Genotypic Characterization of Cryptosporidium Species in Humans and Peri-Domestic Animals in Ekiti and Oyo States, Nigeria.

Cryptosporidiosis is one of the leading causes of diarrhea in humans and several other vertebrate species. Because surveys of Cryptosporidium genotypes from animals and humans living in the same region are rare, our understanding of the importance of zoonotic transmission in the epidemiology of cryptosporidiosis remains superficial. PCR was used to amplify a portion of the Cryptosporidium 18S small subunit ribosomal RNA gene from fecal DNA from humans and livestock living in Ekiti and Oyo states, Nigeria. PCR-positive samples were further analyzed using PCR targeting the heat-shock protein HSP-70, the actin, and the sporozoite glycoprotein gene gp60. A questionnaire was used to collect demographic information. Sixteen of 187 samples collected were Cryptosporidium 18S PCR positive. Of these, 5 samples originating from HIV-positive patients, 5 from otherwise healthy children, 2 from chickens, 3 from goats, and 1 from a dog were positive for at least 1 marker. Sequencing of the 18S rRNA amplicons revealed the presence of Cryptosporidium parvum in 2 HIV positive patients and in a child; the actin sequence confirmed the presence of this species. Two samples of HIV-positive patients amplified Cryptosporidium hominis 18S rRNA, one of them confirmed by the HSP-70, actin, and gp60 sequences. Cryptosporidium meleagridis was found in another HIV patient, while C. hominis was detected in 3 children (of which 2 were confirmed by gp60). Cryptosporidium muris was found in 1 child. In birds, we found C. meleagridis and, significantly, C. parvum, whereas we detected C. parvum and C. muris in 1 goat each. The only dog sampled was positive for Cryptosporidium canis. We conclude that, in the environment we surveyed, humans and animals are a potential part of the same transmission cycle. Measures to prevent zoonotic transmission should therefore be considered to reduce the prevalence of cryptosporidiosis.

Molecular detection of Cryptosporidium species in street-sampled dog faeces in Ibadan, Nigeria.

Cryptosporidium, an intestinal protozoan parasite that infects a wide range of animals, is shed to the environment through the faeces of infected hosts that include humans and companion animals. Environmental contamination with infective oocysts increases the risk of transmission of this zoonotic pathogen to other susceptible host. In this study, Cryptosporidium was detected by polymerase chain reaction amplification of the 18S rRNA gene in 2.5% (5/203) of dog faecal samples randomly collected from 23 streets of Ibadan, southwestern Nigeria. Nucleotide sequencing of the 18S rRNA gene yielded two genotypes, C. parvum and C. muris in three and two samples, respectively. Further amplification of the gp60 gene-coding 60-kDa glycoprotein for subtype determination detected two isolates as C. parvum subtype IIc family. C. parvum subtype IIc is a human-derived pathogen while C. muris has been reported to infect rodents and even humans. The findings of this study suggest that free-ranging urban dogs could act as reservoirs and potential sources of environmental contamination with Cryptosporidium species of public health importance.

Seroprevalence of Toxoplasma gondii in recreational horses in two metropolitan cities of Southwestern Nigeria.

Toxoplasma gondii (T. gondii), an obligate intracellular protozoan parasite is a known etiological factor of reproductive problems and encephalomyelitis in animals and humans. This study investigated the seroprevalence of T gondii infection in recreational horses in two metropolitan cities of southwestern Nigeria. Serum samples were randomly collected from a total of 157 horses in Lagos and Ibadan. Samples were assayed for the presence of T gondii antibodies using the Modified Agglutination Test (MAT). A total of 22 (14%) of the 157 sampled horses were positive for T gondii antibodies by MAT with titers of 1:20 in 12 samples (54.5%), 1:40 in 8 samples (36.4%), 1:80 in 1 sample (4.1%) and 1:160 in 1 sample (4.1%). Seroprevalence varied among gender, breeds, age groups and sampling locations but there was no statistically significant association (p < 0.05) of any of the factors to T. gondii infection. This study showed that recreational horses in southwestern Nigeria are exposed to T. gondii and appropriate measures should be adopted to prevent and control the infection in horses in this region. The zoonotic implication of the disease is also discussed. This is probably the first report on seroprevalence of Toxoplasma gondii in horses in southwestern Nigeria.