Impact of herd mobility on brucellosis seroprevalence and spread risk resulting from cross-border transhumance

BACKGROUND

Cross-border livestock mobility through transhumance is mainly practiced in West African countries for seasonal access to resources and market. Cross-border herds are involved in the dynamic of transboundary animal diseases among them brucellosis taken as model. Brucellosis is a zoonotic disease causing abortion.

OBJECTIVES

This study explores the seroprevalence of brucellosis according to mobility and infection spread between Mali and Côte d'Ivoire in the context of seasonal cross-border transhumance.

METHODS

From February to April 2021, a transversal serological survey of brucellosis was conducted on 521 cattle from 111 transhumant herds and 283 cattle from 59 sedentary herds, all from Mali.

RESULTS

The global individual seroprevalence for Brucella spp. in transhumant and sedentary cattle from Mali was 8.2% (95% CI = 6.0-10.5). At herd level, seroprevalence was 21.2% with a significant variation between transhumant (11.7%) and sedentary (39.0%) herds. For herds in transhumance, cattle seropositivity was associated with a previous infection suspected by herdsmen odds ratio (OR = 4.4; 95% CI = 1.1-18.1) and unknown abortion aetiology (OR = 4.3; 95% CI = 1.0-17.3). The departure region (coming from Sikasso) and previous brucellosis infection or unexplained abortion could be used to predict Brucella infection in transhumant herds with a probability of around 60%. The risk of brucellosis introduction in host regions was high despite the individual animal seroprevalence of 3.6% and a low sale rate in transhumant cattle.

CONCLUSIONS

The findings suggest that testing transhumant during border control and survey of cattle markets and sales could improve risk control of the spread of disease at regional scale.

Assessing farm biosecurity and farmers' knowledge and practices concerning antibiotics and antibiotic resistance in poultry and pig farms in Southern Togo

Background and Aim:

Several factors contribute to the unusual incidence of antibiotic resistance, which is now a primary public health concern. However, failure in managing preventive and therapeutic antibiotic use on farms is one of the most crucial factors. Therefore, this study aimed to evaluate the biosecurity of farms, farmers’ competence, and practices related to antibiotics and their resistance in poultry and pig rearing in Togo.

Materials and Methods:

Through a cross-sectional survey, 121 commercial poultry farmers and 97 commercial pig farmers were questioned to evaluate the biosecurity of farms and farmers’ competence and practices related to antibiotics and antibiotic resistance. Descriptive analyses, including the evaluation of proportions, were carried out. In addition, results from qualitative factors were evaluated in a defined grid and totaled up to assess cleanliness measures, awareness, and behavior regarding antibiotics and their resistance.

Results:

The results demonstrated that most farmers working on poultry farms had a university education, while most working on pig farms had secondary education. Most poultry (69%) and pig (44%) farms were of small sizes (<1000 animals in poultry and <10 animals in pig farming). The footbaths were used in just 51% of poultry farms and 4% of pig farms, respectively, with 37% and 82% of poultry and pig farms having inadequate levels of hygiene. In poultry farms, respiratory issues and periodic decline in egg-laying were the main problems. Simultaneously, skin disorders (scabies) and plagues (African swine fever) were the primary health constraints in pig farming. Tetracycline is the most commonly used antibiotic by farmers. However, in poultry and pig farms, 21% and 67% of farmers were unaware of antibiotics. In addition, 39% and 57% were unaware of antibiotic resistance. Poultry and pig farmers’ competence were substantially linked to their education level. Poultry farmers demonstrated better practices, including procuring antibiotics based on veterinary prescriptions (63%) and they knew where antibiotics should be bought (90%). Nevertheless, 43% of farmers asserted unpleasant activities – no application for laboratory testing (93%) and use of antibiotics for prevention (82%). In pig farming, most farmers (69%) reported inadequate incidents of the use of antibiotics.

Conclusion:

This study identified a crucial non-compliance with biosecurity measures and good practices toward antibiotic use on many farms. Therefore, training of farmers is mandatory for safe livestock products.

Identification of drivers of Rift Valley fever after the 2013–14 outbreak in Senegal using serological data in small ruminants

Rift Valley fever (RVF) is a mosquito-borne disease mostly affecting wild and domestic ruminants. It is widespread in Africa, with spillovers in the Arab Peninsula and the southwestern Indian Ocean. Although RVF has been circulating in West Africa for more than 30 years, its epidemiology is still not clearly understood. In 2013, an RVF outbreak hit Senegal in new areas that weren’t ever affected before. To assess the extent of the spread of RVF virus, a national serological survey was implemented in young small ruminants (6–18 months old), between November 2014 and January 2015 (after the rainy season) in 139 villages. Additionally, the drivers of this spread were identified. For this purpose, we used a beta-binomial (BB) logistic regression model. An Integrated Nested Laplace Approximation (INLA) approach was used to fit the spatial model. Lower cumulative rainfall, and higher accessibility were both associated with a higher RVFV seroprevalence. The spatial patterns of fitted RVFV seroprevalence pointed densely populated areas of western Senegal as being at higher risk of RVFV infection in small ruminants than rural or southeastern areas. Thus, because slaughtering infected animals and processing their fresh meat is an important RVFV transmission route for humans, more human populations might have been exposed to RVFV during the 2013–2014 outbreak than in previous outbreaks in Senegal.

