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1.
Vet Parasitol Reg Stud Reports ; 54: 101095, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39237236

ABSTRACT

The non-cyclic trypanosomiasis (surra), caused by Trypanosoma evansi, and mechanically transmitted by biting flies, hinders camel productivity in Kenya. Trypanocides are the most commonly used drugs to control surra. However, emergence of drug resistance by the parasites is a major limitation to control efforts. There is limited information on the quality of trypanocides, the supply chain and drug-use practices among camel keepers potentially contributing to development of drug resistance in Kenya. We sought to fill this gap by conducting a cross-sectional study among camel keepers in Isiolo and Marsabit counties, Kenya. We mapped the trypanocide drugs supply chain through quantitative and qualitative surveys. We administered a semi-structured questionnaire to camel keepers to generate data on trypanocides-use practices, including the types, sources, person who administers treatment, reconstitution, dosage, route and frequency of administration, among others. Additionally, we tested the quality of trypanocidal drugs retailed in the region. We mapped a total of 55 and 49 agro-veterinary outlets and general (ordinary) shops retailing veterinary drugs in the two counties, respectively. These comprised of 29 and 26 agro-veterinary outlets, as well as 24 and 25 general shops in Isiolo and Marsabit counties, respectively. Overall, the respondents experienced 283 surra cases in the three-month recall period, which were treated with trypanocides. The majority of these cases were diagnosed by camel owners (71.7%) and herders (24.1%). A significant proportion of the cases were treated by camel owners (54.8%), herders (35.3%), the owner's son (3.2%) and veterinary personnel (1.1%) (χ2 = 24.99, p = 0.000). Most of the households sourced the drugs from agro-veterinary outlets (59.0%), followed by general shops (19.8%), veterinary personnel (2.1%), and open-air markets (0.4%) (χ2 = 319.24, p = 0.000). Quinapyramine was the most (56.9%) predominantly used trypanocide in treatment of surra, followed by homidium (19.8%), isometamidium (15.9%), diminazene aceturate (6.7%), and ethidium (0.7%) (χ2 = 340.75, p < 0.000). Only a meager proportion of respondents (15.2%) used the drugs correctly as instructed by the manufacturers. We recorded an association between correct drug usage, with the person who administers the treatment (χ2 = 17.7, p = 0.003), and the type of trypanocide used (χ2 = 19.4, p < 0.001). All the drug samples tested had correct concentrations of active ingredient (100.0%), and therefore of good quality. We have demonstrated that whereas the trypanocides retailed in the region by authorized vendors are of good quality, there is widespread incorrect handling and use of the drugs by unqualified individuals, which may contribute to treatment failure and emergence of trypanocide resistance.


Subject(s)
Camelus , Trypanocidal Agents , Trypanosoma , Kenya , Cross-Sectional Studies , Trypanocidal Agents/pharmacology , Animals , Humans , Female , Male , Trypanosoma/drug effects , Adult , Middle Aged , Trypanosomiasis/drug therapy , Trypanosomiasis/veterinary , Surveys and Questionnaires , Young Adult , Drug Resistance
2.
PLoS One ; 19(8): e0308088, 2024.
Article in English | MEDLINE | ID: mdl-39088513

ABSTRACT

In the absence of effective drugs, vaccines constitute the cornerstone for the prevention of Newcastle disease (ND). Different strategies have been implemented to increase vaccination, but uptake remains low, underscoring the need for novel vaccine delivery methods. We designed and assessed the effectiveness of a community-centered ND vaccine delivery model in southeastern Kenya. Under the model, we sensitized smallholder chicken farmers (SCFs) through structured training on chicken husbandry, biosecurity, ND, and its vaccination, among other aspects. We subsequently engaged trained community vaccinators (CVs) to deliver vaccines and/or provide vaccination services to SCFs at a cost on one hand and, at no cost on the other, in selected sites to address challenges of inadequate service providers, vaccine unavailability, and inaccessibility. We tested this model under paid and free vaccination frameworks over one year and assessed the model's effect on vaccine uptake, ND-related deaths, and vaccine accessibility, among other aspects. Overall, we vaccinated more chickens at free sites compared to paid sites. However, we vaccinated a significantly higher mean number of chickens per household at paid (49.4±38.5) compared to free (28.4±25.9) sites (t = 8.4, p<0.0001). We recorded a significant increase in the proportion of SCFs who vaccinated their chickens from 31.3% to 68.4% (χ2(1, N = 399) = 58.3, p<0.0001) in paid and from 19.9% to 74.9% (χ2(1, N = 403) = 115.7, p<0.0001) in free sites pre- and post-intervention, respectively. The mean number of ND-related deaths reported per household decreased from 18.1±31.6 pre-intervention to 7.5±22.3 post-intervention (t = 5.4, p = 0.000), with higher reductions recorded in paid sites (20.9±37.7 to 4.5±11.2) compared to free sites (15.0±22.6 to 10.7±29.7) pre- and post-intervention, respectively. Farmers with access to vaccines increased significantly from 61.1% to 85.4% (χ2(1, N = 399) = 31.7, p<0.0001) in paid and 43.6% to 74.9% (χ2(1, N = 403) = 38.4, p = 0.0001) in free sites pre- and post-intervention, respectively. We established that type of intervention framework, gender of household head, if the household head attended training on chicken production in the last 12 months, access to information on ND vaccination, and the number of chickens lost to the previous ND outbreak were significant predictors of ND vaccine uptake. Our findings indicate the model has a broader reach and benefits for SCFs. However, policies should be enacted to regulate the integration of CVs into the formal animal health sector.


