Ecto and Intestinal Endo-parasitic Fauna of Bushmeat in Nsukka Ecological Zone, Nigeria
Chapter One
Objectives of the Study
The objectives of the study were to:
- Isolate and identify parasites present in various bushmeat commonly consumed in Nsukka ecological
- Determine the prevalence, intensity and abundance of various parasites
- Assess knowledge, attitude and risks regarding zoonotic infection among bushmeat suppliers .
- Characterize possible zoonotic links with in the human population in Nsukka ecological
Chapter Two
Literature Review
Factors that determine the distribution of parasites on a host (bushmeat)
The distribution of a parasite within a host species is not solely the result of random processes (Bordes et al. 2009). Instead, it has been associated to different exposure rates to the parasite and to variable host susceptibility to infection (Thomas et al., 2000). Gaston and Lawton (1988) and Gregory (1997) grouped the main potential determinants of parasite distribution in a specific host population into three groups of factors: host individual factors (such as age, sex, body size, diet), host population factors (abundance, range, and migration), and environmental factors (habitat). The interactions between different types of factors modulate parasite abundance in a given host population.
Environment factors
Temperature and humidity are two factors that influence host parasite relationships greatly; this is largely due to the fact that most parasites spend part of their life-cycle outside the host and must be able to persist long enough to infect a new host. Seasonal environmental changes can influence transmission rates of gastrointestinal parasites by affecting the development and survival of parasites in the environment and host contact with infectious free-living parasites (Stromberg, 1997)
Host population factors
Parasite diversity and prevalence is expected to be positively correlated to group density (Nunn and Altizer, 2006), as transmission rates (for parasites with direct or indirect life cycles) are likely to increase with greater contact rates (Stuart et al., 1990). Though density is the most consistent host trait influencing parasite diversity (Nunn, 2003), effects of density require large-scale studies that are able to factor out other variables. For example, recent studies have suggested that habitat characteristics may play a larger role than once realized (Gillespie et al., 2004; Gillespie et al., 2005). Nonetheless, density of hosts remains of prime importance for studying parasite infection rates (Poulin, 1998). Overlap in ranges of phylogenetically similar animals can lead to cross infections between species some of which are better able to cope with certain parasites than others (Chapman et al., 2005). This is important for animals being housed together in crowded sanctuaries, which are often un- avoidable in developing countries (Karesh, 1995).
Host individual factors
Richness, prevalence and intensity of parasites species are predicted to increase with greater degrees of insectivory, folivory or omnivory and with specific feeding and drinking behaviours. For example, folivorous animals tend to eat more which exposes them to a greater amount of contaminated vegetation; however, they also consume a greater amount of secondary compounds that can fight off infection. Frugivorous animals tend to feed on a wider variety of plants, which potentially exposes them to a wider variety of parasites; and insectivores consume arthropods, which are often intermediate hosts for parasites (Nunn and Altizer, 2006). Conversely, dietary stress and malnutrition can affect parasitism through immunosuppressant of the host (Chapman et al., 2006).
Prevalence, intensity and abundance of parasites of different species of bushmeat
In many part of the world, different species of parasites have been found in bushmeat Macleod et al., (1977) stated that the larger the host the more adult ticks it seems to carry. This is confirmed by the observation of Horak and Knight (1986). They determined the total tick burdens of various sympatric host species and found that, with some exceptions, the larger the animal species the better host it is particularly for the adults. In Weza State forest Natal, during an extensive survey of arthropod parasites, Three of the 5 antelopes examined between December and April each harboured 2 adult Rhicicephalus lunulatus. Six of the 8 antelopes examined between October and May harboured the louse-fly, Lipopteria paradoxa. Then from common duiker, they recorded 7 ixodid tick species and 2 species of lice from the 13 animals examined. The 3 animals examined between November and January was each infested with adult Haemaphysalis aciculifer. Although ticks of the genus ixodes were the most numerous, no pattern of seasonal abundance was evident. Each of the animals examined from May to September was infested with 2-4 nymph of Rhipicephalus appendiculatus. Only the animals shot during March were infested with adult R. lunulatus.
