scholarly journals Molecular and morphological identification of suspected Plasmodium vivax vectors in Central and Eastern Sudan

2020 ◽  
Author(s):  
Omnia Fathelrhman Abdelwhab ◽  
Arwa Elaagip ◽  
Musab M. Albsheer ◽  
Ayman Ahmed ◽  
Giacomo Maria Paganotti ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Natural Infection ◽  
Sub Saharan Africa ◽  
Morphological Identification ◽  
Remarkable Change ◽  
Malaria Epidemiology ◽  
Central Sudan ◽  
First Time ◽  
Eastern Sudan

Abstract Background: In spite of the global effort to eliminate malaria, it remains the most significant vector-borne disease of humans. Plasmodium falciparum remains the dominant malaria parasite in Sub-Saharan Africa. However, P. vivax is becoming widely spread throughout Africa. The overuse of vector control methods has resulted in a remarkable change in the behaviour of mosquito that feeds on human as well as on vector composition. The aim of this study was to identify Anopheles mosquito species in vivax malaria endemic regions and to investigate their role in P. vivax malaria transmission.Methods: Mosquito samples were collected from Central Sudan (Khartoum and Sennar States) and Eastern Sudan (New Halfa) using Pyrethrum Spray Catch (PSC) and CDC light traps. Mosquitoes were identified using appropriate morphological identification keys and Anopheles gambiae complex were confirmed to species level using molecular analysis. A subset of blood-fed anopheline mosquitoes were dissectedto study the presence of natural infection of malaria parasites. In addition, the rest of the blood-fed samples were investigated for presence of infective sporozoites of P. vivax that detecting the P. vivax circumsporozoite protein (pvcsp) gene using nested-PCR.Results: A total of 644 adult anopheline blood-fed mosquitoes were collected from New Halfa (N = 214 mosquitoes), Khartoum (N = 132 mosquitoes), and Sennar (N = 298 mosquitoes). Morphological and molecular identification of the collected mosquitoes revealed the presence of An. arabiensis, An. funestus, and An. pharoensis. Out of 644 anophelines subjected to P. vivax sporozoite detection (N = 40, 6.2%) were positive for P. vivax.An. arabiensis 6.7% (39/583) and An. pharoensis 1.8% (1/56) were found positive for the parasite. While An. funestus was detected for the first time in New Halfa with low abundance (5/214 mosquitoes) and were found negative for the parasite.Conclusion: This study documented the presence of An. funestus for the first time in New Halfa, Eastern Sudan. However, An. arabiensis is the most abundant vector detected, together with An. pharoensis. This findings suggests change in malaria epidemiology. Further studies are needed to investigate their contribution in malaria transmission.

scholarly journals Molecular and morphological identification of suspected Plasmodium vivax vectors in Central and Eastern Sudan

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Omnia Fathelrhman Abdelwhab ◽  
Arwa Elaagip ◽  
Musab M. Albsheer ◽  
Ayman Ahmed ◽  
Giacomo Maria Paganotti ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Nested Pcr ◽  
Disease Transmission ◽  
Malaria Parasite ◽  
Large Scale ◽  
Natural Infection ◽  
Sub Saharan Africa ◽  
Morphological Identification ◽  
Anopheline Mosquitoes ◽  
Eastern Sudan

Abstract Background In spite of the global effort to eliminate malaria, it remains the most significant vector-borne disease of humans. Plasmodium falciparum is the dominant malaria parasite in sub-Saharan Africa. However, Plasmodium vivax is becoming widely spread throughout Africa. The overuse of vector control methods has resulted in a remarkable change in the behaviour of mosquito that feeds on human as well as on vector composition. The aim of this study was to identify Anopheles mosquito species in vivax malaria endemic regions and to investigate their role in P. vivax circumsporozoite protein (Pvcsp) allele diversity. Methods Mosquito samples were collected from Central Sudan (Rural Khartoum and Sennar) and Eastern Sudan (New Halfa, Kassala state) using pyrethrum spray catch (PSC) and CDC light traps. Mosquitoes were identified using appropriate morphological identification keys and Anopheles gambiae complex were confirmed to species level using molecular analysis. A subset of blood-fed anopheline mosquitoes were dissected to determine the presence of natural infection of malaria parasites. In addition, the rest of the samples were investigated for the presence of Pvcsp gene using nested-PCR. Results A total of 1037 adult anopheline mosquitoes were collected from New Halfa (N = 467), Rural Khartoum (N = 132), and Sennar (N = 438). Morphological and molecular identification of the collected mosquitoes revealed the presence of Anopheles arabiensis (94.2%), Anopheles funestus (0.5%), and Anopheles pharoensis (5.4%). None of the dissected mosquitoes (N = 108) showed to be infected with malaria parasite. Overall P. vivax infectivity rate was 6.1% (63/1037) by Pvcsp nested PCR. Co-dominance of An. arabiensis and An. pharoensis is reported in Sennar state both being infected with P. vivax. Conclusion This study reported P. vivax infection among wild-caught anopheline mosquitoes in Central and Eastern Sudan. While An. arabiensis is the most abundant vector observed in all study areas, An. funestus was recorded for the first time in New Halfa, Eastern Sudan. The documented Anopheles species are implicated in Pvcsp allele diversity. Large-scale surveys are needed to identify the incriminated vectors of P. vivax malaria and determine their contribution in disease transmission dynamics.