Subject(s)
Chickens , Newcastle Disease , Vaccination , Kenya , Animals , Newcastle Disease/prevention & control , Viral Vaccines/administration & dosage , Viral Vaccines/economics , Viral Vaccines/immunology , Newcastle disease virus/immunology , Poultry Diseases/prevention & control , Humans , Animal Husbandry/methods , Farmers
4.
Onderstepoort J Vet Res ; 91(1): e1-e6, 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38426744

ABSTRACT

Trypanosomosis is a disease complex which affects both humans and animals in sub-Saharan Africa, transmitted by the tsetse fly and distributed within the tsetse belt of Africa. But some trypanosome species, for example, Trypanosoma brucei evansi, T. vivax, T. theileri and T. b. equiperdum are endemic outside the tsetse belt of Africa transmitted by biting flies, for example, Tabanus and Stomoxys, or venereal transmission, respectively. Trypanocidal drugs remain the principal method of animal trypanosomosis control in most African countries. However, there is a growing concern that their effectiveness may be severely curtailed by widespread drug resistance. A minimum number of six male cattle calves were recruited for the study. They were randomly grouped into two (T. vivax and T. congolense groups) of three calves each. One calf per group served as a control while two calves were treatment group. They were inoculated with 105 cells/mL parasites in phosphate buffered solution (PBS) in 2 mL. When parasitaemia reached 1 × 107.8 cells/mL trypanosomes per mL in calves, treatment was instituted with 20 mL (25 mg/kg in 100 kg calf) ascofuranone (AF) for treatment calves, while the control ones were administered a placebo (20 mL PBS) intramuscularly. This study revealed that T. vivax was successfully cleared by AF but the T. congolense group was not cleared effectively.Contribution: There is an urgent need to develop new drugs which this study sought to address. It is suggested that the AF compound can be developed further to be a sanative drug for T. vivax in non-tsetse infested areas like South Americas.


Subject(s)
Sesquiterpenes , Trypanocidal Agents , Trypanosomiasis, African , Animals , Cattle , Male , Sesquiterpenes/pharmacology , Sesquiterpenes/therapeutic use , Trypanocidal Agents/pharmacology , Trypanocidal Agents/therapeutic use , Trypanosoma , Trypanosomiasis, African/drug therapy , Trypanosomiasis, African/veterinary , Trypanosomiasis, African/epidemiology , Tsetse Flies/parasitology
5.
J Parasitol Res ; 2023: 7218073, 2023.
Article in English | MEDLINE | ID: mdl-37153519

ABSTRACT

Camel trypanosomiasis (Surra) is endemic in the Horn of Africa. Understanding the spatiotemporal variations in Surra prevalence, vector dynamics, and host-related risk factors is important in developing effective control strategies. A repeated cross-sectional study was conducted to determine the Surra parasitological prevalence, livestock reservoirs, vector density/diversity, and host-related risk factors in Kenya. Random samples of 847, 1079, and 824 camels were screened at the start of the dry season, peak dry season, and during the rainy season, respectively. Blood samples were examined using the dark ground/phase contrast buffy-coat technique, and Trypanosoma species were identified based on their movement and morphology in wet and stained thin smears. Reservoir status for Trypanosoma evansi was assessed in 406 cattle and 372 goats. A rainy and dry seasons entomological surveys were conducted to determine the Surra vector abundance/diversity and spatiotemporal density changes. Surra prevalence was 7.1%, 3.4%, and 4.1% at the start of the dry season, peak dry season, and rainy season, respectively. Camel co-infections by Trypanozoon (T. evansi or Trypanosoma brucei brucei) and Trypanosoma vivax were recorded. Spatial variations in Surra prevalence were recorded at the beginning of dry (X (7, N = 846) 2 = 110.9, p ≤ 0.001), peak dry (X (7, N = 1079) 2 = 42.2, p ≤ 0.001), and rainy (X (7, N = 824) 2 = 29.1, p ≤ 0.001) seasons. The screened cattle and goats tested negative for Trypanozoon (T. evansi or T. b. brucei), while two cattle tested positive for Trypanosoma congolense. Biting fly catches were composed of a single species from Tabanus, Atylotus, Philoliche, Chrysops, and Stomoxys genera. The total catches for Philoliche, Chrysops, and Stomoxys were higher in the rainy than dry season consistent with the prevalence results. Surra remains an important camel disease in the region with its prevalence varying in space and time. Camel co-infections by Trypanozoon (T. evansi or T. b. brucei) and T. vivax necessitate proper diagnosis of suspected cases and targeted therapy.

