Prevalence of intestinal parasitic infections and associated risk factors among Jawi primary school children, Jawi town, north-west Ethiopia

Intestinal parasitosis refers to a group of diseases caused by one or more species of protozoa, Cestodes, trematodes and nematodes. Several infectious diseases caused by some members of these previously listed organisms have been considered as Neglected Tropical Diseases (NTDs) [1‐4]. Intestinal parasitic infections (IPIs) caused by pathogenic helminthes and protozoan species are endemic throughout the world. Globally, about 3.5 billion and over 450 million people are affected and ill with parasitic infections, respectively [5]. One of the sustainable development goals of the United Nations (2030 Agenda;Goal 3.3) is to end, among others, the epidemics of NTDs through the control of the transmission of IPIs and the mitigation of possible risk factors.

Despite the improvements on the quality of medical services in terms of diagnosis of parasitic diseases, most parasitic diseases are still considered as major challenges for health centers and staff in many developing countries. And IPIs constitute to be one of the top ten major public health problems in developing countries primarily affecting school children [5]. The high prevalence rate of IPIs in developing countries depends on several factors. Socio-demographic variables associated with poverty such as reduced access to adequate sanitation, scarcity of potable water, unsafe human waste disposal systems, open field defecations and unavailability of sufficient health care as well as the prevailing bad climatic and environmental conditions are the most important risk factors.

Young children are reported to be disproportionately affected by IPIs compared to adults due to their increased nutritional requirements and a less developed immune systems. IPIs in this age group have been linked with significantly reduced growth, increased risk of protein-energy malnutrition, iron deficiency anemia and reduced cognitive/psychomotor development [1, 6, 7]. The World Health Organization (WHO) estimated that over 270 million pre-school children and over 600 million school children are living in areas where the parasites are widely transmitted and are in need of urgent treatment and preventive interventions [1]. Thus, infections by parasitic worms namely round worm (ascaris), hookworm and whipworm remain global burdens in low income countries [1, 3, 8, 9]. Global prevalence of IPIs caused by pathogenic protozoan species is also reported to be high. E. histolytica/dispar, the cause of amoebiasis, is one of the infective and severe diseases in 48 million individuals around the globe. In the same report, worldwide prevalence of giardiasis in both developed and developing countries was estimated to be 2.8 million new cases annually [1, 5].

In sub-Saharan Africa, the protozoan parasite (E. histolytica and G. intestinalis) and the soil transmitted helminthes (Ascaris lumbricoides, Trichuris trichiura, and hookworm) are the leading intestinal parasites causing significant morbidity and mortality [1, 10]. Thus, the frequency of IPIs in the region is extremely high, affecting nearly all inhabitants at some point during their lives.

The Federal Ministry of Health of Ethiopia launched the Health Extension Program in 2003 and operational since 2004 with Health Extension Workers, trained to work mainly in disease prevention and health promotion at village level. The Health Extension Workers have been serving almost all villages in rural as well as urban areas, and some improvement on health services have been shown. The program was expected to help accelerate the country’s progress in meeting some of the Millennium Development Goals.

Despite the great efforts by the ministry of health, Ethiopia is still known to be heavily affected by IPIs due to the aforementioned socio-demographic variables, behavioral factors, personal hygiene and environmental sanitation factors [1, 11‐16]. Indeed, ascariasis, hookworm and trichuriasis are listed among the most common public health burdens in Ethiopia [3]. A number of other studies have also shown a considerably high prevalence of IPIs in Ethiopia. For instance, extreme prevalence (84%) was reported among Debre Elias Primary School children (north-west Ethiopia) [14] though a relatively lower overall prevalence rate of IPIs (26.53%) was reported from Mekelle town (Tigray Region, northern Ethiopia [11]. In a number of other studies conducted in the different regions of Ethiopia, overall prevalence of IPIs, ranging from 54.5 to 81%, were reported from primary school children [12, 13, 16‐19].

According to clinical reports from the health center in Jawi town (north-west Ethiopia), intestinal infections are currently listed as the top reasons why people visit health facilities. However, there was no previous study conducted on the prevalence of IPIs and associated risk factors in the area. Therefore, the present study was undertaken to assess the prevalence of IPIs and associated risk factors among school children in Jawi Primary School, Jawi Town, Ethiopia.

