Joseph Erume

Campylobacteriosis, salmonellosis, and shigellosis in free-ranging human-habituated mountain gorillas of Uganda

For conservation purposes and due to growing ecotourism, free-ranging mountain gorillas (Gorilla gorilla beringei) have been habituated to humans. Fecal specimens (n = 62) collected in January 1999 from mountain gorillas of the Bwindi and Mgahinga National Parks, Uganda, were tested for Campylobacter spp., Salmonella spp., and Shigella spp., and the overall prevalence of infection was 19%, 13%, and 6%, respectively. The prevalence of positive specimens was not related to the year of habituation of a gorilla group to humans. Campylobacter spp., Salmonella, and Shigella spp. infections were not distributed equally among the age classes of gorillas; most of the enteropathogens (80%), and all Shigella spp. organisms, S. sonnei, S. boydii, and S. flexneri, were isolated from subadults and adult gorillas with ages ranging from 6.0 to 11.9 yr. The prevalence of Campylobacter spp. and Salmonella spp. infections among human-habituated gorillas has doubled during the last 4 yr, and isolation of Shigella spp. for the first time from mountain gorillas, may indicate enhanced anthropozoonotic transmission of these enteropathogens.

Molecular characterization of peste des petits ruminants virus from the Karamoja region of Uganda (2007-2008)

Antibodies against peste des petits ruminants virus (PPRV) were first detected in goats in East Africa in 1995 without any clinical disease. It was not until during the years 2006 and 2007 that the disease outbreaks were first reported in Kenya and Uganda, respectively. This study was carried out to detect and characterize PPRV from a suspected outbreak in sheep and goats in the Karamoja region in 2007-2008. Oculo-nasal and blood samples were tested using F-gene-based primers, and their genetic relationships to other sequences in the GenBank database were investigated. A total of 383 samples suspected to contain PPRV were randomly collected and tested. Sixty-seven (17.5%) were positive when F protein gene primers were used. During the years 2007 and 2008, 38.1% (26/67) and 13.0% (41/316) of samples were positive by PCR, respectively. The 2007 sequences clustered with Asian sequences in lineage 4 and Cote d’Ivoire 86 (ICV 86) in lineage 2, while all of the 2008 samples clustered in lineage 1. Over the years, the implicated strains were genetically close (88%–91%) to the vaccine strain (Nig 75/1). Based on this study, the circulating PPR strains in Uganda are heterogeneous, and therefore, the disease may have been introduced from different sources.

Isolation and Molecular Characterization of Brucella Isolates in Cattle Milk in Uganda

Brucellosis is endemic in livestock and humans in Uganda and its transmission involves a multitude of risk factors like consumption of milk from infected cattle. To shed new light on the epidemiology of brucellosis in Uganda the present study used phenotypic and molecular approaches to delineate the Brucella species, biovars, and genotypes shed in cattle milk. Brucella abortus without a biovar designation was isolated from eleven out of 207 milk samples from cattle in Uganda. These isolates had a genomic monomorphism at 16 variable number tandem repeat (VNTR) loci and showed in turn high levels of genetic variation when compared with other African strains or other B. abortus biovars from other parts of the world. This study further highlights the usefulness of MLVA as an epidemiological tool for investigation of Brucella infections.

Prevalence of and factors associated with Brucella sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Uganda

Brucellosis is a key zoonosis of major public health, animal welfare and economic significance, and is endemic in livestock in Uganda. A cross-sectional epidemiological study was carried out to estimate the sero-prevalence of brucellosis and identify factors associated with sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Northern and Eastern Uganda, respectively. A total of 1007 sera and data on biologically plausible risk factors from 166 herds and their spatial locations, were collected from cattle reared in urban and peri-urban Gulu and Soroti towns of Uganda. The sera were analyzed using indirect ELISA and sero-positive reactors confirmed by competitive ELISA. Multivariable models were used to investigate for risk factors. The overall animal-level and herd-level sero-prevalence was 7.5% (76/1007, 95% Confidence Interval (CI): 6.15–9.4%) and 27.1% (45/166, 95% CI: 20.9–34.3%), respectively. Herd-level sero-prevalence was significantly (P<0.001) higher in Soroti than Gulu. In Gulu town, sero-positivity increased with an increase in herd size (P=0.03) and age (P=0.002), and was higher in cattle brought in from western Uganda (P<0.0001). In Soroti town, introduction of new cattle into a herd was significantly (P=0.027) associated with herd sero-positivity. There was a geographically differential risk (clustering) of Brucella sero- positivity in herds in Soroti, while sero-positivity was homogeneously distributed in Gulu. The data highlight brucellosis occurrence and major risk factors for its transmission in cattle in urban and peri-urban areas.

Molecular characterization and phylogenetic study of peste des petits ruminants viruses from North central States of Nigeria

BackgroundPeste des petits ruminants is an endemic disease of sheep and goats in Nigeria and vaccination has been the method of control but sporadic outbreaks have been reported. This study was carried out to characterize PPR viruses from outbreaks in 2007 and 2009 from Kaduna and Plateau States.ResultsOf the 33 clinical samples analysed, 51.52% (n = 17) were positive for F protein gene primers (F1/F2). All the samples had a sequence similarity of 98-100% among them and 92-97% with the reference vaccine (Nig 75/1) strain. The deduced amino acid homology ranges between 96.3-99.7%. Phylogenetically all the Nigerian sequences cluster with Nig 75/1 and Nig 76/1 in lineage 1.ConclusionsPPR is still a problem in Kaduna and Plateau States of Nigeria. The strains involved were genetically closely related to the vaccine strain (Nig 75/1) used in the country. Based on this study, the continued outbreaks in the Country is not due to the efficacy of the vaccine. Therefore, to achieve effective control and possibly eradication of PPR in Nigeria, the current control strategies should be revisited.

