Papers by Davies Pfukenyi
South African Journal of Botany, 2014
Background: Boophone disticha is commonly used in southern Africa for the management of mental-re... more Background: Boophone disticha is commonly used in southern Africa for the management of mental-related illnesses. Recently, it was shown to reduce blood pressure (BP) in maternally separated mice immediately after withdrawal of treatment. However, the long-term cardiovascular effects and the underlying mechanisms are still illusive. Based on the reputed traditional use of the plant for anxiety and stress-related disorders, the aqueous-ethanolic extract of B. disticha was screened for its long-term effects on the cardiovascular and autonomic responses to repeated acute stressors in adult early maternally separated BALB/c mice. Methods: Five groups (n = 6 each) of adult BALB/c mice subjected to early maternal separation (MS) were given six daily oral doses of vehicle (normal saline); low, medium and high doses of B. disticha (10, 25 and 40 mg/kg body weight, respectively); and 1 mg/kg body weight diazepam during adulthood. The control (un-separated) group (n = 6) received vehicle treatment. Cardiovascular parameters (BP and heart rate (HR)) were recorded using non-invasive tail-cuff methods on post-treatment days (PTDs) 9 and 30 to compare short-term and long-term effects of the plant extract, respectively. Autonomic responses were measured by estimating BP variability (BPV) and HR variability (HRV). Results: Early maternal separation significantly increased systolic BP (SBP), and decreased HR on PTD9 while raising BPV on PTD30 when compared to control un-separated mice (p b 0.05). B. disticha at low dose significantly reduced short-term SBP and mean arterial pressure (MAP), while medium dose reduced long-term diastolic BP (DBP) and MAP in maternally separated mice when compared to vehicle and diazepam (p b 0.05). High dose significantly decreased SBP and MAP at both occasions (p b 0.05). Conclusions: The current results have led to the identification of long-term antihypertensive-like activity of the aqueous ethanolic extract of B. disticha which was found to last for several weeks after withdrawal of treatment.
Diseases transmitted between wildlife and livestock may have significant impacts on local farmers... more Diseases transmitted between wildlife and livestock may have significant impacts on local farmers’ health, livestock health and productivity, overall national economies, and conservation initiatives, such as Transfrontier Conservation Areas in Southern Africa. However, little is known on local farmers’ awareness of the potential risks, and how they perceive the role played by wildlife in the epidemiology of these diseases.We investigated the knowledge base regarding livestock diseases of local cattle owners living at the periphery of conservation areas within the Great Limpopo TFCA and the Kavango-Zambezi TFCA in Zimbabwe, using free-listing and semi-structured questionnaires during dipping sessions. The results suggest that information related to cattle diseases circulates widely between cattle farmers, including between different socio-cultural groups, using English and vernacular languages. Most respondents had an accurate perception of the epidemiology of diseases affecting their livestock, and their perception of the potential role played by wildlife species was usually in agreement with current state of veterinary knowledge. However, we found significant variations in the cultural importance of livestock diseases between sites, and owners’ perceptions were not directly related with the local abundance of wildlife. As the establishment of TFCAs will potentially increase the risk of Transboundary Animal Diseases, we recommend an increased participation of communities at a local level in the prioritisation of livestock diseases control and surveillance, including zoonoses.
Tropical Animal Health and Production, 2011
A cross-sectional questionnaire-based study was conducted to assess milk producers' awareness of ... more A cross-sectional questionnaire-based study was conducted to assess milk producers' awareness of milkborne zoonoses in selected smallholder and commercial dairy farms of Zimbabwe. The questionnaire was designed to obtain information on dairy breeds, milk production, dairy farmers' knowledge and awareness of zoonoses with particular emphasis on milk-borne zoonoses and farmers' behavioural practices that may lead to increased risk of milk-borne zoonoses transmission. A total of 119 dairy farmers were interviewed, and 41.5% were aware of milkborne zoonoses with a significantly (P <0.01) higher percentage of commercial dairy farmers (65.0%) being aware compared to smallholder dairy farmers (36.7%). The behavioural practices of dairy farmers observed to increase the risk of milk-borne zoonoses transmission were; consumption of raw milk (68.1%), sale of raw milk to the local public (25.2%), lack of cooling facilities by smallholder farmers (98%), and no routine testing (84.9%) and medical check-ups (89.1%) for milk-borne zoonoses. General hygienic and disease control practices need to be integrated in the milk production process particularly at the smallholder level. Awareness, teaching and training programmes for smallholder dairy farmers can improve disease control in animals and reduce the public health risk of milk-borne zoonoses.
