Introduction

Lizards are one of the most common rep- tiles that apparently exist in many tropical parts of the world because of their adap- tive and poikilothermic nature. The African lizard family Agamidae consists of several species of lizards usually found in Africa and Eurasia (Brown et al., 2002; Brito et al., 2008). Studies have revealed that the Agama agama lizards are the most popu- lar species amongst the Agamidae identi- fied (Spawls et al., 2002), and are usually considered to be native to western  Afri- can countries especially the sub-Saharan (Matthee and Flemming, 2002;  Enge  et  al., 2004; Mediannikov et al., 2012). They live in social groups including a lead male, about half a dozen females, and subordinate males (Wagner et al., 2009a; Wagner et al., 2009b; Wagner et al., 2009c). The Agama agama lizards are primarily insectivores; they play a significant role as biological control of insects and other arthropod pests around households as well as in agriculture involving  crop  production   (Vasconcelos et al., 2009; Lazić et al., 2013). Unfortu- nately, Agama agama lizards have been re- ported to serve as transport and reservoir host to several protozoan and helminthes parasites, some of which are of zoonotic importance (Wekhe and Olayinka, 1999; Adeoye and Ogunbanwo, 2007). Human beings can get infection  during  handling of objects contaminated with infected fae- ces or saliva, and accidentally  ingesting  the parasite eggs (Nash, 2005). The prev- alence of several species of gastrointesti- nal parasites in Agama agama lizards has been reported from some parts of Nigeria (Adeoye and Ogunbanwo, 2007; Omono- na et al., 2011; Mbaya et al., 2013; Nwa- dike and Ilozumba, 2015; Sowemimo    and

Oluwafemi, 2017). Ascaris spp. Capillaria spp. and Raillietiella spp. from Agama ag- ama lizard origin have been documented in human beings. Despite the various studies, there is still a paucity of information on the prevalence of gastrointestinal parasites in Agama agama lizard from Gombe State, and the risk of transmission to human and commercial poultry flocks. Therefore, the present study aimed at providing infor- mation on the occurrence of gastrointesti- nal parasites of free-living Agama agama lizard in close proximity with commercial poultry farms and to determine those that harbor parasites of zoonotic importance so as to provide control measures where nec- essary.

Materials and Methods

Study Area

This study was conducted in Gombe State, Northeastern Nigeria (Fig. 1) which shares boundaries with Bauchi, Taraba, Adamawa, Yobe and Borno states. Gombe State is lo- cated between latitude 9◦ 30’ and 12 3’ N and longitude 8◦ 45’ and 11◦ 45’ E (Anonymous, 2017). The state has Eleven Local Govern- ment Areas viz: Gombe, Akko, Funakaye, Kwami, Dukku, Billiri, Shongom, Nafada, Yamaltu-Deba, Kaltungo and Balanga Lo- cal Government Areas. The state has a mean annual rainfall of 818.5mm, with a mean maximum temperature of 37 ◦C and a mean minimum temperature of 12 ◦C. The major economic activities of the people of Gombe State include crop and livestock production  as well as trading.

Study Design

Cross-sectional study involving Non-prob- ability convenience sampling method was adopted for the selection of 6 out of the    11

Figure 1. Map of Gombe State showing the study areas          Figure  2.  Male  and  female  Agama  agama  Lizards in

commercial poultry pen in the study area (Black  arrows)

Figure 3. Female Agama agama Lizard outside commer- cial poultry pen in the study area

Figure 4. Male Agama agama Lizard outside commer- cial poultry pen in the study area

Local Government Areas of the state viz: Dukku, Yamaltu-Deba, Kaltungo, Shongom, Akko and Kwami Local Government Ar-  eas. By the consent of commercial poultry farmers, selected poultry houses within these LGAs were visited for agama lizard capture. Birds in any selected pen were first relocat- ed to other different pens within the poultry farm, and then capture of Agama lizard was done using traps with cockroaches as bait on alternate days throughout the sampling peri- ods. Criteria considered for the selection of commercial poultry pens for lizard capture include: availability of Agama agama lizard of both sexes and willingness of the poultry farmers  to  allow  researchers  into  the pens

during the period of study for lizard  capture.

