MERS coronaviruses from camels in Africa exhibit region-dependent genetic diversity.

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal-human interface.

Functional characterization of Copy Number Variations regions in Djallonké sheep.

A total of 184 Djallonké (West African Dwarf) sheep of Burkina Faso were analysed for Copy Number Variations (CNV) using Ovine 50 K SNP BeadChip genotyping data and two different CNV calling platforms: PennCNV and QuantiSNP. Analyses allowed to identify a total of 63 candidate Copy Number Variations Regions (CNVR) on 11 different ovine chromosomes covering about 82.5 Mb of the sheep genome. Gene-annotation enrichment analysis allowed to identify a total of 751 potential candidate ovine genes located in the candidate CNVR bounds. Functional annotation allowed to identify five statistically significant Functional Clusters (FC; enrichment factor > 1.3) involving 61 candidate genes. All genes forming significantly enriched FC were located on ovine chromosome (OAR) 21. FC1 (22 genes including PAG4 and PAG6) and FC5 (three genes: CTSC, CTSW and CTSF), coding proteases (peptidases and cathepsins, respectively), were involved in reproductive performance and modulation of gestation. Both FC3 and FC4 were involved in inflammatory and immunologic response through coding serum amyloid A and B-box-type zinc finger proteins, respectively. Finally, FC2 consisted of 27 genes (including OR10G6 and OR8B8) involved in olfactory receptor activity, key for animals adapting to new food resources. CNVR identified on at least 15% of individuals were considered CNVR hotspots and further overlapped with previously reported quantitative trait loci (QTL). CNVR hotspots spanning genes putatively involved with lipid metabolism (SKP1, TCF7, JADE2, UBE2B and SAR1B) and differential expression in mammary gland (SEC24A and CDKN2AIPNL) on OAR5 and dairy traits (CCDC198 and SLC35F4) on OAR7 overlapped with QTL associated with lipid metabolism, milk protein yield and milk fat percentage. Information obtained from local sheep populations naturally adapted to harsh environments contributes to increase our understanding of the genomic importance of CNV.

Population structure, inbreeding and admixture in local cattle populations managed by community-based breeding programs in Burkina Faso.

High-throughput genomic markers provide an opportunity to assess important indicators of genetic diversity for populations managed in livestock breeding programs. While well-structured breeding programs are common in developed countries, in developing country situations, especially in West Africa, on-farm performance and pedigree recordings are rare, and thus, genomic markers provide insights to the levels of genetic diversity, inbreeding and introgression by other breeds. In this study, we analysed key population parameters such as population structure, admixture and levels of inbreeding in three neighbouring populations of African taurine and taurine × Zebu crosses managed by community-based breeding programs in the South-West of Burkina Faso. The three populations were pure Baoulé (called Lobi locally) in sedentary production systems, Baoulé x Zebu crossbreds in sedentary systems and Zebu × Baoulé crossbreds in transhumant production systems, respectively. The total sample analysed included 631 animals and 38,207 single nucleotide polymorphisms after quality control. Results of principal component and admixture analyses confirmed the genetic background of two distinct ancestral populations (taurine and zebuine) and levels of admixture in all three breeding populations, including the presumably pure Baoulé group of animals. Inbreeding levels were moderate, compared to European dairy and beef cattle populations and higher than those of Brazilian Nellore cattle. Very few animals with inbreeding levels indicating parent-offspring or full sib mating were observed, and inbreeding levels indicating half sib mating were also rare. For the management of breeding populations, farmers were advised to exchange best young bulls. The crossbreeding levels of presumably pure Baoulé animals are of concern to the breeding program due to the high level of endangerment of pure African taurine cattle populations across West Africa. Future rounds of bull selection in the community-based breeding program will make use of genomic information about admixture levels.

Prevalence of trypanosomes, salivary gland hypertrophy virus and Wolbachia in wild populations of tsetse flies from West Africa.

BACKGROUND: Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia, Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia, trypanosomes, and SGHV in four tsetse species (Glossina palpalis gambiensis, G. tachinoides, G. morsitans submorsitans, and G. medicorum) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal. RESULTS: The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis. The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia. In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species (9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected. CONCLUSION: The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.

