Assessing the Determinants of Ebola Virus Disease Transmission in Baka Community
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1 1 Title: Assessing the determinants of Ebola Virus Disease Transmission in Baka Community 2 of the Tropical Rainforest of Cameroon 3 4 Authors: Wirsiy FranklineSevidzem,1 5 [email protected] 6 7 Um Boock Alphonse,2 8 [email protected] 9 10 Akoachere Jane-Francis Tatah Kihla1* 11 jakoachere @yahoo.com 12 13 1 Department of Microbiology and Parasitology, Faculty of Science, University of Buea, 14 Cameroon 15 2FAIRMED Yaounde Cameroon 16 17 *Corresponding Author 18 E-mail: [email protected] (J-F.K.T). 19 20 2 21 ABSTRACT 22 Background: Ebola virus disease (EVD) is a severe, often fatal illness in humans and nonhuman 23 primates caused by the Ebola virus. Treatment and vaccine are under development, hence 24 prevention is paramount. Design of effective prevention interventions requires an understanding 25 of the factors that expose communities at risk. It was based on this that we investigated the Baka 26 community (Pygmies) of Abong-Mbang Health District in tropical rain forest of Cameroon. 27 Methods: A cross-sectional study was conducted with participants randomly selected from13 28 villages in Abong-Mbang by multi-stage cluster sampling. A questionnaire was administered to 29 them to collected demographic information, data on knowledge of EVD, their feeding and 30 health-seeking behaviour. Data was analyzed using the chi-square test. Knowledge of EVD was 31 assessed using an 8 item Morisky Scale. An adapted Threat Capability Basic Risk Assessment 32 Guide was used to determine their risk of exposure to infection. 33 Results: A total of 510 participants, most of who were hunters (31.4%), farmers (29.8%), and 34 had primary education (62.7%), were included in this study. Although 83.3% participants had 35 heard of EVD, most did not know its cause. Their source of information was mainly informal 36 discussions in the community (49%). Misconceptions were identified with regards to knowledge 37 on the cause and mode of transmission. Only 43.1% accepted EVD could be transmitted from 38 human-to-human. Generally, participants’ knowledge on EVD was poor. Demographic factors 39 such as level of education, occupation and ethnic group significantly affected knowledge on 40 EVD. The majority of participants were at a very high risk of exposure to infection as they 41 consumed various forms of bush meat and were involved in other risky practices as scarification 42 and touching of corpses. Although over half of participants seek medical care, most of them 43 preferred traditional medicine. Socio-cultural and service related factors were deterrent factors to 44 medical care. 3 45 Conclusion: Participants generally had poor knowledge of EVD and were at high risk of to 46 infection. We recommend rigorous sensitization campaigns in study area to educate the 47 population on EVD and clarify the misconceptions identified. EVD surveillance is recommended 48 particularly as outbreaks continue to be reported in the Congo Basin 49 50 Key Words: Ebola Virus Disease, Knowledge, Practices, Determinants, Misconceptions, 51 Transmission, Cameroon. 52 BACKGROUND 53 Ebola virus disease (EVD) also called Ebola haemorrhagic fever (EHF), is a fatal illness 54 affecting humans and nonhuman primates caused by the Ebola virus, a member of the family 55 Filoviridae. The disease begins with flu-like symptoms. Haemorrhagic symptoms usually appear 56 late resulting in delayed diagnosis [1]. There is an increasing evidence of asymptomatic 57 infections [2-4]. Outbreaks have been caused by four of the six species of the Ebola virus: Zaire, 58 Bundibugyo, Taї Forest and Sudan [5]. The Ebola virus was discovered during simultaneous 59 outbreaks of febrile illness with shock and hemorrhage in Sudan and Democratic Republic of 60 Congo-DRC (former Zaire) in 1976 [6]. Since then, over 25 outbreaks have been reported with 61 most of them occurring in the Congo Basin [7]. The largest and deadliest outbreak ever 62 registered occurred in 2014 and was caused by the Zaire Ebola virus. It resulted in a very high 63 case-fatality ratio of up to 90% [8]. The Ebola virus has largely circulated in sub-Saharan Africa 64 causing dreadful epidemics of EVD [7]. Following the West African outbreak in 2014, it has 65 become a global public health security threat [9]. 