This study aimed to analyse the perception of various forms of malaria in three sympatric ethnic groups with various sociolinguistic backgrounds. Different terms were used to indicate six forms of malaria across ethnic groups. This diversity on the forms of malaria is not unique to our study area. In fact, in Africa several studies have shown various communities whose have distinguished many forms of malaria. For example, in Mali the communities of Sélingué subdistricts, have identified malaria through five forms sumaya, nènèdimi, djontè, djokoadjo and farigan [6]. Besides, in Zimbabwe, in the Chipinge District, traditional healers have recognized two forms of malaria, muswarara and ndangaranga [10]. However, the knowledge on the symptoms changes from one ethnic group to another. In fact, this variation of the symptoms was allowed to distinguish a simple form and a serious form of malaria. Thus, the symptoms as disjointed movements, fever, pale skin have been frequently reported by the ethnic groups in our study area. In the similar observations, the communities of Chipinge in Zimbabwe have mentioned those symptoms [10]. Moreover, in Mali the Sélingué communities have considered convulsions as an uncomplicated symptom of malaria [6]. Traditional medicine distinguishes a varied range of symptoms. Those symptoms evolve from one country to another. In fact, the variations of symptoms depend on traditional practices and cultural backgrounds [33, 34]. Better, those variations depend on the accessibility of rural communities to conventional medicine [10]. Therefore, local perceptions of malaria can be matched to conventional medicine. In fact, conventional medicine distinguishes two main forms of malaria (simple and complicated form) with many variations [35]. However, traditional medicine as well as conventional medicine cannot cope some disorders as mystical malaria and cerebral malaria. Those difficulties have conducted to the integration of traditional medicine in the region health system [6–10, 33].
However, the high transmission of malaria creates a tendency for people to catch that disease. Indeed, the susceptibility to the malaria changes from one country to another according to cultural backgrounds and was revealed by the ethnic groups behavior. In fact, the immunogenetic factors might be taken in account for distinguishing the susceptibility to malaria [34]. For example, in Mali two sympatric communities have been compared. Their studies have shown that in spite of fever which is a common symptom of malaria, Peulh communities are more susceptible to catch malaria than Dogon communities.
Traditional medicine is a part of people’s culture and is closely linked to their beliefs. In fact, people combine religion, sorcery and interpersonal conflict into a single form of belief and practice [36]. As an example, Amazonian people of Upper Rio Negro of Brazil associated malaria to spiritual beings and used to be cured with the blessings of shamans [37].
However, the other issue raised in this study is the importance of antimalarial plants species. As well as mentioned by some authors [37, 38], the use of plants depends on the culture. Indeed, the doctrine of signatures [39], has been used as a means to understand the medicinal plant selection process in traditional cultures. Moreover, for some authors [40] in Mexico and in Côte d’Ivoire [17], the organoleptic properties (bitter taste of bark stems and leaves or yellow color of the bark stems and the shape of plant organs) indicate that a given plant, has a medicinal potential and a therapeutic application. Thus, several studies have confirmed the antiplasmodial activities of the most important antimalarial plant species mentioned in this study. For example, stem bark of Annickia polycarpa [41], stem bark of Nauclea latifolia [42], stem bark of Harungana madagascariensis [43], leaves of Gymnanthemum amygdalinum [44], leaves of Ocimum gratissimum [45] and leaves of Senna occidentalis [46] were confirmed efficiency to manage malaria and related symptoms. However, the stem bark of Alstonia boonei was revealed inactive for inhibition concentration higher than 50 µg/ml against Plasmodium falciparum in, in vitro culture [43]. Even so, this plant species was prescribed against shiver and aches [15] in both Côte d’Ivoire and Ghana. For example, in Ghana, the leaves of Alstonia boonei have shown that the alkaloid extract of the species have an anti-plasmodial activity at 8.4 µg/ml [47]. Thus, the efficiency of a given plants depends on the parts of plant which were used differently by people to treat malaria [48].