Tropical Animal Health and Production, 2012
This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to ... more This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to identify risk areas in Zimbabwe. The data were extracted from the monthly and annual reports of the Division of Livestock Production and Veterinary Services for the period 1967 to 2006. The data were analyzed in relation to temporal and spatial factors. The hot-dry season was found to be significantly (X 2 =847.8, P<0.001) associated with the occurrence of anthrax in cattle, and the disease was found to be approximately three times more likely to occur during this season compared to other seasons. Anthrax outbreaks demonstrated a gradual temporal increase from an annual mean of three outbreaks for the 5-year period (1967)(1968)(1969)(1970)(1971) to 42 for the 5-year period (2002)(2003)(2004)(2005)(2006). Similarly, the data demonstrated a spatial increase in the number of districts affected by anthrax between 1967 and 2006, with 12 districts affected for the 10-year period (1967-1976) that expanded to 42 districts for the 10-year period (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006). The majority of outbreaks (83.7%) were recorded in rural areas, and 11 districts were found to be at a higher risk than others. There is need to develop differential vaccination strategy, other control strategies and preventive recommendations to reduce anthrax in high-risk districts. In the medium-to low-risk districts, maintenance of effective surveillance systems and improve-ment of awareness is very important to detect and contain outbreaks early.
Onderstepoort J Vet Res, 2013
Vector-Borne and Zoonotic Diseases, 2013
We conducted a cross-sectional study to assess cattle owners' awareness, perceptions, and attitud... more We conducted a cross-sectional study to assess cattle owners' awareness, perceptions, and attitudes toward zoonoses, with particular emphasis regarding anthrax. Data on awareness of zoonoses, clinical signs of anthrax in animals and human, its routes of transmission and methods of prevention, the families' consumption habits of anthrax-infected carcasses, and other family activities that increase exposure to anthrax were collected using an interviewer-administered questionnaire. A total of 41.4% (135/326) of the farmers were from high-anthrax-risk districts, whereas 28.5% and 30.1% were from medium-and low-risk districts, respectively. Overall, the level of awareness amongst the farmers for the named zoonoses were rabies (88.7%), anthrax (71.5%), and brucellosis (20.9%). Except for anthrax, awareness of other zoonoses did not differ significantly ( p > 0.05) among the district categories. Farmers from anthrax high-risk districts were significantly more aware of anthrax compared to those from moderate-( p = 0.000) and low-( p = 0.000) risk districts. All of the farmers were aware that anthrax occurs in cattle, and 73% indicated the presence of unclotting blood oozing from natural orifices as a consistent finding in cattle that died of anthrax, whereas 86.7% of them indicated the presence of skin lesions as the most common sign of the disease in humans. The good efficacy of human anthrax treatment (58.3%), slaughter of moribund cattle and selling of meat from cattle found dead to unsuspecting consumers (59.8%), reluctance to lose animals (47.9%), and forgetting about anthrax (41.1%) were cited as the major reasons for consuming anthrax-infected carcasses. Given that 75.2% of cattle owners indicated that they would not consume meat from cattle found dead, because they were discouraged by veterinary authorities, introducing meat inspection services is likely to have a positive impact in preventing human anthrax outbreaks in Zimbabwe.
