Molecular Diversity of Nematode Parasites in Afrotropical Reed Frogs (Hyperolius spp.)

The diversity of nematodes infecting amphibians is understudied in tropical Africa and unknown in Rwanda. Diversity assessment is hampered by the fact that species descriptions refer mostly to morphological features that are unlinked to DNA sequences of marker genes available in public databases. In this paper, we explore the abundance and diversity of parasitic nematodes in reed frogs Hyperolius kivuensis (n = 115), H. parallelus (n = 45) and H. viridiflavus (n = 100) collected in Rwanda. Five nematode species were identified morphologically as Orneoascaris chrysanthemoides, O. schoutedeni, Gendria leberrei, Aplectana chamaeleonis and Rhabdias collaris. Corresponding DNA sequences of 18S and COI genes were determined and subsequently deposited in GenBank. Aplectana chamaeleonis showed the highest prevalence (8.7%), but O. chrysanthemoides the highest mean intensity of infection (6.0) and largest number (24) of individuals in H. kivuensis. To the best of our knowledge, all amphibian hosts are new records for these nematode species, which are known to infect a wide range of amphibian and reptile species. Our findings suggest that nematode diversity is probably lower than previously assumed due to low host specificity. As morphological species identification is often challenging, our data facilitate molecular identification of adult and specifically larval nematodes found in amphibians of Sub-Saharan Africa.

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Abundance and diversity of plant-parasitic nematodes associated with watermelon in Nigeria, with focus on Meloidogyne spp.

Nematology ◽

10.1163/15685411-00003340 ◽

2020 ◽

Vol 22 (7) ◽

pp. 781-797

Author(s):

Tesleem T. Bello ◽

Danny L. Coyne ◽

Milad Rashidifard ◽

Hendrika Fourie

Keyword(s):

Nematode Species ◽

Sub Saharan Africa ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

South West ◽

Meloidogyne Enterolobii ◽

Baseline Information ◽

Sub Saharan ◽

Abundance And Diversity ◽

Plant Parasitic

Summary Little information is available for nematode pests associated with watermelon in sub-Saharan Africa (SSA). This study recorded the abundance and prevalence of plant-parasitic nematodes from 25 localities across south-west Nigeria during 2016/2017. Of the 11 nematode species identified, those belonging to Meloidogyne spp. were predominant according to Prominence Values, followed by Helicotylenchus dihystera, Pratylenchus zeae and Scutellonema bradys. Morphological and molecular analyses revealed the identity of four species of root-knot nematodes: Meloidogyne enterolobii, M. incognita, M. javanica and M. arenaria (in descending order of abundance and occurrence). Meloidogyne arenaria is reported for the first time from south-west Nigeria, while S. bradys and Xiphinema nigeriense are first reports for watermelon. Significant associations were observed between the frequency of occurrence of the predominant nematode species and soil properties as well as rainfall. Results provide baseline information on the nematode pest occurrence on watermelon in Nigeria and in a wider context for SSA.

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Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

Parasites & Vectors ◽

10.1186/s13071-021-04602-y ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Peter Halvarsson ◽

Johan Höglund

Keyword(s):

Species Richness ◽

Diversity Index ◽

Nematode Species ◽

Abundant Species ◽

Anthelmintic Treatment ◽

Host Age ◽

Larval Culture ◽

Nematode Parasites ◽

South Central ◽

Nematode Diversity

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.

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Addressing Pediatric HIV Pretreatment Drug Resistance and Virologic Failure in Sub-Saharan Africa: A Cost-Effectiveness Analysis of Diagnostic-Based Strategies in Children ≥3 Years Old

Diagnostics ◽

10.3390/diagnostics11030567 ◽

2021 ◽

Vol 11 (3) ◽

pp. 567

Author(s):

Mutita Siriruchatanon ◽

Shan Liu ◽

James G. Carlucci ◽

Eva A. Enns ◽

Horacio A. Duarte

Keyword(s):

