Veterinary Medicine

Epidemiology of Cryptosporidiosis in dogs in Lusaka district, Zambia

Fri, 01 Jan 2016 00:00:00 GMT

Epidemiology of Cryptosporidiosis in dogs in Lusaka district, Zambia Mugala, Lamson Cryptosporidium is an intracellular zoonotic protozoan parasite that causes cryptosporidiosis, a diarrhoeal disease of humans and domestic animals. The parasite has been reported in a variety of domestic animals including dogs. Several species of Cryptosporidium infecting animals have also been reported in humans highlighting the zoonotic nature of the disease. This study was aimed at determining the prevalence and associated risk factors of Cryptosporidium infection in domestic dogs in Lusaka district of Zambia. It was a prospective cross-sectional descriptive study carried out from October, 2015 to May, 2016 in three Veterinary Clinics as well as Kalingalinga and Kabanana residential areas within Lusaka District. A total of 390 dog faecal samples were collected and analyzed at the University of Zambia, School of Veterinary Medicine laboratory and at the parasitology laboratory at the University Teaching Hospital. The modified Ziehl Neelsen and fluorochrome (Auramine) staining techniques were used to identify positive samples. A sample was considered positive if at least one oocyst was identified under the microscope. Proportions were compared using chi-square, fisher’s exact test and logistic regression, where appropriate. Overall, 390 dogs ranging from 2 months to 13 years were examined for the presence of Cryptosporidium. Out of these, 280 (71.8%) were of mixed breed while 110 (28.2%) were pure breeds; and 75.6% (295/390) were vaccinated while 24.4% (95/390) were not. Majority of the dogs (62.3%; 243/390) were males compared to only 37.7% (147/390) females. Most of the dogs (89. 2%; 348/390) were fed leftovers while the rest were fed pet food (5.9%; 23/390), sawdust (2.1%; 8/390) or both leftovers and pet food (2.8%; 11/390). The overall prevalence of Cryptosporidium infection in the dogs was 5.9% (23/390). Of the 23 positive dogs, 21 (5.4%) were detected by both Ziehl Neelsen and fluorochrome methods, while the other two were detected by fluorochrome method only, giving a prevalence of 5.9% (23/390) for the latter. The prevalence of Cryptosporidium in males was 5.3% (13/243) while that for females was 6.8% (10/147) but the difference was not significant (P= 0.658). There was a statistically significant difference in Cryptosporidium infection between mixed breed and pure breed dogs (P=0.012), with prevalence being higher in the mixed breed type. Water source was another variable found to be significantly associated with Cryptosporidium infection (P=0.041). Other factors investigated were not associated with Cryptosporidium infection. There was no statistically significant difference in the detection of Cryptosporidium using Auramine and Modified Ziehl Neelsen as the results obtained from the two methods were found to be in almost perfect agreement (Kappa=0.95). The study detected Cryptosporidium oocysts in dogs with most of them being asymptomatic. Most of the factors investigated apart from breed and water source were not associated with the Cryptosporidium infection. The two compared techniques, namely; Modified Ziehl Neelsen and Auramine can be adopted for routine examination of Cryptosporidium oocysts since both showed similar analytical results.

Isolation and molecular characterization of Non-Tuberculous Mycobacteria of Public Health significance from Humans and water in Namwala Districts of Zambia

Fri, 01 Jan 2016 00:00:00 GMT

Isolation and molecular characterization of Non-Tuberculous Mycobacteria of Public Health significance from Humans and water in Namwala Districts of Zambia Monde, Ngula Globally, opportunistic infections due to environmental Non-tuberculous Mycobacteria are increasingly becoming a public health threat due to the Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome pandemic. In Zambia, Non tuberculous Mycobacteria are gaining recognition as pathogens of public health significance. However, there is scanty information on the isolation and speciation of these organisms for better patient management, which could consequentially reduce the burden of these infections. Given the above information, the thrust of this study was to isolate and characterize NTM of public health significance from humans and water in Namwala district of Zambia. The study was a cross-sectional study were 306 sputum samples from adult human patients with suspected Tuberculosis were collected from four health centres in Namwala district. Additionally, 149 water samples were collected from different water drinking sources such as Tap water, Borehole water, rivers, wells and streams. Standard TB culture methods were employed to isolate Nontuberculous Mycobacteria. The isolates were then characterized using the 16S-23S internal transcribed spacer region Sequencing. One hundred and fifty three (153) individuals with suspected TB were sampled and 7(4.6%) were found to have NTM with M. arupense (3, 2%) being the most common organism. Out of the 149 water samples collected, (23, 15%) NTM were isolated with the common species being Mycobacterium gordonae (5, 3%), Mycobacterium senegalense (3, 2%), Mycobacterium peregrinum (3, 2%) and Mycobacterium fortuitum (3, 2%). Mycobacterium avium and Mycobacterium fortuitum were both isolated from humans and water.