Sample collection

A total of 200 Agama agama lizards of both sexes were captured between the months of February and December, 2017. The cap- tured lizards were humanly euthanized using halothane, and then taken to the Parasitolo- gy Laboratory of Department of Biological Sciences, Gombe State University. All pro- cedures employed for the examination of the lizards for the presence or absence of gastro- intestinal parasite were in accordance with standard parasitological procedures. Follow- ing evisceration, the entire gastrointestinal tract for each Agama lizard was examined  for the presence of adult worm. Adult worms

recovered were placed in petri dish contain- ing saline and were later identified according to reference parasitology  pictures.

Coprology

In the laboratory, each lizard  was placed in dorsal recumbence on a dissection board, then using thumb  forceps,  scalpel  blade  and scissors, the abdomen was incised to expose the gastrointestinal tracts, removed and placed in a Petri dish containing phys- iological saline. Each organ was cut open longitudinally and fresh faecal samples were collected, expressed in a Petri-dish contain- ing physiological saline. The contents were then examined closely on a dark background under a dissecting microscope. Adult worms observed were removed and sorted using ref- erence atlas. Faecal materials were washed   in saline to remove adhering debris; concen- trated salt solution was used to increase the possibility of finding ova, cyst, oocyst, or larva in the sample where they are too insuf- ficient to be seen by direct microscopy. Stan- dard coproscopic methods comprising direct smear, flotation technique followed by sedi- mentation technique, direct saline and iodine smear observations were used to detect par- asite infections as described  by Kandasamy et al. (2013). Protozoans were identified by sodium-acetate acetic acid formaldehyde (SAF) method and modified Ziehl-Neelsen staining. Parasites eggs were identified using standard   parasitological   techniques   as de-

scribed by Garcia et al. (2017).

Data analysis: Data were analyzed using the Graphpad prism software package (ver- sion 17). Prevalence was expressed as per- centages, differences in prevalence between lizards’ sexes and season of sample collec- tion were assessed using Chi-squared (ᵡ²)  test.

Results

Table 1 summarizes the result of the preva- lence of gastrointestinal parasites in Agama ag- ama lizards captured in and around commer- cial poultry pens in Gombe State Nigeria. Out of the 200 lizards examined, 154 (77.0%) were found to be infected with gastrointestinal par- asites. Out of the gastrointestinal parasites in- fected lizards, 116 (58.0) were found to harbor gastrointestinal helminthes while 38 (19.0%) were found to harbor coccidian oocyts.

Table 2 summarizes the prevalence of the species of the gastrointestinal parasites encoun- tered in the infected Agama agama lizards in Gombe State. Strongyluris spp. (25.5%) was found to be the more prevalent helminthes, followed by Trichuris spp. (13.5%), Oxyuris spp. (8.0%), Ascaris spp. (5.5%), Heterakis spp. (4.0%), and the least prevalent helminthes encountered were Capillary spp. (1.5%). How- ever, Eimeria spp (17.5%) was found to be the most prevalent coccidian parasites followed by Isospora spp. (1.5%).

Table 1. Prevalence (%) of Gastrointestinal Parasites of Lizard (Agama agama) in Gombe State, Nigeria

N= Total Number of Lizards Examined

Table 2. Species-specific Prevalence (%) of Gastrointestinal Parasites of Lizard (Agama agama) in Gombe State, Nigeria

N = Total number of Agama Lizards examined

Table 3. Sex-specific Prevalence (%) of Gastrointestinal Parasites of Lizard (Agama agama) in Gombe State, Nigeria

Parasites            Sex

Number of Lizards Examined

Number of Lizard infected (%)

(Confidence Interval) 95%

Lower limit     Upper limit

p-value       Relative risk

Male               108

74 (68.5)a

0.2289             0.4118

Helminthes

Female               92

42 (45.7)b

0.4360             0.6473

0.0018            0.5793

Male               108

21 (19.4)a

0.7183            0.8753

Coccidia

Female               92

17 (18.5)a

0.7209            0.8887

0.8622           0.9881

abDifferent superscripts within columns indicates statistically significant difference (P<0.05)

Table 3 reveals the sex – specific prevalence of gastrointestinal parasites in Agama agama lizards in Gombe State, helminthes infection was found to be significantly (p 0.05 at 95% confidence Interval).