Although the most important antimalarial plants above, have already been mentioned in literature for their antiplasmodial activities, there is no reference in the literature describing some antiplasmodial activities about Blighia unijugata Baker, Diospyros sanzaminika A.Chev., Cola nitida (Vent.) Schott & Endl., Macaranga barteri Müll.Arg., Parkia bicolor A.Chev., Plectranthus monostachyus (P.Beauv.) B.J.Pollard, Tarrietia utilis (Sprague) Sprague and Vitex grandifolia Gürke. These plant species were less known in our study. Nevertheless, these plant species are known for their analgesic, feverishness and antianaemic properties [15], which represent remedies against certain symptoms of malaria. There is a lack of information exchanges about their uses among informants [3, 9].
On the other hand, the similarity rate between antimalarial plant species was under 50%. The geographical proximity of ethnic groups have influenced the local culture in the uses of medicinal plants [39, 49]. For example, in Pakistan, the communities of Dhirkot, Azad Jammu and Kashmir which share the same vegetation, have the same knowledge on the medicinal plants [3]. In the similar case, the communities of Allada in Benin have shared their knowledge [9].
The different cultural backgrounds have explained, however the uses of plant species to cure malaria. In fact, in our study the greatest amount of plant species was recorded in the family of Lamiaceae, Asteraceae, Leguminosae and Apocynaceae, whereas, in Abidjan plant species belonging to Rubiaceae, Combreataceae, Leguminosae and Meliaceae families were mainly used for their antimalarial properties. Therefore, trees and shrubs were more used than herbaceous plants. Inversely, in Brazil herbaceous plants were observed by [50].
The last issue of this study is to determine the intracultural and intercultural variations of the knowledge within ethnic groups. Thus, the local knowledge on plant uses was influenced by the culture of people which included ethnic group, language, acquired practical experiences [14]. As an example, in the North-East and Central-East of Côte d’Ivoire, four Agni tribes used wild edible plants in two different vegetation. Agni-Barabo and Agni-Bini shared their knowledge [51]. In fact, they shared the same migration histories, the same religion and the same vegetation [14–39, 49]. Meanwhile, the intercultural variation on the common antimalarial plant species, was not significantly different, in this study. Indeed, the common plant species usually shared, are actively used through time and are considered effective. For example, in the South-Central of Ethiopia, four ethnic communities living in two different areas (Gurage, Mareqo, Qebena and Silti), have used the common plants and on the same time are considered effective [13, 48]. In contrary, two ethnic groups Koulango and Lobi, living around the East side of the Comoé National Park of Côte d’Ivoire, were compared about the availability of wild edible plants [52]. These authors have shown in their studies that, in spite of their close contact, Koulango and Lobi ethnic groups like differently wild edible plants. In fact, their studies have revealed that the uses of a given wild plant species are specific to one ethnic group and its culture [12, 39]. Otherwise, the knowledge sharing depends on the ethnic groups [13], and the preference of the plant species uses [12]. For example, 14 different ethnic groups in the Northern of Benin, were compared through the uses of the parts of Parkia biglobosa (Jacq.) G.Don [53]. In their studies, local knowledge varied from one ethnic group to another according to the form of uses and the organs of Parkia biglobosa, in the same geographical area. In fact, Lokpa, Waama and Bariba ethnic groups assigned high consensus value for bark, leaves, roots, seeds and pulp. In contrast, Nago, Anii, Dendi, Otamari, Mokolé, Foodo, Yom, Berba, Boko and assigned low value to bark and leaves. For the different form of uses of Parkia biglobosa, there is a consensus values for decoction, condiments were high for Bariba, Dendi, Fulani, Waama and Lokpa but low for other ethnic groups.
On the other hand, the extent of the knowledge on the medicinal plants according to the FL, changes from one country to another. As an example, in the rural communities of Dhirkot, Azad Jammu and Kashmir in Pakistan, preferred different plants to cure specifically wound healing, gastrointestinal disorders, body weakness, diabetes and cough [3].