scholarly journals Presence of additional P. vivax malaria in Duffy negative individuals from Southwestern Nigeria

2019 ◽  
Author(s):  
Mary Aigbiremo Oboh ◽  
Upasana Shyamsunder Singh ◽  
Daouda Nidaye ◽  
Aida S. Badiane ◽  
Anwar Ali ◽  
...  

AbstractMalaria in sub-Saharan Africa (sSA) is thought to be hugely caused by Plasmodium falciparum and very infrequently by P. ovale, P. malariae, with P. vivax not even being considered to be of any significant role. However, with the availability of very sensitive diagnostic tool, it has become more clear that, the percentage of non-falciparum malaria in this sub-region has been underestimated. P. vivax was historically thought to be absent in sSA due to the high prevalence of the Duffy null antigen in individuals residing here. Nevertheless, recent studies reporting the detection of vivax malaria in Duffy-negative individuals challenges this notion. Following our earlier report of P. vivax in Duffy-negative individuals, we have re-assessed all previous samples following the classical PCR method and sequencing to confirm both single/mixed infections as well as the Duffy status of the individuals.Interestingly, fifteen additional Plasmodium infections were detected, representing 5.9% in prevalence from our earlier work. In addition, P. vivax represents 26.7% (4/15) of the new isolates collected in Nigeria. Sequencing results confirmed, all vivax isolates as truly vivax malaria and their Duffy status to be that of the Duffy-negative genotype. The identification of more vivax isolates among these Duffy-negative individuals from Nigeria, substantiate the expanding body of evidence of the ability of P. vivax to infect RBCs that do not express the DARC gene. Hence, such geno-epidemiological study should be conducted at the national level in order to evaluate the actual burden of P. vivax in the country.


2020 ◽  
Author(s):  
MARY Aigbiremo OBOH ◽  
Upasana Shyamsunder Singh ◽  
Daouda Ndiaye ◽  
Aida Sadikh Badiane ◽  
Nazia Anwar Ali ◽  
...  

Abstract Background Malaria in sub-Saharan Africa (sSA) is thought to be hugely caused by Plasmodium falciparum . Recently, growing reports of cases due to P. ovale , P. malariae , and P. vivax have been significantly reported to play a role in malaria epidemiology in sSA. This in fact is due to the usage of very sensitive diagnostic tools (e.g. PCR) which have highlighted the underestimation of non-falciparum malaria in this sub-region. P. vivax was historically thought to be absent in sSA due to the high prevalence of the Duffy null antigen in individuals residing in this sub-continent. For example, recent studies reporting the detection of vivax malaria in Duffy-negative individuals from Mali, Mauritania, Cameroon to mention a few challenges this notion.Methods Following our earlier report of P. vivax in Duffy-negative individuals, we have collected and assessed RDT and/or microscope malaria positive samples following the conventional PCR method and DNA sequencing to confirm both single/mixed infections as well as the Duffy status of the individuals.Results Amplification of Plasmodium gDNA was possible in 59.9% (145/242) of the evaluated isolates and as expected P. falciparum was the most predominant (91.7%) species identified. Interestingly, four P. vivax isolates were identified either as single (3) or mixed (1 – P. falciparum / P. vivax ) infection. Sequencing results confirmed, all vivax isolates as truly vivax malaria and their Duffy status to be that of the Duffy-negative genotype.Conclusion Identification of more vivax isolates among these Duffy-negative individuals from Nigeria, substantiate the expanding body of evidence on the ability of P. vivax to infect RBCs that do not express the DARC gene. Hence, such genetic-epidemiological study should be conducted at the national level in order to evaluate the actual burden of P. vivax in the country.



2021 ◽  
Vol 3 (1) ◽  
pp. 110-115
Author(s):  
Regis Ndahiro ◽  
Pascal Bizimana ◽  
Ella Larissa Ndoricyimpaye ◽  
Alphonse Hakizimana ◽  
Jean Damascene Mfizi

