The prevalence and distribution of the amyloidogenic transthyretin (TTR) V122I allele in Africa

Transthyretin (TTR) pV142I (rs76992529-A) is one of the 113 variants in the human TTR gene associated with systemic amyloidosis. It results from a G to A transition at a CG dinucleotide in the codon for amino acid 122 of the mature protein (TTR V122I). The allele frequency is 0.0173 in African Americans

Timing of releases of the parasitoid Habrobracon hebetor and numbers needed in augmentative biological control against the millet head miner Heliocheilus albipunctella

Heliocheilus albipunctella de Joannis (Lepidoptera: Noctuidae) is one of the major insect pests of pearl millet in the Sahel. The native parasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae), is currently being promoted for augmentative biological control of the pest in the Sahel. The current study was carried out to identify the right time for releases of the parasitoid using either pearl millet growing stage, or pest occurrence as reference, and to determine the optimal number of parasitoids needed to cover a given area. Our results indicate that release of parasitoids at the panicle emergence stage or six weeks after first sight of eggs of H. albipunctella lead to highest parasitism of H. albipunctella larvae by H. hebetor. The dose of 800 parasitoids for a distance of 3 km radius was enough for controlling H. albipunctella. The implications of the results are discussed toward cost effective and practical recommendation adapted to the Sahelian conditions

Development of an Optimum Diet for Mass Rearing of the Rice Moth, Corcyra cephalonica (Lepidoptera: Pyralidae), and Production of the Parasitoid, Habrobracon hebetor (Hymenoptera: Braconidae), for the Control of Pearl Millet Head Miner

The rice moth, Corcyra cephalonica Stainton, an alternate host for the production of the parasitoid, Habrobracon hebetor Say, was reared on different diets, including pearl millet [Pennisetum glaucum (L.) R. Br.] (Poales: Poaceae) flour only, and in combinations of flours of sorghum [Sorghum bicolor (L.) Moench] (Poales: Poaceae), peanut (Arachis hypogea L.) (Fabales: Fabaceae), and cowpea [Vigna unguiculata (L.) Walp.] (Fabales: Fabaceae) to identify the optimal and economical proportion to be used under the conditions of Niger. The addition of cowpea or peanut to the pearl millet diet slightly increased C. cephalonica larval development time. Likewise, the addition of cowpea or peanut to cereal diets yielded a higher C. cephalonica larval survival. Female moths emerging from larvae fed on cereal and legume mixed diets produced higher eggs compared to the ones fed on sole and mixed cereals. Among legumes, cowpea addition is most interesting in terms of cost/production of C. cephalonica larvae. However, female moths emerging from larvae fed on different millet cowpea mix (5, 25, and 50%) laid significantly more eggs than those fed on sole pearl millet. Further, individual C. cephalonica larvae fed on 75% pearl millet + 25% cowpea produced significantly more H. hebetor. With an initial 25 C. cephalonica larvae kept for a 3-mo rearing period, the number of H. hebetor parasitoids produced will reach 2.68–10.07 million. In terms of cost/production ratio, the 75% pearl millet: 25% cowpea yielded better results

Native parasitoids recruited by the invaded fall army worm in Niger

Surveys of fall army worm Spodoptera frugiperda (J. S. Smith) on maize and sorghum in Niger revealed the occurrence of egg parasitoids (Trichogrammatoidea sp., Trichogramma sp., and Telenomus sp.), egg-larval parasitoids (Chelonus sp.), and larval parasitoids (Cotesia sp., and Charops sp.)

Field screening of groundnuts for resistance to seed infection by Aspergillus flavus

1107 genotypes d'arachide, au total, ont ete cribles pour l'infestation naturelle des graines par Aspergillus flavus dans des essais avec repetitions au champ au centre ICRISAT, a Patancheru, Inde, de 1984 a 1989. Par la suite, les plus interessants ont ete evalues pour leur resistance a l'infestation des graines au champ par A. flavus dans des essais de criblage plus pousses au centre ICRISAT et au Senegal pendant la saison des pluies et la saison seche de 1985 a 1990. Vingt-cinq genotypes se sont averes resistants a l'infestation des graines par A. flavus, dont 9 testes au Senegal ont egalement montre leur resistance dans des situations differentes. La resistance a l'infestation des graines au champ par A. flavus est restee stable dans toutes les situations. Une secheresse severe en fin de culture, surtout pendant la maturation des gousses, a joue un role important pour un bon criblage de la resistance. Certains genotypes sensibles a la colonisation in vitro des graines par A. flavus (Exotie 6, U4-7-5 et VRR 245) ont presente une resistance a l'infestation des graines au champ. Le rendement en gousse et la qualite commerciale de certains genotypes resistants au champ (55-437, J11, U4-7-5 et VRR 245) sont satisfaisants. L'interet d'une telle resistance est consider

