Ecological correlates and predictors of Lassa fever incidence in Ondo State, Nigeria 2017-2021: an emerging urban trend.

Lassa fever (LF) is prevalent in many West African countries, including Nigeria. Efforts to combat LF have primarily focused on rural areas where interactions between rodents and humans are common. However, recent studies indicate a shift in its occurrence from rural to urban areas. We analysed secondary data of reported LF outbreaks from 2017 to 2021 in Ondo State, Nigeria to identify the distribution pattern, ecological variations, and other determinants of disease spread from the ward level using nearest neighbour statistics and regression analysis. Data utilised include LF incidence, ecological variables involving population, nighttime light intensity, vegetation, temperature, market presence, road length, and building area coverage. ArcGIS Pro 3.0 software was employed for spatial analysis. Results revealed spatio-temporal clustering of LF incidents between 2017 and 2021, with an increasing trend followed by a decline in 2021. All wards in Owo Local Government Area were identified as LF hotspots. The ecological variables exhibited significant correlations with the number of LF cases in the wards, except for maximum temperature. Notably, these variables varied significantly between wards with confirmed LF and those without. Therefore, it is important to prioritise strategies for mitigating LF outbreaks in urban areas of Nigeria and other LF-endemic countries.

Vector-Borne Pathogens in Guard Dogs in Ibadan, Nigeria.

Canine vector-borne diseases are of great relevance not only regarding animal welfare but also in relation to the One Health concept. Knowledge concerning the most relevant vector-borne pathogens in dogs is scarce and limited to stray dogs in most western African regions, and there is virtually no information about the situation in kept dogs presenting (regularly) to vets. Therefore, the blood samples of 150 owned guard dogs in the Ibadan area-in the southwest of Nigeria-were collected and analyzed for the DNA of Piroplasmida (Babesia, Hepatozoon, Theileria), Filarioidea (e.g., Dirofilaria immitis, Dirofilaria repens), Anaplasmataceae (e.g., Anaplasma, Ehrlichia), Trypanosomatidae (e.g., Leishmania, Trypanosoma), Rickettsia, Bartonella, Borrelia and hemotropic Mycoplasma using molecular methods. Overall, samples from 18 dogs (12%) tested positive for at least one pathogen. Hepatozoon canis (6%) was the most prevalent blood parasite, followed by Babesia rossi (4%). There was a single positive sample each for Babesia vogeli (0.6%) and Anaplasma platys (0.6%). Moreover, one mixed infection with Trypanosoma brucei/evansi and Trypanosoma congolense kilifi was confirmed (0.67%). Generally, the prevalence of vector-borne pathogens in this sample group of owned dogs in southwest Nigeria was lower than in prior studies from the country and in other parts of Africa in total. This leads to the assumption that, firstly, the exact geographical location has a major influence on the incidence of vector-borne diseases, and, secondly, it seems to make a difference if the dogs are owned and, therefore, regularly checked at a veterinary clinic. This study should raise awareness of the importance of routine health check-ups, tick and mosquito prophylaxis, and a well-managed infectious disease control program to prevent vector-borne diseases in canines.

Molecular characterisation of Cryptosporidium isolates from rivers, water treatment plants and abattoirs in Ibadan, Nigeria.

To understand the molecular characteristics of Cryptosporidium species contaminating rivers, water treatment plants and abattoirs in Ibadan Nigeria, water samples were obtained from ten rivers used for household and agricultural purposes, three major functional water treatment plants and three major abattoirs located within Ibadan metropolis during dry and rainy seasons between November, 2016 to October, 2017. Obtained samples were examined for Cryptosporidium oocysts using microscopy after using modified formalin-ether concentration method and modified acid-fast staining. Cryptosporidium oocysts were detected in samples from five rivers with mean oocyst count/field ranging from 7.70 ±â€¯0.57-1.34 ±â€¯0.57, oocysts were also detected in samples from two abattoirs with mean oocyst count/field ranging from 4.60 ±â€¯0.33-2.50 ±â€¯0.33. Genomic DNA were extracted from microscopy positive river and abattoir samples using sucrose gradient purification method and genotypes and subtypes of parasites were detected by nested PCR amplification and nucleotide sequence analysis of both 18S rRNA and 60-kDa glycoprotein (gp60) genes. Cryptosporidium parvum, C. muris and C. fragile were the only genotypes detected in some river samples, while gp60 gene sequence analysis showed that the C. parvum strain detected was subtype IIa. This study provides evidence that rivers used for household and agricultural purposes in studied area may be potential reservoirs and infection sources for Cryptosporidium species and zoonotic subtypes of public health importance.

