Molecular detection of Trypanosoma spp. and Hepatocystis parasite infections of bats in Northern Nigeria.

Bats are mammalian hosts to a large diversity of eukaryotic protozoan blood parasites, including different genera of haemosporidians and diverse species of trypanosomes. Phylogenetic studies suggest that bats, particularly in Africa, have played an important role in the evolutionary histories of these parasite groups. However, our understanding of the diversity and distribution of chiropteran haemosporidians and trypanosomes in Africa remains tenuous. We investigated the prevalence and phylogenetic relationships of the blood parasites in different bat species in Northern Nigeria using molecular methods. A low prevalence of Hepatocystis parasites was detected in a potentially rare host species, the African straw-coloured fruit bat (Eidolon helvum) confirming yet another fruit bat species in the diverse range of African bat hosts. Trypanosome infections were identified in 3 different bat species. The trypanosomes of Mops cf. pumilus were recovered as a distinct lineage that is related to Trypanosoma erneyi, a species which is closely related to Trypanosoma dionisii and Trypanosoma cruzi. Nycteris cf. macrotis bats were infected with trypanosomes that are related to the distinct lineage of Trypanosoma cf. livingstonei parasites. Further, 2 different lineages of trypanosomes in E. helvum bats share highest nucleotide identities with Trypanosoma livingstonei and a group of Trypanosoma sp. parasites that are closely related to T. cf. livingstonei and T. livingstonei, respectively. The findings of this study confirm the notion that trypanosomes of African bats are phylogenetically diverse and that African bats might harbour a variety of yet undescribed trypanosome species.

Parasitological, serological, and molecular survey of trypanosomosis (Surra) in camels slaughtered in northwestern Nigeria.

Surra is a parasitic disease caused by Trypanosoma evansi and transmitted non-cyclically by biting flies. The disease significantly affects the health, productivity, and market value of camels thereby constituting a major constraint to food safety, security, and economy. This is the first study on the prevalence of surra in northwestern Nigeria, using a range of diagnostic tests along the parasitological-serological-molecular continuum hence, emphasizing it as a major enzootic risk for camels in Nigeria. In this cross-sectional study, 600 blood samples were collected from camels at major abattoirs in northwestern Nigeria and evaluated for the prevalence of T. evansi using parasitological (Giemsa staining), serological (CATT/T. evansi), and molecular (VSG-PCR and sequencing) methods. The overall prevalence of surra recorded in this study was 5.3%, 11.5%, and 22.5% using Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR respectively. However, higher prevalence rates at 6.0%, 13.7%, and 26.7% by Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR were recorded in Katsina State compared with results from Kano State. A significantly (p < 0.05) higher prevalence by VSG-PCR was observed when compared with both parasitological and serological methods used. Although age and body condition scores were associated (p < 0.05) with surra prevalence in sampled camels, no seasonal association (p > 0.05) was recorded. Sequencing of the VSG region of Trypanosoma spp. Further confirmed the presence of T. evansi as the aetiological agent of surra from the sampled camels. Findings from this study call for the implementation of adequate control measures aimed at reducing the impact of T. evansi infections on camel production in Nigeria.

Serological evidence of exposure to Toxoplasma gondii infection in wild birds and local chickens (Gallus gallus domesticus) in Plateau State, North Central Nigeria.

Toxoplasma gondii, the cause of toxoplasmosis is an obligate intracellular protozoan parasite of veterinary and public health importance. Ground feeding birds play an active role in the epidemiology of the disease and are the best indicators of soil contamination with the oocysts. Thirteen (14.1%; 95% CI = 7.7-23.0) of the 92 wild birds (6 of Coliformes; 4 of Columbiformes; 67 of Passeriformes and 15 of Piciformes) captured from Shere hills and 43 (9.3%; 95%CI = 4.9-12.4) of the 460 local chickens obtained across 3 senatorial regions of Plateau State, Nigeria were positive for anti-T. gondii antibodies using enzyme linked immunosorbent assay (ELISA). Varying prevalence (16.7-100%) of anti-T. gondii antibodies were recorded across 10 of 35 wild bird species; 2 (28.6) of 7 African thrush (Turdus pelios), 2 (33.3) of 6 speckled mouse bird (Colius striatus), 1 (20.0%) of 5 speckled fronted weaver (Sporopipes frontalis), 1 (33.3%) of 3 Northern Red bishop (Euplectes franciscanus), 1 (50.0%) of 2 village weaver (Ploceus cucullatus), 2 (28.6%) of 7 common bulbul (Pycnonotus barbatus), 1 (50.0%) of 2 black crowned tchagra (Tchagra senegalus), 1 (50.0%) of 2 black billed wood dove (Turtur abyssinicus), 1 (100.0%) of 1 mocking cliff chat (Thamnolaea cinamomeiventris), 1 (16.7) of 6 vieillot's barbet (Lybius vieilloti). The prevalence did not vary significantly based on the sex (p = 0.14), feeding guild (p = 0.53) and the taxonomic order (p = 0.62) of the wild birds. Regional based prevalence among local chickens ranged between 8.0 and 11.8% across the 3 senatorial zones. The source (p = 0.513; 95% CI = 4.9-16.8) and age (p = 0.797; 95% CI = 4.9-16.8) of local chickens were not associated with T. gondii seropositivity. Seropositivity was higher in the females (95% CI = 9.1-18.3) than in the males (p = 0.004; 95% CI = 3.0-9.4). This is the first report of the serological evidence of exposure to T. gondii infection in a wide variety of wild birds and local chickens in the area. It suggest that birds in this region are important asymptomatic intermediate hosts and play a role in the maintenance of the organism in the ecosystem.

