RESUMO
Through a collaborative effort across six Sub-Saharan African countries, using recognized international assessment techniques, 23 stocks of three tick species (Rhipicephalus microplus, Rhipicephalus appendiculatus and Amblyomma variegatum) of economic importance for rural small holder farming communities from East and West Africa were collected from cattle, and evaluated in in vitro larval packet tests (LPT). The results demonstrated medium to high resistance to chlorfenvinphos and amitraz across species. Rhipicephalus microplus demonstrated high level alpha-cypermethrin and cypermethrin resistance. Stocks of A. variegatum (West Africa) and R. appendiculatus (Uganda) demonstrated medium level ivermectin resistance. The four least susceptible stocks (East and West African R. microplus, A. variegatum and R. appendiculatus) were taken into in vivo controlled cattle studies where fipronil was found effective against West and East African R. microplus isolates although persistent efficacy failed to reach 90%. Cymiazole and cypermethrin, and ivermectin based acaricides were partially effective against R. microplus without persistent efficacy. Flumethrin spray-on killed A. variegatum within 72 h for up to 10 days posttreatment, however product application was directly to tick attachment sites, which may be impractical under field conditions. A flumethrin pour-on formulation on goats provided persistent efficacy against A. variegatum for up to one-month. Therapeutic control was achieved against R. appendiculatus through weekly spraying cattle with flumethrin, amitraz or combined cymiazole and cypermethrin. A fipronil pour-on product offered four-week residual control against R. appendiculatus (with slow onset of action). Few studies have assessed and directly compared acaricidal activity in vitro and in vivo. There was some discordance between efficacy indicated by LPT and in vivo results. This observation calls for more research into accurate and affordable assessment methods for acaricide resistance. No single active or product was effective against all three tick species, emphasising the need for the development of alternative integrated tick management solutions.
Assuntos
Acaricidas , Doenças dos Bovinos , Resistência a Medicamentos , Rhipicephalus , Infestações por Carrapato , Animais , Acaricidas/farmacologia , Bovinos , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/veterinária , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/parasitologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/tratamento farmacológico , África Ocidental , Gado/parasitologia , Amblyomma/efeitos dos fármacos , Larva/efeitos dos fármacos , Piretrinas/farmacologia , Controle de Ácaros e Carrapatos/métodosRESUMO
BACKGROUND: The majority of the African population lives in rural areas and depends on agriculture for their livelihoods. To increase the productivity and sustainability of their farms, they need access to affordable yield-enhancing inputs of which parasite control is of paramount importance. We therefore determined the status of current tick species with the highest economic impact on cattle by sampling representative numbers of animals in each of seven sub-Saharan countries. METHODS: Data included tick species' half-body counts from approximately 120 cattle at each of two districts per country, collected four times in approximately 1 year (to include seasonality). Study sites were chosen in each country to include high cattle density and tick burden. RESULTS: East Africa (Ethiopia, Uganda and Tanzania) showed overall a higher diversity and prevalence in tick infestations compared to West African countries (Benin, Burkina Faso, Ghana and Nigeria). In East Africa, Amblyomma variegatum (vector of Ehrlichia ruminantium), Rhipicephalus microplus (Babesia bovis, B. bigemina, Anaplasma marginale), R. evertsi evertsi (A. marginale) and R. appendiculatus (Theileria parva) were the most prevalent tick species of economic importance. While the latter species was absent in West Africa, here both A. variegatum and R. microplus occurred in high numbers. Rhipicephalus microplus had spread to Uganda, infesting half of the cattle sampled. Rhipicephalus appendiculatus is known for its invasive behaviour and displacement of other blue tick species, as observed in other East and West African countries. Individual cattle with higher body weights, as well as males, were more likely to be infested. For six tick species, we found reduced infestation levels when hosts were treated with anti-parasiticides. CONCLUSIONS: These baseline data allow the determination of possible changes in presence and prevalence of ticks in each of the countries targeted, which is of importance in the light of human-caused climate and habitat alterations or anthropogenic activities. As many of the ticks in this study are vectors of important pathogens, but also, as cattle may act as end hosts for ticks of importance to human health, our study will help a wide range of stakeholders to provide recommendations for tick infestation surveillance and prevention.