PFUKENYI, D.M., MUKARATIRWA, S., WILLINGHAM, A.L. & MONRAD, J. 2007. Epidemiological studies of p... more PFUKENYI, D.M., MUKARATIRWA, S., WILLINGHAM, A.L. & MONRAD, J. 2007. Epidemiological studies of parasitic gastrointestinal nematodes, cestodes and coccidia infections in cattle in the high- veld and lowveld communal grazing areas of Zimbabwe. Onderstepoort Journal of Veterinary Re- search, 74:129-142 Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and
Vector-Borne and Zoonotic Diseases, 2013
We conducted a cross-sectional study to assess cattle owners' awareness, perceptions, and attitud... more We conducted a cross-sectional study to assess cattle owners' awareness, perceptions, and attitudes toward zoonoses, with particular emphasis regarding anthrax. Data on awareness of zoonoses, clinical signs of anthrax in animals and human, its routes of transmission and methods of prevention, the families' consumption habits of anthrax-infected carcasses, and other family activities that increase exposure to anthrax were collected using an interviewer-administered questionnaire. A total of 41.4% (135/326) of the farmers were from high-anthrax-risk districts, whereas 28.5% and 30.1% were from medium-and low-risk districts, respectively. Overall, the level of awareness amongst the farmers for the named zoonoses were rabies (88.7%), anthrax (71.5%), and brucellosis (20.9%). Except for anthrax, awareness of other zoonoses did not differ significantly ( p > 0.05) among the district categories. Farmers from anthrax high-risk districts were significantly more aware of anthrax compared to those from moderate-( p = 0.000) and low-( p = 0.000) risk districts. All of the farmers were aware that anthrax occurs in cattle, and 73% indicated the presence of unclotting blood oozing from natural orifices as a consistent finding in cattle that died of anthrax, whereas 86.7% of them indicated the presence of skin lesions as the most common sign of the disease in humans. The good efficacy of human anthrax treatment (58.3%), slaughter of moribund cattle and selling of meat from cattle found dead to unsuspecting consumers (59.8%), reluctance to lose animals (47.9%), and forgetting about anthrax (41.1%) were cited as the major reasons for consuming anthrax-infected carcasses. Given that 75.2% of cattle owners indicated that they would not consume meat from cattle found dead, because they were discouraged by veterinary authorities, introducing meat inspection services is likely to have a positive impact in preventing human anthrax outbreaks in Zimbabwe.
Onderstepoort Journal of Veterinary Research, 2012
Brucellosis is an endemic disease in Zimbabwe caused by the genus Brucella. Brucella seroprevalen... more Brucellosis is an endemic disease in Zimbabwe caused by the genus Brucella. Brucella seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate Brucella species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of Brucella species from whole blood (n = 18) and milk samples (n = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzymelinked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. Brucella abortus was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The Brucella-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that B. abortus is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.
Vector-Borne and Zoonotic Diseases, 2011
The study was aimed at determining the seasonal abundance of Xenopsylla brasiliensis, an importan... more The study was aimed at determining the seasonal abundance of Xenopsylla brasiliensis, an important vector of plague in Zimbabwe, from rodent hosts captured in selected habitat types of two periurban suburbs of Harare, Zimbabwe. The removal-trapping method was used to capture the rodents, from which fleas were collected and identified. Percentage incidence index (PII) and specific flea index (SFI) were calculated for X. brasiliensis in relation to rodent species host. Mastomys natalensis, Rattus rattus, Tatera leucogaster, and Rhabdomys pumilio were the rodent species present in the study areas and all species were infested with X. brasiliensis. PII for T. leucogaster in relation to X. brasiliensis was significantly higher (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) compared with that of the other rodent species and T. leucogaster also recorded the highest SFI, whereas R. pumilio recorded the lowest indices. In both formal and informal settlements, the highest PII of X. brasiliensis was attained for M. natalensis, followed by R. rattus. In the cultivated habitat, T. leucogaster recorded the highest indices and R. pumilio the lowest. X. brasiliensis was found to cohabitat with Dinopsyllus lypusus and Ctenophthalmus calceatus on M. natalensis, R. rattus, and T. leucogaster. No cohabitation was recorded for R. pumilio. For all the rodent species captured, both the PII and SFI of X. brasiliensis were highest during the hot-dry season, followed by the hot-wet season, with the cold-dry season recording the lowest indices. The overall cohabitation was highest during the hot-dry season and lowest during the hot-wet season. The findings of the present study fit the reported occurrence of plague outbreaks during the hot-dry season in periurban Zimbabwe.
Tropical Animal Health and Production, 2012
A cross-sectional study was conducted to determine the seroprevalence of bovine brucellosis in co... more A cross-sectional study was conducted to determine the seroprevalence of bovine brucellosis in communal cattle and wildlife at a wildlife-livestock interface in the southeast lowveld of Zimbabwe, part of the Great Limpopo Transfrontier Conservation Area. RBT and c-Elisa were used in serial for detection of antibodies against Brucella spp. Between a total of 1,158 cattle were tested and the overall seroprevalence of brucellosis was 9.9%. A total of 97 wild animals (African buffaloes (n=47), impala (n=33), kudu (n=16), and giraffe (n=1)) were tested and only one animal (giraffe) was seropositive for brucellosis (1.03%). Brucella seroprevalence showed an increasing trend with age, with adult cattle (>6 years) recording the highest seroprevalence (11.1%), but the differences were not statistically significant. Similarly, female cattle recorded a relatively higher seroprevalence (10.8%) compared to males (7.9%), but the difference was not significant. However, a significant (P<0.001) association between Brucella seropositivity and abortion history was recorded in female cattle. Similarly, Brucella seropositivity was significantly (P<0.01) associated with a history of grazing in the park for female cattle. Overall, from the interface area, cattle with a history of grazing in the park recorded a significantly (P<0.01) higher Brucella seroprevalence (13.5%) compared to those with no history of grazing in the park (4.9%). The significant association between abortion history and seropositivity observed in this study illustrates the potential economic significance of Brucella in cattle in this area. Hence, public awareness and further epidemiological studies of the disease in wildlife, livestock, and humans in the study area are of great importance.
