Trypanosoma evansi is enzootic in camels in Egypt, and water buffaloes act as a reservoir for camel infection. Molecular techniques have contributed towards understanding the epidemiology of T. evansi. Trypanosoma evansi was detected in acute and chronic stages of the disease in male and female mice by polymerase chain reaction (PCR) using two primers. Two experiments were conducted. In experiment I, two groups consisting of 26 female and 26 male mice received 10(4) trypanosome by I/P inoculation for each mouse. In experiment II, 42 female and 42 male mice were inoculated I/P with 10² trypanosome/mouse. In addition, five mice were kept as uninfected control for each group. Mice were monitored daily for parasitaemia level during the pre-patent period using the micro-haematocrit centrifugation technique (MHCT) and conventional PCR. The primer pairs, (Trypanosoma brucei) TBR1/2 and TeRoTat1.2 (T. evansi Rode Trypanozoon antigen type [RoTat] 1.2), detected the infection after 24 hours earlier than MHCT in both experiments. The course of infection that was detected by MHCT revealed three waves of parasitaemia in female mice and two waves in male mice in the chronic stage of infection. In addition, PCR was able to detect T. evansi in different organs in the chronic stage (i.e. disappearance of parasite from blood). Application of the two primer sets on blood samples from camels showed that all samples were positive by TBR1/2 primers and only 32 of 44 were positive by TeRoTat1.2 primers. Acutely and chronically Trypanosoma-infected mice were detected by PCR in blood and organs. TBR1/2 primers were more sensitive than TeRoTat1.2 primers in detecting Trypanosoma-infected mice, and more reliable in detecting field-infected camels and excluding carrier animals.

Tick-borne diseases (TBDs) caused by Theileria, Babesia, Anaplasma and Ehrlichia species are common in tropical and subtropical regions. In this study, we investigated the presence and genetic diversity of Theileria spp., Anaplasma ovis, B. ovis, E. ruminantium and Anaplasma spp. in sheep from the Machakos and Homa Bay counties of Kenya. In order to improve the diagnosis and control of ovine TBDs, a total of 76 blood samples from apparently healthy sheep were screened using a polymerase chain reaction (PCR). The assays were conducted using primers based on Theileria spp. 18S rRNA, Anaplasma ovis Major surface protein-4 (AoMSP4), B. ovis 18S rRNA, E. ruminantium pCS20 and Anaplasma spp. 16S rRNA. The overall infection rates for Theileria spp., A. ovis, E. ruminantium and Anaplasma spp. were 39/76 (51.3%), 26/76 (34.2%), 6/76 (7.9%) and 31/76 (40.8%), respectively. The overall co-infection was 47/76 (61.8%). All Theileria spp. positive samples were confirmed to be of Theileria ovis on sequencing. A phylogenetic analysis of the 18S rRNA gene sequences of T. ovis revealed that all isolates of this study clustered with T. ovis sequences extracted from the GenBank suggesting this gene is highly conserved. E. ruminantium pCS20 sequences were in the same clade on the phylogenetic tree. However, three AoMSP4 sequences from this study appeared in the same clade, while one sequence formed a separate branch revealing genetic divergence. The 16S rRNA sequencing revealed uncharacterised Anaplasma spp. and A. ovis. The phylogenetic analyses of the uncharacterised Anaplasma spp. revealed that the two sequences from this study appear in an independent clade from other sequences extracted from the GenBank. This study provides important information regarding the occurrence of tick-borne pathogens and their degree of genetic diversity among sheep in Kenya, which is useful for the diagnosis and control of TBDs.

The classification and description of digenean trematodes are commonly accomplished by using morphological features, especially in adult stages. The aim of this study was to provide an analysis of the genetic composition of larval digenean trematodes using polymerase chain reaction (PCR) and sequence analysis. Deoxyribonucleic acid (DNA) was extracted from clinostomatid metacercaria, 27-spined echinostomatid redia, avian schistosome cercaria and strigeid metacercaria from various dams in the proximity of Tshwane metropolitan, South Africa. Polymerase chain reaction was performed using the extracted DNA with primers targeting various regions within the larval digenean trematodes' genomes. Agarose gel electrophoresis technique was used to visualise the PCR products. The PCR products were sequenced on an Applied Bioinformatics (ABI) genetic analyser platform. Genetic information obtained from this study had a higher degree of discrimination than the morphological characteristics of seemingly similar organisms.