Assuntos
Doenças dos Bovinos , Rhipicephalus , Infestações por Carrapato , Doenças Transmitidas por Carrapatos , Humanos , Masculino , Animais , Bovinos , Gado , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Doenças Transmitidas por Carrapatos/parasitologia , Doenças dos Bovinos/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Infestações por Carrapato/parasitologia , Uganda/epidemiologia , Burkina FasoRESUMO
We previously reported the emergence of amitraz-resistant Rhipicephalus (Boophilus) decoloratus ticks in the western region of Uganda. This study characterized the octopamine/tyramine receptor gene (OCT/Tyr) of amitraz-resistant and -susceptible R. (B.) decoloratus ticks from four regions of Uganda. The OCT/Tyr gene was amplified from genomic DNA of 17 R. (B.) decoloratus larval populations of known susceptibility to amitraz. The amplicons were purified, cloned and sequenced to determine mutations in the partial coding region of the OCT/Tyr gene. The amplified R. (B.) decoloratus OCT/Tyr gene was 91-100% identical to the R. (B.) microplus OCT/Tyr gene. Up to 24 single nucleotide polymorphisms (SNPs) were found in the OCT/Tyr gene from ticks obtained from high acaricide pressure areas, compared to 8 from the low acaricide pressure areas. A total of eight amino acid mutations were recorded in the partial OCT/Tyr gene from ticks from the western region, and four of them were associated with amitraz-resistant tick populations. The amino acid mutations M1G, L16F, D41G and V72A were associated with phenotypic resistance to amitraz with no specific pattern. Phylogenetic analysis revealed that the OCT/Tyr gene sequence from this study clustered into two distinct groups that separated the genotype from high acaricide pressure areas from the susceptible populations. In conclusion, this study is the first to characterize the R. (B.) decoloratus OCT/Tyr receptor gene and reports four novel amino acid mutations associated with phenotypic amitraz resistance in Uganda. However, lack of mutations in the ORF of the OCT/Tyr gene fragment for some of the amitraz-resistant R. (B.) decoloratus ticks could suggest that other mechanisms of resistance may be responsible for amitraz resistance, hence the need for further investigation.
RESUMO
Background: Despite the investments made in veterinary diagnostic laboratory service delivery in Uganda, the scope and level of utilization remains low. This study aimed to determine the priority livestock diseases for which farmers and animal health professionals require veterinary diagnostic laboratory services, document the perceptions and opinions of key stakeholders on veterinary diagnostic laboratory services, and determine the factors that influence the delivery and utilization of animal disease diagnostic services in Uganda. Methods: A qualitative study approach involving a survey and key informant interviews was used to collect relevant data from four stakeholder groups: animal health workers, laboratory technologists and technicians, farmers, and key informants. The survey data were exported to excel, and descriptive statistics performed. The key informant interview recordings were transcribed, and thematic analysis performed. Results: The most reported diseases and conditions for which diagnostic services were needed were hemoparasites (including East Coast fever, anaplasmosis, babesiosis, and trypanosomosis), viral (including Foot and mouth disease, lumpy skin disease, rift valley fever, and papillomatosis), bacteria (including brucellosis, colibacillosis, anthrax, leptospirosis, and paratuberculosis) and protozoa diseases (coccidiosis), endoparasites (helminths), and mastitis. The most common diagnostic laboratory tests requested by clients, but laboratories were unable to provide included: rapid tests for contagious bovine pleuropneumonia, Foot and mouth disease, Newcastle disease, acaricide analysis, culture and antimicrobial sensitivity test, serology, and complete blood count. The most frequently reported challenges to providing diagnostic laboratory services were poor or lack of relevant equipment, insufficient or lack of supplies and reagents, high cost of reagents, inadequate or lack of laboratory staff to perform tests, and inadequate training of laboratory staff. Conclusions: This study highlighted the need to improve provision of laboratory diagnostic services to meet the prioritized diagnostic needs of farmers and animal health professionals. Increased intersectoral engagement and funding support from the private, industry, and government sectors is necessary to help address the observed challenges to provision of diagnostic laboratory services, including equipping of the laboratories, provision of supplies, and hiring and training of laboratory staff. Finally, the findings also suggest that the education of farmers and animal health workers on the value and benefits of laboratory diagnostic services may contribute to increase in sample submission and subsequent demand for diagnostic laboratory services.
