Prevalence and intensity of haemoparasites infecting the white-spotted gecko, Tarentola annularis in Sudan

Thirty-five white-spotted geckos, Tarentola annularis were collected from Shendi area, River Nile State, Sudan, between June and September 2019 and examined for the presence of haemoparasites infection. Six (17.14%) geckos were found to be positive for intra erythrocytic haemogregarine (Apicomplexa: Haemogregarinidae) species with a mean overall infection intensity of 1.20% ± 0.32 and parasitemia level between ~0.70% and ~1.70%. However, most parasite gamonts were found intracellular, and no damage on the infected erythrocytes was observed. The prevalence of infection between adult and juvenile geckos was significantly different (P = 0.012); however, no substantial difference between males and females was found. On the other hand, the mean intensity of infection did not differ between adult and juvenile geckos. In conclusion, no obvious negative impact on the local T. annularis gecko community was observed due to haemogregarine species infection.

Prevalence of intestinal helminth parasites of stray dogs in Shendi area, Sudan

Three hundred and sixty fecal samples of stray dogs were collected between July and December 2018, from open grounds of Shendi city and two suburbs (Gulia and Musiab), River Nile State, Sudan, and were examined for helminthic infections. The results showed 43 (11.9%) of the samples were positive for at least one species of helminth. A total of four helminth species were identified, including two nematodes (Ancylostoma caninum and Trichuris vulpis) and two cestodes (Dipylidium caninum and Taenia spp.). Taenia spp. was found to be the most common helminth infection in stray dogs (6.7%) followed by D. caninum (3.1%), while the least was the nematode, A. caninum (0.8%). The prevalence of infection among stray dogs in the suburbs was found to be higher than those in the city; however, there was no statistical significance (P = 0.07). In conclusion, stray dogs in Shendi area were found to be harboring several important zoonotic helminthes such as A. caninum and Taenia spp.; this shows the necessity of stray dog population management in this area as they present a health risk to the community.

Helminth parasites of the white-spotted wall gecko, Tarentola annularis (Squamata: Gekkonidae), from Shendi area, Sudan

This is the first report on helminths parasitize the white-spotted wall gecko, Tarentola annularis from Shendi area in Sudan. A total of 32 geckos were collected between January and May 2018, and examined for helminth infections. Three nematode species of the family Pharyngodonidae were identified: Pharyngodon mamillatus, Spauligodon brevibursata and Parapharyngodon sp. The most prevalent nematode found was P. mamillatus followed by S. brevibursata. The overall prevalence and intensity of infections was 81.3% and 6.8 nematodes per one infected gecko, respectively. The prevalence and intensity of infections were observed to be more in adult male geckos compared to adult females. On the other hand, the prevalence and intensity of infections were significantly higher in adult geckos compared to the juveniles.

Ectoparasites of the Nile Rat, Arvicanthis niloticus from Shendi area, Sudan

This study investigated the ectoparasites of the Nile Rat, Arvicanthis niloticus in Shendi area, River Nile State, Sudan. Eighty nine A. niloticus were collected for the first time from the horticultural fields of Shendi, between January to June 2018, and their entire fur was combed thoroughly, using a fine-tooth comb. Any removed ectoparasites were relaxed, mounted and examined under a microscope for morphological identification. Forty two (47.2%) of the collected rats was found infested, with an overall mean intensity of 13.4 (range 2–67) ectoparasites per an infested rat; 10 different species of ectoparasites were identified, including: 2 species of flea – Xenopsylla cheopis, Leptopsylla segnis; 3 species of louse – Polyplax spinulosa, P. abyssinica, P. serrata; a species of tick – Rhipicephalus sp.; 4 species of mite – Laelaps agilis, L. nuttalli, Ornitonyssus bacoti, Dermanyssuss gallinae. The most prevalent ectoparasite found was the flea Xenopsylla cheopis, 23.6%, followed by the mite Laelaps nuttalli, 10.1%, while the least was the mite Ornitonyssus bacoti, 1.1%. Significantly higher prevalence and intensity of infestation was found among male rats. Likewise, older rats significantly harbored a higher prevalence and intensity of infestation.

Helminth parasites of the Nile Rat, Arvicanthis niloticus, from Shendi area, Sudan

Eighty nine rats, Arvicanthis niloticus, were collected from the horticultural fields of Shendi area in Sudan, between January and June 2018, and examined for the first time for helminth parasites. Thirty seven (41.6%) of the collected rats were infected, with an overall mean intensity of 4.4 helminths per a rat. A total of 6 helminth species were identified including three nematodes (Nippostrongylus brasiliensis, Monanema nilotica and Capillaria hepatica) and three cestodes (Hymenolepis diminuta, H. nana and Taenia taeniae formis). The most prevalent helminth was found to be the nematode, N. brasiliensis (21.3%), followed by the cestode, H. diminuta (10.1%), while the least was the nematode, C. hepatica (1.1%). Higher prevalence and intensity of infection were observed among older rats. Likewise, male rats were found to harbor a higher prevalence and intensity of infection. In conclusion, the rat, A. niloticus in Shendi area has found to be parasitized by various species of helminths, which some are of zoonotic importance, thus, any possible contact between this rat and humans or their pets may pose potential risk to public health.

Development and Effects of Schistosoma japonicum (Trematoda) on its Intermediate Host, Oncomelania hupensis (Gastropoda)

BACKGROUND

Trematodes belonging to the genus Schistosoma cause schistosomiasis. The relationship between schistosomes and their intermediate hosts varies among snails. This study investigated the effects of S. japonicum on its snail host, Oncomelania hupensis, and cercarial release rythmicity of S. japonicum and the effects of light on it.

METHODS

Seven groups of O. hupensis (n = 40 each) were exposed individually to 0 (control), 2, 4, 6, 10, 15, and 20 S. japonicum miracidia. Mortality of the snails was recorded for 10 weeks. Snails in each group were checked for infection at seven weeks post-exposure. Positive snails were exposed to artificial light from 06:00 am - 18:00 pm and the liberated cercariae were collected every 2 hours to determine the rhythmicity of cercarial release. Three groups of positive snails (n = 6 each) were exposed to artificial light, daylight, and darkness from 06:00 am - 18:00 pm, the liberated cercariae were collected every 2 hours to determine the effects of light.

RESULTS

The highest infection rate and host mortality occurred among snails in the groups exposed to 15 and 20 miracidia. Cercariae were liberated after eight weeks of exposure of O. hupensis to S. japonicum. The circarial emerging pattern was circadian, with a single peak of emerging between 10:00 am and 12:00 pm. Light intensity had a positive influence on cercariae shedding and rhythmicity.

CONCLUSION

Further research, including the influence of biotic and abiotic factors is deemed necessary to fine-tune elucidation of the effects of S. japonicum upon O. hupensis snail.