Drug Resistance ◽

Cost Effectiveness ◽

Virologic Failure ◽

Pediatric Hiv ◽

Sub Saharan Africa ◽

Financial Investment ◽

Switching Strategy ◽

Wide Range ◽

Sub Saharan ◽

Living With Hiv

Improvement of antiretroviral therapy (ART) regimen switching practices and implementation of pretreatment drug resistance (PDR) testing are two potential approaches to improve health outcomes for children living with HIV. We developed a microsimulation model of disease progression and treatment focused on children with perinatally acquired HIV in sub-Saharan Africa who initiate ART at 3 years of age. We evaluated the cost-effectiveness of diagnostic-based strategies (improved switching and PDR testing), over a 10-year time horizon, in settings without and with pediatric dolutegravir (DTG) availability as first-line ART. The improved switching strategy increases the probability of switching to second-line ART when virologic failure is diagnosed through viral load testing. The PDR testing strategy involves a one-time PDR test prior to ART initiation to guide choice of initial regimen. When DTG is not available, PDR testing is dominated by the improved switching strategy, which has an incremental cost-effectiveness ratio (ICER) of USD 579/life-year gained (LY), relative to the status quo. If DTG is available, improved switching has a similar ICER (USD 591/LY) relative to the DTGstatus quo. Even when substantial financial investment is needed to achieve improved regimen switching practices, the improved switching strategy still has the potential to be cost-effective in a wide range of sub-Saharan African countries. Our analysis highlights the importance of strengthening existing laboratory monitoring systems to improve the health of children living with HIV.

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Genetic polymorphism and population structure ofEchinococcus ortleppi

Parasitology ◽

10.1017/s0031182016001840 ◽

2016 ◽

Vol 144 (4) ◽

pp. 450-458 ◽

Cited By ~ 17

Author(s):

F. ADDY ◽

M. WASSERMANN ◽

F. BANDA ◽

H. MBAYA ◽

J. ASCHENBORN ◽

...

Keyword(s):

Genetic Polymorphism ◽

South America ◽

Southern Africa ◽

Dna Sequences ◽

Intraspecific Variability ◽

Sensu Stricto ◽

Sub Saharan Africa ◽

Geographical Regions ◽

Sub Saharan ◽

Eastern And Southern Africa

SUMMARYThe zoonotic cestodeEchinococcus ortleppi(Lopez-Neyra and Soler Planas, 1943) is mainly transmitted between dogs and cattle. It occurs worldwide but is only found sporadically in most regions, with the notable exception of parts of southern Africa and South America. Its epidemiology is little understood and the extent of intraspecific variability is unknown. We have analysed in the present study the genetic diversity among 178E. ortleppiisolates from sub-Saharan Africa, Europe and South America using the complete mitochondrialcox1(1608 bp) andnad1(894 bp) DNA sequences. Genetic polymorphism within the loci revealed 15cox1and sixnad1haplotypes, respectively, and 20 haplotypes of the concatenated genes. Presence of most haplotypes was correlated to geographical regions, and only one haplotype had a wider spread in both eastern and southern Africa. Intraspecific microvariance was low in comparison withEchinococcus granulosussensu stricto, despite the wide geographic range of examined isolates. In addition, the various sub-populations showed only subtle deviation from neutrality and were mostly genetically differentiated. This is the first insight into the population genetics of the enigmatic cattle adaptedEchinococcus ortleppi. It, therefore, provides baseline data for biogeographical comparison amongE. ortleppiendemic regions and for tracing its translocation paths.

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Cassava Processing in Sub-Saharan Africa: the Implications for Expanding Cassava Production

Outlook on Agriculture ◽

10.1177/003072709402300307 ◽

1994 ◽

Vol 23 (3) ◽

pp. 197-205 ◽

Cited By ~ 10

Author(s):

Felix Izu Nweke

Keyword(s):

Food Security ◽

Water Supply ◽

Sub Saharan Africa ◽

Wide Range ◽

Intensive Use ◽

Cassava Production ◽

Sub Saharan ◽

Processing Techniques ◽

Technical Solutions ◽

Poor Soil

Cassava makes an important contribution to improving food security and rural incomes in sub-Saharan Africa, as it is tolerant of drought and poor soil and its cultivation does not require much labour. However, the fresh roots are bulky and perishable and need to be processed before they can be marketed; processing also removes the cyanogens which make many varieties poisonous in their raw form. Cassava roots are turned into granules, flours, pastes and chips, with a wide range of flavours and appearances for different areas and markets. Many different processing techniques are used, some of which make intensive use of fuelwood while others require a plentiful water supply. These requirements, as well as the need for a good transport and marketing infrastructure, limit the expansion of cassava production in sub-Saharan Africa, but technical solutions are being found.