[Evaluation of epidemiological monitoring of post-vaccination adverse reactions in Abidjan]. / Évaluation de la surveillance épidémiologique des manifestations adverses post-immunisations à Abidjan.

INTRODUCTION: This study was designed to evaluate the adverse events following immunization (AEFI) monitoring system in Abidjan health districts. METHODS: This cross-sectional study focused on activities conducted between 1st January and 31st December 2015 in the nine health districts of Abidjan. Data were collected by means of a questionnaire based on the model of World Health Organization evaluation forms. These questionnaires were administered to personnel in charge of epidemiological surveillance in the health districts and the personnel of district hospitals and health centres. RESULTS: The AEFI monitoring system, apart from its simplicity and flexibility, remains fairly ineffective due to the relatively low acceptability by all health workers involved. Only 4% of healthcare personnel respondents participate in this activity; 55% of health districts reported cases of AEFI and 25% of health centres reported cases of adverse events. The low acceptability makes this system less sensitive and ineffective for health policy decision-making designed to reduce adverse events following immunization. CONCLUSION: Improved performance of the AEFI monitoring system requires better training of health workers, better data processing equipment and improved community participation.

Risk factors for MERS coronavirus infection in dromedary camels in Burkina Faso, Ethiopia, and Morocco, 2015.

Understanding Middle East respiratory syndrome coronavirus (MERS-CoV) transmission in dromedary camels is important, as they consitute a source of zoonotic infection to humans. To identify risk factors for MERS-CoV infection in camels bred in diverse conditions in Burkina Faso, Ethiopia and Morocco, blood samples and nasal swabs were sampled in February-March 2015. A relatively high MERS-CoV RNA rate was detected in Ethiopia (up to 15.7%; 95% confidence interval (CI): 8.2-28.0), followed by Burkina Faso (up to 12.2%; 95% CI: 7-20.4) and Morocco (up to 7.6%; 95% CI: 1.9-26.1). The RNA detection rate was higher in camels bred for milk or meat than in camels for transport (p = 0.01) as well as in younger camels (p = 0.06). High seropositivity rates (up to 100%; 95% CI: 100-100 and 99.4%; 95% CI: 95.4-99.9) were found in Morocco and Ethiopia, followed by Burkina Faso (up to 84.6%; 95% CI: 77.2-89.9). Seropositivity rates were higher in large/medium herds (≥51 camels) than small herds (p = 0.061), in camels raised for meat or milk than for transport (p = 0.01), and in nomadic or sedentary herds than in herds with a mix of these lifestyles (p < 0.005).

A genome-wide perspective about the diversity and demographic history of seven Spanish goat breeds.

BACKGROUND: The main goal of the current work was to infer the demographic history of seven Spanish goat breeds (Malagueña, Murciano-Granadina, Florida, Palmera, Mallorquina, Bermeya and Blanca de Rasquera) based on genome-wide diversity data generated with the Illumina Goat SNP50 BeadChip (population size, N = 176). Five additional populations from Europe (Saanen and Carpathian) and Africa (Tunisian, Djallonké and Sahel) were also included in this analysis (N = 80) for comparative purposes. RESULTS: Our results show that the genetic background of Spanish goats traces back mainly to European breeds although signs of North African admixture were detected in two Andalusian breeds (Malagueña and Murciano-Granadina). In general, observed and expected heterozygosities were quite similar across the seven Spanish goat breeds under analysis irrespective of their population size and conservation status. For the Mallorquina and Blanca de Rasquera breeds, which have suffered strong population declines during the past decades, we observed increased frequencies of large-sized (ROH), a finding that is consistent with recent inbreeding. In contrast, a substantial part of the genome of the Palmera goat breed comprised short ROH, which suggests a strong and ancient founder effect. CONCLUSIONS: Admixture with African goats, genetic drift and inbreeding have had different effects across the seven Spanish goat breeds analysed in the current work. This has generated distinct patterns of genome-wide diversity that provide new clues about the demographic history of these populations.