Prevalence and Risk factors of East Coats Fever (ECF) in the Coppersbelt and Central Provinces of Zambia

Fri, 01 Jan 2016 00:00:00 GMT

Prevalence and Risk factors of East Coats Fever (ECF) in the Coppersbelt and Central Provinces of Zambia Chipuku, David Chabala East Coast fever (ECF) is an infectious tick-borne disease of cattle, caused by a protozoan parasite Theileria parva. It is a disease of major economic importance in Zambia as it is the main cause of cattle morbidity and mortality. Despite its economic importance, the epidemiology of ECF in Zambia is poorly understood, thereby making ECF prevention and control difficult. Further, there is limited published literature on this disease in Zambia, with the little available research concentrating on Southern and Eastern provinces. Such literature is mostly based on serological techniques such as indirect fluorescent antibody test (IFAT) which have limited sensitivity and specificity. Thus, this study was conducted to determine the prevalence and associated risk factors of ECF in Copperbelt and Central provinces of Zambia. The study was cross sectional in design. Multistage cluster sampling was used involving district, veterinary camp, herd and individual animals. The provinces and districts were selected based on their vast potential for livestock production and the previously reported incidence of ECF. From each district, two veterinary camps were randomly selected. From each camp herds were randomly selected from which individual animals were randomly sampled. Samples were collected from Mpongwe and Masaiti districts (Copperbelt province) and Kapiri Mposhi and Chibombo districts (Central province). Samples were examined for presence of schizonts on giemsa stained lymph smears. The lymph smear examinations revealed that 6.4% (95%, CI=4.9-7.9) of the samples were positive for T. parva schizonts. In Central province, the overall prevalence was 6.7% (95%, CI=4.0-8.2), while on the Copperbelt province it was 6.1% (95%, CI=4.0-8.2). Among the districts in these provinces, Kapiri Mposhi did not record any schizont positive cattle, while Masaiti recorded 2.4% (95%, CI=0.5-4.3). Mpongwe had a prevalence of 9.7% (95%, CI=6.0-13.4) and Chibombo had the highest prevalence at 13.6% (95%, CI=9.4-17.9). Risk factors that were identified to be associated with ECF were the district, frequency of veterinary service provision, tick control frequency, age and previous experience of ECF. The results indicate that ECF is prevalent in Copperbelt and Central provinces and hindering livestock production. There is hence the need for concerted efforts to control ticks and prevent ECF transmission through farmer sensitization, routine, regular, mandatory and supervised dipping and spraying of cattle and stringent livestock movement control. Key words: East Coast fever, microscopy, prevalence, risk factors, schizonts, Theileria parva.

Molecular characterization of infectious bursal disease virus from broiler flocks in Lusaka, Zambia

Thu, 01 Jan 2015 00:00:00 GMT

Molecular characterization of infectious bursal disease virus from broiler flocks in Lusaka, Zambia Ndashe, Kunda This study was aimed at determining the strains of infectious bursal disease virus (IBDV) present in Zambia causing disease in vaccinated broiler flocks. Despite routine vaccinations with appropriate IBDV vaccines, which is a control strategy of infectious bursal disease (IBD), many poultry farms still experience high mortalities to the disease (PAZ, 2013). A molecular study on IBDV isolated from Lusaka District was performed based on partial sequences of segments A (VP2) and segment B (VP1) of the viral genome from IBD outbreaks from 20 broiler farms. In total, 16 and 11 partial nucleotide sequences of VP2 and VP1 were determined, respectively. Evolutionary analysis of both VP1 and VP2 showed that most Zambian isolates belonged to the African very virulent IBDV (VVIBDV) group which includes isolates from Nigeria, Tanzania and South Africa (Kasanga et al., 2013). In contrast, it was interesting to note that one isolated strain (LUSC11-12) was genetically identical to an attenuated vaccine strain (MB) and showed 100% nucleotide sequence identity to the strain in both the VP2 and the VP1. The current study does not only demonstrate the predominance of African-like VVIBDV, but also documents for the first time the possible involvement of attenuated vaccine strains in the evolution and epidemiology of IBD in Zambia. From the above study findings, several recommendations were made which included ;further studies, surveillance and characterization of IBDV in poultry; monitoring of live vaccine use in the field, Development of a vaccine from local or regional IBDV field strains and Strict biosecurity of poultry farms

