Browsing by Author "Kazibwe, Anne"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Assessment of the Impact of Early Diagnosis and Early Treatment in the Integrated Control of East Coast Fever (ECF) Involving Acquired Immunity Induced by Natural Infection in Ankole Cattle
    (Pathogens, 2023) Nanteza, Ann; Nsubuga, Julius; Kazibwe, Anne; Terundaja, Clare; Matovu, Enock; Lubega, George William
    The integrated control of East Coast fever (ECF) by early diagnosis and treatment involving acquired immunity induced by natural infection in Ankole cattle was assessed. A longitudinal study was carried out in Kiruhura district, southwestern Uganda for six months on 244 Ankole breed of cattle from 18 herds under natural tick challenge and relaxed tick control measures. Calves aged three to six months old were recruited and monitored daily by farmers for detection of ECF clinical symptoms. The reported sick animals were treated using Buparvaquone and treatment outcome determined. Monthly follow-ups and blood collections were done to monitor ECF status. Blood was analyzed for Theileria parva parasites by microscopy, DNA by polymerase chain reaction (PCR) and antibodies by enzyme-linked immunosorbent assay (ELISA). The overall prevalence of ECF clinical disease within six months period was 30.3% (74). The major symptoms of early clinical ECF disease were fever and enlarged parotid or prescapular lymph nodes. Clinical cases were categorized as mild, 24% (18) or moderate, 76% (56). There was an overall recovery rate of 100% (74) of the ECF cases whereby 94.6% (70) recovered promptly and 5.4% (4) recovered slowly. Based on blood analysis, prevalence of ECF at baseline was 3.7% (9) by microscopy, 31.1% (76) by PCR and 38.1% (93) by ELISA. A significant increase (p < 0.05) was shown by the increased number of calves with T. parva specific antibodies in the sera from 38.1% at baseline to 68.8% after six months. High antibody levels (positive percentage ≥ 50%) were detected in all ECF-treated and recovered calves at the end of six months. The acquired immunity to ECF was high in treated and recovered cattle, indicating that natural exposure to infection, accurate early diagnosis and effective treatment enhance development of immune-protection in indigenous cattle in an endemic area. The prominent early clinical symptoms for ECF could be exploited in the development of decision support tools for chemotherapy and other integrated control measures.
  • Thumbnail Image
    Item
    East Coast Fever Carrier Status and Theileria parva Breakthrough Strains in Recently ITM Vaccinated and Non-Vaccinated Cattle in Iganga District, Eastern Uganda
    (Pathogens, 2023) Oligo, Stephen; Nanteza, Ann; Nsubuga, Julius; Musoba, Abubakar; Kazibwe, Anne; Lubega, George Willy
    East Coast fever (ECF) is a tick-borne disease of cattle that hinders the development of the livestock industry in eastern, central and southern Africa. The ‘Muguga cocktail’ live vaccine, delivered by an infection and treatment method (ITM), remains the only immunisation strategy of controlling ECF. However, there are challenges of the live vaccine inducing ECF carrier status in immunised animals and the possibility of lack of protection from parasite strains that are antigenically different from the vaccine strains. In Uganda, there are insufficient data regarding the ECF carrier status and T. parva genetic diversity in vaccinated and associated non-vaccinated cattle to assess the effectiveness of ITM vaccination. Blood was collected from recently ECF vaccinated (98) and non-vaccinated (73) cattle from Iganga district in Eastern Uganda at 120 days post-vaccination. The p104 gene nested PCR was used to screen for T. parva DNA, 11 minisatellite and 3 microsatellite markers (SSR) were used for genotyping. Two minisatellite markers (MS7 and MS19) were used to determine whether ECF carrier status was due to the T. parva vaccine or local strains. The prevalence of T. parva based on p104 nPCR was 61.2% (60/98) (RR 2.234, 95% CI 1.49–3.35, p-value < 0.001) among recently vaccinated cattle and 27.4% (20/73) (RR 1.00) among associated non-vaccinated cattle. The Muguga cocktail vaccine strains were responsible for carrier status in 10 (58.8%) by MS7 and 11 (64.7%) by MS19 in vaccinated cattle. Genotypes of T. parva with different-sized alleles to the vaccine strains that could be potential ‘breakthroughs’ were detected in 2 (11.8%)) and 4 (23.5%) isolates from vaccinated cattle based on MS7 and MS19 minisatellite markers, respectively. Using 14 SSR markers, T. parva diversity was higher in vaccinated (Na = 2.214, Ne = 1.978, He = 0.465) than associated non-vaccinated (Na = 1.071, Ne = 1.048, He = 0.259) cattle. The principal component analysis (PCA) showed isolates from vaccinated cattle were closely related to those from non-vaccinated cattle. The analysis of molecular variance (AMOVA) revealed high genetic variation (96%) within T. parva isolates from vaccinated and non-vaccinated cattle but low variation (4%) between vaccinated and non-vaccinated cattle. This study reveals the role of ITM in inducing the carrier status and higher T. parva genetic diversity in vaccinated cattle. The low genetic variation between T. parva isolates in both vaccinated and non-vaccinated cattle may be suggestive of the protective role of vaccine strains against genetically related local strains in the study area.
  • Thumbnail Image
    Item
    Occurrence of Cryptosporidium hominis in cattle bordering the Lake Mburo National Park in Kiruhura district, Western Uganda
    (bioRxiv, 2019) Witto, Sarah Gift; Kankya, Clovice; Kazibwe, Anne; Akurut, Gloria; Ochwo, Sylvester
    Cryptosporidium is an emerging opportunistic zoonotic pathogen that causes diarrhea illness in a wide range of hosts including livestock and humans. Globally there is exponential increase in livestock production to meet the worlds’ demand for animal protein as well as for financial reasons. However, there is raised concern of the public health threat due to contamination of the environment by livestock waste carrying zoonotic pathogens such as Cryptosporidium. This study set out to establish the prevalence of Cryptosporidium as well as the circulating genotypes in order to elucidate the potential role of cattle in the spread of human cryptosporidiosis. We collected rectal coprological samples from 363 cattle in 11 households in Kiruhura district, Southwestern Uganda. The samples were screened for presence of Cryptosporidium oocysts using the phenol auramine staining method followed by fluorescent microscopy. DNA was then extracted from the microscopy positive samples and the COWP gene amplified using PCR. Amplified gene products were sequenced and subjected to phylogenetic analysis.
  • Thumbnail Image
    Item
    The prevalence and genetic characterisation of Cryptosporidium isolates from cattle in Kiruhura district, South Western Uganda
    (Journal of Parasitic Diseases, 2021) Witto, Sarah Gift; Kankya, Clovice; Akurut, Gloria; Mugasa, Claire Mack; Kazibwe, Anne; Ochwo, Sylvester
    Cryptosporidium is an emerging opportunistic zoonotic pathogen that causes diarrheal illness in a wide range of hosts including livestock and humans. This study set out to establish the prevalence of Cryptosporidium as well as the circulating genotypes in order to elucidate the potential role of cattle in the spread of human cryptosporidiosis. Rectal coprological samples from 363 cattle in 11 households in Kiruhura district, Southwestern Uganda were collected and screened for the presence of Cryptosporidium oocysts using the phenol auramine staining method followed by fluorescent microscopy. DNA was extracted from the microscopy positive samples and the COWP gene amplified using PCR. PCR products were sequenced and subjected to phylogenetic analysis. Additionally a multiplex realtime PCR was used to identify the Cryptosporidium spp. Multivariable mixed effect logistic regression models were used to identify potential risk factors for Cryptosporidium infection. The overall