Horak et al., (1991) surveyed the incidence of ectoparasites of red duiker and bushpig in different locality in North-Eastern Natal, 18 red duikers, Cephalophus natalensis, from the Charters Creek Nature Reserve that were processed for arthropod parasites recovery, harbour 8 species of ixodid ticks and 2 lice species. All were infested with Haemaphysalis parmata and the nymphs of Rhipicephalus muehlensi and again 2 bushpig, Potamochoerus porcus, from the Ndumu Natural Reserve, 5 from the Eastern Shores Nature Reserve and 1 from Cape Vidal that were also examined, infested with 8 ixodid tick species of which Rhipicephalus maculates was the most abundant, and with 1 louse specie. They further stated that the small size of red duiker and their habitat preference make them ideal hosts for immature stages of many tick species unlike bushpig like warthogs that.
CHAPTER THREE
MATERIALS AND METHODS
The study area was Nsukka ecological zone of Enugu State, Nigeria Figure 1. Nsukka is located in northern part of Enugu State on longitude 7o08′ and 7o20′ East and latitude 6o46′ and 6o49′ North. It is made up of seven densely populated Local Government Areas: Igbo- Etiti, Uzo-Uwani, Isi-Uzo, Nsukka, Udenu, Igbo-Eze North and Igbo Eze South. Its population is over 49% of the current Enugu state. As of 2007, Nsukka Cultural Zone had an estimated population of 1,377,001 (NBS, 2007). Nsukka town is known as the site of the first full-fledged indigenous university in Nigeria (University of Nigeria, Nsukka).
Climate: Two main seasons prevail in these areas. They are the rainy and dry season. While the southeast trade wind brings rain, the northeast trade wind brings a dry period known as Harmattan (Uguru). The annual rainfall range of 200 – 400mm is recorded between March and December. Rainfall is minimal in the dry season month of October to February.
Vegetation: The zone formerly belonged to the rainforest zone, but because of incessant human and other anthropogenic factors, has turned into a derived savannah. Numerous green hill and valleys intersect the area. Patches of forests exist around the valleys of some parched streams, springs and rivers within the area. The complex of trees and grasses that make up the zone has led to the region being termed “the savannah mosaic” (SRAE, 2012). The soil consists of humus, mixed with clay particles. The area is characterised by tall trees and grasslands vegetation where bushmeat are widely distributed.
Much of the bushmeat range in Nsukka is remote from the centers of human habitation. Nsukka local government shares a common border with Igbo-etiti and Isi uzo Local Government Area at Opi agu, located around Ekwegbe, Umunkoo and Umulumgbe, which is a very large hunting area with varieties of different animal species, ranging from birds, reptiles, rodents and antelopes. According to the hunters, almost all the bushmeat consumed in Nsukka area originated from Uzouwani and that border. It is common for hunters to bring their game from the wild to urban centres where it fetches a good price. In Nsukka, bushmeat are transported from forests and grassland (where the hunting mainly takes place) to markets within local communities or to larger markets in urban centres, where it is then sold to bushmeat traders that buy them directly from hunters (Source of supply).
CHAPTER FOUR
RESULTS
The checklist of all bushmeat sampled and the parasites recovered
The checklist of all the wild animal hosts collected, all the recovered ectoparasites of different kinds which include ticks, fleas, lice and mites and intestinal parasites belonging to different genera are presented in Table 1. Out of the 143 examined, 114 were infected with at least one ectoparasite while 141 were infected with at least one intestinal parasite. This represents about 79.7%% and 98.6% infection respectively. Amongst the 143 bushmeat with ecto and intestinal parasites, 12 ectoparasites and 18 intestinal parasites were identified plate 10 – 21 and Plate 22 – 39 respectively shown.
CHAPTER FIVE
DISCUSSION, CONCLUSION AND RECOMMENDATIONS
Discussion
This study has provided for the first time detailed quantitative data on infection with ecto and intestinal endoparasitic fauna of bushmeat, commonly consumed wild animal hosts, which are relatively poorly studied and about which little is known in Nsukka. The results revealed that animals from the wild are heavily infected with parasites that can be transmitted to their offspring and other mammals, including humans that may be exposed to them. This poses health problems to humans.