African Cattle do not Carry Unique Mutations on the Exon 9 of the ARHGAP15 Gene.

A panel of 81 Asian, African and European cattle (Bos taurus and B. indicus) was sequenced for the exon 9 of the ARHGAP15, a strong candidate for cattle trypanotolerance on BTA2. The analyses provided five different haplotypes defined by four (two nonsynonymous) mutations. Neutrality tests suggest a recent sweep in the studied bovine sequences. The two most frequent haplotypes (H1 and H3) gathered 88% of the chromosomes analyzed and were present in all the cattle groups analyzed, including Asian zebu and European cattle. The current results question the sole association of the polymorphism identified, including mutation c.53317501A > C, with the trypanotolerant response in West African cattle.

Prevalence of Primary HPV in Djibouti: Feasibility of Screening for Early Diagnosis of Squamous Intraepithelial Lesions.

OBJECTIVE: In many African Sub-Saharan countries, human papilloma virus (HPV) prevalence data are not available. The current study estimated the prevalence of HPV virus in the female population of Djibouti. METHODS: Approximately 1000 asymptomatic women 16 to 64 years old were enrolled from 3 of the main health structures of Djibouti in 2014 and 2015; 998 cervical samples were tested for HPV-DNA of high risk types, 499 during the first year, and 499 during the second. Positive samples were typed with an HPV genotyping kit. RESULTS: The women were an average age of 38.8 years (SD, 10.2); 54 women tested positive for HPV (prevalence rate, 5.4% [95% confidence interval, 4.0-6.8]). The highest prevalence was observed among the women younger than 35 years. HPV66 was the most prevalent (15.4% of the infections), followed by HPV31 and HPV52 (10.8% both) and HPV16 (9.2%). All 54 women who tested HPV-positive underwent a Pap test, which was positive in 8 cases (14.8%): 2 high-grade squamous intraepithelial lesion (HSIL) and 6 low-grade (LSIL). CONCLUSIONS: The HPV prevalence shows a curve by age similar to that of other African countries. The proportion of HPV16 is among the lowest ever seen in similar studies. The findings suggest to Djibouti the choice of a strategy of screening that includes forms of cytological triage, thus limiting recourse to colposcopy.

Geographical assessment of body measurements and qualitative traits in West African cattle.

A total of 1015 adult cows belonging to nine West African cattle breeds were assessed for 16 body measurements and 18 qualitative traits to ascertain the existence of geographical patterns of variation. Sampling was carried out in 29 different provinces of Mali, Burkina Faso and Benin. For body measurements, taurine breeds took lower average values than the zebu breeds. Sanga cattle took intermediate values. Qualitative traits did not allow to differentiate among cattle groups (taurine, zebu or sanga) or breeds. Principal component analysis identified two factors explaining 56.4 and 9.2 % of the variance for body measurements, respectively. Two correspondence analysis dimensions computed on qualitative traits explained a small proportion of the variability (20.8 and 13.5 %, respectively). Contour plots were constructed using the eigenvalues computed for each individual and either factor or dimension identified; confidence regions calculated confirmed that body measurements clearly differentiated zebu and taurine cattle breeds while qualitative traits did not. Factor 1 was projected on a geographical map, using provinces as nodes, to assess breed-free variation for body measurements. A pattern of continuous variation from the Sahel area southwards was identified. Probably, breeding decisions promoting the crosses between zebu-like and taurine cattle are underlying this geographical pattern of variation. The implementation of selection strategies aiming at the increase of the productivity of native West African taurine cattle breeds while avoiding looses in trypanotolerant ability would be highly advisable.

Anal disorders in pregnant and postpartum women: epidemiological, diagnostic and therapeutic aspects in 10 maternities of Bamako in Mali.