An outbreak of Rift Valley fever (RVF)–a zoonotic mosquito-borne viral infection widespread in Africa, was reported in 2013–14 in Senegal. After its end in late 2014, its spatial distribution and drivers were assessed using a national serological survey in small ruminants, thus highlighting the high exposition of humans to RVF virus in urban areas.

Adoption of the One Health approach to improve zoonosis control in low-income countries: Insights from the case of rabies management in Burkina Faso

Background and Aim: Rabies is a neglected zoonotic disease transmissible to humans and domestic and wild animals through biting, scratching, or licking. This study aimed to analyze the adoption of the One Health approach by the stakeholders involved in rabies control in Burkina Faso. Materials and Methods: The stakeholders involved in rabies control were from the Ministry of Livestock, Ministry of Health, Ministry of the Territory Administration, Ministry of Environment and Wildlife, and Ministry of Higher Education and Research. A structured questionnaire was used in face-to-face interviews to collect data from the stakeholders. The collected data included stakeholders' knowledge of rabies and the One Health approach and their levels of involvement in the multisectoral collaboration. Results: Most participants could not describe rabies correctly (80%), and only 52.9% had heard of the One Health approach. In addition, there was no significant association between knowledge of rabies and participants' characteristics, and the knowledge of the One Health approach was significantly influenced by a participant's affiliation (place of work). Conclusion: The results call for an increase in One Health education for its effective adoption by all the rabies control stakeholders. Additional efforts should focus on continual training of the One Health workforce, from policy-makers to frontline personnel.

Assessing factors associated with owner's individual decision to vaccinate their dogs against rabies: A house-to-house survey in Ouagadougou, Burkina Faso

BACKGROUND AND AIM

In rabies endemic area, dog vaccination is an effective way of controlling the disease in animals and humans if a minimum of 70% vaccination coverage is reached. This study aimed to identify dog demographics and household characteristics associated with dogs' vaccination against rabies in Ouagadougou, Burkina Faso.

MATERIALS AND METHODS

A questionnaire was used to collect data from respondents with regard to their dogs' demographics and their household characteristics. Chi-square test and Fisher's exact test were performed to assess the association between explicative variables and the dogs' vaccination status.

RESULTS

Overall, as per the findings of this study, it was determined that out of 424 dogs, 57.8% were reportedly vaccinated. The vaccination status was significantly associated with most of the household variables (e.g., gender of the respondent, age, level of education, main means of transportation, participation in a vaccination campaign, knowledge on rabies, and knowledge on dog vaccination) and the dogs' variables (breed of dog, dog origin, purpose for keeping, confinement status, and perceived behavior) (p<0.05). Moreover, only religion, type of housing, knowledge of rabies transmission modes, and dog sex were not significantly associated with vaccination status (p>0.05).

CONCLUSION

Our study generated informative data showing that animal health workers could develop effective rabies vaccination strategy planning by examining owned dog demographics and their husbandry practices in households.

Factors Influencing the Transborder Transmission of Brucellosis in Cattle Between Côte d'Ivoire and Mali: Evidence From Literature and Current Key Stakeholders

Brucellosis is one of the main zoonoses affecting ruminants. Cattle and small ruminants are involved in transhumance and trade between Côte d'Ivoire and Mali. The endemic nature of the disease in both countries, connected through transhumance, poses unique challenges and requires more information to facilitate disease surveillance and the development of integrated control strategies. This study aimed to assess the main factors influencing the historical and current transborder transmission of brucellosis between Côte d'Ivoire and Mali. A literature review was conducted and data collection was performed through a participatory, transdisciplinary process by holding focus group discussions and interviews with key stakeholders. Cattle breeders, herdsmen, professionals of animal and human health, border control agents and experts took part. The data was analyzed to generate essential new knowledge for transborder brucellosis transmission factors and control strategies. From the literature, the seroprevalence of brucellosis in both countries varied from 11% (1987) to 20% (2013) and 15% (1972-1973) to 5% (2012-2014) in Mali and Côte d'Ivoire, respectively. The reduction of seroprevalence in Côte d'Ivoire was the result of the annual vaccination campaigns which lowered it from 28% (1978) to 14% (1984) after an increase due to livestock policy implemented in 1976. The meta-analysis and interviews jointly showed that the cross-border mobility was associated with the livestock development policy in Côte d'Ivoire as well as the ECOWAS act on the free movement of people and goods. This act supported the seasonal transhumance of livestock for access to pasture land in southern humid zones in Côte d'Ivoire. The seasonal mobility for grazing and trade was the main risk factor for the spread of brucellosis between pastoral zones of both countries. The existing legal health framework and border control mechanism do not achieve transborder surveillance to control brucellosis. Existing sanitary regulations should be adapted at regional scale to integrate a joint surveillance of high priority zoonotic diseases like brucellosis at border controls.

