RESUMO
Improved management of livestock in resource-limited settings can provide a means towards improved human nutrition and livelihoods. However, gastrointestinal nematodes (GIN) are a significant production-limiting factor. Anthelmintics play a role in GIN management; however, few anthelmintic classes are available in many low-middle-income countries. Utilising a limited range of classes may increase selection for anthelmintic resistance; therefore, strategies to reduce other selective pressures are of heightened importance. Avoiding anthelmintic underdosing is one such strategy, but it can be challenging without access to accurate bodyweight measurement. Many previous studies have used thoracic girth as a practical proxy for bodyweight in goats; however, they have rarely considered the potential impact of natural variation on therapeutic doses. Here, the relationship between bodyweight and thoracic girth was modelled using data from 820 goats from three Malawian biomes in two seasons, with the specific aim of avoiding underestimation of bodyweight. The internally cross-validated linear regression (âWeight ~ 0.053 + 0.040*Girth, R2 = 0.92, rounded up to the nearest 5 kg) was validated against data from an additional 352 Malawian goats (1.4% of goats allocated an underdose and 10.2% allocated a dose > 200% of bodyweight). The equation was further externally validated using an historical dataset of 150 goats from Assam, India (2.7% of goats were allocated to an underdose and 24.8% allocated to a > 200% of bodyweight). These results suggest that a more globally generalisable approach may be feasible, provided the accuracy of the estimate is considered alongside the therapeutic index of the pharmaceutical.
Assuntos
Anti-Helmínticos , Doenças das Cabras , Nematoides , Infecções por Nematoides , Animais , Humanos , Infecções por Nematoides/veterinária , Cabras , Doenças das Cabras/tratamento farmacológico , Resistência a Medicamentos , Contagem de Ovos de Parasitas/veterinária , Anti-Helmínticos/farmacologiaRESUMO
The world's growing population is becoming increasingly centred around large cities, affording opportunities for peri-urban food production. Goats are well-suited to conversion of resources that are available in peri-urban settings into meat and occasionally milk. Haemonchus contortus has been described as "the nemesis of small ruminant production systems in tropical and subtropical regions"; hence control of haemonchosis through planned animal health management affords a pragmatic first step in improving the production efficiency of peri-urban goats. This study of peri-urban goat production investigated the potential value of targeted selective treatment of haemonchosis. 452 peri-urban goat keepers in southern Malawi were visited during three seasonal periods with relevance to the epidemiology of haemonchosis. 622, 599 and 455 individually identified goats were clinically examined during the dry season, the rainy season, and shortly after the end of the rainy season, respectively. Data were recorded for sex, age, weight, conjunctival mucous membrane colour score (FAMACHA©), body condition score (BCS) and faecal worm egg count (FEC); and where possible for pregnancy and lactation status. Animals with pale ocular mucous membranes were treated with 10 mg/kg albendazole, then re-examined 14 days later. Animals with pink mucous membranes, but FECs ≥250 eggs per gram were also re-examined and treated 14 days later. The results show high variability in growth rates deduced from the ages and bodyweights of each of 999 goats at the time of their enrolment. FAMACHA© scores alone were a poor index for the targeted selective treatment of haemonchosis, because they failed to identify too many animals that would have required treatment at different times of year and using different FAMACHA© and FEC cut-offs. Combining the indices of FAMACHA© scores ≥4, body condition scores ≥2, and age >18 months was more reliable in identifying those animals requiring treatment when different epidemiologically-relevant FEC thresholds for different seasons were taken into account. Inclusion of late pregnancy or early lactation status would have resulted in very few animals requiring treatment being missed. The use of conjunctival mucous membrane colour scoring in this way provided a valuable insight of the general health status of the peri-urban goats, to create opportunities for planned animal health management to improve productivity. The efficacy of albendazole treatment was poor, putatively due to drug resistance, or poor drug bioavailability in goats. In summary, our study shows opportunities for better production efficiency in peri-urban goats, and demonstrates the value of simple clinical diagnostic indices as decision support tools in planned animal health management.
Assuntos
Anti-Helmínticos/administração & dosagem , Túnica Conjuntiva/fisiologia , Resistência a Medicamentos , Doenças das Cabras/tratamento farmacológico , Cabras/fisiologia , Hemoncose/veterinária , Animais , Cor , Feminino , Doenças das Cabras/parasitologia , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/fisiologia , Malaui , Masculino , Mucosa/fisiologiaRESUMO
Despite successful eradication programmes in many regions, rabies remains responsible for approximately 60,000 human deaths annually, and no country in Africa is rabies-free. Dogs are the principal reservoir of the virus in Africa and the World Health Organisation recommends that at least 70% of the dog population be vaccinated in order to break the transmission cycle. Most attempts at mass rabies vaccinations in Africa have failed to vaccinate high numbers of dogs at a high coverage. Successful studies have often used a door-to-door (DTD) approach, which is logistically challenging and expensive compared to a static point (SP) approach. Mission Rabies has successfully implemented a combined SP and DTD method in cities in India and Malawi. This campaign used a combined methodology in rural Uganda, starting with a SP campaign, followed by a DTD campaign, and then subsequent transect surveys to assess vaccination coverage. This was facilitated by the use of a smartphone application which recorded all vaccinations and survey responses along with their Global Positioning System location. A total of 4172 dogs were vaccinated in 7 days, attaining an estimated 88.4% coverage. This campaign is of particular note as 95.9% of the vaccinations were performed at SPs. The human-to-dog ratio was 4.9 with a mean dogs per house of 1.2. Most dogs were owned (93.7%). This demonstrates that high-number, high-coverage vaccination is achievable in rural Uganda and provides data that may refine future campaign approaches.