Bowel transit disturbances favored by pregnancy and injuries during childbirth would be triggering or aggravating factors for anal pathologies. The objective of this work was to study the epidemiology, diagnosis, and treatment of anal pathologies during pregnancy and 6 weeks after delivery. We carried out a prospective, multi-centric, and analytical study in 10 obstetric units in Bamako from June 1st, 2019, to May 31st, 2020. After informed consent, we enrolled all first-trimester pregnant women admitted to the hospitals and who were followed up through the postpartum. We conducted a rectal examination in each participant and an anoscope in those with an anal symptom. Hemorrhoidal diseases were diagnosed in the case of external hemorrhoids (thrombosis or prolapse) or internal hemorrhoids. During the study period, we followed up 1,422 pregnant women and we found 38.4% (546) with anal pathologies (hemorrhoidal diseases in 13% (192), anal fissure in 10.5% (150) and anal incontinence in 8.6% (123). Risk factors for the hemorrhoidal disease were age of patient ≥30 years old aRR=5.77, 95% CI 4.57-7.34; p=0.000; a existence of chronic constipation aRR=2.61, 95% CI 1.98-3.44; p=0.000; newborn weight >3500 g aRR= 1.61, 95% CI 1.25-2.07; p=0.000 and fetal expulsion time >20 minutes aRR= 6.04, 95% CI 5.07-7.27; p=0.000. The clinical signs observed were constipation, anal pain, bleeding, and pruritus. The treatment was based on counseling on hygiene and diet, the use of laxatives, local topicals, and analgesics along perineal rehabilitation. Anal pathologies were common during pregnancy and 6 weeks after delivery. Pregnant women must be screened systematically for such pathologies. Early diagnostic and appropriate treatment would reduce serious complications.

Modeling clinical malaria episodes in different ecological settings in Mali, 2018-2022.

Objectives: Following the scaling-up of malaria control strategies in Mali, understanding the changes in age-specific prevalence of infection and risk factors associated with remains necessary to determine new priorities to progress toward disease elimination. This study aimed to estimate the risk of clinical malaria using longitudinal data across three different transmission settings in Mali. Methods: Cohort-based longitudinal studies were performed from April 2018 to December 2022. Incidence of malaria was measured through community health center-based passive case detection. Generalized estimation equation model was used to assess risk factors for clinical malaria. Results: A total of 21,453 clinical presentations were reported from 4500 participants, mainly from July to November. Data shows a significant association between malaria episodes, sex, age group, season, and year. Women had lower risk, the risk of clinical episode increased with age up to 14 years then declined, and in both sites, the dry-season risk of clinical episode was significantly lower compared to the rainy season. Conclusion: Determining factors associated with the occurrence of clinical malaria across different ecological settings across the country could help in the development of new strategies aiming to accelerate malaria elimination in an area where malaria transmission remains intense.

Effect of textile colour on vector mosquito host selection: a simulated field study in Mali, West Africa.

BACKGROUND: The effect of clothing colour on the biting rates of different vector mosquito species is not well understood. Studies under tropical field conditions are lacking. This study aimed to determine the influence of clothing colours on mosquito biting rates in rural and suburban settings in West Africa. METHODS: We performed a simulated field study in a suburban and a rural site in Mali using Mosquito-Magnet traps utilizing CO2 and other attractants, which were covered with black, white, and black/white striped textile sheets covers. These targets operated continuously for 10 consecutive days with bright nights (around full moon) and 10 consecutive days with dark nights (around new moon). Trapped mosquitoes were collected and catch rates counted hourly. Mosquitoes were morphologically identified to the species complex level (Anopheles gambiae s.l. and Culex pipiens s.l.) or species level (Aedes aegypti). A subset of Anopheles specimens were further identified by molecular methods. RESULTS: Under bright-night conditions, An. gambiae s.l. was significantly more attracted to black targets than to white and striped targets; during dark nights, no target preference was noted. During bright nights, Cx. pipiens s.l. was significantly more attracted to black and striped targets than to white targets; a similar trend was noted during dark nights (not significant). For day-active Ae. aegypti, striped targets were more attractive than the other targets and black were more attractive than white targets. CONCLUSIONS: The study firstly demonstrated that under field conditions in Mali, West Africa, mosquito catch rates were influenced by different clothing colours, depending on mosquito species and light conditions. Overall, light colours were least attractive to host-seeking mosquitoes. Using white or other light-coloured clothing can potentially reduce bite exposure and risk of disease transmission in endemic tropical regions.

