Comoro Islands Research Articles

Epidemiological Analysis of Cassava Mosaic and Brown Streak Diseases, and Bemisia tabaci in the Comoros Islands.

A comprehensive assessment of cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) was carried out in Comoros where cassava yield (5.7 t/ha) is significantly below the African average (8.6 t/ha) largely due to virus diseases. Observations from 66 sites across the Comoros Islands of Mwali, Ngazidja, and Ndzwani revealed that 83.3% of cassava fields had foliar symptoms of CBSD compared with 95.5% for CMD. Molecular diagnostics confirmed the presence of both cassava brown streak ipomoviruses (CBSIs) and cassava mosaic begomoviruses (CMBs). Although real-time RT-PCR only detected the presence of one CBSI species (Cassava brown streak virus, CBSV) the second species (Ugandan cassava brown streak virus, UCBSV) was identified using next-generation high-throughput sequencing. Both PCR and HTS detected the presence of East African cassava mosaic virus (EACMV). African cassava mosaic virus was not detected in any of the samples. Four whitefly species were identified from a sample of 131 specimens: Bemisia tabaci, B. afer, Aleurodicus dispersus, and Paraleyrodes bondari. Cassava B. tabaci comprised two mitotypes: SSA1-SG2 (89%) and SSA1-SG3 (11%). KASP SNP genotyping categorized 82% of cassava B. tabaci as haplogroup SSA-ESA. This knowledge will provide an important base for developing and deploying effective management strategies for cassava viruses and their vectors.

STAC3 related congenital myopathy: A case series of seven Comorian patients

The Bailey-Bloch congenital myopathy, also known as Native American myopathy (NAM), is an autosomal recessive congenital myopathy first reported in the Lumbee tribe people settled in North Carolina (USA), and characterized by congenital weakness and arthrogryposis, cleft palate, ptosis, short stature, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH) triggered by anesthesia. NAM is linked to STAC3 gene coding for a component of excitation-contraction coupling in skeletal muscles. A homozygous missense variant (c.851G > C; p.Trp284Ser) in STAC3 segregated with NAM in the Lumbee families. Non-Native American patients with STAC3 related congenital myopathy, and with other various variants of STAC3 have been reported. Here, we present seven patients from the Comoros Islands (located in the Mozambique Channel) diagnosed with STAC3 related congenital myopathy and having the recurrent variant identified in the Lumbee people. The series is the second largest series of patients having STAC3 related congenital myopathy with a shared ethnicity after le Lumbee series. Local history and geography may explain the overrepresentation of NAM in the Comorian Archipelago with a founder effect. Further researches would be necessary for the understanding of the onset of the NAM in Comorian population as search of the “classical” STAC3 variant in East African population, and haplotypes comparison between Comorian and Lumbee patients.

Historical Malaria Epidemics on Previously Non-Endemic Indo-Pacific Islands.

Islands without prior malaria have on occasion had severe epidemics after its initial introduction, the most infamous example being the Indian Ocean island of Mauritius in 1867. The historical record was examined to see if additional examples of malaria epidemics on Indo-Pacific islands, which were originally non-malarious had been documented. The late nineteenth century depopulation of Polynesian outliers such as Ontong Java has largely been blamed on malaria. Similar but less well-documented instances exist with both the Western Islands, Papua New Guinea, and Rennell in the Solomon Islands. Specific instances of malaria introduction to Grand Comoros and Aldabra Island in the Seychelles occurred by the early twentieth century. In some cases, the epidemics were caused by changes in anopheline vectors while in others new human populations carrying parasites were the important ecological change. It is, however, remarkable how rarely major malaria epidemics have occurred on Indo-Pacific islands.

Habitat Suitability and Population Size Estimates for the Mongoose Lemurs (Eulemur mongoz) of Madagascar and the Comoro Islands, and Implications for Their Conservation

Habitat Suitability and Population Size Estimates for the Mongoose Lemurs (Eulemur mongoz) of Madagascar and the Comoro Islands, and Implications for Their Conservation

Two new species of Phronia Winnertz, 1864 (Diptera, Mycetophilidae) from Taita Hills, Kenya

Two new Phronia Winnertz, 1864 species—P. hannarostiaesp. nov. and P. ristoisp. nov.—are described from Taita Hills in Kenya, representing the first named species of this genus in the African continent. The new species are morphologically similar to each other as well as to P. flobertae Matile – a species described from the Comoro Islands. These three species can be distinguished by details of the male terminalia, in particular by comparing the structures of the gonostyli. The new species are photographed and hand-drawn figures provided, and their taxonomy is discussed.