Ticks (Acari: Ixodidae) infesting dogs in Nigeria: epidemiological and public health implications.

Ticks are haematophagous arthropods that exert direct and indirect effects on their hosts. Their global importance as reservoirs and vectors of diseases of veterinary and public health importance is well recognized. However, the level of understanding of their role in disease epidemiology varies from one country to the other based on available data. Information on ticks infesting dogs across Nigeria and the public health significance is scarce. Therefore, this study aimed to provide information on ixodid ticks infesting dogs in Nigeria. Ticks were collected from 608 owned dogs presented to veterinary clinics and hospitals in 10 out of 36 states of Nigeria over a 14-month period and identified using taxonomic descriptions and morphological keys. In all, 1196 ticks belonging to three genera were identified. Rhipicephalus (including the subgenus Boophilus) ticks were collected from dogs from all the states surveyed and accounted for 95.2% of the ticks collected, followed by Haemaphysalis (3.7%) and Amblyomma species (1.2%). The brown dog tick, Rhipicephalus sanguineus sensu lato was the only tick identified in all the climatic zones of Nigeria. There is a statistically significant association between tick infection rate and rainy season, female animals, local and cross breed against exotic animals, total lack of control practice by dog owners, frequency of the control and with traditional methods of tick control but not the age of the dogs. The epidemiological and public health implications of these findings were discussed.

Morphological and molecular identification of Rhipicephalus (Boophilus) microplus in Nigeria, West Africa: a threat to livestock health.

The cattle tick Rhipicephalus (Boophilus) microplus was first reported in West Africa in Ivory Coast, in 2007. Since then it has made an aggressive eastward advancement having been reported in four other West African countries: Mali, Burkina Faso, Togo and Benin. We herein report the first molecular identification of this tick species in Nigeria, West Africa, and highlight the threat it poses to livestock health. A nation-wide tick survey was conducted in 12 out of 36 states across the various agro ecological zones of Nigeria over a 1 year period (April 2014-March 2015). In total 1498 ticks belonging to three genera collected from cattle were morphologically identified. Overall, Amblyomma species constituted the highest percentage of sampled ticks, 50.2% (752/1498), followed by Rhipicephalus (including the subgenus Boophilus) species, 29.4% (440/1498) and Hyalomma species, 20.4% (306/1498). The presence of Rh. (B.) microplus was identified morphologically from four out of the 12 states. This finding was confirmed for the first time in Nigeria using a molecular method targeting the ITS-2 region of the ticks in three of the 12 states. This study ascertained the presence of Rh. (B.) microplus in Nigeria in addition to a broad variety of cattle tick species, most of which are of veterinary importance. The implication of this finding is that there may be additional economic burden to livestock farmers due to increased cost of tick control occasioned by the acaricide resistance by this tick species widely reported from different climes. Additionally, there may be a potential upsurge in incidence of hemoparasitic infections in cattle leading to increased morbidity, cost of treatment and mortalities.

Analysis of risk factors and prevalence of haemoplasma infection in dogs.

Mycoplasma haemocanis (Mhc) and 'Candidatus Mycoplasma haematoparvum' (CMhp) are canine haemoplasma species that can induce anaemia in immunocompromised and/or splenectomised dogs. This study aimed to determine the prevalence and phylogeny of canine haemoplasma species in dogs from Nigeria and describe any risk factors for infection. Canine haemoplasma species-specific and generic haemoplasma qPCR assays were used. The species-specific qPCR assays found Mhc infection in 18 of 245 dogs (7.3%), and CMhp infection in only one dog (0.4%). The generic haemoplasma qPCR assays were positive in 44 of 245 (17.9%) dogs. Twenty-five dogs had discordant qPCR results in that they were generic haemoplasma qPCR positive but species-specific qPCR negative. Further evaluation of these dogs by 16S rDNA sequencing gave limited results but 5 were confirmed to be infected with non-haemoplasma species: 2 Anaplasma phagocytophilum, 1 Anaplasma ovis, 1 Serratia marcescens and 1 Aerococcus spp. The 16S rRNA gene sequences from Mhc species showed>99.8% identity with each other and>99.6% identity with GenBank sequences, and resided in a single clade with other global Mhc and Mycoplasma haemofelis sequences, indicating low 16S rRNA genetic variability amongst this canine haemoplasma species.