RESUMO
In Uganda, ticks and tick-borne diseases (TBDs) pose a big challenge to farmers. They reduce cattle productivity and cause severe economic damage. Several studies have documented the prevalence of tick-borne pathogens in cattle; however, their genetic characteristics and the role of wildlife-livestock interaction in the epidemiology of the TBDs are not well documented. This study assessed the prevalence and genetic diversity of various tick-borne pathogens (TBPs) as well as the risk factors associated with the occurrence of TBPs in blood samples of 208 randomly selected cattle from 16 farms located around Queen Elizabeth National Park (QENP) in Kasese District in western Uganda. Farming practices, disease challenges, and the level of wildlife-livestock interactions were assessed by a questionnaire survey amongst farm owners. Polymerase chain reaction (PCR) assays revealed that 62.9% (131/208) cattle samples were positive for one or more pathogens. Using specific PCR assays, we detected Theileria spp., Theileria parva, Anaplasma marginale, Anaplasma platys-like, and Babesia bigemina at 50.5%, 27.9%, 19.2%, 11.5% and 8.7%, respectively. We also confirmed the infection of samples by Theileria velifera and Theileria mutans after sequencing the Theileria spp. 18S rRNA gene. The risk factors associated with the occurrence of TBPs included communal grazing, herd size, age, and proximity to QENP. Phylogenetic analysis of the T. parva p104 gene showed a high identity to the previous isolates from Uganda and other East African countries and clustered closer to the buffalo (Syncerus caffer) isolates, suggesting a possible cross-species transmission. The sequences of A. marginale groEL and B. bigemina RAP-1a formed well-supported clades with high identities to the previous isolates identified from central and eastern Uganda. The isolates obtained from A. phagocytophilum 16S rRNA gene sequences showed relationship with A. platys-like, Anaplasma sp., uncultured Anaplasma species and A. phagocytophilum isolates from Africa, Asia, Europe, and the USA. The findings of the present study showed that TBDs are still a burden to farmers and that management practices in this area may increase the transmission of pathogens between livestock and wildlife.
Assuntos
Doenças dos Bovinos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Variação Genética , Parques Recreativos , Prevalência , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Uganda/epidemiologiaRESUMO
Ticks and tick-borne diseases are major impediments to livestock production. To date, there have been several studies on the prevalence of tick-borne pathogens (TBPs) in cattle, but very few studies have documented TBPs in goats in Uganda. In this study, polymerase chain reaction assays and sequence analysis of different molecular markers were used to assess the presence and genetic characteristics of TBPs in 201 goats from Kasese district in western Uganda. The risk factors associated with TBP infections were also analyzed. We detected Theileria spp. (13.4%), Anaplasma phagocytophilum (10.9%), Anaplasma ovis (5.5%), Babesia ovis (5.5%), and Ehrlichia ruminantium (0.5%). The sequences of B. ovis ssu rRNA and A. ovismsp4 genes showed some degree of diversity among the parasite isolates in this study. The E. ruminantium pCS20 sequence formed a well-supported clade with isolates from Amblyomma variegatum ticks from Uganda. Wildlife interaction, sampling location, low body condition score, tick infestation, and herd size were significantly associated with TBP infections in the goats. The findings in this study provide important information on the epidemiology of tick-borne pathogens in Uganda, and show that goats could be potential reservoirs for tick-borne pathogens.
RESUMO
Hemoplasmas (hemotropic mycoplasmas) are small pleomorphic bacteria that parasitize the surface of red blood cells of several mammalian species including cattle, goats, and humans, causing infectious anemia. However, studies on hemoplasmas have been neglected and to date, there are no studies on bovine and caprine hemoplasmas in Uganda or the entire East African region. In this study, a polymerase chain reaction (PCR) assay targeting the 16S rRNA gene was used to investigate the presence of hemoplasma in 409 samples (cattle = 208; goats = 201) collected from Kasese district, western Uganda. Results showed that 32.2% (67/208) of cattle samples and 43.8% (88/201) of goat samples were positive for hemoplasmas. Sequencing analysis identified Candidatus Mycoplasma haemobos and Mycoplasma wenyonii in cattle, while Candidatus Mycoplasma erythrocervae and Mycoplasma ovis were identified in goats. Statistical analysis showed that goats were at a higher risk of infection with hemoplasmas compared with cattle. To the best of our knowledge, this is the first molecular evidence of hemoplasmas in bovine and caprine animals in Uganda and the entire east African region.