Distribution and habitat use of the Madagascar Peregrine Falcon: first estimates for area of habitat and population size

SummaryAccurately demarcating distributions of biological taxa has long been at the core of ecology. Yet our understanding of the factors defining species range limits is incomplete, especially for tropical species in the Global South. Human-driven threats to the survival of many taxa are increasing, particularly habitat loss and climate change. Identifying distributional range limits of at-risk and data-limited species using Species Distribution Models (SDMs) can thus inform spatial conservation planning to mitigate these threats. The Madagascar Peregrine FalconFalco peregrinus radamais the resident sub-species of the Peregrine Falcon complex distributed across Madagascar, Mayotte, and the Comoros Islands. There are currently significant knowledge gaps regarding its distribution, habitat preferences, and population size. Here, we use penalized logistic regression and environmental ordination to identify Madagascar Peregrine Falcon habitat in both geographic and environmental space and propose a population size estimate based on inferred habitat. From the penalized logistic regression model, the core habitat area of the Madagascar Peregrine Falcon extends across the central and northern upland plateau of Madagascar with patchier habitat across coastal and low-elevation areas. Range-wide habitat use in both geographic and environmental space indicated positive associations with high elevation and aridity, coupled with high vegetation heterogeneity and >95% herbaceous landcover, but general avoidance of areas >30% cultivated land and >10% mosaic forest. Based on inferred high-class habitat from the penalized logistic regression model, we estimate this habitat area could potentially support a population size ranging between 150 and 300 pairs. Following IUCN Red List guidelines, this subspecies would be classed as ‘Vulnerable’ due to its small population size. Despite its potentially large range, the Madagascar Peregrine Falcon has specialised habitat requirements and would benefit from targeted conservation measures based on spatial models to maintain viable populations.

Enterovirus meningitis in Mayotte French Comoros Island, March-June 2019.

Enteroviruses (EV) are the most frequent cause of acute meningitis worldwide, and regularly responsible for outbreaks. Human parechoviruses (PeV) are associated with sepsis and meningitis in young infants. In Mayotte, a French department located in the Comoros archipelago, EVs and PeVs are not part of the routine screening of cerebrospinal fluids (CSFs) of patients with meningitis. Consequently, no data is available on EV or PeV epidemiology. Assess the need for EV and PeV diagnosis in Mayotte. CSFs collected between March and June 2019 from patients addressed to Mayotte Hospital were retrospectively screened for EV and PeV by PCR. If positive for EV, genotyping was attempted. EV and PeV RT-PCR were performed on 122/263 (46%) CSFs (45 adults, 77 children). EV meningitis was diagnosed in 16/77 children (21%) with a median age of 32 days (8-62). One 30-days-aged infant presented with a PeV infection. Fever was reported in 94% cases (16/17), followed by gastrointestinal disorders in 29% cases (5/17). EV genotyping achieved identification for 10/16 (63%) EV-positive samples. Four different EV types were identified: Echovirus 16 (E-16, n=6), EV-B100 (n=2), and E-14 and E-18 (n=1, each). EV/PeV prevalence of 14% highlights the importance of implementing this diagnosis which can impact duration of hospitalization and administration of antibiotics thus reducing risk of antimicrobial resistance. Surveillance of circulating EV types is needed to understand the range of enteroviruses detected in meningitis cases in places that have been underrepresented in enterovirus surveillance studies.