Table 4 summarizes the results of the season   –

specific prevalence of gastrointestinal parasites in Agama agama lizards in Gombe State. Helminthes infection was found to be significantly (p 0.0001 at 95% confidence Interval).

Table 4. Season-specific Prevalence (%) of Gastrointestinal Parasites of Lizard (Agama agama) in Gombe State, Nigeria

abDifferent superscripts within columns indicates statistically significant difference (P<0.05)

Discussion

This result of the present study revealed that all the helminthes detected in the gas- trointestinal parasites infected Agama ag- ama lizards belong to the class Nematoda. This finding of the present study  suggests that the nematodes species are the most prevalent helminthes in Agama lizards in Gombe State, Nigeria. Our finding coincides with several reports from previous studies which revealed nematodes as the most prev- alent gastrointestinal parasites of lizards of the Agama species in Nigeria (Adeoye and Ogunbanwo, 2007; Omonona et al., 2011; Mbaya et al., 2013; Nwadike and Ilozumba, 2015; Sowemimo and Oluwafemi, 2017). Even though other species of helminthes belonging to the classes Trematoda, Cesto- da, Pentastomes and Acanthocephalan have been previously reported from Agama liz- ards and other lizards species from some de- veloping countries of Africa and other parts of the world (Goldberg and Bursey, 2005; McAllister et al., 2011, Norval et al., 2013; Yang et al., 2014; Norval et al., 2014),   most

of these studies have also implicated nema- todes as the most dominant of amongst the helminthes species that infect Agama lizards. The predominance in the incidence of nema- todes species in Agama lizards as reported in the present study concurs  with  the findings of other previous similar studies in Nigeria. The high prevalence of nematode as report- ed could be attributed to the feeding habits  of lizards and the direct life cycles of nem- atodes which do not usually require inter- mediate host in the transmission of infective stage of the parasite to host (Sanchis et al., 2000; Martin and Rocha, 2004). This may result in their widespread infective stages. Infections by nematode parasites in the vast majority of the land-dwelling vertebrates are bound to happen during the terrestrial stages of the life cycle of these parasites (Al-bar- wari and Saeed, 2007). The microscopic detection of gastrointestinal parasites of Ag- ama lizard in the present study did not reveal the presence of cestodes, trematodes, pentas- tomes or acanthocephalan from the infected lizards examined. This might be attributed to

the complex life cycle of these parasites and their requirement for an intermediated host for the transmission of the infective stage of the parasite (Roberts and Janovy, 2005; Ken- nedy, 2006). There is the possibility that the Agama lizards are less susceptible to these classes of gastrointestinal parasites due to some barriers of phylogenetic  incompeten- cy and host specificity nature (Norval et al., 2013). Moreover, there were no previous reports of these parasites from the Agama lizards examined in previous similar studies in Nigeria (Adeoye and Ogunbanwo, 2007; Omonona et al., 2011; Mbaya et al., 2013; Nwadike and Ilozumba, 2015; Sowemimo and Oluwafemi, 2017).