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Comparative Area Studies and the Study of the Global South

Vestnik RUDN International Relations ◽

10.22363/2313-0660-2020-20-2-279-287 ◽

2020 ◽

Vol 20 (2) ◽

pp. 279-287

Author(s):

Rudra Sil ◽

Ariel I. Ahram

Keyword(s):

Social Science ◽

Science Inquiry ◽

Global South ◽

Sub Saharan Africa ◽

Theory Building ◽

Spatial And Temporal Variation ◽

Area Studies ◽

Wide Range ◽

Range Theory ◽

Sub Saharan

Comparative Area Studies (CAS) offers a template to bring the Global South back into the foreground of social science inquiry. CAS urges researchers to grapple directly with empirical variations derived from across the seemingly different global regions. CAS offers three comparative modes: intra-regional, cross-regional, and trans-regional. A number of scholars have used CAS’s comparative rubrics, even without knowing about the wider CAS agenda and program. CAS unsettles assumptions about discrete, fixed “regional” or civilizational blocks as well as about nomothetic theory-building aimed at universal or general laws. At the same time, CAS engages in the idea of medium-range theory-building, focusing empirical rigor and induction in order to create concepts and analyses that are portable yet contextualized. These macro-historical theories must be attentive to spatial and temporal variation in the social world. Claims of universalism are suspect. For the study of the Global South, in particular, CAS provides a path for aggregating and leveraging the wide range of observations and interpretations area specialists have to offer on regions as diverse as South Asia, the Middle East, Latin America, and sub-Saharan Africa. CAS thus changes the division of labor within social science to allow greater input for scholarship derived from and originating in the developing world.

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Student-perceived criteria for assessing university relevance in community development

South African Journal of Science ◽

10.17159/sajs.2016/20160071 ◽

2016 ◽

Vol Volume 112 (Number 11/12) ◽

Cited By ~ 1

Author(s):

Joseph Francis ◽

Beata Kilonzo ◽

Pertina Nyamukondiwa ◽

◽

...

Keyword(s):

Community Development ◽

Rural Area ◽

Undergraduate Students ◽

Rural Areas ◽

Sub Saharan Africa ◽

Community Members ◽

Sustainable Solutions ◽

Wide Range ◽

Perceptions Of Students ◽

Sub Saharan

Abstract In sub-Saharan Africa, universities are increasingly being called upon to contribute more towards combating poverty and promoting development in rural areas. Yet, it is still argued that universities are ivory towers, and as a result, their contribution to finding sustainable solutions to issues hampering the realisation of improved quality of life of people in rural areas remains unsatisfactory. This perception emanates from the universities’ apparent failure to articulate and demonstrate how they can achieve the desired goal stated above. Moreover, there are no universally embraced criteria for assessing the relevance of a rural area based university to the community it serves. This study was therefore carried out to determine the perceptions of University of Venda undergraduate students on what they believed were appropriate criteria for assessing the relevance of a rural area based university in community development in South Africa. Reflection circles, anchored on participatory research techniques, were used to engage the students. The results of the engagement were organised into sub-themes. The most prominent perceptions were: ‘A university has active long-term community-based development initiatives’; ‘A university is continuously addressing the real needs of the communities in question’; ‘University initiatives are creating jobs for its graduates and community members’; and ‘Continuous community requests for university assistance in solving the challenges militating against development’. The wide range of perceptions of students observed in this study is a useful input into initiatives seeking to develop an objective tool for assessing the relevance of a rural area based university in community development.

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Strategies for Representing Tone in African Writing Systems

Written Language & Literacy ◽

10.1075/wll.2.1.02bir ◽

1999 ◽

Vol 2 (1) ◽

pp. 1-44 ◽

Cited By ~ 19

Author(s):

Steven Bird

Keyword(s):