6.
PLoS One ; 18(3): e0283076, 2023.
Article in English | MEDLINE | ID: mdl-36928483

ABSTRACT

The exploitation of the full benefits of chicken rearing by smallholder farmers in Sub-Saharan (SSA) Africa is often impeded by poultry diseases which is compounded by limited uptake of vaccination. We interrogate the structural and socioeconomic factors associated with vaccine uptake by women farmers in Southeastern Kenya. A mixed methods design with a convergent approach for comparison of quantitative and qualitative findings was adopted. This involved the administration of a cross section survey to 1274 households, conduct of 23 Focus Groups Discussions (FGDs) and 7 Key informant Interviews (KIIs). Chi Square and t-tests were used to identify factors associated with vaccine uptake. Logistics regression analysis was used to identify the influence of the structural and socioeconomic barriers to vaccine uptake. Findings indicate that having knowledge of Newcastle disease (ND) vaccine increases the likelihood of farmers vaccinating their chicken by up to 32.5 times (95% CI [8.46-124.53]) with a 1 unit increase in vaccine knowledge. A farmer's distance away from the nearest ND vaccine vendor was found to reduce the likelihood of farmers vaccinating their chicken by up to 4% (95% CI ([0.93-1.00]) for every 1-kilometre increase in distance away from the vaccine vendors. Farmers who considered vaccines to be effective in preventing ND were 39 times (95% CI [6.23-239.8]) more likely to use ND vaccines than those that did not consider ND vaccine to effective. We surmise that a comprehensive approach that addresses increased ND vaccine knowledge among smallholder women chicken farmers, proximity of ND vendors, as well as cost holds the potential for regular and increased ND vaccine uptake.


Subject(s)
Newcastle Disease , Viral Vaccines , Animals , Female , Humans , Newcastle Disease/prevention & control , Farmers , Kenya , Vaccination , Family Characteristics , Chickens
7.
PLoS One ; 18(2): e0281180, 2023.
Article in English | MEDLINE | ID: mdl-36730273

ABSTRACT

Trypanocidal resistance is a major cause of treatment failure. This study evaluated the sensitivity of Trypanosoma evansi field isolates collected from Marsabit and Isiolo counties, Kenya. A total of 2,750 camels were screened using parasitological tests for trypanosomes. Of the screened camels, 113 tested positive from which 40 T. evansi isolates were tested using the single dose mice sensitivity test. Five treatment groups each comprising of 6 mice were inoculated intraperitoneally with 1x105 trypanosomes of each isolate and treated 24 hours later with isometamidium chloride at 1 mg/kg, homidium chloride at 1mg/kg, diminazene aceturate at 20 mg/kg and quinapyramine sulphate & chloride at 1 mg/kg. The fifth group was left untreated (positive control). The mice were monitored daily for 60 days. A survey on camel owners' practices that influence development of resistance to trypanocidal drugs was then conducted. Results indicated presence of drug resistance in all the 7 study sites that had infected camels. Seven of the isolates tested were resistant to diminazene aceturate whereas, 28, 33 and 34 were resistant to isometamidium chloride, quinapyramine sulphate & chloride and homidium chloride, respectively. Seven (17.5%) isolates of the 40 tested were sensitive to all 4 drugs, whereas, 7.5%, 10%,55% and 10% were resistant to 1,2,3 and 4 drugs, respectively. The prevalence of multiple drug resistance was 75%. Survey data indicated that camel management practices influenced the prevalence and degree of drug resistance. In conclusion, the multiple drug resistance observed in the two counties may not be an indication of total trypanocidal drug failure. Judicious treatment of confirmed trypanosomiasis cases with correct dosage would still be effective in controlling the disease since the observed resistance was at the population and not clonal level. However, integrated control of the disease and the vectors using available alternative methods is recommended to reduce drug use.