Tropical Animal Health and Production, 2012
This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to ... more This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to identify risk areas in Zimbabwe. The data were extracted from the monthly and annual reports of the Division of Livestock Production and Veterinary Services for the period 1967 to 2006. The data were analyzed in relation to temporal and spatial factors. The hot-dry season was found to be significantly (X 2 =847.8, P<0.001) associated with the occurrence of anthrax in cattle, and the disease was found to be approximately three times more likely to occur during this season compared to other seasons. Anthrax outbreaks demonstrated a gradual temporal increase from an annual mean of three outbreaks for the 5-year period (1967)(1968)(1969)(1970)(1971) to 42 for the 5-year period (2002)(2003)(2004)(2005)(2006). Similarly, the data demonstrated a spatial increase in the number of districts affected by anthrax between 1967 and 2006, with 12 districts affected for the 10-year period (1967-1976) that expanded to 42 districts for the 10-year period (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006). The majority of outbreaks (83.7%) were recorded in rural areas, and 11 districts were found to be at a higher risk than others. There is need to develop differential vaccination strategy, other control strategies and preventive recommendations to reduce anthrax in high-risk districts. In the medium-to low-risk districts, maintenance of effective surveillance systems and improve-ment of awareness is very important to detect and contain outbreaks early.
Tropical Animal Health and Production, 2009
To assess the epidemiological features of wildlife rabies in Zimbabwe, a retrospective study cove... more To assess the epidemiological features of wildlife rabies in Zimbabwe, a retrospective study covering a period of 12 years (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003) was conducted using rabies records of the Central Veterinary Laboratories (CVL), Department of Veterinary Technical Services at Harare. Records of monthly and annual wildlife rabies were perused with regard to total samples submitted to the CVL and corresponding positive cases. Positive cases were analyzed in relation to the animal species involved, seasonal trends, and land-use categories. A total of 2107 samples were submitted and 1 540 (73.1%) were positive. Jackals (Canis mesomelas and C. adustus), with a peak occurrence of rabies between January and March were the major maintenance host, representing approximately 91% of the total rabies cases confirmed. The Canidae family recorded the highest number of cases followed by the Viverridae, Mustelidae, Felidae, Herpestidae and Hyaenidae families in that order. During the present study rabies cases were confirmed in 7 additional wild animals. The majority of the positive cases (83.7%) were recorded in commercial farming areas in the northeast parts of the country.
Tropical Animal Health and Production, 2011
A cross-sectional questionnaire-based study was conducted to assess milk producers' awareness of ... more A cross-sectional questionnaire-based study was conducted to assess milk producers' awareness of milkborne zoonoses in selected smallholder and commercial dairy farms of Zimbabwe. The questionnaire was designed to obtain information on dairy breeds, milk production, dairy farmers' knowledge and awareness of zoonoses with particular emphasis on milk-borne zoonoses and farmers' behavioural practices that may lead to increased risk of milk-borne zoonoses transmission. A total of 119 dairy farmers were interviewed, and 41.5% were aware of milkborne zoonoses with a significantly (P <0.01) higher percentage of commercial dairy farmers (65.0%) being aware compared to smallholder dairy farmers (36.7%). The behavioural practices of dairy farmers observed to increase the risk of milk-borne zoonoses transmission were; consumption of raw milk (68.1%), sale of raw milk to the local public (25.2%), lack of cooling facilities by smallholder farmers (98%), and no routine testing (84.9%) and medical check-ups (89.1%) for milk-borne zoonoses. General hygienic and disease control practices need to be integrated in the milk production process particularly at the smallholder level. Awareness, teaching and training programmes for smallholder dairy farmers can improve disease control in animals and reduce the public health risk of milk-borne zoonoses.