Understanding the prevalence of Intestinal parasitic infections (IPIs) and associated risk factors in different localities is the key to identify high risk communities and designing appropriate intervention mechanisms. In line with this view, the present study attempted to assess the prevalence of IPIs and associated risk factors among the students at Jawi Primary School, Iawi town, north-west Ethiopia.

The overall prevalence of IPIs among the study participants was considerably high (58%). Reports from different regions of Ethiopia, too, showed elevated prevalence of IPIs ranging from 35% to as high as 80% without showing reduction [13, 16, 18, 25‐30] regardless of a community-based accelerated expansion of health facilities in Ethiopia being operational since 2004. High prevalence rates of IPIs have also been reported from other developing nations including in India (49%) [31], in Nepal (51.9%) [32], in Oshoidi Logos, Nigeria (58.3%) [33], in Burkina Faso (84.7%) [34]. And even 100% prevalence rate was reported in a rural area of Peru [35] showing that IPIs are still big threats to poor society. Low socio-economic status, low family educational level, individual behavioral and personal conditions of the participants, the level of environmental sanitation, source of drinking water and low personal hygiene are widely recognized risk factors accountable for the elevated prevalence of IPIs among communities in the poor societies . In this study, sex was not found to be associated with the rate of IPIs (p > 0.05) (Table 3). Similar observations were reported by previous studies in Tilili (north west Ethiopia) and Babile towns (Southern Ethiopia) [29, 36, 37] though there is much evidence supporting that males are more exposed to IPIs than females [18, 30, 38, 39] mainly related to differences in gender roles. However, age and residence were found to have associations with IPIs (Table 3). High prevalence rate was recorded in young children (6–18 years old). Reports from different parts of Ethiopia [30, 38] have also shown lower rate of infection among older children. This is obviously related to their behavioral activities such as playing in contaminated soil and water, and level of awareness of transmission of IPIs. With regard to residence, those children who came from rural areas had higher IPI (56.4%) than urban dwellers (45%). This was supported by many other studies (e.g [38, 40]) and has been well documented. Poor environmental sanitation, not using toilet, inadequate water supply, low level of knowledge and practices in personal hygiene, and low living standards of the subjects are often mentioned as major factors for the high prevalence of intestinal parasites among rural dwellers than urban dwellers.

Seven types of intestinal parasites were identified from the students of Jawi Primary School (Table 2), the most prevalent being G.lambila (close to 20%). This high prevalence rate of G.lamblia infection may be attributed to one or more of the risk factors as half of the participants were found to have open field defecation habit, 66% of them ate raw vegetables and unwashed fruits, 70% had poor hand washing habit before meals and all of them lacked safe drinking water. This parasite was also found to be highly prevalent (11–23%) among other school children in Ethiopia [17‐19, 40, 41]. About 6% of Jawi Primary School children were positive for another protozoan parasite, E. histolytica/dispar, which is considered to be low compared with previous reports from Ethiopia and some other developing nations [17‐19, 28, 32, 42, 43].

