‘Anemia’ refers to a condition in which the hemoglobin content of the blood is lower than normal as a result of deficiency of one or more essential nutrients [1], heavy blood loss, parasitic infections and congenital hemolytic diseases [2].

Globally, anemia is a public health problem affecting people in both developed and developing countries with bad consequences of human health as well as social and economic development [3, 4]. Anemia is a critical health concern because it affects growth and energy levels adversely [2]. It damages immune mechanisms and is also associated with increased morbidity [3]. It occurs at all age groups, but is more prevalent in pregnant women and children [2]. Especially, young children from low income families have a higher risk for developing anemia due to iron deficiency that occurs as a result of high demand for iron during the period of rapid growth [5].

Globally, anemia affects 1.62 billion (24.8%) of the population [4], and an estimated 36% of developing world’s population suffers from this disease [6]. Anemia is known to be a significant global problem affecting 305 million (25.4%) school age children (SAC) [4].

In developing countries, the prevalence of anemia among school age children is 40%, and it is classified as severe public health problem [2, 4]. The problem is alarming in Sub-Saharan African Countries such as Kenya 48.9% [7]; Mali 55.8% [8] and Tanzania 79.6% [9]. Lack of awareness among the mothers about the problem coupled with their low educational status [10], poor nutritional practices and unhealthy food habits [11], low iron bioavailability of the diet [12], decreased physical activities [13], malaria and parasitic infestations are additional factors associated with lower hemoglobin (Hb) level in children [14].

Although anemia remains a widespread public health problem in most developing countries, and even developed countries, there are very few studies on the prevalence and severity of anemia among school age children in Jimma area, Ethiopia. Because of its impact on cognitive development and physical growth, studies on the magnitude of anemia among school age children have paramount importance. Anemia creates long term effects among female children resulting in low birthweight babies and post partum hemorrhage. Therefore, the main aim of the present study was to determine the prevalence and severity of anemia on school children.

The criteria for determining the presence of anemia, as recommended by the World Health Organization (WHO), are based on hemoglobin cutoff values for age and sex with an additional epidemiological criterion for assessing the severity and magnitude of the problem.

Measurement of hemoglobin level is a vital physiological parameter that helps diagnose the extent and severity of anemia, polycythemia as well as other diseases of red blood cells. The magnitude of anemia determined in this study (37.6%) is considered as a moderate public health problem according to World WHO standards [2].

The present finding is in agreement with those of related studies done in developing countries. The prevalence of anemia was 39.1% as it was done on 271 school-age children (age range: 7–14 years) in Asendabo Town, Southwest of Ethiopia [22]. It was 39.4% of 531 school-age children in Cote Divoire [23]; 36.9% in a group of 250 school-age children in Leyte, Philippines [24] and 36.4% among Vietnamese school age children [25] as determined by the same techniques. The result of this study also revealed that the prevalence rates of mild and moderate anemia were 18% and 19.6%, respectively. No single case of severe anemia (Hb < 7 g/dL) was detected in this study.

In the present study, mothers’ educational level and average monthly income were found to be important determinants of anemia. Low level of mothers’ education may affect children’s nutritional status negatively, and low income limits the type and amount of food available. In line with this finding, Mohamed et al. [26], Alemayehu [22], Jemal and Rebecca [27], Kaya et al.[28] and Bassam [29] reported that mothers’ educational level and low family income were found important determinants of anemia. Similarly, studies conducted on school-age children show the relationship between occurrence rate of anemia and family size [29] and anthropometric status of the children [29, 30]. Additionally, father’s working status was found to be an important correlate of anemia as evidenced by studies done on 256 children (age range: 2 to 15 years) of Um-unnasser Village, Gaza [29] and in a group of 1295 school girls (age range: 6 to 18 years) in Ahmedabad city, Slums [30].

In the present study, about half of the children with anemia had lower intake of foods from animal sources, which is a source of heme iron. There are two forms of dietary iron: non-heme and heme iron. Non-heme iron takes the simplest form of free iron atoms such as ferric (Fe3+) or ferrous (Fe2+) iron. Non-heme iron is obtained from foods such as grains, pulses, legumes, fruits and vegetables [7]. In most populations throughout the world, non-heme iron is the main form of dietary iron. Heme iron is well absorbed in the intestine better than non-heme food obtained from plant sources. The finding of the present study indicated that more than half of the children who had anemia were eating food of plant source less frequently than non-anemic children. This dietary pattern would also result in low level of zinc and iron, which was found to be a strong predictor of hemoglobin level as studied in a group of 99 pregnant women [31] and in a group of 970 reproductive age women [27] in Ethiopia. A study conducted on pre-school children in Northern Ethiopia, Mekele, showed that the cultural food Teff-Enjera, which contains high amount of iron but bioavailability, was restricted because the type of iron is non-heme iron and there is an inadequate vitamin C, which reduces the absorption of iron [32]. Additionally, the major components of the diet in young children in developing countries are cereals and roots, which are not favorable for iron absorption as compared with meat and fish [33]. The present finding suggests high prevalence of anemia based on the fact that low level of Hb among school-age children probably due to dietary factors, inadequate consumption of animal food as mentioned above. Furthermore, reports of Djokic et al.[13] Kaya et al.[28] and Tiwari [34] show irregular consumption of meat and vegetable were found to be important correlates of anemia among school-age children. This fact supports the finding of this study.

Although not included in the present study, additional factors that may contribute to anemia in this population could be infection with intestinal parasites such as schistosomiasis, helminthes (hookworm in particular) and malaria.

The prevalence of anemia among school-age children (6–14 years old) in Jimma Town was high (37.6%). This study also showed that mild and moderate levels of anemia were found to be 18% and 19.6% respectively, while no single case of severe anemia observed in the present study. It was established that occurrence of anemia is directly correlated with parents’ income and maternal literacy status. Children whose maternal education was limited to reading, and writing and children who were from families earning an average monthly income of less than 500 ETB (=US $26.5) were more likely to be affected by anemia. Participants who consumed animal and plant foods less frequently were more likely to develop anemia than that of more frequent users of these foods. This shows that the problem of anemia is linked with food insecurity because of economic constraints in the community.

Therefore, poverty alleviation and improving the economic status of the society is a crucial strategy to reduce the prevalence of anemia. General adult education to parents and health education to the community are also important strategies to reduce the burden of anemia. Consumer education is also recommended to encourage the use of diversified diets including iron-rich foods and fruits that contain vitamin C that enhances iron absorption. Additional studies are needed on micronutrients deficiency, parasite infections, hereditary disorders and environmental pollutants.