Genomic Reference Resource for African Cattle: Genome Sequences and High-Density Array Variants.

The diversity in genome resources is fundamental to designing genomic strategies for local breed improvement and utilisation. These resources also support gene discovery and enhance our understanding of the mechanisms of resilience with applications beyond local breeds. Here, we report the genome sequences of 555 cattle (208 of which comprise new data) and high-density (HD) array genotyping of 1,082 samples (537 new samples) from indigenous African cattle populations. The new sequences have an average genome coverage of ~30X, three times higher than the average (~10X) of the over 300 sequences already in the public domain. Following variant quality checks, we identified approximately 32.3 million sequence variants and 661,943 HD autosomal variants mapped to the Bos taurus reference genome (ARS-UCD1.2). The new datasets were generated as part of the Centre for Tropical Livestock Genetics and Health (CTLGH) Genomic Reference Resource for African Cattle (GRRFAC) initiative, which aspires to facilitate the generation of this livestock resource and hopes for its utilisation for complete indigenous breed characterisation and sustainable global livestock improvement.

Serological evidence and factors associated with Crimean-Congo haemorrhagic fever in sheep in Burkina Faso.

BACKGROUND: Crimean-Congo haemorrhagic fever (CCHF) is caused by an orthonairovirus transmitted by bites from infected ticks or by direct contact with blood or tissues of infected ticks, viraemic patients or viraemic livestock. OBJECTIVE: It was implemented to access the seropositivity and associated factors with CCHF in sheep in two provinces in Burkina Faso. METHODS: Three hundred and sixty-four sheep sera have been taken from 73 herds in four municipalities and two provinces. The double-antigen sandwich ELISA test was used to test for antibodies against CCHF virus (CCHFV). Data have also been collected using questionnaire to assess factors associated with CCHF seropositivity. RESULTS: Fifty-four (54 out to 364 sheep were seropositive given an overall seropositivity of 14.8% (95% confidence interval [CI]: 10.9%-19.8%) with an adjusted seropositivity of 13.1%. The study showed that 15.6% (95% CI: 10.2-21.0) and 14.1% (95% CI: 9.2-19.1) of sheep in the provinces of Mouhoun and Kénédougou, respectively, had antibodies against CCHFV. The highest seropositivity was found in Dédougou municipality (24.4%). The study showed that sheep from the municipalities of Dédougou (AOR = 8.4; 95% CI: 2.2-31.8), N'dorola (AOR = 14.7; 95% CI: 3.8-56.8), Sindou (AOR = 4.9; 95% CI: 1.2-20.7), sheep aged between 27 and 36 months (AOR = 6.4; 95% CI: 2.3-17.3) and sheep with ticks (AOR = 24.8; 95% CI: 7.7-80.1) were more likely to be seropositive to CCHF. CONCLUSIONS: The study revealed that sheep in Burkina Faso experienced contacts with CCHFV and suggests the importance of implementing control action in the country.

In vitro anthelmintic activity of Euphorbia forskalii J. Gay aqueous extracts evaluation on different life stages of Haemonchus contortus.

The use of medicinal plants in the control of gastrointestinal parasitosis is a promising solution for improving the productivity of sheep flocks. In order to evaluate the anthelmintic activity of Euphorbia forskallii, in vitro bioassays were performed on three life stages of Haemonchus contortus. Five aqueous extracts concentrations namely 10 mg/mL; 5 mg/mL; 2.5 mg/mL; 1.25 mg/mL and 0.62 mg/mL were used for adult worm mortality tests. Egg hatch inhibition and L3 larval migration inhibition tests were studied at 5 mg/mL; 2.5 mg/mL; 1.25 mg/mL; 0.62 mg/mL and 0.31 mg/mL. A negative control PBS and a positive control levamisole 2.5 mg/mL were established for each test. A phytochemical screening was performed to determine the presence of some secondary metabolites. The results obtained showed the presence of total polyphenols, total flavonoids and condensed tannins within the aqueous extracts of E. forskalii. A high and significant (P < 0.05) morality rate compared to the negative control with an LC50 of 2.30 mg/mL was obtained. Inhibition of egg hatch and larval migration were high and significant (p < 0.05) compared to the negative control. There was an IC50 of 1.03 mg/mL and 0.92 mg/mL respectively for inhibition of egg hatching and L3 larval migration. The present study revealed the in vitro anthelmintic activity of E. forskalii aqueous extracts and allows us to consider in perspective complementary studies to confirm this activity.