Background: Malaria is a leading cause of mortality and morbidity in sub-Saharan Africa including Rwanda. Though the prevalence of malaria has been reduced due to the use of indoor residual sprayings and insecticide-treated bed nets, it is still a disease that kills many people annually. Many studies conducted revealed that in sub-Saharan Africa including Rwanda there is a high prevalence of Plasmodium falciparum. However, there is still a gap in the identification of the presence of mixed Plasmodium infection. This study was conducted to determine the overall prevalence of Plasmodium species as well as that of mixed plasmodium infection in Ruhango and Kibilizi Health centres. Methods: Descriptive cross-sectional study was conducted on 126 participants in Ruhango, Bunyogombe and Kibilizi health centres located in the southern province of Rwanda. The conventional sampling strategy was used for the selection of individuals who consented to participate in the study. Blood samples were used to detect Plasmodium species and the obtained data were analyzed using Microsoft excel and IBM SPSS version 21. Results: Among 126 participants presenting with signs and symptoms of malaria, the overall positive cases of Plasmodium species were 61(48.4%) and among the total positive cases 56 (44.5%) were infected with single Plasmodium species while 5 (4%) were infected with mixed Plasmodium species. Plasmodium falciparum was the most prevalent species infecting 49 (39%) participants while Plasmodium vivax was the least prevalent infection, detected in only 1(0.8%) participant. Conclusion: The study identified the significant prevalence of mixed-species of Plasmodium infection as well as the high prevalence of Plasmodium falciparum infection in the study population. These findings suggest that there is a need for continued monitoring of non-falciparum infection in this population and the introduction of species-specific RDTs that can be used for diagnostic purposes.



Author(s):  
Isaac K. Quaye ◽  
Larysa Aleksenko

In recent times, several countries in sub-Saharan Africa have reported cases of Plasmodium vivax (Pv) with a considerable number being Duffy negative. Current efforts at malaria elimination are focused solely on Plasmodium falciparum (Pf) excluding non-falciparum malaria. Pv and Plasmodium ovale (Po) have hypnozoite forms that can serve as reservoirs of infection and sustain transmission. The burden of these parasites in Africa seems to be more than acknowledged, playing roles in migrant and autochthonous infections. Considering that elimination and eradication is a current aim for WHO and Roll Back Malaria (RBM), the inclusion of Pv and Po in the elimination agenda cannot be over-emphasized. The biology of Pv and Po are such that the same elimination strategies as are used for Pf cannot be applied so, going forward, new approaches will be required to attain elimination and eradication targets.



2020 ◽  
Vol 31 (2) ◽  
pp. 79-82
Author(s):  
Fredrick Luoga ◽  
Agness Jonathan ◽  
Lulu Chirande ◽  
Emmanuel Balandya

Sickle Cell Disease (SCD) is an inherited disorder of the Haemoglobin molecule of the red blood cells that is associated with serious complications and reduced life expectancy. Over 75% of people with SCD live in Sub-Saharan Africa (SSA), and this proportion are projected to increase to 85% by the year 2050. In Tanzania, approximately 11,000 babies are born with SCD each year, ranking 5th in the world. The high prevalence of SCD in SSA is compounded by the disproportionately higher mortality compared to that observed in the high-income countries. In Tanzania, SCD is a major contributor to under-five mortality and is estimated to account for 7% of all-cause mortality in this age group. Newborn screening (NBS) is the practice of testing babies right after delivery to ascertain whether they have diseases that are potentially lethal if not treated early. Where routinely practiced, NBS has significantly reduced morbidity and mortality associated with such diseases. The Sickle Cell Programme at Muhimbili University of Health and Allied Sciences (MUHAS) in Dar-es-salaam and Bugando Medical Center in Mwanza have both conducted pilot NBS for SCD, showing that the intervention is generally feasible and acceptable in Tanzania. The successful introduction and expansion of NBS in Tanzania will require careful planning and advocacy at community to national level.



Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 982
Author(s):  
Jana Těšíková ◽  
Jarmila Krásová ◽  
Joëlle Goüy de Bellocq

Rodents are a speciose group of mammals with strong zoonotic potential. Some parts of Africa are still underexplored for the occurrence of rodent-borne pathogens, despite this high potential. Angola is at the convergence of three major biogeographical regions of sub-Saharan Africa, each harbouring a specific rodent community. This rodent-rich area is, therefore, strategic for studying the diversity and evolution of rodent-borne viruses. In this study we examined 290 small mammals, almost all rodents, for the presence of mammarenavirus and hantavirus RNA. While no hantavirus was detected, we found three rodent species positive for distinct mammarenaviruses with a particularly high prevalence in Namaqua rock rats (Micaelamys namaquensis). We characterised four complete virus genomes, which showed typical mammarenavirus organisation. Phylogenetic and genetic distance analyses revealed: (i) the presence of a significantly divergent strain of Luna virus in Angolan representatives of the ubiquitous Natal multimammate mouse (Mastomys natalensis), (ii) a novel Okahandja-related virus associated with the Angolan lineage of Micaelamys namaquensis for which we propose the name Bitu virus (BITV) and (iii) the occurrence of a novel Mobala-like mammarenavirus in the grey-bellied pygmy mouse (Mus triton) for which we propose the name Kwanza virus (KWAV). This high virus diversity in a limited host sample size and in a relatively small geographical area supports the idea that Angola is a hotspot for mammarenavirus diversity.