Tropical Animal Health and Production, 2010
A cross-sectional questionnaire-based survey was carried out in Harare to assess pet ownership an... more A cross-sectional questionnaire-based survey was carried out in Harare to assess pet ownership and public awareness with regard to pet zoonoses. The questionnaire was designed to obtain information on pet ownership, health and welfare of pets, pet owners' knowledge and awareness of pet zoonoses with particular emphasis on hookworms and roundworms. The results demonstrated that the proportion of pet owners who knew helminths as zoonoses in dogs (21.3%) and cats (1.1%) was low compared to rabies (95.7%) with ancylostomosis (4.3%) and toxocariosis (2.1%) being the specific parasitic zoonoses known to occur in dogs and toxoplasmosis (2.1%) in cats. More than 50% of the pet owners indicated that veterinarians never discussed the potential hazards of zoonoses or discussed it only when asked and 33% indicated that veterinarians initiated discussion of the subject whenever zoonoses were diagnosed in pets. Over 90% of the pet owners indicated that veterinarians should discuss zoonoses with them. Further investigations are necessary to determine the current prevalence of intestinal nematode infections in dogs and cats in the various regions of the country.
Journal of the South African Veterinary Association, 2014
Preventive Veterinary Medicine, 2013
Anthrax continues to cause significant mortalities in livestock, wildlife and humans worldwide. I... more Anthrax continues to cause significant mortalities in livestock, wildlife and humans worldwide. In Zimbabwe, anthrax outbreaks have been reported almost annually over the past four decades. In this study we tested whether anthrax outbreak data and a set of environmental variables can be used to predict the ecological niche for Bacillus anthracis using maximum entropy modelling for species geographical distribution (Maxent). Confirmed geo-referenced anthrax outbreaks data for the period 1995-2010 were used as presence locations and a set of environmental parameters; precipitation, temperature, vegetation biomass, soil type and terrain as predictor variables. Results showed that the environmental variables can adequately predict the ecological niche of B. anthracis (AUC for test data=0.717, p&lt;0.001), with soil type as the most important predictor followed by variance of vegetation biomass and maximum temperature. These results imply that the model we tested may be used by animal health authorities in devising better control strategies for anthrax.
Onderstepoort Journal of Veterinary Research, 2012
Onderstepoort J Vet Res, 2013
In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemio... more In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. Nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in Zimbabwe. The main genera reported to date are Cooperia, Haemonchus, Trichostrongylus and Oesophagostomum and the dominant species are Cooperia pectinata, Cooperia punctata, Haemonchus placei and Trichostrongylus axei. The mixed infection by several species from the genera is the cause of parasitic gastroenteritis in cattle in Zimbabwe. Production and husbandry practices, season, host age and environment are considered to be the main factors that influence gastrointestinal nematode infection in cattle. The geographical distribution of the gastrointestinal nematodes is also reviewed in relation to the climatic conditions of the country. Various control options are discussed and how they are applicable to the Zimbabwean situation. Based on reports and existing data on the epidemiological features of the gastrointestinal nematode infection in cattle, practical control measures are critically reviewed and recommendations are made for a national control programme.
Journal of Applied Microbiology, 2012
Aims: To isolate Bacillus anthracis from cattle carcass burial sites from highrisk districts in Z... more Aims: To isolate Bacillus anthracis from cattle carcass burial sites from highrisk districts in Zimbabwe. Methods and Results: Soil samples were collected from carcass burial sites from seven areas, including two national game parks. Samples were collected from top 5-10 cm, and for spore extraction, 25 g of soil was suspended in sterile distilled water overnight. Supernatants were filtered through 0Á45-lm pore cellulose nitrate, deposits suspended in 5 ml phosphate-buffered saline, aliquoted and heated at temperature regimen of 65, 70, 75 and 80°C for 15 min. Samples were plated onto PLET agar. B. anthracis isolates were identified using growth morphology and PCR detecting pXO1 and pXO2 virulence plasmids. From samples heated at 75°C for 15 min, B. anthracis were isolated from 9 of 81 (11Á1%) soil samples representing five of the seven sampled areas. Conclusions: We isolated B. anthracis from soil collected from carcass burial sites. PCR targeting virulence plasmids provided a rapid confirmation of B. anthracis. Significance and Impact of the study: The positive isolation indicated that some carcass burial sites may retain viable spores for at least 12 months after the previous outbreak, which suggests that they may be important sources of B. anthracis and new disease outbreaks.
Uploads
Papers by Davies Pfukenyi