Many of the ecto and intestinal parasites encountered in this study have been reported among wildlife elsewhere in the world. They have been reported in a reservoir status among bushmeat in other African countries (Banga-mboko et al.,2006; Kankam et al., 2009; Wendy and Wayne, (2010); Futagbi et al.,2010; Hiva et al., 2011) and in Nigeria; Mbaya et al., 2008; Okoye and Obiezue, (2008); Opara, M. N. and Fagbemi B. O. (2008); Madinah et al.,2011; Ibrahim et al.,2012) .
Apart from hookworm, which is well known to be transmitted through soil- contaminated hands, all the other species of intestinal parasites found are transmitted through contaminated food and water, and mostly cause diseases with symptoms of anaemia, diarrhoea and weight loss (Olsen, 1974; Smyth, 1996; Roberts et al., 2010). The occurrence of intestinal parasites which comprised more of nematodes agrees with, (Rossanigo and Gruner,1995) who reported that nematodes are responsible for most of the helminthes diseases of health importance.
These findings are similar to the observations made by (Nadchatram, 2008) who observed that most ectoparasites that are vectors of zoonotic diseases live in close association with their animal hosts in a stable habitat and in equilibrium with the climate and soil, undisturbed by humans. This present study has shown that any shift in this equilibrium due to the pressure of human activities in Nsukka, there is a great danger of zoonotic pathogen been transmitted to humans and their domesticated animals through these ectoparasites bite.
Most of these bushmeat animals sampled don’t normally feed on aquatic vegetation, therefore relatively few were infected with trematodes, (Condy, 1972) and hence only one trematodes, Dicrocoeluim sp (10.5%) was recovered in this work. Dicrocoelium sp has two intermediate hosts (slugs and ants). The final host is infected when it ingests ants with metacercariae. So when the temperature is low the ant attaches itself to the grass stem and can infect a new host. The fact that most of the bushmeat animals examined during this study have been resident in same ecological zone together for a long time may explain the finding of similar parasite in different animal types. Many of these animals share many things in common and thus could easily transfer infection among themselves.
This study recorded the presence of Strongyloides sp, Ascaris sp, Trichuris sp, Capillaria sp, Emeria sp and Ascaridia sp in birds while Ajibade et al.,(2010) recorded no infection of birds in Obafemi Awolowo University Zaria and University Ibadan Zoos in Nigeria, This may be attributed to the fact that Animals that are known to roam considerably, especially because their movement are not restricted by fences, are more likely to become infected with accidental parasites (Horak, 1980). Wild birds are known to migrate over long distances and wide areas of land and could acquire more parasites or introduce parasites to new areas in the process (Mbaya et al., 2007). The lowest prevalence of Dermamyssus sp ecountered in this work is line with the work of (Swai et al., 2010) who recorded Dermamyssus sp least in prevalence of all the parasites recovered while working with ectoparasites and heamoparasites of free-range fowls of Northern Tanzania.
This study reported the presence of Rhipicephalus sp, Dicrocoelium sp, Ancyclostoma sp, Entamoeba sp, Trichostrongylus sp, Heligomosmoides sp, Enterobius sp, in wild rabbits, while Trichuris leporis, Trichostrongylus sp, Eimeria spp., Haemaphysalis sp. Ixodes spp., Rhipicephalus sp. have been observed in hare in Cantabria north of Spain (Alzaga et al., 2009), which is in line with this present study. Differences in wild rabbit species examined may have been responsible for the differences in some of parasites observed. It might also be associated with the difference in the ecological zone (Opara et al, 2006).
Two reptiles V. orantus and V. exanthematicus were examined and the ectoparasite observed include Amblyomma sp. Parasitic tick Amblyomma sp found on lizards V. orantus and V. exanthematicus has been recorded for the first time in the Nigeria monitor lizard’s fauna. The result of this survey has shown the tick, Ambylomma sp as the most dominant ectoparasite in Nsukka and mostly recovered from lizards. This finding is in agreement with the work of (McCracken, 1994), where he reported that ticks of the genera Amblyomma sp is most commonly found infesting reptiles. According to Theiler (1945) and Norval (1985) large lizards are its preferred hosts.
Low incidence of the ectoparasites in some of the animals in this study are in close agreement with the work of Eke and Ekechukwu (2009), who reported that some animals are in habit of riding themselves off the parasites by licking one another and so while they lick one another it bring them into close proximity and therefore increases the risk of transmitting parasites with direct life cycle (Gillespie,2006), in addition, many ectoparasites are intermediate host for intestinal parasites, therefore the animals may become infected through the ingestion of these hosts.