Author(s):  
Daniel Kepple ◽  
Alfred Hubbard ◽  
Musab M Ali ◽  
Beka R Abargero ◽  
Karen Lopez ◽  
...  

Abstract Plasmodium vivax malaria was thought to be rare in Africa, but an increasing number of P. vivax cases reported across Africa and in Duffy-negative individuals challenges this conventional dogma. The genetic characteristics of P. vivax in Duffy-negative infections, the transmission of P. vivax in East Africa, and the impact of environments on transmission remain largely unknown. This study examined genetic and transmission features of P. vivax from 107 Duffy-negative and 305 Duffy-positive individuals in Ethiopia and Sudan. No clear genetic differentiation was found in P. vivax between the two Duffy groups, indicating between-host transmission. P. vivax from Ethiopia and Sudan showed similar genetic clusters, except samples from Khartoum, possibly due to distance and road density that inhibited parasite gene flow. This study is the first to show that P. vivax can transmit to and from Duffy-negative individuals and provides critical insights into the spread of P. vivax in sub-Saharan Africa.



2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ommer Mohammed Dafalla ◽  
Mohammed Alzahrani ◽  
Ahmed Sahli ◽  
Mohammed Abdulla Al Helal ◽  
Mohammad Mohammad Alhazmi ◽  
...  

Abstract Background Artemisinin-based combination therapy (ACT) is recommended at the initial phase for treatment of Plasmodium falciparum, to reduce morbidity and mortality in all countries where malaria is endemic. Polymorphism in portions of P. falciparum gene encoding kelch (K13)-propeller domains is associated with delayed parasite clearance after ACT. Of about 124 different non-synonymous mutations, 46 have been identified in Southeast Asia (SEA), 62 in sub-Saharan Africa (SSA) and 16 in both the regions. This is the first study designed to analyse the prevalence of polymorphism in the P. falciparum k13-propeller domain in the Jazan region of southwest Saudi Arabia, where malaria is endemic. Methods One-hundred and forty P. falciparum samples were collected from Jazan region of southwest Saudi Arabia at three different times: 20 samples in 2011, 40 samples in 2016 and 80 samples in 2020 after the implementation of ACT. Plasmodium falciparum kelch13 (k13) gene DNA was extracted, amplified, sequenced, and analysed using a basic local alignment search tool (BLAST). Results This study obtained 51 non-synonymous (NS) mutations in three time groups, divided as follows: 6 single nucleotide polymorphisms (SNPs) ‘11.8%’ in samples collected in 2011 only, 3 (5.9%) in 2011and 2016, 5 (9.8%) in 2011 and 2020, 5 (9.8%) in 2016 only, 8 (15.7%) in 2016 and 2020, 14 (27.5%) in 2020 and 10 (19.6%) in all the groups. The BLAST revealed that the 2011 isolates were genetically closer to African isolates (53.3%) than Asian ones (46.7%). Interestingly, this proportion changed completely in 2020, to become closer to Asian isolates (81.6%) than to African ones (18.4%). Conclusions Despite the diversity of the identified mutations in the k13-propeller gene, these data did not report widespread artemisinin-resistant polymorphisms in the Jazan region where these samples were collected. Such a process would be expected to increase frequencies of mutations associated with the resistance of ACT.



2009 ◽  
Vol 7 (2) ◽  
pp. 361-363 ◽  
Author(s):  
James D. Fearon

When Things Fell Apart manages to be wonderfully concise but still compelling. The thing Robert Bates seeks to explain is the secular trend in sub-Saharan Africa toward civil war, although he often characterizes this in broader terms, as a trend toward “political conflict” or “political disorder.” He explains the trend as follows: Public revenues fell in the 1970s and 1980s as a result of commodity price declines, effects of the second oil shock, and bad economic policy choices that overtaxed farmers so that politicians could dispense patronage to smaller, politically more important urban constituencies. The decline in public revenues led elites to become more predatory, which caused an increase in political conflict by mobilizing opposition. Popular demands for political reform, along with increased international pressure for the same at the end of the Cold War, heightened elite insecurity and led to more predation. This had the effect of “provoking their citizens to take up arms” (p. 109). Further, state decline and national-level conflicts exacerbated simmering subnational conflicts, typically in the form of land disputes between locals and migrants from other tribes.



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