Determination of Aflatoxin Levels in Raw Groundnuts From Markets in Lusaka District,Zambia

Thu, 01 Jan 2015 00:00:00 GMT

Determination of Aflatoxin Levels in Raw Groundnuts From Markets in Lusaka District,Zambia Nsoni, Bumbangi Groundnuts, one of the most susceptible crops to aflatoxin (AF) contamination, are widely produced and consumed in Zambia. Previous studies have reported high levels of AFs in groundnuts produced in Zambia. However, there has been no study on the levels of AFs in groundnuts sold in different market types. This cross-sectional study was designed to determine the levels of AFs in raw groundnuts sold in Lusaka District’s markets as well as identify factors associated with increased AF presence. Raw groundnut samples were collected from open markets and supermarkets in Lusaka District and analyzed for AF presence using high performance liquid chromatography (HPLC). A questionnaire was also administered to the groundnut’s venders to investigate factors contributing to increased levels of AFs in groundnuts. Of the 92 groundnut samples, 51 (55.4%; 95% CI: 44.9 ‒ 65.4) tested positive for presence of AF. The overall median and geometric mean  standard deviation (SD) concentration for AF were 0.23 parts per billion (ppb) (range: 0.014 to 48.67 ppb) and 0.43  9.77 ppb, respectively. The presence of AF was almost the same in both types of markets. However, the highest concentration was recorded in a sample collected from a supermarket (48.67 ppb). Despite this, the association between market type and presence of AFs was not statistically significant (Pearson Χ2 = 0.0587, p = 0.809). Of 51 samples that tested positive to AF, 6.5% and 12% were above the maximum permissible limits (MPLs) set by the Codex Alimentarius Commission and European Union standards, respectively. There was a significant difference in the levels of AF between Chalimbana and Kadononga (p<0.0001), and also Chalimbana and Makulu red (p<0.0001). Chalimbana was the most at risk of AF contaminations, when compared to other groundnut varieties. The high level of AFs in raw groundnuts from both supermarket and open market samples constitutes a health hazard for the population of Lusaka district. Therefore, intervention strategies that reduce the level of AFs contamination in groundnuts should be given priority. Keywords: Aflatoxin; Groundnut; Risk factors; Zambia

Field assessment of the efficacy of Tephrosia Vogelii(hook)plant leaf extracts for control of ticks on naturally infested Cattle in Njola Veterinary Camp of Monze District,Zambia