Practical Experience ◽

Sub Saharan Africa ◽

Writing Systems ◽

Tone Languages ◽

Wide Range ◽

Two Factors ◽

Sub Saharan ◽

Vernacular Literacy ◽

Methodological Principles ◽

As Stress

Tone languages provide some interesting challenges for the designers of new orthographies. One approach is to omit tone marks, just as stress is not marked in English (zero marking). Another approach is to do phonemic tone analysis, and then make heavy use of diacritic symbols to distinguish the "tonemes" (shallow marking). While orthographies based on either system have been successful, this may be thanks to our ability to manage inadequate orthographies, rather than to any intrinsic advantage which is afforded by one or the other approach. In many cases, practical experience with both kinds of orthography in sub-Saharan Africa has shown that people have not been able to attain the level of reading and writing fluency that we know to be possible for the orthographies of non-tonal languages. In some cases this can be attributed to a socio linguistic setting which does not favour vernacular literacy. In other cases, the orthography itself may be to blame. If the orthography of a tone language is difficult to use or to learn, then a good part of the reason may be that the designer either has not paid enough attention to the FUNCTION of tone in the language, or has not ensured that the information encoded in the orthography is ACCESSIBLE to the ordinary (non-linguist) user of the language. If the writing of tone is not going to continue to be a stumbling block to literacy efforts, then a fresh approach to tone orthography is required — one which assigns high priority to these two factors. This article describes the problems with orthographies that use too few or too many tone marks, and critically evaluates a wide range of creative intermediate solutions. I review the contributions made by phonology and reading theory, and provide some broad methodological principles to guide those who are seeking to represent tone in a writing system. The tone orthographies of several languages from sub-Saharan Africa are presented throughout the article, with particular emphasis on some tone languages of Cameroon.

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Assessing the Monophyly of Alectra and its Relationship to Melasma (Orobanchaceae)

Systematic Botany ◽

10.1600/036364409789271281 ◽

2009 ◽

Vol 34 (3) ◽

pp. 561-569 ◽

Cited By ~ 4

Author(s):

Jeffery J. Morawetz ◽

Andrea D. Wolfe

Keyword(s):

Dna Sequences ◽

Sub Saharan Africa ◽

African Species ◽

Widespread Species ◽

Tropical America ◽

Agricultural Weed ◽

The Subject ◽

Out Of Africa ◽

Sub Saharan ◽

India And China

Alectra (Orobanchaceae) consists of primarily hemiparasitic herbaceous species distributed mainly in sub-Saharan Africa, with two species native to tropical America, and two widespread species extending out of Africa into India and China. Despite containing an economically important noxious agricultural weed, Alectra has never been the subject of a phylogenetic analysis. The monophyly of Alectra was assessed using DNA sequences from the nuclear (internal transcribed spacer) and chloroplast (rpl16, trnT-L) genomes, including 11 of 12 species. One of two holoparasitic species, Alectra alba, was placed outside of Alectra, supported as sister to a lineage containing the Asian holoparasitic genera Aeginetia + Christisonia. Two highly supported lineages of Melasma were revealed: one containing the two included African species, and the other comprising the tropical American Melasma rhinanthoides and the single accession of the tropical American Escobedia. The placement of the Madagascan endemic Alectra fruticosa was shown to be unresolved in relationship to the remaining Alectra species and the two lineages containing Melasma. The monophyly of the remaining species of Alectra was highly supported.

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Place Names as an Historical Source: An Introduction with Examples from Southern Senegambia and Germany

History in Africa ◽

10.2307/3171995 ◽

1992 ◽

Vol 19 ◽

pp. 45-101 ◽

Cited By ~ 4

Author(s):

Stephan Bühnen

Keyword(s):

Fifteenth Century ◽

Oral Tradition ◽

Sub Saharan Africa ◽

Place Names ◽

Research Experience ◽

Wide Range ◽

History Of ◽

Egg Shells ◽

Sub Saharan ◽

Written Sources

Written sources for the history of sub-Saharan Africa (with the exception of East Africa) only begin to appear with the inception of Arabic records from the ninth century onwards, and these are restricted to the Sahel and the northern part of the savanna belt. European sources begin in the mid-fifteenth century, first for Senegambia. They, in turn, confine themselves to the coast and its immediate hinterland, as well as the navigable courses of rivers, with few, and often vague, references to the interior. For the time before the early written sources and for those extensive areas which only much later entered the horizon of writing witnesses, other sources illuminating the past have to be traced and tapped. Among such non-written sources are the findings of anthropology and archeology, of research in oral tradition and place names. Because of their interdependence, working with different source types contributes to the reliability of results.So far little systematic use has been made of place names as a source for African history. Houis' 1958 dictum, “la toponymie ouest-africaine n'est pas encore sortie de l'oeuf,” has not yet been proven obsolete. In this paper I hope to stimulate the process of shedding the egg shells. It is intended as a short introduction to the potential historical treasures place names may yield, into their characteristics, and into some principles guiding their interpretation. With the aim at illustrating my arguments, I add examples of place names. These I have chosen from two areas which, at first sight, seem to have been selected rather randomly; southern Senegambia and Germany. In fact both areas share few features, both geographically and historically. Two reasons have led me to select them. First, they simply are the regions I know best. Secondly, the recourse to German place names is instructive, as research on place names has been undertaken there for more than a century, leading to a wide range of data and to the accumulation of rich research experience.

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