Mayotte 2018 eruption likely sourced from a magmatic mush

Despite significant advancements in understanding crustal melt transport, determining the shallow magmatic architecture at any given volcanic system remains a significant challenge with geophysical methods alone. In this study, we present a new conceptual model combining previously studied models for geomechanical magma reservoirs and dyke-shaped conduits. Supplementary to previous work, we include a model for porous mush adjacent to a visco-elastic magma reservoir during the eruption. This addition enables physically consistent magma recharge into the elastic magma reservoir by porous flow instead of employing an arbitrary mantle magma recharge parameterization. We compare our conceptual model with an illustrative test case - the submarine 2018 Mayotte eruption in the Comoros Islands (∼6.55 km3 Bulk Rock Volume, ∼3.5 km water depth, ∼35 km estimated deep magma reservoir). We estimate a magma effusion rate history using a new continuous-time inversion of surface deformation data. A single magma reservoir cannot match the observed eruptive history for any reservoir geometry or crustal and magmatic material properties. However, the presence of a porous mush adjacent to the magma reservoir helps to reconcile the model with the observations. The additional magma flux from the mush region sustains the long eruption at a low effusion rate, as is observed off Mayotte, with a decreasing effusion rate after few months of eruptions and a low persistent effusion rate since then. The mush flow dynamics are a direct consequence of reduced pressure in the magma reservoir during the eruption. Thus, our model provides a parsimonious and physically motivated explanation of the Mayotte eruptive history. Since many historical basaltic eruptions worldwide, such as sometime observed at Piton de la Fournaise, Volcan Arenal, and Laki, have a similar effusion rate history shape as Mayotte, magmatic mushes may be a key component for explaining long-lived basaltic eruptions.

Diversification in the Comoros: Review of the Laccophilus alluaudi Species Group with the Description of Four New Species (Coleoptera: Dytiscidae)

The Laccophilus alluaudi species group is an interesting case of an endemic species radiation of Madagascar and the Comoros. To date, a single species, Laccophilus tigrinus Guignot, 1959 (Anjouan), is known from the Comoro Islands, with eight other species known from Madagascar. Here we review the Laccophilus alluaudi species group from the Comoro Islands based on partly new material. We recognize five species, out of which four are here described as new: L. mohelicus n. sp. (Mohéli), L. denticulatus n. sp. (Grande Comore), L. michaelbalkei n. sp. (Mayotte) and L. mayottei n. sp. (Mayotte). Based on morphology of male genitalia, we hypothesize that the five species form a monophyletic group and originated from a single colonization event from Madagascar. If confirmed, this would constitute one of the few examples of intra-archipelago diversification in the Comoros. The knowledge of species limits in relation to their distribution in the Comoros archipelago is also urgently needed in the face of rapid habitat degradation.

XPC and POLH/XPV Genes Mutated in a Genetic Cluster of Xeroderma Pigmentosum Patients in Northeast Brazil.

Xeroderma pigmentosum (XP) is a rare genetic condition in which exposure to sunlight leads to a high tumor incidence due to defective DNA repair machinery. Herein, we investigated seven patients clinically diagnosed with XP living in a small city, Montanhas (Rio Grande do Norte), in the Northeast region of Brazil. We performed high-throughput sequencing and, surprisingly, identified two different mutated genes. Six patients carry a novel homozygote mutation in the POLH/XPV gene, c.672_673insT (p.Leu225Serfs*33), while one patient carries a homozygote mutation in the XPC gene, c.2251-1G>C. This latter mutation was previously described in Southeastern Africa (Comoro Island and Mozambique), Pakistan, and in a high incidence in Brazil. The XP-C patient had the first symptoms before the first year of life with aggressive ophthalmologic tumor progression and a melanoma onset at 7 years of age. The XP-V patients presented a milder phenotype with later onset of the disorder (mean age of 16 years old), and one of the six XP-V patients developed melanoma at 72 years. The photoprotection is minimal among them, mainly for the XP-V patients. The differences in the disease severity between XP-C (more aggressive) and XP-V (milder) patients are obvious and point to the major role of photoprotection in the XPs. We estimate that the incidence of XP patients at Montanhas can be higher, but with no diagnosis, due to poor health assistance. Patients still suffer from the stigmatization of the condition, impairing diagnosis, education for sun protection, and medical care.

The first complete plastome of Mimusops coriacea (A. DC.) Miq. (Sapotaceae).