Fri, 01 Jan 2016 00:00:00 GMT

Field assessment of the efficacy of Tephrosia Vogelii(hook)plant leaf extracts for control of ticks on naturally infested Cattle in Njola Veterinary Camp of Monze District,Zambia Siame, Pakula christopher Ticks and tick borne diseases (TBDs) are responsible for substantial direct and indirect economic losses in livestock production in the sub-Saharan countries. Conventional acaricide methods for controlling ticks and TBDs have not been very effective among small scale livestock farmers largely due to the high cost of acaricides and lack of adequate extension and outreach services provided to them. Failure to follow instructions and adherence in preparation of the right dilutions of acaricides has been considered to be responsible for development of tick resistance to most acaricides in use which resulted in increase of TBDs out breaks. This occurrence has prompted livestock farmers and researchers to seek none conventional alternative and sustainable tick control methods. None conventional method should be readily available, simple in processing, cheap, and preferably not harmful to the environment. We identified T.vogelii a tropical leguminous herbal plant with natural pesticide and acaricidal properties, as such a bio-acaricide candidate.Tephrosia is a short lived, slow growing, herbaceous, frost susceptible perennial plant and has soft hairy velvet leaves which are pleasant to touch. A baseline survey was done using a questionnaire to find out the levels of indigenous knowledge existing for tick control management. The results indicated that 51 percent of the respondents knew that ticks transmit diseases to cattle and 41 percent revealed the use of cow dung as a method to kill ticks. Cattle used were selected for field experiments from small scale farmers’ herds with no or, poor record of tick control in Monze district. Six groups of five (5) each were allotted into six (6) treatment groups of5, 10, 20, 40 percent w/v whilea negative control group of five (5) animals were also sprayed with ordinary water. A positive control group of five (5) animals were sprayed with a commercial acaricide (Amitraz®) at recommended dosage of 1:500 dilution by the manufacturer (Ecomed limited company of south Africa). All treatment groups were sprayed with same quantities in volume of the different preparations. Tick counts were conducted on each animal before and after treatments. The results showed that, the efficacy of the botanical extracts was sustained up to six days post treatment.There was reduction in tick counts at all concentration levels used in groups. It was however observed that 0.05 percent w/v concentration level of T.vogelii plant leaf extracts had the highest reduction on tick counts of up to 88 percent within 48 hours post treatment. The 0.1percent w/v had 71 percent reduction, 0.2 percent w/v had 74 percent, and lastly 0.4percentw/v had 80 percent reduction The observed tick reductions were found to be statistically significant at all treatment levels (p-value < 0.001). The protection period against reinfection is in excess of six days. The use of T. vogelii as bioacaricide proved effective against ticks at very low concentrations of only 5 percent w/v leaf extract. The extract is cheaper to use by small scale livestock farmers where they cannot afford to use chemical acaricides

Epidemiology of foot and Mouth Disease in Zambia

Thu, 01 Jan 2015 00:00:00 GMT

Epidemiology of foot and Mouth Disease in Zambia Sinkala, Yona Foot-and-mouth disease (FMD) is a highly infectious and devastating disease of livestock that has affected Zambia’s potential to boost the economy through trade in livestock commodities. The inadequate understanding, due to limited research based epidemiology data, of the disease dynamics has impacted negatively on its prevention and control. The aim of this study was to determine specific elements of FMD epidemiology that are important for understanding disease dynamics in Zambia. To conduct this study, firstly a retrospective analysis of FMD outbreaks between 1933 and 2012 was carried out in order to elucidate the temporal and spatial patterns that contributed to their occurrence. This was followed by a cross sectional study involving collection of sera and probang samples from cattle and buffalo including administration of a questionnaire at selected livestock/wildlife interface areas that was carried out to determine the seropositivity and associated risk factors. Included was molecular characterization of the circulating foot and mouth disease virus (FMDV) strains in these species. Furthermore, a transmission model incorporating carrier status was developed. Results of the study confirmed that FMD outbreaks remain confined to three high risk areas of Kafue Flats, lower Zambezi basin and northern Zambia. However, the patterns of occurrence of the disease varied in space and time (relative risk range 2.23 to 29.62) as well as in the causative serotypes and topotypes. Namwala district recorded the highest number of outbreaks with SAT 1 being the most predominant serotype in the district and across country (43.7 percent of the recorded outbreaks). And that agro-ecological zone, rainfall, distance away from buffalo migratory routes and international borders were significant factors of FMD occurrence. Furthermore, FMD animal seropositivity ranging from zero to 23 percent and transhumant husbandry practice as the main risk factor were identified. The study further isolated topotype II of SAT 2 from buffalo in Kafue National Park, a strain previously unknown to exist in Zambia. Furthermore, SAT 1 topotype I, closely related to the FMD outbreak virus of 2004/08, was isolated from vaccinated cattle in the livestock/wildlife interface of Monze and Lochnivar National Park. SAT 1 and SAT 2 were also isolated from buffalo in Lower Zambezi and Luambe National Parks. The FMD transmission model predicted an epidemic to peak by day 40 to 100 and die down by day 140 with an inter-epidemic period of nine to 23 years. The study provides significant elements of FMD epidemiology in Zambia including the spatial and temporal patterns, the subclinical infection and characterisation of circulating FMDV in cattle and buffalo at selected livestock/wildlife interface areas. Other elements included the carrier status in cattle, duration of epidemics and inter-epidemic periods. These elements may be considered in targeted risk surveillance, movement control, risk assessments and other disease prevention strategies at national and regional levels. Further work is recommended for better understanding of circulating FMDV in buffalo, carrier status in cattle within ecosystems and the role of livestock value chains in perpetuation of FMD outbreaks. Included is the optimization of the serological tests in use with antigens that are closely matched to the circulating field strains