RESUMO
Uganda has experienced tick acaricide resistance in the livestock sector. With increase in incidence of tick-borne diseases (TBDs), use of antibiotics for control of TBDs and other opportunistic diseases has raisedserious concerns. The purpose of this study was to compare the farmers' tick control and antibiotic use practices on farms in regions of low (LARA) and high (HARA) tick acaricide resistance in Uganda, determine the prevalence of antibiotic residues in milk from both regions, and identify factors associated with antibiotic residues in milk. One representative district was selected from each region from which 10 farms were randomly selected. Delvotest SP-NT® test kit was used to detect antibiotic residues in milk. Half-body tick counts and acaricide efficacy tests were performed. Majority (70%) of HARA's respondents reported a corresponding increase in a monthly incidence of TBDs with an average of 3.2 cases of TBDs treated per farm compared to 0.2 cases in LARA. East Coast fever (ECF) was identified as the most common TBD in both regions, though cases of coinfection were more common in HARA. Half of HARA's respondents reported a corresponding increase in the use of antibiotics on their farms due to tick resistance compared to LARA. Antibiotics were the most used drugs on farms in both regions with oxytetracycline being the commonly used antibiotic. Ticks from HARA were resistant to deltamethrin, amitraz, and coformulation (chlorpyriphos and cypermethrin) while resistance against deltamethrin was confirmed in LARA. HARA farms had a significantly higher prevalence of antibiotic residues (21.25%) in raw milk than in LARA (4%) farms (p < 0.05). Acaricide resistance and practice of reading drug use instructions were significantly associated with antibiotic residues in milk at farm level. Overall, the study provides vital information linking acaricide resistance to antibiotic use practices, consequently leading to antibiotic residues in milk.
RESUMO
Chemical tick control is a major means of preventing East Coast fever (ECF), especially in sub-Saharan Africa. However, in southwestern Uganda, improper tick control practices have led to severe acaricide resistance. The objectives of this study were to determine the risk factors associated with tick infestation in dairy cattle and Theileria parva infection, and to generate evidence for the prioritization of effective countermeasures for tick control. A cross-sectional study was conducted in 30 farms in Mbarara District, and information on tick control practices and tick infestation were collected. Tick samples were collected from 13 farms to test tick acaricide efficacy. A total of 420 blood samples from calves to adults of exotic- and cross-breed dairy cattle were collected, and T. parva diagnosis via polymerase chain reaction was performed. All the 13 tick populations tested were resistant to deltamethrin (synthetic pyrethroid). Resistance to single-formulation organophosphate-chlorfenvinphos was 39 % (5/13); co-formulations (chlorpyrifos + cypermethrin), 69 % (9/13); and amitraz (amidine), 85 % (11/13). The overall prevalence of T. parva infection at the individual-level was 45.2 % (190/420, 95 % confidence interval (CI): 40.4-50.1), and that at the farm-level was 83 % (25/30, 95 %CI: 65-94). A good quality cattle crush was a preventive factor for tick infestation (odds ratio (OR): 0.32, 95 %CI: 0.15-0.63, pâ¯=⯠0.001). Well-managed acaricide storage (OR: 0.36, 95 %CI: 0.17-0.76, pâ¯=⯠0.008), and a good quality measuring cylinder for acaricide were preventive factors (OR: 0.32, 95 %CI: 0.11-0.93, pâ¯=â¯0.036) for T. parva infection. The risk factors for T. parva infection were a longer period of acaricide use of the same brand (OR: 1.06, 95 %CI: 1.01-1.10, pâ¯=â¯0.012), and a higher frequency (twice a week) of acaricide use rather than once a week (OR: 11.70, 95 %CI: 1.95-70.13, pâ¯=â¯0.007). These risk factors should be given high intervention priority in order to effectively control ticks and prevent T. parva infections in dairy farms. Teaching proper practices to dairy farmers and to technical staff should be used to overcome the severe challenge of acaricide resistance in Mbarara District.