scholarly journals Morphological Identification of Horse Flies (Diptera: Tabanidae) and Estimation of their Seasonal Abundance in Al-Showak District, Gedaref State, Eastern Sudan

2017 ◽  
Vol 6 (2) ◽  
pp. 41 ◽  
Author(s):  
Hamid I. M. N. Croof ◽  
Mai M. Nour ◽  
Nahla O. M. Ali
Keyword(s):  
Morphological Features ◽  
The Other ◽  
Seasonal Abundance ◽  
Morphological Identification ◽  
Vector Species ◽  
High Quality ◽  
Trapping Method ◽  
Horse Flies ◽  
First Time ◽  
Eastern Sudan

<em>The aim of this study was to identify the tabanid flies in the Gedaref State, Eastern Sudan and to estimate their seasonal abundance. A number of 374 flies sample were collected by the trapping method in the period October 2014 to October 2015 and were sorted out using certain morphological features that include; size, head, thorax, wings, legs, antennae and abdomen. The observed features of 47 randomly selected samples were recorded and were used to create an identification key that can be used for future characterization and identification of any member of the Tabanidae family. More tabanids flies were collected during the wet (52.29%) than the dry season (47.71%). A number of 5 species of Tabanidae namely; Tabanus autumnalis (Szilády 1914); Tabanus leleani (Austen 1920); Atylotus pulchellus (Loew 1858); Hybomitra mendica (Villeneuve 1912) and Philoliche sp. were reported for the first time in the state of Gedaref. The method described here has advantages over the other methods of identification; that it is simple, costless, and requires no skillful person to perform. The collection procedure is very crucial, for the specimen must be of high-quality. This key will facilitate the recognition of the vector species and its possible role in the transmission of the parasitic and/or viral animals’ diseases in the area. </em>

scholarly journals Extensive new Anopheles cryptic species involved in human malaria transmission in western Kenya

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daibin Zhong ◽  
Elizabeth Hemming-Schroeder ◽  
Xiaoming Wang ◽  
Solomon Kibret ◽  
Guofa Zhou ◽  
...  
Keyword(s):  
Species Composition ◽  
Vector Control ◽  
Malaria Transmission ◽  
Cryptic Species ◽  
Mosquito Species ◽  
Western Kenya ◽  
Transmission Potential ◽  
Efficient Vector ◽  
Species Composition And Distribution ◽  
First Time

Abstract A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission. It has been well documented in Africa that malaria interventions in the past decade have resulted in major changes in species composition from endophilic Anopheles gambiae to exophilic An. arabiensis. However, the role of cryptic rare mosquito species in malaria transmission is not well known. This study examined the species composition and distribution, with a particular focus on malaria transmission potential of novel, uncharacterized Anopheles cryptic species in western Kenya. Phylogenetic analysis based on ITS2 and COX1 genes revealed 21 Anopheles mosquito species, including two previously unreported novel species. Unusually high rates of Plasmodium sporozoite infections were detected in An. funestus, An. gambiae and eight cryptic rare species. Plasmodium falciparum, P. malariae and P. ovale sporozoite infections were identified with large proportion of mixed species infections in these vectors. This study, for the first time, reports extensive new Anopheles cryptic species involved in the malaria transmission in western Kenya. These findings underscore the importance of non-common Anopheles species in malaria transmission and the need to target them in routine vector control and surveillance efforts.

scholarly journals The dominant malaria vector, Anopheles funestus from rural south-eastern Tanzania, is more strongly resistant to insecticides than Anopheles arabiensis

2020 ◽  
Author(s):  
Polius Gerazi Pinda ◽  
Claudia Eichenberger ◽  
Halfan S Ngowo ◽  
Dickson S Msaky ◽  
Said Abbasi ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Pyrethroid Resistance ◽  
Mosquito Species ◽  
Anopheles Funestus ◽  
Indoor Residual Spraying ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Insecticide Treated Nets ◽  
South Eastern ◽  
Sub Saharan