Economic feasibility of an augmentative biological control industry in Niger

Farmers in Niger are vulnerable to high millet yield losses due to the millet head miner, Heliocheilus albipunctella De Joannis (Lepidoptera: Noctuidae), for which pest control options are limited. Researchers have developed a procedure to multiply and spread an augmentative biological control agent Habrobracon hebetor Say (Hymenoptera: Braconidae) which is effective in limiting millet yield losses due to the pest. This study assesses the economic viability of small businesses to produce and sell biological control agents. It analyzes the profitability of the businesses under alternative pricing regimes given estimated costs to produce and distribute biological control agents. The economic assessment provides budget analysis for potential businesses and discusses options for scaling, price setting, and organizing. Our study suggests that the small H. hebetor industry should turn a profit in Niger at relatively low prices for the biological control agents of $3.00-$4.00 per bag with 15 bags needed per village. Competitive wages are achievable for the businesses that sell to at least 13 villages. Each business would hire three workers from late May to late August. Commercialization of H. hebetor would generate opportunities for wide geographic distribution of the technology on a sustainable basis in Niger

Epidemiological Interactions between Urogenital and Intestinal Human Schistosomiasis in the Context of Praziquantel Treatment across Three West African Countries

© 2015 Knowles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

Genomic characterisation of human monkeypox virus in Nigeria

Monkeypox virus (MPXV) is a large, double-stranded DNA virus belonging to the Orthopox genus in the family Poxviridae. First identified in 1958, MPXV has caused sporadic human outbreaks in central and west Africa, with a mortality rate between 1% and 10%.1 Viral genomes from west Africa and the Congo Basin separate into two clades, the latter being more virulent.2 Recently, MPXV outbreaks have occurred in Sudan (2005), the Republic of the Congo and Democratic Republic of the Congo (2009), and the Central African Republic (2016).3 A suspected outbreak of human MPXV was reported to WHO on Sept 26, 2017, by the Nigeria Centre for Disease Control (NCDC) after a cluster of suspected cases had occurred in Yenagoa Local Government Area, Bayelsa State, Nigeria.4 Since the onset of the outbreak, 155 cases have been reported by the NCDC, of which 56 were confirmed.4 A subset of these samples was sent to the WHO Collaborating Center at the Institut Pasteur de Dakar (IPD) in Senegal for confirmation by PCR

Pharyngeal Carriage of Beta-Haemolytic Streptococcus Species and Seroprevalence of Anti-Streptococcal Antibodies in Children in Bouaké, Côte d’Ivoire

The pharynx of the child may serve as a reservoir of pathogenic bacteria, including beta-haemolytic group A streptococci (GAS), which can give rise to upper airway infections and post-streptococcal diseases. The objective of this study was to determine the prevalence of beta-haemolytic Streptococcus spp. in pharyngeal samples stemming from children aged 3–14 years in Bouaké, central Côte d’Ivoire. Oropharyngeal throat swabs for microbiological culture and venous blood samples to determine the seroprevalence of antistreptolysin O antibodies (ASO) were obtained from 400 children in March 2017. Identification was carried out using conventional bacteriological methods. Serogrouping was performed with a latex agglutination test, while an immunological agglutination assay was employed for ASO titres. The mean age of participating children was 9 years (standard deviation 2.5 years). In total, we detected 190 bacteria in culture, with 109 beta-haemolytic Streptococcus isolates, resulting in an oropharyngeal carriage rate of 27.2%. Group C streptococci accounted for 82.6% of all isolates, whereas GAS were rarely found (4.6%). The ASO seroprevalence was 17.3%. There was no correlation between serology and prevalence of streptococci (p = 0.722). In conclusion, there is a high pharyngeal carriage rate of non-GAS strains in children from Bouaké, warranting further investigation

Quantitative analysis of particles, genomes and infectious particles in supernatants of haemorrhagic fever virus cell cultures

Information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. Here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (HFV), of the Arenaviridae, Filoviridae, Bunyaviridae, and Flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i) electron microscopy for the quantification of virus particles, (ii) quantitative real time PCR for the quantification of genomes, and (iii) determination of focus forming units by coating fluorescent antibodies to infected cell monolayers for the quantification of virus infectivity