Assuntos
Theileria parva/fisiologia , Theileriose/epidemiologia , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Animais , Bovinos , Estudos Transversais , Indústria de Laticínios , Feminino , Fatores de Risco , Theileriose/parasitologia , Theileriose/prevenção & controle , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Uganda/epidemiologiaRESUMO
BACKGROUND: Rhipicephalus microplus, an invasive tick species of Asian origin and the main vector of Babesia species, is considered one of the most widespread ectoparasites of livestock. The tick has spread from its native habitats on translocated livestock to large parts of the tropical world, where it has replaced some of the local populations of Rhipicephalus decoloratus ticks. Although the tick was reported in Uganda 70 years ago, it has not been found in any subsequent surveys. This study was carried out to update the national tick species distribution on livestock in Uganda as a basis for tick and tick-borne disease control, with particular reference to R. microplus. METHODS: The study was carried out in Kadungulu, Serere district, south-eastern Uganda, which is dominated by small scale livestock producers. All the ticks collected from 240 cattle from six villages were identified microscopically. Five R. microplus specimens were further processed for phylogenetic analysis and species confirmation. RESULTS: The predominant tick species found on cattle was Rhipicephalus appendiculatus (86.9 %; n = 16,509). Other species found were Amblyomma variegatum (7.2 %; n = 1377), Rhipicephalus evertsi (2.3 %; n = 434) and R. microplus (3.6 %; n = 687). Phylogenetic analysis of the 12S rRNA, 16S rRNA and ITS2 gene sequences of R. microplus confirmed the morphological identification. CONCLUSIONS: It is concluded that R. microplus has replaced R. decoloratus in the sampled villages in Kadungulu sub-county, since the latter was not any longer found in this area. There is currently no livestock movement policy in force in Uganda, which could possibly limit the further spread of R. microplus ticks. Future surveys, but also retrospective surveys of museum specimens, will reveal the extent of distribution of R. microplus in Uganda and also for how long this tick has been present on livestock without being noticed.
Assuntos
Doenças dos Bovinos/parasitologia , Filogenia , Rhipicephalus/anatomia & histologia , Rhipicephalus/genética , Infestações por Carrapato/veterinária , Animais , Babesia , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Gado/parasitologia , Masculino , RNA Ribossômico/genética , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Carrapatos/anatomia & histologia , Carrapatos/classificação , Uganda/epidemiologiaRESUMO
A cross-sectional study was conducted to investigate the risk factors for sub-clinical mastitis (SCM) in Mbarara District, an intensive dairy production region of Uganda where hand-milking is dominant. In 30 farms, herd-level milking practices and SCM prevalence were studied. The SCM prevalences were 68.6% (417/608, 95% confidence interval (CI): 64.9-72.2%) and 39.2% (946/2,411, 37.3-41.2%) at the cow- and quarter-levels, respectively. A preventive factor for SCM was cow calmness at the end of milking (OR: 0.20, 95%CI: 0.05-0.79, P=0.021); a risk factor was rough teat-end (OR: 1.75, 95%CI: 1.14-2.68, P=0.011). Good cow hygiene was negatively associated with environmental mastitis (P=0.002). Appropriate hand-milking practices that avoid teat damage are expected to reduce SCM in Uganda.
Assuntos
Indústria de Laticínios/métodos , Mastite Bovina/epidemiologia , Criação de Animais Domésticos/métodos , Animais , Infecções Assintomáticas/epidemiologia , Bactérias/isolamento & purificação , Comportamento Animal , Bovinos , Estudos Transversais , Feminino , Glândulas Mamárias Animais , Mastite Bovina/etiologia , Mastite Bovina/microbiologia , Leite/microbiologia , Prevalência , Fatores de Risco , Uganda/epidemiologiaRESUMO
East Coast fever is caused by Theileria parva, and poses serious concerns for dairy farmers owing to massive economic losses. In the current study, we compared three methods (DNA extraction kits, FTA-NaOH and FTA-TENT) of DNA extraction to identify the most economical and reliable method. A survey for T. parva prevalence was conducted in dairy cattle in Mbarara, Uganda. Cytochrome C oxidase subunit I (COI) and T. parva-p104 genes were amplified to compare the methods. FTA-NaOH-based polymerase chain reaction (PCR) yielded the best detection rate for both COI gene and p104 gene. Prevalence of T. parva was 45.0% and 83.3% at animal and farm-level, respectively. FTA-NaOH based-PCR is simple, highly sensitive and cost-effective tool for T. parva diagnosis in resource constrained settings.