Molecular identification of Cryptosporidium parvum in rabbits (Oryctolagus cuniculus) in Nigeria

Rabbits are commonly reared by households and farmers in Nigeria as a source of meat, but there is no information available on Cryptosporidium genotypes occurring in rabbits in Nigeria. Fecal samples were collected from 107 rabbits and examined by modified Ziehl-Neelsen technique for the presence of Cryptosporidium oocysts. An infection rate of 3.7% (4/107) was obtained and all microscopy-positive samples were genotyped and subtyped to determine the circulating Cryptosporidium species using sequence analysis of the 18S rRNA gene and 60-kDa glycoprotein (gp60) gene, respectively. All the four microscopy-positive samples were identified as C. parvum by 18S rRNA gene. However, analysis of the gp60 gene revealed the presence of C. parvum subtype IIc, which is commonly found in humans in two isolates. These findings indicate natural infection of rabbits with C. parvum and underscore the need to investigate the probable role of animal hosts in the epidemiology of Cryptosporidium infection. This is the first report on genetic characterization of Cryptosporidium infecting rabbits in Nigeria.

Host-adapted Cryptosporidium and Enterocytozoon bieneusi genotypes in straw-colored fruit bats in Nigeria.

Few data are available on the distribution and human infective potential of Cryptosporidium and Enterocytozoon bieneusi genotypes in bats. In this preliminary study, we collected 109 fecal specimens during April-July 2011 from a colony of straw-colored fruit bats (Eidolon helvum) in an urban park (Agodi Gardens) of Ibadan, Nigeria, and analyzed for Cryptosporidium spp., Giardia duodenalis and E. bieneusi using PCR targeting the small subunit rRNA gene, triosephosphate isomerase gene, and ribosomal internal transcribed spacer, respectively. Genotypes of these enteric parasites were determined by DNA sequencing of the PCR products. Altogether, 6 (5.5%), 0 and 16 (14.7%) specimens were positive for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. DNA sequence analysis of the PCR products indicated the presence of two novel Cryptosporidium genotypes named as bat genotype XIV (in 5 specimens) and bat genotype XV (in 1 specimen) and one known E. bieneusi genotype (Type IV in 1 specimen) and two novel E. bieneusi genotypes (Bat1 in 13 specimens and Bat2 in 2 specimens). In phylogenetic analysis of DNA sequences, the two novel Cryptosporidium genotypes were genetically related to Bat genotype II previously identified in fruit bats in China and Philippines, whereas the two novel E. bieneusi genotypes were genetically related to Group 5, which contains several known genotypes from primates. With the exception of Type IV, none of the Cryptosporidium and E. bieneusi genotypes found in bats in this study are known human pathogens. Thus, straw-colored fruit bats in Nigeria are mainly infected with host-adapted Cryptosporidium and E. bieneusi genotypes.

Cryptosporidiosis in a fire skink (Lepidothyris fernandi) and molecular identification of infecting species

Cryptosporidiosis is an infectious protozoan disease that affects a wide range of animals including reptiles. This is the first report of cryptosporidiosis in a fire skink (Lepidothyris fernandi), an insectivorous reptile commonly found in tropical West Africa. Faecal sample was collected from a fire skink at necropsy for the detection of parasites by faecal sedimentation method, Ziehl-Neelsen (ZN) acid-fast staining, Nested Polymerase Chain Reaction (PCR) and Nucleotide sequencing. Sections of the intestines were also processed for histopathology. Light microscopy revealed the presence of Ophidascarids sp. eggs and Cryptosporidium oocysts. Amplification of the 18S rRNA gene and nucleotide sequencing confirmed Cryptosporidium varanii as the infecting species. Histopathology revealed cellular infiltration and disruption of the epithelial cells along the brush border characteristic of intestinal inflammation.

Detection and molecular identification of Cryptosporidium species in laboratory rats (Rattus norvegicus) in Ibadan, Nigeria

To study the occurrence of Cryptosporidium infection in laboratory rats (Rattus norvegicus) raised for experimental usage, 134 faecal samples were obtained from two rearing houses in Ibadan and examined for the presence of Cryptosporidium oocyst using the modified acid fast staining technique. Cryptosporidium species in 2 samples positive for microscopy were further characterized by a nested polymerase chain reaction (PCR) amplifying the 18S rRNA gene. Two of 134 samples were positive for the Cryptosporidium oocysts. Sequencing of the small-subunit rRNA amplicons identified the species in the two PCR positive samples as Cryptosporidium andersoni and Cryptosporidium rat genotype. These findings showed that laboratory rat is a potential reservoir for diverse Cryptosporidium species and suggests that laboratory rats should be screened for Cryptosporidium infection prior to experiments, especially where pathogen free animals are not available. This the first report to identify Cryptosporidium species infecting laboratory rats in Nigeria.

SEROLOGICAL SURVEY OF TOXOPLASMOSIS, NEOSPOROSIS AND BRUCELLOSIS AMONG CATTLE HERDS IN OYO STATE, SOUTH-WESTERN NIGERIA.