Abstract Background: Long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) have greatly reduced malaria transmission in sub-Saharan Africa, but are threatened by insecticide resistance in dominant malaria vectors. In south-eastern Tanzania, pyrethroid-resistant Anopheles funestus now transmit more than 80% of malaria infections even in villages where the species occurs at far lower densities than other vectors such as Anopheles arabiensis.Methods: To better understand the dominance of An. funestus in these settings and improve options for its control, this study compared intensities of resistance between females of this species and those of An. arabiensis , using WHO assays with 1×, 5× and 10× insecticide doses. Additional tests were done to assess the reversibility of such resistance using synergists. The mosquitoes were collected from villages across two districts in south-eastern Tanzania.Findings: Both species were resistant to the two pyrethroids (permethrin and deltamethrin) and the organochloride (DDT) but susceptible to the organophosphate (pirimiphos-methyl) at standard baseline doses (1×). However, An. funestus as opposed to An. arabiensis was also resistant to the carbamate (bendiocarb) at standard doses (1×). An. funestus showed strong resistance to pyrethroids, surviving the 5× doses and 10× doses except in one village. Pre-exposure to the synergist, piperonyl butoxide (PBO), reversed the pyrethroid-resistance in both An. arabiensis and An. funestus achieving mortalities >98%, except for An. funestus from two villages for which permethrin-associated mortalities exceeded 90% but not 98%.Conclusions : In these communities where An. funestus now dominates malaria transmission, the species also displays much stronger resistance to pyrethroids than its counterpart, An. arabiensis, and can readily survive more classes of insecticides, including carbamates. The resistance to pyrethroids in both mosquito species appears to be mostly metabolic and can be reversed significantly using synergists such as PBO. These findings may explain the continued persistence and dominance of An. funestus despite widespread use of pyrethroid-treated LLINs, and will also inform future choices of interventions to tackle malaria transmission in this area and other similar settings. Such interventions may include PBO-based LLINs or improved IRS with compounds such as organophosphates against which the vectors are still susceptible.

scholarly journals Predicting mortality for paediatric inpatients where malaria is uncommon

2012 ◽  
Vol 97 (10) ◽  
pp. 889-894 ◽  
Author(s):  
Dana C Clifton ◽  
Habib O Ramadhani ◽  
Levina J Msuya ◽  
Boniface N Njau ◽  
Grace D Kinabo ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Integrated Management ◽  
Child Outcomes ◽  
Oral Candidiasis ◽  
Sub Saharan Africa ◽  
Severe Illness ◽  
Tertiary Referral Centre ◽  
Stiff Neck ◽  
Malaria Epidemiology ◽  
Low Malaria Transmission

ObjectiveAs the proportion of children living low malaria transmission areas in sub-Saharan Africa increases, approaches for identifying non-malarial severe illness need to be evaluated to improve child outcomes.DesignAs a prospective cohort study, we identified febrile paediatric inpatients, recorded data using Integrated Management of Childhood Illness (IMCI) criteria, and collected diagnostic specimens.SettingTertiary referral centre, northern Tanzania.ResultsOf 466 participants with known outcome, median age was 1.4 years (range 2 months–13.0 years), 200 (42.9%) were female, 11 (2.4%) had malaria and 34 (7.3%) died. Inpatient death was associated with: Capillary refill >3 s (OR 9.0, 95% CI 3.0 to 26.7), inability to breastfeed or drink (OR 8.9, 95% CI 4.0 to 19.6), stiff neck (OR 7.0, 95% CI 2.8 to 17.6), lethargy (OR 5.2, 95% CI 2.5 to 10.6), skin pinch >2 s (OR 4.8, 95% CI 1.9 to 12.3), respiratory difficulty (OR 4.0, 95% CI 1.9 to 8.2), generalised lymphadenopathy (OR 3.6, 95% CI 1.6 to 8.3) and oral candidiasis (OR 3.4, 95% CI 1.4 to 8.3). BCS <5 (OR 27.2, p<0.001) and severe wasting (OR 6.9, p<0.001) were independently associated with inpatient death.ConclusionsIn a low malaria transmission setting, IMCI criteria performed well for predicting inpatient death from non-malarial illness. Laboratory results were not as useful in predicting death, underscoring the importance of clinical examination in assessing prognosis. Healthcare workers should consider local malaria epidemiology as malaria over-diagnosis in children may delay potentially life-saving interventions in areas where malaria is uncommon.