Assuntos
Doenças dos Bovinos/diagnóstico , Reação em Cadeia da Polimerase/veterinária , Theileria parva/isolamento & purificação , Theileriose/diagnóstico , Animais , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/parasitologia , DNA/análise , DNA/isolamento & purificação , Indústria de Laticínios , Papel , Reação em Cadeia da Polimerase/economia , Reação em Cadeia da Polimerase/métodos , Prevalência , Hidróxido de Sódio , Manejo de Espécimes/instrumentação , Theileria parva/genética , Theileriose/sangue , Theileriose/epidemiologia , UgandaRESUMO
This study investigated the target site mutations in the partial sequence of voltage-sensitive sodium channel (VSSC) domain II of synthetic pyrethroid (SP)-resistant Rhipicephalus appendiculatus. Genomic DNA was extracted from seven tick populations (two susceptible and five resistant) collected from central, eastern and southwestern Uganda. The PCR amplicons of the VSSC domain II were cloned and sequenced to determine novel single nucleotide polymorphisms (SNP). A non-synonymous mutation C78 A corresponding to C190 A was found in all the five SP-resistant ticks. The C78 A mutation led to amino acid substitution from leucine to isoleucine (L21I) which was previously reported to confer knockdown (kdr) mutation in R. (Boophilus) microplus. The genetic confirmation of SP-resistant R. appendiculatus in central and southwestern Uganda calls for an urgent strategy for controlling the ticks.
Assuntos
Acaricidas/farmacologia , Proteínas de Artrópodes/genética , Resistência a Medicamentos , Mutação Puntual , Piretrinas/farmacologia , Rhipicephalus/efeitos dos fármacos , Canais de Sódio/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Larva , Rhipicephalus/enzimologia , Rhipicephalus/genética , Alinhamento de Sequência , UgandaRESUMO
East Coast fever, babesiosis, and anaplasmosis are the major tick-borne diseases affecting cattle productivity in Uganda. The emergence of acaricide-resistant ticks is suspected to have caused a rise in hemoparasites. This study sought to detect and characterize hemoparasites among farms in acaricide-failure hotspots of central as compared to the acaricide-failure naïve areas in Eastern Uganda. Nested PCR assays were performed to determine the prevalences of Babesia bovis, Babesia bigemina, Theileria parva, and Anaplasma marginale in cattle blood samples sourced from randomly selected farms. Randomly selected isolates were sequenced to determine the genetic diversity of the parasites using the following marker genes: B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, T. parva 104â¯kDa microneme-rhoptry antigen, and A. marginale major surface protein 5. Furthermore, partially and fully engorged adult ticks were collected for taxonomy, and tick-control practices were assessed using a semi-structured questionnaire. The prevalences of B. bigemina, T. parva, and A. marginale in cattle were 17.2, 65.1, and 22.0%, and 10.0, 26.5, and 3% in the central and eastern region, respectively. Whilst, B. bovis was not detected in the farms involved. The sequences for B. bigemina, T. parva, and A. marginale from the central region showed 99% identity with those from the eastern region. Of the 548 ticks collected, 319, 147, 76, and 6 were Rhipicephalus (Boophilus) decoloratus, Rhipicephalus appendiculatus, Amblyomma variegatum, and Rhipicephalus evertsi evertsi, respectively. The Rhipicephalus ticks were more abundant in the central region, whereas A. variegatum ticks were more abundant in the eastern region. Tick control malpractices were found in both Central and Eastern Uganda, and 42 of the 56 surveyed farms lacked appropriate restraining facilities and so they utilized either ropes or a 'boma' (enclosure). In summary, B. bigemina, T. parva, A. marginale and their co-infections were more prevalent in the central than eastern region; even though, tick control malpractices were observed in both regions. Therefore, an urgent tick and TBD control strategy is needed.