Mimusops coriacea (A. DC.) Miq. (Sapotoideae, Sapotaceae, Ericales) is native to Madagascar and the Comoro Islands. This species is cultivated in many countries around the world and grows on sand in coastal vegetation. Here we sequenced, assembled, and annotated the first complete chloroplast genome of M. coriacea. The newly assembled chloroplast was analyzed with other available chloroplasts of Sapotaceae. Our results found a general conserved structure. The complete chloroplast genome has 159,689 bp, including 133 genes distributed in four regions: a large single-copy region of 88,887 bp, a small single-copy region of 18,618 bp, and two inverted repeats of 26,092 bp each. Our maximum likelihood phylogenetic tree was generated with 80 protein-coding genes and recovered a monophyletic Sapotaceae sister to a clade formed by Ebenaceae + Primulaceae. In our analysis, Mimusops coriacea clustered with the other eight species of Sapotaceae included in the study.

Feasibility Study for a Hybrid Power Plant (PV-Wind-Diesel-Storage) Connected to the Electricity Grid

In this work, we present a feasibility study for a new hybrid power plant (PV-Wind-Diesel-Storage) directly connected to the electrical grid. Several simulations are performed to verify the performance of the hybrid system under different scenarios using real meteorological data. It is shown that the performances of the hybrid system connected to the electrical network depend obviously on the available energy resources and constraints because the renewable energies are intermittent. In addition, the price of the kWh of electricity supplied by the hybrid system is determined, which amounts to $0.209/kWh, which is very cost effective and satisfactory for the considered sample conditions (Comoros Island).

Detection of SARS-CoV-2 variant 501Y.V2 in Comoros Islands in January 2021

Background. Genomic data is key in understanding the spread and evolution of SARS-CoV-2 pandemic and informing the design and evaluation of interventions. However, SARS-CoV-2 genomic data remains scarce across Africa, with no reports yet from the Indian Ocean islands. Methods. We genome sequenced six SARS-CoV-2 positive samples from the first major infection wave in the Union of Comoros in January 2021 and undertook detailed phylogenetic analysis. Results. All the recovered six genomes classified within the 501Y.V2 variant of concern (also known as lineage B.1.351) and appeared to be from 2 sub-clusters with the most recent common ancestor dated 30 th Oct-2020 (95% Credibility Interval: 06 th Sep-2020 to 10 th Dec-2020). Comparison of the Comoros genomes with those of 501Y.V2 variant of concern from other countries deposited into the GISAID database revealed their close association with viruses identified in France and Mayotte (part of the Comoros archipelago and a France, Overseas Department). Conclusions. The recovered genomes, albeit few, confirmed local transmission following probably multiple introductions of the SARS-CoV-2 501Y.V2 variant of concern during the Comoros’s first major COVID-19 wave. These findings demonstrate the importance of genomic surveillance and have implications for ongoing control strategies on the islands.

A synoptic revision of the genus Deidamia (Passifloraceae)

Gautier, L. & M.W. Callmander (2021). A synoptic revision of the genus Deidamia (Passifloraceae). Candollea 76: 293–297. In English, English and French abstracts. Deidamia Noronha ex Thouars (Passifloraceae) is a small genus known from Madagascar and the Comoro Islands. The previous treatment by Henri Perrier de la Bâthie for the Flore de Madagascar et des Comores recognized five species: Deidamia alata Noronha ex Thouars, Deidamia bicolor H. Perrier, Deidamia bipinnata Tul., Deidamia commersoniana DC. and Deidamia setigera Tul. A complete study of all material available in G, K, MO and P has facilitated a critical review of the taxonomy of the genus. Only three species are here recognized: Deidamia alata, Deidamia commersoniana and Deidamia thompsoniana DC. Three names are proposed as new synonyms and five lectotypes are designated. An identification key is provided, as well as data concerning distribution, ecology and conservation status for each accepted species. First published online: October 13, 2021.

Phytochemical Composition, Antibacterial Activity, and Antioxidant Properties of the Artocarpus altilis Fruits to Promote Their Consumption in the Comoros Islands as Potential Health-Promoting Food or a Source of Bioactive Molecules for the Food Industry.