Ascertaining gene flow patterns in livestock populations of developing countries: a case study in Burkina Faso goat.

BACKGROUND: Introgression of Sahel livestock genes southwards in West Africa may be favoured by human activity and the increase of the duration of the dry seasons since the 1970's. The aim of this study is to assess the gene flow patterns in Burkina Faso goat and to ascertain the most likely factors influencing geographic patterns of genetic variation in the Burkina Faso goat population. RESULTS: A total of 520 goat were sampled in 23 different locations of Burkina Faso and genotyped for a set of 19 microsatellites. Data deposited in the Dryad repository: http://dx.doi.org/10.5061/dryad.41h46j37. Although overall differentiation is poor (FST = 0.067 ± 0.003), the goat population of Burkina Faso is far from being homogeneous. Barrier analysis pointed out the existence of: a) genetic discontinuities in the Central and Southeast Burkina Faso; and b) genetic differences within the goat sampled in the Sahel or the Sudan areas of Burkina Faso. Principal component analysis and admixture proportion scores were computed for each population sampled and used to construct interpolation maps. Furthermore, Population Graph analysis revealed that the Sahel and the Sudan environmental areas of Burkina Faso were connected through a significant number of extended edges, which would be consistent with the hypothesis of long-distance dispersal. Genetic variation of Burkina Faso goat followed a geographic-related pattern. This pattern of variation is likely to be related to the presence of vectors of African animal trypanosomosis. Partial Mantel test identified the present Northern limit of trypanosome vectors as the most significant landscape boundary influencing the genetic variability of Burkina Faso goat (p = 0.008). The contribution of Sahel goat genes to the goat populations in the Northern and Eastern parts of the Sudan-Sahel area of Burkina Faso was substantial. The presence of perennial streams explains the existence of trypanosome vectors. The South half of the Nakambé river (Southern Ouagadougou) and the Mouhoun river loop determined, respectively, the Eastern and Northern limits for the expansion of Sahelian goat genes. Furthermore, results from partial Mantel test suggest that the introgression of Sahelian goat genes into Djallonké goat using human-influenced genetic corridors has a limited influence when compared to the biological boundary defined by the northern limits for the distribution of the tsetse fly. However, the genetic differences found between the goat sampled in Bobo Dioulasso and the other populations located in the Sudan area of Burkina Faso may be explained by the broad goat trade favoured by the main road of the country. CONCLUSIONS: The current analysis clearly suggests that genetic variation in Burkina Faso goat: a) follows a North to South clinal; and b) is affected by the distribution of the tsetse fly that imposes a limit to the Sahelian goat expansion due to their trypanosusceptibility. Here we show how extensive surveys on livestock populations can be useful to indirectly assess the consequences of climate change and human action in developing countries.

Multicentre studies of insecticide-treated durable wall lining in Africa and South-East Asia: entomological efficacy and household acceptability during one year of field use.