Molecular detection of Rickettsia aeschlimannii in Hyalomma spp. ticks from camels (Camelus dromedarius) in Nigeria, West Africa.

Several species of the spotted fever group rickettsiae have been identified as emerging pathogens throughout the world, including in Africa. In this study, 197 Hyalomma ticks (Ixodida: Ixodidae) collected from 51 camels (Camelus dromedarius) in Kano, northern Nigeria, were screened by amplification and sequencing of the citrate synthase (gltA), outer membrane protein A (ompA) and 17-kDa antigen gene fragments. Rickettsia sp. gltA fragments were detected in 43.3% (42/97) of the tick pools tested. Rickettsial ompA gene fragments (189 bp and 630 bp) were detected in 64.3% (n = 27) and 23.8% (n = 10) of the gltA-positive tick pools by real-time and conventional polymerase chain reaction (PCR), respectively. The amplicons were 99-100% identical to Rickettsia aeschlimannii TR/Orkun-H and R. aeschlimannii strain EgyRickHimp-El-Arish in GenBank. Furthermore, 17-kDa antigen gene fragments of 214 bp and 265 bp were detected in 59.5% (n = 25) and 38.1% (n = 16), respectively, of tick pools, and sequences were identical to one another and 99-100% identical to those of the R. aeschlimannii strain Ibadan A1 in GenBank. None of the Hyalomma impressum ticks collected were positive for Rickettsia sp. DNA. Rickettsia sp. gltA fragments (133 bp) were detected in 18.8% of camel blood samples, but all samples were negative for the other genes targeted. This is the first report to describe the molecular detection of R. aeschlimannii in Hyalomma spp. ticks from camels in Nigeria.

Antioxidants in patients with dengue viral infection.

An alteration in the oxidation/reduction (redox) status of humans infected with virus infections may contrioute to tefl pariiogeiiesin anu ciniiua1 manifestations of the disease. Alterations in redox markers begin prior to the onset of clinical symptoms, suggesting early changes in the oxidant/antioxidant balance. Early identification of redox markers may be of clinical usefulness in the management of patients with dengue virus infection. We conducted a hospital based comparative cross sectional study of 55 patients serologically confirmed to have dengue infection and 55 clinically healthy age and sex matched subjects as controls to assess oxidative stress in acute dengue virus infection. Blood samples were drawn on the fifth day after symptom onset and analyzed for Trolox equivalent antioxidant capacity (TEAC), reduced glutathione (GSH), glutathione peroxidase (GPx) and paraoxonase (PON) activity. The results showed significantly lower levels of plasma TEAC, serum PON and erythrocyte GSH and GPx activity among dengue patients than in controls. Of the antioxidants investigated, PON appeared to be the most sensitive marker of oxidative stress in dengue virus infection. Serum PON may be a potentially useful marker of oxidative stress in patients with dengue virus infection.

Seroprevalence of human infection with Toxoplasma gondii and the associated risk factors, in Maiduguri, Borno state, Nigeria.

The prevalence of antibodies (IgG) to Toxoplasma gondii among 180 adults from the Nigerian city of Maiduguri was determined as 23.9%, using a commercial ELISA. Although the men investigated were more likely to be seropositive than the women, the difference was not statistically significant (27.3% v. 19.8%; P>0.05). There was also no apparent association between educational level and seroprevalence. There was a positive correlation between the mean antibody titre and the age of the subjects, with seroprevalence highest among the subjects aged 51-60 years and lowest in the subjects aged<21 years. Worryingly, 10 (20%) of the 50 female subjects who were of child-bearing age (15-40 years) were among those found seropositive for anti-T. gondii IgG. The mean antibody titres of the seropositive subjects ranged between 16.5 IU/ml (the threshold for positivity being 16 IU/ml) and >1000 IU/ml. In addition to age, occupation and eating habits were also significantly associated with seropositivity. Compared with the subjects who had no pets, dog owners were twice as likely to be seropositive. The relative risks for cat and dog ownership were, however, only 0.79 and 0.69, respectively, indicating that these animals might not be the main sources of human infection with T. gondii in the study area.