATTEC), with the ultimate objective being the eradication of tsetse and trypanosomiasis from Africa. With a view to pursuing this objective, PATTEC will undertake the organization and coordination of the campaign and mobilize the necessary human, financial and material resources to do so.

Box 6


Combating trypanosomiasis is technically and organizationally difficult. First, civil stability is needed for any large-scale vector control programme. Moreover, the sustainability of funding that takes into account the permanent nature of the commitment of maintaining an area's trypanosomiasis-free status is necessary.

Drug therapy
Drug therapy currently protects more cattle than all other artificial techniques combined. At a cost of about $35 million (about $1 per dose), it protects 10-15 million head of cattle living in tsetse-infested areas from the full effects of trypanosomiasis. A drawback to drug therapy is that cattle that have been treated are not as productive as those in a completely disease-free environment.1 Moreover, there is concern that the level of resistance to the two main drugs (isometamidium and diminazine), which were developed in the 1950s, may be increasing.

Trypanotolerant and partially or semi-trypanotolerant cattle in West Africa account for about 10 million (in 1983) of the 45 million head of cattle living in and in close proximity to tsetse-infested areas.2 Although these cattle are not immune, they do possess a degree of tolerance that allows them to remain productive while being infected.

Vector control or eradication
Tsetse flies require a tree habitat. Early in the twentieth century, wide areas of land were cleared of trees and game. After the Second World War, insecticide-based control techniques, i.e. ground and aerial spraying, were developed and deployed widely. Ground spraying and sequential aerosol technique (SAT) have been tried and proven in field situations, with variable results but general technical success in Nigeria, South Africa and Zimbabwe.

In response to increasing concern about the environmental impact of control measures, and with the advancement of science, different bait systems such as various traps and odour-baited targets impregnated with insecticide were developed. Artificial bait techniques are appealing for their cheapness, flexibility, low pollution factor and relatively larger local input. A drawback that is preventing their widespread use is the recurrent costs of continuous tsetse suppression, which is necessary to keep re-invading flies at bay. The use of herd animals treated with insecticide is a technique that is currently being evaluated on a significant scale. The cost of this control method is difficult to compare with those of other methods as it is proportional to the number of cattle per square kilometre. However, where dipping infrastructure is in place, the use of live animals as bait is invariably the most appropriate method of tsetse control.

The sterile insect technique (SIT) is very sophisticated and, under specific conditions, potentially powerful. It is also relatively expensive and may therefore prove cost-effective only when implemented on a relatively large scale and in an organized manner. This method was successfully applied against New World screwworm in the Libyan Arab Jamahiriya, Mexico and the United States, and in Central America, and against the fruit fly in countries in the Mediterranean basin, the Near East and South America. SIT was successfully applied against the tsetse fly in Zanzibar, where eradication was achieved by the aerial release of sterilized males over Unguja island (1 500 km2) in 1995-97.

Following successful control or eradication, re-invasion must be controlled in order to sustain livelihoods. Tsetse flies are estimated to be able to regenerate their population from very low levels within four years. In practice, the greatest threat of re-invasion comes from outside the cleared area.

1 J.C.M. Trail, K. Sones, J.M.C. Jibbo, J. Durkin, D.E. Light and M. Murray. 1985. Productivity of Boran cattle maintained by chemoprophylaxis under trypanosomiasis risk. ILCS Research Report No. 9. Addis Ababa, International Livestock Centre for Africa.
2 FAO. 1987. Trypanotolerant cattle and livestock development in West and Central Africa. Vol. 1. International supply and demand for breeding stock, by A.P.M. Shaw and C.H. Hoste. FAO Animal Production and Health Paper No. 67/1. Rome.

Previous PageTop Of PageNext Page