BACKGROUND: Indoor residual spraying (IRS) is a primary method of malaria vector control, but its potential impact is constrained by several inherent limitations: spraying must be repeated when insecticide residues decay, householders can tire of the annual imposition and campaign costs are recurrent. Durable lining (DL) can be considered an advanced form of long-lasting IRS where insecticide is gradually released from an aesthetically attractive wall lining material to provide vector control for several years. A multicentre trial was carried out in Equatorial Guinea, Ghana, Mali, South Africa and Vietnam to assess the feasibility, durability, bioefficacy and household acceptability of DL, compared to conventional IRS or insecticide-treated curtains (LLITCs), in a variety of operational settings. METHODS: This study was conducted in 220 households in traditional rural villages over 12-15 months. In all sites, rolls of DL were cut to fit house dimensions and fixed to interior wall surfaces (usually with nails and caps) by trained teams. Acceptability was assessed using a standardized questionnaire covering such topics as installation, exposure reactions, entomology, indoor environment, aesthetics and durability. Bioefficacy of interventions was evaluated using WHO cone bioassay tests at regular intervals throughout the year. RESULTS: The deltamethrin DL demonstrated little to no decline in bioefficacy over 12-15 months, supported by minimal loss of insecticide content. By contrast, IRS displayed a significant decrease in bioactivity by 6 months and full loss after 12 months. The majority of participants in DL households perceived reductions in mosquito density (93%) and biting (82%), but no changes in indoor temperature (83%). Among those households that wanted to retain the DL, 73% cited protective reasons, 20% expressed a desire to keep theirs for decoration and 7% valued both qualities equally. In Equatorial Guinea, when offered a choice of vector control product at the end of the trial (DL, IRS or LLITCs), DL consistently emerged as the most popular intervention regardless of the earlier household allocation. CONCLUSIONS: Just as long-lasting insecticidal nets overcame several of the technical and logistical constraints associated with conventionally treated nets and then went to scale, this study demonstrates the potential of DL to sustain user compliance and overcome the operational challenges associated with IRS.

Prion protein gene polymorphism in four West African sheep populations.

A total of 162 individuals, belonging to three Burkinabé and one Niger sheep populations, were analysed for prion protein (PrP) gene polymorphism at codons 136, 154 and 171. The ARQ allele was the most frequent in both the Burkinabé (86.7%) and the Niger (67.5%) sheep populations. The highly sensitive allele VRQ was not found in the sampled individuals. The highly resistant ARR allele was in very low frequency in the Burkina-Sahel (4.4%) and Mossi (3.2%) populations and was not present in the Djallonké and Touareg populations. Only 4 out of 15 possible PrP genotypes were identified in the sampled individuals. No favourable ARR/ARR genotypes were found in either of the breeds. Sequencing a subgroup of the samples allowed the identification of other five polymorphisms on the PrP gene sequence at codons 116, 138, 151, 237 and 240. The very low frequency of the ARR allele in the West African sheep should dissuade the implementation of a preventive selection programme aimed to increase resistance to scrapie, to avoid an extreme erosion of the genetic stock.

Pigs' management practices and exposure to Trichinella spp. in pigs and warthogs in the northern area of Senegal.

Background and Aim: Trichinellosis is a neglected and emerging foodborne zoonosis in Africa. Trichinella infection occurs through the consumption of raw or undercooked infected meat and meat products. This study aimed to assess pigs' management practices and determine the exposure of pigs and warthogs to Trichinella spp. in the northern area of Senegal. Materials and Methods: Surveys and observations were carried out among 40 pig farmers to assess husbandry practices regarding Trichinella spp. life cycle. In addition, 201 pig meat juices and 83 warthog meat juices were extracted and tested for anti-Trichinella antibodies by indirect enzyme-linked immunosorbent assay. Results: Most (97%) of farms practiced a traditional farming system with free-ranging of pigs in 85% of farms. Farms had local pig breed without housing and supplementary feeding. Some farmers (27.5%) used slaughter waste to feed pigs and farmers were not aware that free-range farming is a source of infection to Trichinella infection. They were also unaware that some pig diseases could be transmitted to humans. The seroprevalence of Trichinella infection was 10.9% (95% confidence interval [CI]: 6.6-15.2%) in pigs and 10.8% (95% CI: 4.16-17.52%) in warthogs with significantly higher seroprevalence in male (22.2%: 95% CI: 6.6-37.8%) compared to female (9.2%; 95% CI: 4.9-13.5%) (p < 0.05). Conclusion: The confirmation of exposure to Trichinella spp. in this area in pigs and warthogs shows a significant risk of transmission of this disease to humans if the farming conditions and the health surveillance system are not respected. However, control measures are needed to reduce any risk of transmission of Trichinella infection to humans.