Subject(s)
Trypanocidal Agents , Trypanosoma , Trypanosomiasis, African , Mice , Animals , Trypanocidal Agents/pharmacology , Trypanocidal Agents/therapeutic use , Camelus , Trypanosomiasis, African/drug therapy , Trypanosomiasis, African/veterinary , Kenya , Chlorides/pharmacology , Phenanthridines/pharmacology , Phenanthridines/therapeutic use , Diminazene/pharmacology , Diminazene/therapeutic use , Drug Resistance
8.
PLoS One ; 17(8): e0269243, 2022.
Article in English | MEDLINE | ID: mdl-35925935

ABSTRACT

Small ruminant production facets like decision-making, ownership, labour allocation, access to- and control over assets are gendered. This study investigates intra-household gender dynamics and practices around sheep and goat production among smallholder farmers in South East region of Kenya. A quantitative study was conducted on 358 dual-headed (married) households to generate gender-disaggregated data on ownership, decision-making and labour allocation around small ruminant production. Qualitative data was collected through focused group discussions to bring out the community perspectives. From the findings, the average number of small ruminants owned by the households as reported by men was slightly higher than women. The average number of small ruminants solely owned by men was significantly higher than by women. Men reported a relatively higher number of jointly owned small ruminants compared to women. More women than men reported that they could give as a gift, sell-off and slaughter jointly owned small ruminants without consulting their spouses. Small ruminants were considered the most important livestock asset in supporting a household's livelihood by relatively more women than men. Men had more decision-making autonomy over jointly owned small ruminants compared to women. Production tasks around small ruminants such as feeding, watering, selling milk and cleaning housing structures were mostly performed by the women. Qualitative data identified men as the de facto owners of small ruminants with a higher power position in making the important production decisions. The study offers three implications on the design of livestock interventions to empower women, the interventions should ensure that; 1) women are not just owners of livestock assets but also share power and decision-making rights in all aspects of production, 2) production labour is shared equitably between men and women and, 3) women access benefits from livestock production even when animals are owned by men.


Subject(s)
Animal Husbandry , Family Characteristics , Animals , Female , Gender Identity , Goats , Humans , Kenya , Livestock , Ruminants , Sheep
9.
PLoS One ; 15(11): e0229060, 2020.
Article in English | MEDLINE | ID: mdl-33151938

ABSTRACT

We assessed the virulence and anti-trypanosomal drug sensitivity patterns of Trypanosoma brucei rhodesiense (Tbr) isolates in the Kenya Agricultural and Livestock Research Organization-Biotechnology Research Institute (KALRO-BioRI) cryobank. Specifically, the study focused on Tbr clones originally isolated from the western Kenya/eastern Uganda focus of human African Trypanosomiasis (HAT). Twelve (12) Tbr clones were assessed for virulence using groups(n = 10) of Swiss White Mice monitored for 60 days post infection (dpi). Based on survival time, four classes of virulence were identified: (a) very-acute: 0-15, (b) acute: 16-30, (c) sub-acute: 31-45 and (d) chronic: 46-60 dpi. Other virulence biomarkers identified included: pre-patent period (pp), parasitaemia progression, packed cell volume (PCV) and body weight changes. The test Tbr clones together with KALRO-BioRi reference drug-resistant and drug sensitive isolates were then tested for sensitivity to melarsoprol (mel B), pentamidine, diminazene aceturate and suramin, using mice groups (n = 5) treated with single doses of each drug at 24 hours post infection. Our results showed that the clones were distributed among four classes of virulence as follows: 3/12 (very-acute), 3/12 (acute), 2/12 (sub-acute) and 4/12 (chronic) isolates. Differences in survivorship, parasitaemia progression and PCV were significant (P<0.001) and correlated. The isolate considered to be drug resistant at KALRO-BioRI, KETRI 2538, was confirmed to be resistant to melarsoprol, pentamidine and diminazene aceturate but it was not resistant to suramin. A cure rate of at least 80% was achieved for all test isolates with melarsoprol (1mg/Kg and 20 mg/kg), pentamidine (5 and 20 mg/kg), diminazene aceturate (5 mg/kg) and suramin (5 mg/kg) indicating that the isolates were not resistant to any of the drugs despite the differences in virulence. This study provides evidence of variations in virulence of Tbr clones from a single HAT focus and confirms that this variations is not a significant determinant of isolate sensitivity to anti-trypanosomal drugs.


Subject(s)
Trypanocidal Agents/pharmacology , Trypanosoma brucei rhodesiense/drug effects , Trypanosomiasis, African/drug therapy , Virulence/drug effects , Animals , Diminazene/analogs & derivatives , Diminazene/pharmacology , Disease Models, Animal , Drug Resistance/drug effects , Kenya , Male , Melarsoprol/pharmacology , Mice , Pentamidine/pharmacology , Suramin/pharmacology , Treatment Outcome , Trypanosomiasis, African/parasitology , Uganda
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