Hookworm was the second most prevalent (about 14%) parasite among the study participants. It was significantly associated with defecation habit, sex, protective shoe wearing habit and age (Table 4). High prevalence of hookworm infection (11–33%) was also reported in studies at different schools in Ethiopia [17, 19, 27, 28, 37, 38]. S. mansoni was the third most prevalent parasite (10.3%) among the study participants. This is a high prevalence rate andmay most likely be related to the students’ habit of swimming in the canal water constructed near the town for sugar cane irrigation (Additional file 1). Furthermore, water contact activities such as crossing rivers, bathing in rivers, washing closes in rivers and lack of protective shoes could contribute for S. mansoni infection among the study participants. Reports from different parts of Ethiopia also showed high prevalence rates of S. mansoni infections ranging from 10 to as high as 83% [11, 12, 38, 42, 44‐47]. The prevalence of H. nana among the study participants seems relatively low (4.2%). Of course, similar prevalence rates (4.5 to 4.7%) were reported in studies on school children in four Primary School in north-west Ethiopia [13, 19, 38] as well as a little higher rate (5.5%) in Yemen [37]. A bit higher infection rates (6.5 to 9%) were reported from some rural areas in Ethiopia as well as in other African countries [34, 48, 49]. The prevalence of Taenia species among the study participants was also low (3%). Similarly, low infection rates (1.5 to 3.4%) were reported from other areas in Ethiopia [13, 17] and in Nigeria [39] as well. Even much lower infection rates (0.2 to 0.8%) were reported in some regions of Ethiopia [14, 18, 44]. However, an extremely high prevalence (64%) was reported from three selected districts of west Shoa (Central Ethiopia) [50].The least frequently encountered parasite in this study was A.lumbricoides (0.73%) which is also found to be rare (0.6 to 1.6%) among some other school children in north west Ethiopia [14, 44]. However, much higher infection rates (8.3 to 15.5%) than observed in this study were reported from some Primary School children, still in north-west Ethiopia [17, 28, 49]. Even though the prevalence of these parasites vary from localities to localities, they remain public health burden in low income societies.

In the attempt to identify the associated risk factors for prevalence of IPI among school children in Jawi town, factors including residence, age, hand washing habit before meals, open field defecation habit, river water contact activities, eating raw vegetables and unwashed fruit, and dirty and untrimmed finger nail were significantly associated with the prevalence of IPIs (p < 0.05). This, more or less, concurs with previous studies conducted elsewhere in Ethiopia (e.g. [19, 28, 30]).

Multivariate logistic regression analysis was conducted to determine the degree of association between IPIs and the demographic variables as well as other risk factors (Table 3).The age of the study participants was strongly associated with IPIs, and children in both mid-childhood and early adolescence were approximately twice more at risk of IPIs than those in late adolescence. Likewise, hand washing before meals, open field defecation, shoes wearing consistency, eating raw vegetables and fingernail cleanliness were found to be predicators of IPIs among the participants of the study. Students who used to defecate in open field were at risk by twofold than those who defecated in latrine. Similarly, shoes wearing habit of students were strongly associated with IPIs. Student who did not wear protective shoes were four times likely to be infected compared with those who wore regularly, and those who wore sometimes were two times likely to be infected than those who wore always. Moreover, students who did not regularly wash hands before meals were five times likely to have IPIs than those who washed their hands regularly before meals. These observations were consistent with reports of studies elsewhere (e.g. [18, 19, 30]).

There was also strong association between the two most prevalent parasites and some risk factors. The risk of G.lamblia infection was increased by two fold in study subjects who had a habit of open field defecation, poor hand washing habit, and habit of eating raw vegetables and unwashed fruit compared with those who used latrine, washed their hands as well as did not eat raw vegetable (Table 4). This finding was supported by other studies [27, 28, 30, 40] suggesting that contamination of vegetables with fecal matter in farming area could be among the primary causes. Sex, age, open field defecation habit and shoes wearing consistency were found to be predicators of hookworm infection among Jawi Primary School children (Table 4). Participants who did not wear protective shoes and those wearing irregularly were threefold and twofold, respectively, more likely to be infected compared to the study subjects who always wore shoes. This result was consistent with other reports in some rural Ethiopia [28, 40].

Generally, the present study showed that school children in Jawi town were heavily infected with IPIs, implying that IPIs continue to be major public health problems in low income communities. G. lambilia, hookworm and S. mansoni were the most predominant intestinal parasites detected among the school children. The most important risk factors for these infections were found to be age, inconsistency of wearing shoes, poor hand washing habit before eating, open field defecation, habit of frequent river water contact, having dirty and untrimmed finger nails, and eating uncooked vegetables. Urgent actions are needed to, at least, reduce intestinal parasitic infections through concerted approaches involving politicians (decision makers), health extension workers, school teachers, the mass media, community and religious leaders. All these bodies should design practical action plans for effective prevention and control of IPIs in the study area in general and. to create awareness among school children and their parents in particular. It is also recommended regular inspection be conducted on school children for personal hygienic practices and shoe wearing habits.