Assuntos
Anaplasmose/prevenção & controle , Babesiose/prevenção & controle , Theileriose/prevenção & controle , Controle de Ácaros e Carrapatos/métodos , Anaplasma marginale/genética , Anaplasma marginale/fisiologia , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Animais , Babesia/genética , Babesia/fisiologia , Babesiose/epidemiologia , Babesiose/parasitologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Epidemiologia Molecular , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Proteínas de Protozoários/análise , Análise de Sequência de DNA/veterinária , Theileria parva/genética , Theileria parva/fisiologia , Theileriose/epidemiologia , Theileriose/parasitologia , Uganda/epidemiologiaRESUMO
Tick acaricide failure is one of the leading challenges to cattle production in Uganda. To gain an understanding into the possible drivers of acaricide failure, this study characterized the current chemical tick control practices in the southwestern (Mbarara, Mitooma and Rukungiri districts) and northwestern (Adjumani district) regions of Uganda. A total of 85 farms participated in a survey that utilized a semi-structured questionnaire. Moreover, ticks were collected to determine the most common species on the farms. Tick acaricide failure was mainly encountered in the districts where 95% (60/63) of the farms reared exotic cattle (dairy cross-breeds) under a paddocking (fenced) system. In the northwestern region, local cattle were reared in communal grazing areas. All farms used chemical acaricides for tick control, predominantly amidine (amitraz) (48%, 41/85) and co-formulated organophosphates and pyrethroids (38%, 32/85). The spraying method was the most common (91%, 77/85) acaricide application technique, with cattle crush (81%, 69/85) as a common means of physical restraint. Less than optimal tick control practices encountered included use of substandard equipment for spraying, inappropriate dilutions, frequent interaction between animals in neighboring farms despite lack of synchronized chemical tick control and malpractices in acaricide rotation. Only Rhipicephalus appendiculatus and R. (Boophilus) decoloratus ticks were found in the southwestern region, where 51% (32/63) of the farmers used high acaricide concentrations above the manufacturers' recommendation. Farmers in the northwestern region used 2.2 times less acaricide volume per cattle than those in the southwestern region, and more diverse tick species were encountered. Toxic effects of acaricide to cattle and workers were reported by 13% (11/85) and 32% (27/85) of the respondents, respectively. All 27 cases of human acaricide toxicity reported were from the southwestern region. Overall, our findings may inform strategies for more prudent chemical tick control and safe acaricide handling to benefit animal welfare, food safety and public health.
Assuntos
Acaricidas/efeitos adversos , Doenças dos Bovinos/tratamento farmacológico , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Acaricidas/administração & dosagem , Acaricidas/toxicidade , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Estudos Transversais , Resistência a Medicamentos , Fazendas , Humanos , Saúde Pública , Piretrinas/administração & dosagem , Piretrinas/efeitos adversos , Rhipicephalus/efeitos dos fármacos , Inquéritos e Questionários , Controle de Ácaros e Carrapatos/estatística & dados numéricos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/prevenção & controle , Doenças Transmitidas por Carrapatos/veterinária , Toluidinas/administração & dosagem , Toluidinas/efeitos adversos , Uganda/epidemiologiaRESUMO
The emergence of multi-acaricide resistant ticks has led to unprecedented level of acaricide failure in central and western Uganda. In the absence of a national acaricide resistance management strategy, the country's dairy sector is threatened by upsurge of ticks and tick-borne diseases. In this study, we developed a short-to-medium-term intervention approach called Evidence-Based Acaricide Tick Control (EBATIC): Identify, Test, Intervene and Eradicate (IT-IE). Furthermore, the perception of 199 farmers and extension workers, 12 key informants in four districts and 47 stakeholders in the animal industry in Uganda were assessed using semi-structured questionnaires. We report that the establishment of a specialized laboratory is pivotal in identifying and testing (IT) acaricide resistant ticks for prompt intervention and eradication (IE). The laboratory test results and the farm tick control gaps identified are very important in guiding acaricide resistance management strategies such as evidence-based acaricide rotation, development and dissemination of extension materials, training of farmers and extension workers, and stakeholders' engagement towards finding sustainable solutions. All the 47 stakeholders and 91.0% (181/199) of the farmers and extension workers reported that the EBATIC approach will help in solving the tick acaricide resistance crisis in Uganda. Similarly, all the 12 key informants and 92.5% (184/199) of the farmers and extension workers suggested that the EBATIC approach should be sustained and rolled out to other districts. The EBATIC stakeholders' dialogue generated both short-to-medium and long-term strategies for sustainable management of tick acaricide resistance in the country. Overall, the positive feedback from farmers, district veterinarians and stakeholders in the animal industry suggest that the EBATIC approach is a useful proof-of-concept on scalable intervention pathway against tick acaricide resistance in Uganda with possibility of adoption in other African countries.