This study recorded the following intestinal parasites, Strongyloides sp, Ascaris sp, Trichuris sp, Capillaria sp, Entamoeba sp and Dicrocoeluim sp in monitor lizards and is contrary to the report of Enabulele et al., (2013). They reported presence of Duthiersia fimbriata, Pseudoneodiplostomum thomasi Camallanus sp. Cosmocerca ornate, Dujardinascaris sp. Tanqua tiara, Oswaldocruzia hoepplii Sebekia and other undentified parasites in the same animals in Benin City, Nigeria. The differences in the infection may be attributed to location and their samples may have been obtained within the riverine area.
Montor lizards are opportunistic carnivorous/insectivorous (PHS, 2014). In the wild, juveniles feed predominantly on invertebrates such as snails, earthworms, grasshoppers, cockroaches, beetles, mealworms, and crickets and should be properly gut loaded prior to feeding. The adults eat a variety of vertebrates: amphibians, reptiles, birds, and small mammals (PHS, 2014) and they serve as transport hosts to many parasites.
This study recorded the presence of Strongyloides sp, Ascaris sp, Metastrongylus sp, Globcephalus sp Oesophagostomum sp in ungulates, while Strongyloides sp has been observed in the same animals in the semi-arid region of northern eastern Nigeria (Ibrahim et al., 2012), which is in line with this present study. Also in line with this study is the work of Magi et al.,(2005) who recorded the same parasites in wild ungulates in a Mediterranean Central Italy
This study recorded the presence of Hymenolepis sp, Ascaris sp, Metastrongylus sp, Globcephalus sp Oesophagostomum sp, Heligomosmoides sp Moniliformis sp, Metasronglylus sp in rodents, while Hymenolepis sp, Raillietina sp Trichuris muris, Ascaris sp. Cyathostomum sp and Mornilifomis morniliformis, have been observed in the rodents in the same area (Okoye and Obiezue, 2008), which is partial in line with this present study though not exactly the same rodents were used. This work is in contrary to the report of (Opara and Fagbemi, 2008) in the T. swinderanus in south eastern Nigeria who documented the occurrence of trematode in their work. Differences in the number of T. swinderanus examined and the prevailing environmental conditions and availability of intermediate hosts in the study area may have been responsible for the differences observed.
Apart from age, sex, season and immunity related factors, the difference in prevalence or intensity or abundance of the parasites among or between the animals that had the same parasites in this study may be attributed to differences in feeding habits (Nunn and Altizer, 2006) and differences in the types of ecology (Opara et al, 2006).
In this study, it was observed that statistical difference (P<0.05) existed in the prevalence of endo, ecto parasites between and among the animals that had the same parasites. This may be due to the reason that animals sampled are under different risk factors of infection with ecto and intestinal parasites.
Conclusion and Recommendations
This work not only highlighted the parasite diversity in bushmeat but also exposed the level of knowledge, attitude and risks related to bushmeat – borne zoonosis among bushmeat dealers in Nsukka ecological zone and use the information generated to describe possible zoonotic links within the human population in Nsukka ecological zone. Identified weakness was noted in knowledge, attitude as well as in practice level which are likely to expose them to an increased risk of contracting zoonoses, as they are unlikely to take proper precautions. Therefore, there is need for health sectors to educate the inhabitants of Nsukka ecological zone on risk of bushmeat borne zoonotic diseases and zoonosis in general and to mount control interventions in this area. Bushmeat trade should be controlled and done in a manner approved to be safe and not likely to spread infection. Bushmeat handlers, such as hunters, traders and consumers, need to be informed about possible danger of infection with parasites of the bushmeat. Human health care professionals and veterinarians are a crucial link in keeping bushmeat handlers fully informed of ways to reduce the risk of zoonotic transmission. Without information on bushmeat-borne zoonoses, bushmeat hunters and traders are neither informed nor motivated to take the simple precautions necessary to protect themselves. Regular interventions about the disease transmission in animals need to be addressed to communities. The establishment of wildlife information centers in villages or at ward level might also be useful in enhancing knowledge skills and increasing awareness and efficient control of the spread of this newly emerging disease in the country “ Ebola virus.”
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