66 Fruitsbats (Pteropodidae family) have been identified as the reservoir of Ebola virus [10] though 67 there is a possibility that other animals could also harbour the pathogen. Studies have 68 demonstrated pigs to replicate the Zaire Ebola virus [11] and there is evidence of transmission 4 69 from pigs without direct contact [12] indicating that pigs should be considered a potential 70 amplifier host during outbreaks of EVD. No other domestic animal has been shown to have an 71 association with filovirus outbreak. Spread of infection to human (primary transmission) occurs 72 by the spillover effect, following contact with blood, secretions, organs and bodily fluids of an 73 infected reservoir or an infected non-human primate [8, 13-15]. Person-to-person transmission 74 (secondary transmission) occurs in the community following contact with blood, secretions or 75 other bodily fluids of patient or individual who have died of Ebola. Healthcare workers in close 76 contact with an Ebola patient without using appropriate infection control measures and adequate 77 barrier procedures have been infected while treating patients [16]. Ebola virus can survive in 78 liquid or dry material for days [17] facilitating transmission by fomites. 79 Many factors increase the risk of acquiring and transmitting the Ebola virus [18]. Social 80 conditions such as human mobility, behavioural and cultural practices, bushmeat consumption, 81 burial practices, preference for traditional medicines and cures, and fear and obstruction of health 82 interventions have greatly enabled and enhanced human to human transmission [14, 19]. In 83 addition to these, increasing household transmission and individual secondary attack rate have 84 been linked to reported death of an index patient in the house who reported no fever, providing 85 care to the index case, length of time of wet symptoms in an index patient and index patient 86 being ˂20 years old [20]. Risk of transmission in the absence of direct contact is low [19]. 87 At present, there is no licensed treatment or vaccine for EVD. Patients are only given 88 symptomatic treatment which when administered early can improve the chances of recovery. 89 Prevention and control measures of an outbreak of EVD aim at interrupting transmission. This is 90 largely through avoidance of practices that predispose to infection [14]. For prevention to be 91 successful there is a need for an understanding and avoidance of the risky behaviours of a 92 community. 5 93 EVD epidemics have been reported in some countries that border Cameroon [21]. Although the 94 disease has never been reported, there is serologic evidence of Ebola virus in Cameroon [4, 22, 95 23] with highest rates of seropositivity among the pygmies (Baka people) and rain forest farmers 96 [22]. In a large scale survey of non-human primates across Central Africa, Leroy et al. [24] 97 reported serologic evidence of exposure to Ebola infection in Chimpanzees in Cameroon. These 98 findings confirm exposure to the Ebola virus and show that a less-virulent virus could be 99 circulating in Cameroon, accounting for the absence of human cases and/or observed epizootics. 100 The Southeastern equatorial rain forest of Cameroon harbours fruitbats which are reservoirs of 101 the Ebola virus, as well as animals susceptible to the Ebola virus disease [25]. Being that this is 102 part of the tropical rainforest of the Congo Basin; inhabitants of this area are at a high risk of 103 exposure to the virus. In addition, studies have revealed a high exposure to non-human primates 104 in Cameroon [26] . As a huge resource investment is needed to contain an Ebola virus disease 105 outbreak than to prevent it, prevention is mandatory in areas at risk such as the rainforest of 106 Cameroon. For prevention to be effective there is need for data to guide the design of health 107 promotion interventions. It was against this background that we assessed the risk of exposure of 108 the Baka community of Abong-Mbang Health District, South Eastern Cameroon to the Ebola 109 virus infection by investigating their knowledge on EVD and practices that could expose them to 110 infection. 111 112 METHODS 113 Study design and setting 114 This was a community based cross-sectional descriptive study carried out in the Abong-Mbang 115 Health District, Upper Nyong Division of East Cameroon. The Abong-Mbang Health District is 116 located in the south eastern rain forest of Cameroon which is part of the rainforest of Central 6 117 Africa, where most Ebola virus disease outbreaks except the 2014 West African outbreak have 118 originated [7, 27]. 119 The Abong-Mbang has an estimated population of about 28,904 inhabitants and covers an area 120 of about 15.000 km2. It is made of 92 villages that are grouped into 8 health areas; Mindourou, 121 Nkouak, Mbomba, Angossas, Ankoung, Atok, Abong-Mbang North and Abong-Mbang South 122 and has 25 public and private health facilities. It has a wet equatorial climate (also known as a 123 Guinea type climate). It’s forest has abundant and diverse animal life with animals such as 124 monkeys, some of the last populations of gorillas and chimpanzees etc. [27]. Fruit and 125 insectivorous bats and birds of various species are also common, as are various rodents. Our 126 study involved 13 villages (Figure 1)[28]. 127 128 Figure 1: Map of Abong-Mbang Health District 129 Source: [28] 130 131 Study Population 132 The study population comprised the Baka community of Abong-Mbang Health District.