The result of the present study has also encountered the occurrence of Eimeria and Isospora species in infected Agama Lizards. This finding concurs with the reports of Amo et al. (2005) and Adeoye and Ogunbanwo (2007) who have also reported the Eimeria species as one of the most prevalent protozo- ans in reptiles. These ubiquitous protozoans are considered as one of the most important gastrointestinal organisms that cause the disease of coccidiosis in many vertebrates including the Agama lizards (Sharma et al., 2013; Opara et al., 2014). The occurrence of coccidian parasites in Agama lizards is not surprising due to the feeding habit of the lizards. They might possibly  ingest  oocyst of the organisms from contaminated soil or by ingestion of other accidental hosts  such as arthropods during feeding activities. The results of the present study showed that the overall prevalence of gastrointestinal para- sites infection in Agama lizards in Gombe State was 77.0%. This finding is lower than the 95.5% reported by Adeoye and Ogun- banwo (2007) in Lagos and 100% reported from  Maiduguri  and  Ibadan  by  Mbaya   et

al. (2007) and Sowemimo and Oluwafemi (2017) respectively. However, the preva- lence rate reported from this present study    is higher than prevalence rate of 76.1% that was reported by Rataj et al. (2011) in Slove- nia. These variations in the prevalence rates from various studies might be attributed to difference in method of diagnosis, scope of the research, study areas, sample sizes, type of lizard and organs examined, geographical regions and season of samples collections which might influence the detection and oc- currence of the parasites. To the best of our knowledge, the present study is the first of its kind to report the presence of Isospora spe- cies in Agama lizards in Nigeria.

Amongst the six nematodes species de- tected in the infected Agama lizards, Stron- gyluris species is the most predominant with a prevalence of 25.5%. This finding is in agreement with that of Adeoye and Ogunban- wo (2007), Nwadike and Ilozumba (2015) as well as Sowemimo and Oluwafemi (2017) who have also reported this parasite as the most frequently encountered gastrointestinal parasite in Agama lizard in Nigeria, although Mbaya et al. (2013) in a similar study did not recover the parasite in their study area. How- ever, the finding of the present study is lower than 82.3%, 85.6% and 92.5% reported from Lagos, Anambra and Ibadan by Adeoye and Ogunbanwo (2007) and Nwadike and Ilo- zumba (2015), Sowemimo and Oluwafemi (2017) respectively.

The result of this present study also re- vealed the 13.5% prevalence rate of Trichu- ris species. This finding is lower than 70.0% reported from Maiduguri by Mbaya et al. (2013). The variation in the prevalence rates of these two studies may be associated with difference in method of detection, geograph- ical location, study areas, study sites,   period

of sample collection, and the species of Ag- ama lizard examined (wild, captive reared or pet). It has been well established that some lizard species are more susceptible to gas- trointestinal parasites infection compared to others (Rataj et al., 2011). The finding of the present study encountered respectively 8.0% and 1.5% prevalence rates of Oxyuris and Capillaria species from the gastrointestinal parasites infected Agama lizards. This report is in contrast to previous findings by Adeoye and Ogunbanwo (2007) who in a similar study revealed 1.6% and 8.4% prevalence rates of Oxyuris and Capillaria species from Lagos respectively. The prevalence of Asca- ris species as reported from the present study was 5.5% which is lower than 30% reported by Mbaya et al. (2013). The present study represents the first to discover Heterakis species in free range Agama lizards trapped in pens of intensively reared exotic breed of chickens in Nigeria. However, Ascaris and Capillaria  species  have   been   implicated to pose zoonotic risk to man (Nash, 2005) while Heterakis species have been reported  in chickens (Kaingu et al., 2010; Lawal et al., 2015).

The result of the present study revealed more frequency of multiple gastrointestinal parasites infections while single infections were less commonly detected  in the infect- ed Agama lizards. This finding is consistent with the results previously reported by Nwa- dike and Ilozumba (2015) and Sowemimo and Oluwafemi (2017) who have also detect- ed more frequency of multiple infections of gastrointestinal parasites compared to single infections.