Sample type is vital for diagnosing infection with peste des petits ruminants virus by reverse transcription PCR.

Peste des petits ruminants (PPR) diagnosis from suspected samples from sheep and goats was carried out. Buffy coat, tissues, and oculo-nasal swabs were analyzed using nucleoprotein (NP3/NP4) and fusion protein (F1/F2) gene primers, respectively. Analysis of the sample types and primer set revealed that buffy coat are the best type of samples for PPR diagnosis and the use of two set of primers will increase the number of positives.

Prevalence of pathogenic free-living amoeba and other protozoa in natural and communal piped tap water from Queen Elizabeth protected area, Uganda

BackgroundPathogenic water dwelling protozoa such as Acanthamoeba spp., Hartmannella spp., Naegleria spp., Cryptosporidium spp. and Giardia spp. are often responsible for devastating illnesses especially in children and immunocompromised individuals, yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers, public health officials and medical practitioners. The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba (FLA), Cryptosporidium and Giardia in Queen Elizabeth Protected Area (QEPA).MethodsSamples were collected from communal taps and natural water sites in QEPA. Physical water parameters were measured in situ. The samples were processed to detect the presence of FLA trophozoites by xenic cultivation, Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique. Parasites were observed microscopically, identified, counted and recorded. For FLA, genomic DNA was extracted for amplification and sequencing.ResultsBoth natural and tap water sources were contaminated with FLA, Cryptosporidium spp. and Giardia spp. All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp. and Naegleria spp. which occurred more in the warmer months. The prevalence of all parasites was higher in tap water than in natural water samples. There was a strong negative correlation between the presence of Acanthamoeba spp., Hartmannella spp., Cryptosporidium spp. and Giardia spp. with Dissolved Oxygen (DO) (P < 0.05). The presence of Cryptosporidium spp. showed a significant positive correlation (P < 0.05) with conductivity, pH and Total Dissolved Solids (TDS); whereas the presence of Giardia spp. had only a strong positive correlation with TDS. Molecular genotyping of FLA produced 7 Acanthamoeba, 5 Echinamoeba, 2 Hartmannella, 1 Bodomorpha, 1 Nuclearia and 1 Cercomonas partial sequences.ConclusionsAll water collection sites were found to be contaminated with pathogenic protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA. This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported, thus necessitating adoption of proper water safety measures.

Molecular detection and characterization of Brucella species in raw informally marketed milk from Uganda

This study identified and characterized Brucella species in the informal milk chain in Uganda. A total of 324 cattle bulk milk samples were screened for the genus Brucella by real-time PCR with primers targeting the bcsp31 gene and further characterized by the omp25 gene. Of the samples tested, 6.5% were positive for Brucella species. In the omp25 phylogeny, the study sequences were found to form a separate clade within the branch containing B. abortus sequences. The study shows that informally marketed cattle milk in Uganda is a likely risk factor for human brucellosis and confirms that B. abortus is present in the cattle population. This information is important for potential future control measures, such as vaccination of cattle.

Brucellosis: Community, medical and veterinary workers’ knowledge, attitudes, and practices in Northern Uganda

Aim: This study aimed at determining the knowledge, attitudes, and practices of the community, medical and veterinary workers regarding brucellosis. Materials and Methods: A cross-sectional study was conducted at selected health facilities in Apac, Gulu, Lira, and Pader districts of Northern Uganda using a standardized questionnaire. A total of 251 patients testing positive for brucellosis using the Brucella plate agglutination test, 59 medical and 29 veterinary workers were studied. Chi-square test at 95% confidence level was used to analyze data. Results: Only 8% patients, 15.3% medical, and 21.4% veterinary workers were knowledgeable on transmission methods and symptoms for brucellosis and knowledge differed according to the level of education among patients (p=0.001), medical (p=0.001), and veterinary workers (p=0.012). Over 80% patients, medical and veterinary workers had a positive attitude. Only 8% patients, 13.6% medical, and 7.1% veterinary workers had good practices regarding brucellosis control. Conclusion: Poor knowledge, poor practices, and positive attitude provide an opportunity for health education and policy formulation for the control of brucellosis. The prevalence studies of human and animal brucellosis are recommended to determine the magnitude of the problem.

Identification of Echinococcus granulosus strains using polymerase chain reaction–restriction fragment length polymorphism amongst livestock in Moroto district, Uganda

A descriptive study was conducted to identify the different strains of Echinococcus granulosus occurring in livestock in Moroto district, Uganda. Echinococcus cysts from 104 domestic animals, including cattle, sheep, goats and camels, were taken and examined by microscopy, polymerase chain reaction with restriction fragment length polymorphism and Sanger DNA sequencing. Echinococcus granulosus genotypes or strains were identified through use of Bioinformatics tools: BioEdit, BLAST and MEGA6. The major finding of this study was the existence of a limited number of E. granulosus genotypes from cattle, goats, sheep and camels. The most predominant genotype was G1 (96.05%), corresponding to the common sheep strain. To a limited extent (3.95%), the study revealed the existence of Echinococcus canadensis G6/7 in three (n = 3) of the E. granulosus–positive samples. No other strains of E. granulosus were identified. It was concluded that the common sheep strain of Echinococcus sensu stricto and G6/7 of E. canadensis were responsible for echinococcal disease in Moroto district, Uganda.