Evaluation of immunomagnetic beads and loop mediated Isothermal amplification in detecting mycobacterium tuberculosis complex in Bovine Milk

Thu, 01 Jan 2015 00:00:00 GMT

Evaluation of immunomagnetic beads and loop mediated Isothermal amplification in detecting mycobacterium tuberculosis complex in Bovine Milk Mwape, Rosaline N. The study evaluated the use of immunomagnetic beads (IMB) in detecting Mycobacterium tuberculosis complex (MTC) in bovine milk. A total of 161 animals from traditional small scale farmers of Mphango and Itope areas of Chisamba and Rufunsa districts of Zambia were tested for tuberculosis using the comparative intradermal tuberculin skin test. Of the tested animals, 4 (2.5%, 95% CI=0.1%-4.9%) out of the 161 animals tested positive on tuberculin skin test and 12 (7.5%) showed inconclusive results. Furthermore, milk samples from the 161 animals were tested for tuberculosis (TB) using the immunomagnetic beads technique and, DNA from the captured cells was used as samples for the loop mediated isothermal amplification (LAMP) test. A total of 24 (14.9%, 95% CI= 9.4%-20.4%) animals tested positive on IMB-LAMP. This technique was also able to detect 12 (8.3%, 95% CI=3.8%-12.8%) animals that initially tested negative with the tuberculin skin test as positives. The twenty four (24) milk samples that tested positive on IMB-LAMP were further cultured on Lowenstein-Jensen media supplemented with Tween 80. Out of the 24 samples, 4 (16.7%, 95% CI=1.8%-31.6%) showed signs of Mycobacterium growth and were considered positive. The rest 20 (83.3%) did not grow and were considered negative. The suspected culture positives were confirmed by multiplex PCR as Mycobacterium bovis. The study has demonstrated that immunomagnetic beads can be used to capture MTC from milk of naturally infected animals and that the Mycobacterium can be isolated from milk samples of animals certified negative by the comparative intradermal tuberculin skin test. The study also demonstrated that the culturing technique, though regarded as a ‘Gold standard method’ need to be conducted alongside molecular tests. The study recommends the use of IMB-LAMP as a complementary diagnostic test for detecting Mycobacterium bovis besides the intradermal tuberculin skin test and the culture method. It further suggests that milk be considered as a diagnostic specimen for tuberculosis in animals. Further studies may be carried out to establish the minimum number of mycobacterial cells that can be captured by the beads in milk samples.

Extended spectrum beta-lactamase (ESBL) producing escherichia coli in poultry and water in Lusaka district