Assuntos
Acaricidas/farmacologia , Doenças dos Bovinos/prevenção & controle , Resistência a Medicamentos , Fazendeiros/psicologia , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/veterinária , Acaricidas/administração & dosagem , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/prevenção & controle , UgandaRESUMO
We previously reported emergence of super synthetic pyrethroid (SP) resistant Rhipicephalus (Boophilus) decoloratus ticks in Uganda. This study investigated the genetic basis of phenotypic resistance against SP in R. (B.) decoloratus and sought to identify novel diagnostic mutations for rapid detection of SP resistance in the above tick species. Genomic DNA was extracted from pooled larvae of 20 tick populations (19 of known SP susceptibility and 1 unknown susceptibility). The voltage sensitive sodium channel (VSSC) domain II S4-5 linker (SP target) and partial carboxylesterase (SP metabolizing enzyme) genes were amplified by PCR, cloned and sequenced. The resultant sequences were analyzed to determine single nucleotide polymorphisms (SNPs) associated with phenotypic resistance in the various tick populations investigated. Novel SNPs that introduced Eco RI and Eco RII restriction sites in carboxylesterase gene were identified in silco and validated with restriction fragment length polymorphism (RFLP) against 18 tick populations of known SP susceptibility. The study identified a super knock down resistance (kdr) mutation T58C in R. (B.) decoloratus VSSC associated with stable SP resistance. We further identified multiple nonsynonymous mutations in carboxylesterase of SP resistant ticks; one of which conferred novel EcoRII (G195C) restriction site for PCR-RFLP detection of SP resistance. In conclusion, this study is the first to report super kdr mutation in sodium channel domain II and multiple mutations in carboxylesterase genes that may concurrently mediate stable resistance against synthetic pyrethroids in R. (B.) decoloratus ticks from Uganda. The Eco RII based PCR-RFLP is a useful tool for rapid detection of stable SP resistant R. (B.) decoloratus ticks.
Assuntos
Proteínas de Artrópodes/genética , Carboxilesterase/genética , Resistência a Inseticidas/genética , Rhipicephalus/genética , Canais de Sódio/genética , Acaricidas/toxicidade , Animais , Mutação , Nitrilas/toxicidade , Fenótipo , Polimorfismo de Nucleotídeo Único , Domínios Proteicos/genética , Piretrinas/toxicidade , UgandaRESUMO
Cattle and poultry enterprises are among the major contributors to food security and socioeconomic empowerment of households in Uganda. However, various diseases constrain their productivity. A two-year retrospective study between April 2012 and March 2014 was conducted using records for cattle and poultry diseases diagnosed at the Central Diagnostic Laboratory (CDL) to determine prevalent diseases in Uganda. The laboratory received 836 samples from poultry (36.3%) and cattle (63.7%). Of the 836 samples, 47.5% had a definitive diagnosis of disease causation. Most of the cattle and poultry diseases diagnosed were protozoan diseases (39.3%) followed by bacterial (21.4%), viral (17.1%), helminthiasis (11.1%), nutritional diseases (4%) and others (7.1%). For poultry, viral diseases (29.5%) and protozoan diseases (27.1%) especially newcastle disease (44.3%) and coccidiosis (100%) respectively, were the most diagnosed. While for cattle, hemo-protozoan parasites (52.1%) were the most prevalent, of which 92.9% were east coast fever infection. Bacterial infection (20.5%) in cattle were the second most diagnosed diseases and mastitis was the most diagnosed (46.2%). In summary, coccidioisis, collibacillosis, newcastle disease, gumboro disease, and avian helminthiasis were the most prevalent poultry diseases while in cattle, east coast fever, helminthiasis, mastitis, brucellosis and rabies were the most frequently diagnosed diseases. This study has identified the major diseases that hinder poultry and cattle production in Uganda. The data generated by CDL could be used for surveillance, monitoring and designing strategic interventions for control of poultry and cattle diseases in Uganda.