The result of the present study revealed that the male Agama lizards are more suscep- tible to helminthes and coccidian infections compared  to the females. The difference   in

the prevalence rates of helminthes infection between the two sexes was found to be sta- tistically significant, but the difference  in  the prevalence rates of coccidian infection between the two sexes was not statistically significant. This finding might  be attributed to certain genetic factors which might make the male more susceptible to gastrointestinal parasites than females. The findings of the present study tallies with reports of Adeoye and Ogunbanwo (2007) who have also re- ported high prevalence of gastrointestinal parasites in males compared to the Agama lizards and there was significant  difference in the intensity of infection. However, Fadiel et al. (2005) in a similar study has reported an insignificant difference between prev- alence of gastrointestinal parasites among sexes of lizards  in  Libya.  Moreover,  Amo et al. (2005), Nwadike and Ilozumba (2015) as well as Mbaya et al. (2013) have reported that the sex of lizards had no influence on the overall prevalence of helminthes  infections in the Agama agama, as both sexes have the same prevalence of infection. This finding was attributed to the fact that both sexes of lizards share equal chance of exposure to similar  infection.  Although  recent   studies in lizards have revealed that males are more susceptible to parasites infection probably due to the immune suppressive effects of testosterone at least during the reproductive period (Uller and Olsson, 2003; Roberts et al., 2004). It has been reported that some par- asites species could be transmitted from one host to another during copulation; therefore, they are usually only recorded from sexually mature lizards (Norval et al., 2011; Langford et al., 2013).

This present study was unable to detect or categorize the occurrence of gastrointestinal parasites  in Agama  lizards  in Gombe  State

based on age of lizards. This is because the study limited its scope to sample collection from adult lizards trapped in the poultry pens as well as considering some factors related to welfare issues.

The findings of the present study have also revealed season-specific prevalence of gas- trointestinal parasites in infected Agama liz- ards in the study area. Both helminthosis and coccidiosis were more frequently encoun- tered in samples collected and examined during the rainy season compared to samples collected during the dry season. This find- ing suggested that Agama lizards are more predisposed to gastrointestinal parasites in- fection during the raining season compared  to the dry season in the present study area. This might be attributed to the abundance of optimum temperature and humidity expe- rienced during the rainy season which may favor sporulation of oocyst and helminthes eggs that facilitates direct  infections.

There was significant statistical difference (P Agama lizards captured from poultry farms during the rainy compared to dry season is consistent with several reports of high prevalence of gastro- intestinal parasites species in free range poul- try species in developing countries includ- ing Nigeria (Alam et al., 2014; Opara et al., 2014; Udoh et al., 2014; Lawal et al., 2015; Biu et al., 2016). The dry season is usually considered as the period that is unfavorable for the development and persistence of para- sitic phases of parasites (Mbaya et al., 2006). This could have been partly responsible for the comparative low prevalence of gastroin- testinal parasites in the present  study.

Reports from similar studies have suggest- ed the role of reptiles and rodents in the trans- mission of the pathogenic parasites to inten- sively reared poultry species (Mbaya et al., 2013; Gulani et al., 2016). It was observed and noted in the present study locations, that Agama lizards frequently visit the poultry pens to feed on poultry feeds and other ar- thropods. This indicates that during these times they may accidentally contaminate the pen, litter and feeds with the parasites they may have harbored from contaminated envi- ronment. However, birds can become infect- ed by the ingestion of contaminated material or feed. Therefore, it reasonable to keep all species of reptiles including the Agama liz- ards away from the poultry pens to prevent the incidence of gastrointestinal  parasites.

Conclusion: The findings of  the  pres-  ent study unleashed evidence of likelihood which may initiate the sharing of gastroin- testinal parasites between the reptile fauna and intensively reared poultry. In situations where free range Agama lizards frequently have access into poultry pens and possibly contaminate poultry feed and water with gastrointestinal parasites infected faeces will inevitably aid in the sharing of vectors of diseases faster and more efficiently, thereby making disease transmission faster, effec- tive and efficient between the lizards and birds. The fact that some similar species of the gastrointestinal parasites detected in Ag- ama lizard in Gombe State have previously been reported in man and domesticated birds elsewhere; these parasites might utilize Ag- ama lizards as host or reservoirs to enhance zoonotic diseases transmission. The 77.0% prevalence rate of helminthosis and coccid- iosis is considered high in Agama lizards captured  in  commercial  poultry  houses   in