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum

2017 ◽  
Vol 1 (6) ◽  
pp. 533-537
Author(s):  
Lorenz von Seidlein ◽  
Borimas Hanboonkunupakarn ◽  
Podjanee Jittmala ◽  
Sasithon Pukrittayakamee
Keyword(s):  
Protective Efficacy ◽  
Age Groups ◽  
Sub Saharan Africa ◽  
Phase Iii ◽  
European Medicines Agency ◽  
Older Children ◽  
Pivotal Phase ◽  
Malaria Epidemiology ◽  
Maximum Benefit ◽  
Sub Saharan

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5–17 months) and one-fourth of infants (aged 6–12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

scholarly journals Labellum and gynostemium micromorphology in Polystachya (Orchidaceae)

2020 ◽  
Vol 307 (1) ◽  
Author(s):  
Mytnik Joanna ◽  
Davies L. Kevin ◽  
Narajczyk Magdalena ◽  
Łuszczek Dorota ◽  
Kubiak Joanna ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sub Saharan Africa ◽  
Capitate Trichomes ◽  
Sub Saharan ◽  
First Time ◽  
Scanning Electron

AbstractPolystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy (SEM). Our results show the scale of infrageneric diversity of trichomes and papillae relative to the sampled sections. They also demonstrate the taxonomic value of labellar micromorphology at the sectional level. The study revealed seven types of papillae and five types of trichomes (uni- and multi-cellular) in Polystachya, some of which, are described here for the first time. Clavate trichomes are the most common and are present in 60% of the species studied. Moniliform trichomes mainly occur in sect. Polystachya and are strongly characteristic of the section. Pseudopollen is formed by fragmentation of moniliform trichomes or the detachment of other trichomes as bicellular units. We provide, for the first time, evidence for the detachment of the terminal cells of capitate trichomes.

scholarly journals An increasing role of pyrethroid-resistant Anopheles funestus in malaria transmission in the Lake Zone, Tanzania

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nancy S. Matowo ◽  
Jackline Martin ◽  
Manisha A. Kulkarni ◽  
Jacklin F. Mosha ◽  
Eliud Lukole ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Anopheles Funestus ◽  
Sub Saharan Africa ◽  
North West ◽  
Vector Population ◽  
Lake Zone ◽  
Sub Saharan ◽  
Long Lasting Insecticidal Nets ◽  
Study District

AbstractAnopheles funestus is playing an increasing role in malaria transmission in parts of sub-Saharan Africa, where An. gambiae s.s. has been effectively controlled by long-lasting insecticidal nets. We investigated vector population bionomics, insecticide resistance and malaria transmission dynamics in 86 study clusters in North-West Tanzania. An. funestus s.l. represented 94.5% (4740/5016) of all vectors and was responsible for the majority of malaria transmission (96.5%), with a sporozoite rate of 3.4% and average monthly entomological inoculation rate (EIR) of 4.57 per house. Micro-geographical heterogeneity in species composition, abundance and transmission was observed across the study district in relation to key ecological differences between northern and southern clusters, with significantly higher densities, proportions and EIR of An. funestus s.l. collected from the South. An. gambiae s.l. (5.5%) density, principally An. arabiensis (81.1%) and An. gambiae s.s. (18.9%), was much lower and closely correlated with seasonal rainfall. Both An. funestus s.l. and An. gambiae s.l. were similarly resistant to alpha-cypermethrin and permethrin. Overexpression of CYP9K1, CYP6P3, CYP6P4 and CYP6M2 and high L1014S-kdr mutation frequency were detected in An. gambiae s.s. populations. Study findings highlight the urgent need for novel vector control tools to tackle persistent malaria transmission in the Lake Region of Tanzania.

scholarly journals Schistosoma mansoni eggs induce Wnt/β-catenin signaling and activate the protooncogene c-Jun in human and hamster colon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jakob Weglage ◽  
Friederike Wolters ◽  
Laura Hehr ◽  
Jakob Lichtenberger ◽  
Celina Wulz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Colorectal Carcinogenesis ◽  
Sub Saharan Africa ◽  
Interleukin 4 ◽  
Health Burden ◽  
Sub Saharan ◽  
Considerable Morbidity ◽  
First Time

AbstractSchistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia, in sub-Saharan Africa, and particularly also in Europe. The WHO describes an increasing global health burden with more than 290 million people threatened by the disease and a potential to spread into regions with temperate climates like Corsica, France. The aim of our study was to investigate the influence of S. mansoni infection on colorectal carcinogenic signaling pathways in vivo and in vitro. S. mansoni infection, soluble egg antigens (SEA) and the Interleukin-4-inducing principle from S. mansoni eggs induce Wnt/β-catenin signaling and the protooncogene c-Jun as well as downstream factor Cyclin D1 and markers for DNA-damage, such as Parp1 and γH2a.x in enterocytes. The presence of these characteristic hallmarks of colorectal carcinogenesis was confirmed in colon biopsies from S. mansoni-infected patients demonstrating the clinical relevance of our findings. For the first time it was shown that S. mansoni SEA may be involved in the induction of colorectal carcinoma-associated signaling pathways.

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