Thu, 01 Jan 2015 00:00:00 GMT

Extended spectrum beta-lactamase (ESBL) producing escherichia coli in poultry and water in Lusaka district Chishimba, Kennedy Extended Spectrum Beta-Lactamase are enzymes that hydrolyse the beta-lactam ring on most of the beta-lactam antibiotics which comprise of penicillins, cephalosporins, and the monobactam aztreonam thereby rendering the antibiotics ineffective to treatment. These antimicrobial resistant strains have become a global public health challenge affecting both humans and domestic livestock such as cattle, pork and poultry. In Lusaka, poultry is considered as a universal protein source consumed by a larger population of people. Coupled with this is a relatively increased number of shallow well water points located in various peri-urban communities within Lusaka district where part of the people access drinking water from. Antimicrobial resistant ESBL-producing Escherichia coli bacteria have been detected in some domestic poultry and shallow well water sources world over. In addition, the frequent usage and administering of antibiotics in the treatment of various diseases in poultry could contribute to the emergence of antimicrobial resistant E .coli strains in the normal intestinal flora. The objective of the research was to detect the presence of extended-spectrum β-lactamase (ESBL) producing E. coli in poultry and water in Lusaka district. This study was conducted in Lusaka district, the capital city of Zambia with a total population of 1,747,152. A total of 384 poultry faecal samples and 145 shallow well water samples were collected between September 2014 and March 2015 and later submitted for laboratory analysis by the Laboratory Technicians at the University of Zambia, School of Veterinary Medicine, Department of Paraclinical Studies, Microbiology Laboratory. Mapping of unprotected shallow wells was conducted using GPS and spatial distribution of ESBL producing E. coli isolates was determined. Seventy seven potential ESBL producing E. coli isolates were later characterized by polymerase chain reaction (PCR) for detection of ESBL genes and also tested for antimicrobial sensitivity. Overall 54.5% (95% CI; 43.2 – 65.5%) of total samples analyzed possessed ESBL genes, 42.9% for poultry and 11.6% for water. 85.7% (95% CI; 75.7 – 92%) of the total samples analyzed for antibmicrobial disc sensitivity suggested that ESBL producing E. coli isolates had conferred resistance to beta-lactum antibiotics and other common antimicrobial agents. The results obtained require strengthening and reinforcement of the antibiotic administering policy for poultry and surveillance on the emergence of antimicrobial resistance in other food animal products

Risk mapping and ECO-Anthropological assessment of anthrax in the upper Zambezi Basin

Thu, 01 Jan 2015 00:00:00 GMT

Risk mapping and ECO-Anthropological assessment of anthrax in the upper Zambezi Basin Kamboyi, Harvey Kakoma Anthrax is an acute and invariably fatal zoonotic disease affecting multi-species and caused by a bacteria, Bacillus anthracis. In Zambia, anthrax has emerged as a serious ecosystem disease resulting in mortalities across humans, livestock and wildlife. The disease has had devastating effects on tourism resulting in socio-economic destabilisation of three pristine wildlife sanctuaries, namely the upper Zambezi basin, the Lower Zambezi and the Luangwa valley. Preliminary trend analysis revealed sporadic annual outbreaks in the upper Zambezi basin. Consequently, the thrust of this study was to establish the spatial distribution of anthrax and determine ecological drivers of its recurrence, maintenance and epidemiological linkage to human activities in the study area. Particular emphasis was given to establish an epidemiological linkage between socio-cultural and economic activities of the inhabitants and the incidence of anthrax at ecosystem level. Environmental and biological samples were collected within the livestock production and conservation areas in upper Zambezi Basin (n=80). Questionnaires (n=113) and focused group interviews (n=4) were conducted at independently distinct villages in terms of space and time. Interviewees admitted consuming animals that died from anthrax and consequently suffered from the cutaneous form of anthrax. They were not aware of the fatal pulmonary and gastrointestinal forms of the disease. “Hunger for meat” was the main driver of consumption of anthrax carcasses. Dressing of anthrax where they lay contributed to environmental contamination with anthrax spores which was a major source of primary infection for livestock and wildlife. These anthropogenic activities together with lack of knowledge about anthrax strongly intimated their contribution to anthrax recurrence and maintenance in the upper Zambezi basin. From the samples analysed, fifteen (15) pure isolates of anthrax were obtained which were spatially distributed across four districts. Twelve, biologically plausible variables were found to be highly significant on multivariable logistic regression analysis model for questionnaires which included poor access to veterinary services (OR = 10.87; CI = 4.8-15.9; p ≤ 0.004), herd size (OR = 10.46; CI 8.8-16; p ≤ 0.005), anthrax carcass dressing (OR = 6.9; CI = 3.4-9.8; p ≤ 0.001 and management system (OR = 2.57; CI = 1.3-7.5; p ≤ 0.001). In summary, the majority (78.7%) of anthrax outbreaks were observed in areas with low veterinary services (χ2 = 8.6162, p ≤ 0.013) within the newly created districts of Nalolo, Mwandi and Luampa. This study has revealed that access to good quality veterinary services is critical in preventing anthrax outbreaks. We therefore highly recommend strengthening of veterinary and livestock extension services delivery and establishing a government anthrax surveillance programme for early detection, vaccination and decontamination of anthrax graves within the upper Zambezi basin. In that effect, there is need to embark on public health awareness campaigns aimed at promoting active participation of the general public in the control of anthrax in the identified hotspots and their surrounding areas.