BACKGROUND: Several zoonotic diseases are known to constitute great impediment to livestock management and production worldwide, especially in developing countries where control measures are largely non-existent. This study sets out to investigate the occurrence of toxoplasmosis, neosporosis and brucellosis among cattle herds in Oyo State, southwest Nigeria. MATERIALS AND METHODS: A cross-sectional survey to screen for antibodies to Toxoplasma gondii, Neospora caninum and Brucella abortus was conducted among 174 cattle in 17 herds. Sera obtained from the cattle were screened for antibodies to Toxoplasma gondii and Neospora caninum using enzyme-linked immunosorbent assay (ELISA) and for Brucella abortus antibodies using Rose Bengal test and Competitive Enzyme Linked Immunosorbent Assay (cELISA). RESULTS: Overall, herd level prevalence of 52.9%, 23.5% and 23.5% as well as individual prevalence of 7.5%, 3.4% and 3.4% was obtained for toxoplasmosis, neosporosis and brucellosis, respectively. Antibodies to T. gondii, N. caninum and B. abortus were detected in 2 of the 17 herds, T. gondii and N. caninum in 4 herds, and T. gondii and B. abortus in 4 herds. Statistically significant association was only found between seropositivity to T. gondii antibodies and sex (p<0.05). CONCLUSION: Our results showed that toxoplasmosis, neosporosis and brucellosis are prevalent among cattle herds screened in the study area. Considering the potential impact of these diseases on livestock management and production, extensive surveillance is necessary for development and implementation of effective control and prevention strategies.

Prevalence of potentially zoonotic gastrointestinal parasites in canine faeces in Ibadan, Nigeria.

BACKGROUND: Humans can get infected through direct or indirect contact with infective stages of zoonotic parasites shed to the environment through dog faeces. OBJECTIVES: This study was designed to investigate the presence of gastrointestinal parasites present in dog faeces shed on the street of Ibadan metropolis, one of the largest cities in Africa. METHODS: Twenty-three locations were randomly selected using grid-sampling method. A total of 203 faecal samples collected from the streets of selected areas were processed for detection of helminth eggs and protozoan oocysts using flotation technique. Eggs/oocysts per gram of faeces was counted using modified McMaster technique. RESULTS: The prevalence of gastrointestinal parasites was 43.3% (88/203). Single and multiple infections were 69 (78.4%) and 19 (21.6%) respectively. The parasites detected were Ancylostoma sp. 24.6% (50/88) Isospora sp. 14.2% (29/88), Toxocara sp. 9.8% (20/88), Uncinaria sp. 2.5% (5/88) and Strongyloides sp, 3.9% (8/88). Ancylostoma sp. (320 × 102 epg) and Uncinaria sp. (5 × 102 epg) had the highest and least intensity respectively. Streets within residential areas having markets had the highest number of positive samples. All the genera of parasites detected in this study have zoonotic potential. CONCLUSION: The high prevalence of zoonotic parasites detected in dog faeces from Ibadan metropolis showed that infected stray dogs roam the streets and constitute potential risk to human health. This study suggests the need for enforcement of laws restraining roaming or straying dogs and proper veterinary care of dogs. FUNDING: None declared.

Molecular characterization of Cryptosporidium in children in Oyo State, Nigeria: implications for infection sources.

A study was conducted to detect and identify Cryptosporidium spp. in 43 children from Oyo State, Nigeria. Using nested polymerase chain reaction, 11.6% of the children were identified as positive for Cryptosporidium spp. Restriction fragment length polymorphism analysis and DNA sequencing of the PCR products showed the presence of three subtype families of Cryptosporidium hominis (two isolates of Ia and one isolate of Ib) and Cryptosporidium parvum (two isolates of IIc), all anthroponotic in nature. This study identified a high diversity of Cryptosporidium subtypes and clearly suggested that anthroponotic rather than zoonotic transmission played a more important role in the epidemiology of Cryptosporidium in the studied area.

Molecular Identification of Enterocytozoon bieneusi Isolates from Nigerian Children.

A study was conducted to detect and identify enteric microsporidian species in 43 children from Oyo state, Nigeria. Using nested polymerase chain reaction, 9.3% of the children were identified as positive for Enterocytozoon bieneusi. DNA sequencing of the PCR products showed the presence of three known genotypes (two isolates of genotype D and one of genotype K) and one new genotype. This study suggests that either human or animal (or both) could be the infection source for the children, since identified genotypes D and K have been previously detected in both immunocompromised and immunocompetent patients and domestic animals. The identification of high diversity also suggests intensive transmission of microsporidiosis in the studied area.

Molecular characterization of Cryptosporidium spp. in native calves in Nigeria.

Most studies on the distribution of Cryptosporidium species in cattle were done with dairy breeds in industrialized nations. In this study, 65 fecal samples from randomly selected 12-24-week-old diarrheic calves in four white Fulani herds in southwestern Nigeria were screened for Cryptosporidium spp. using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small subunit rRNA gene. Thirty-four (52.3%) of the samples were positive for Cryptosporidium. RFLP analysis of PCR products showed that 18 (27.7%) and five (7.7%) of the positive samples had Cryptosporidium bovis and Cryptosporidium ryanae, respectively, and 11 (16.9%) had mixed infections of the two species. The absence of C. parvum suggests that the age group of calves studied is not likely to be source of zoonotic infection to humans.