Diversity and prevalence of gastrointestinal parasites with zoonotic potential of Green Monkeys in Bandia Reserve in Senegal

Background and Aim: Parasitic and infectious diseases are ubiquitous threats to primate and human populations. This study was carried out to study the diversity and frequency of gastrointestinal parasites with zoonotic potential in green monkeys in the Bandia Reserve located in Senegal. Materials and Methods: For this study, 164 stool samples of Chlorocebus aethiops sabaeus (green monkey) were collected from October to November 2018 from Bandia Reserve. Stool samples were processed using the merthiolate-iodine-formalin staining technique and the modified Ritchie method. The slides were examined under a microscope and the identification of parasites was based on the morphology of protozoan cysts and helminth eggs. The analysis of data was conducted using R version 3.4.3 with p=0.05. Results: A total of six species of parasites were found, including five protozoa (Entamoeba coli, Entamoeba histolytica/ dispar, Entamoeba hartmanni, Endolimax nana, and Iodamoeba butschlii) and one nematode (Strongyloides spp.). The overall prevalence of gastrointestinal parasite was 76.2% (95% CI: 69.7%-82.7%). Two parasites with zoonotic potential, mainly E. histolytica/dispar with a prevalence of 13.4% (95% CI: 8.2%-18.6%) and Strongyloides spp. with a prevalence of 6.7% (95% CI: 2.9%-10.5%), were found. Conclusion: This study indicated that the monkeys of the Bandia Reserve are infested by zoonotic parasites and can, therefore, ensure transmission to visitors to the Reserve. The parasitological data that we report are the first available for these species of monkeys in the Bandia Reserve.

A novel MLSA allelic profile 'A15' of Mycoplasma mycoides subsp mycoides in Niger

Mycoplasma mycoides subsp. mycoides (Mmm) is the aetiological agent of contagious bovine pleuropneumonia (CBPP). The aim of the present study was to identify the profiles of the Mmm strains isolated in Niger using the ‘Multilocus Sequence Analysis’ (MLSA) typing technique based on polymorphism analysis of housekeeping and non‐coding genes. The investigation was conducted on samples (n=22) comprising of lung tissues, lymph node and pleural fluids. Following classical PCR, Mmm positive amplicons (n=6) were identified. These positive amplicons were then amplified using eight loci of the PG1 reference strain (LocPG1‐0001, Loc‐PG1‐0103, Loc‐PG1‐0287, Loc‐PG1‐0431, Loc‐PG1‐0489, Loc‐PG1‐0523, Loc‐PG1‐0710 and Loc‐PG1‐0827). Sequencing followed by the determination of the profile of each strain by the combination of the allele numbers revealed three different MLSA profiles namely; A11, E01 and A15. The profiles A11 and E01 were previously identified. The novel profile identified in this study was named profile A15. The difference was detected while comparing sequences of non‐coding loci. This novel profile was named ‘A15’ according to the similarities with African reference strain profile ‘A00’ at the seven loci level (loc‐0103, loc‐0287, loc‐0431, loc‐0489, loc‐0523, loc‐0710 and loc‐0827). For CBPP control measures, identification and molecular characterization of Mmm strains is very important. Thus, the use of MLSA technique is relevant to identify profiles of Mmm circulating in Niger. Other countries where CBPP is still endemic are encouraged to use a MLSA scheme to address this issue and, most importantly, to rapidly trace back the origin of outbreaks, which will help reduce the transmission and spread of the disease. In addition, mapping the profiles of strains circulating in each of the countries of the sub‐region is necessary for effective control of CBPP.

Serological Prevalence of Contagious Bovine Pleuropneumonia in Niger in 2017

Contagious bovine pleuropneumonia (CBPP) is a highly contagious disease of cattle caused by Mycoplasma mycoides subsp. mycoides Biotype Small Colony (MmmSC). The disease currently occurs in most of sub-Saharan Africa and where it is endemic and a major constraint for improving pastoral productivity. Following the persistence of this scourge, and in order to control this disease, a serological survey was conducted to determine the prevalence of CBPP in Niger. In fact, 1,590 sera were collected following a stratified sampling plan based on the risk factor of dissemination of CBPP. The analysis were performed at the Central Livestock Laboratory using the c-Elisa test. The results obtained show a wide distribution of the disease with an overall prevalence of 4.15% at individual level. The highest prevalences were recorded in the South-East regions [Zinder (7.5%), Diffa (7.5%)] and the West part [Tahoua (6.9%)]. The prevalence at the commune level was about 36.55%, which was relatively high. The prevalence at strata level was 36.55% (95% PI 0.2428-0.4882). The expected prevalences did not match those found. The results of this serological survey are considered the reference situation (T0) of CBPP in Niger with the PRAPS project, and allowed to the country to redefine control policies for better control of the disease at national and sub-regional level.