The present study aimed to evaluate the health-promoting potential of breadfruit (Artocarpus altilis (Parkinson) Fosberg, Moraceae family), a traditional Comorian food, considering the sample variability according to geographic localisation. Moreover, the main aims of this research were also to promote its consumption in the Comoros Islands as potential health-promoting food and evaluate it as a source of bioactive molecules for the food industry thanks to its antioxidant and antibacterial properties. Investigations on biologically active substances were carried out on the extracts obtained from breadfruit flours from five regions of Grande Comore (Ngazidja), the main island in Comoros. Phytochemical screening revealed the presence of tannins and polyphenols, flavonoids, leucoanthocyanins, steroids, and triterpenes. The considered secondary metabolites were phenolic compounds, vitamin C, monoterpenes, and organic acids. The contents of total phenolic compounds (mgGAE/100 g of dry weight—DW) in the extracts ranged from 29.69 ± 1.40 (breadfruit from Mbadjini—ExMBA) to 96.14 ± 2.07 (breadfruit from Itsandra—ExITS). These compounds included flavanols, flavonols, cinnamic acid and benzoic acid derivatives, and tannins which were detected at different levels in the different extracts. Chlorogenic acid presented the highest levels between 26.57 ± 0.31 mg/100 g DW (ExMIT) and 43.80 ± 5.43 mg/100 g DW (ExMBA). Quercetin was by far the most quantitatively important flavonol with levels ranging from 14.68 ± 0.19 mg/100 g DW (ExMIT) to 29.60 ± 0.28 mg/100 g DW (ExITS). The extracts were also rich in organic acids and monoterpenes. Quinic acid with contents ranging from 77.25 ± 6.04 mg/100 g DW (ExMBA) to 658.56 ± 0.25 mg/100 g DW of ExHAM was the most important organic acid in all the breadfruit extracts, while limonene was quantitatively the main monoterpene with contents between 85.86 ± 0.23 mg/100 g DW (ExMIT) and 565.45 ± 0.24 mg/100 g DW (ExITS). The antibacterial activity of the extracts was evaluated on twelve pathogens including six Gram (+) bacteria and six Gram (−) bacteria. By the solid medium disc method, except for Escherichia coli and Pseudomonas aeruginosa, all the bacteria were sensitive to one or more extracts. Inhibitory Halo Diameters (IHDs) ranged from 8 mm to 16 mm. Salmonella enterica, Clostridium perfringens, and Vibrio fischeri were the most sensitive with IHD > 14 mm for ExITS. By the liquid microdilution method, MICs ranged from 3.12 mg/mL to 50 mg/mL and varied depending on the extract. Bacillus megaterium was the most sensitive with MICs ≤ 12.5 mg/mL. Pseudomonas aeruginosa, Shigella flexneri, and Vibrio fischeri were the least sensitive with all MICs ≥ 12.5 mg/mL. ExHAM was most effective with a MIC of 3.12 mg/mL on Staphylococcus aureus and 6.25 mg/mL on Salmonella enterica. The antioxidant power of the extracts was evaluated by the FRAP method. The activity ranged from 5.44 ± 0.35 (ExMBA) to 14.83 ± 0.11 mmol Fe2+/kg DW (ExHAM). Breadfruit from different regions of Comoros contained different classes of secondary metabolites well known for their important pharmacological properties. The results of this study on phenolics, monoterpenes, and organic acids have provided new data on these fruits. The obtained results showed that breadfruit from the biggest island of the Union of Comoros also presented antimicrobial and antioxidant properties, even if some differences in effectiveness existed between fruits from different regions.

FROM SUAKIN ISLAND TO COMOROS ISLANDS: EAST AFRICAN MUSLIMS' STRUGGLE FOR EXISTENCE

Suakin Island is a strategically important island in the northeast of the Sudanese Republic and on the Red Sea coast. The Comoros Islands, on the other hand, are islands located in the south east of Africa, in the west of the Indian Ocean. East Africa coasts extending from the Red Sea coast in the north of Africa, to the Comoros Islands located in the south of Africa are very special and fertile lands that have hosted the culture and civilization of Muslim peoples. These lands, which are the subject of this article, have a difficult nature in terms of both geographical and climatic conditions, have been exposed to the invasion and influx of powerful states throughout history. Especially the dreams of Portuguese sailors who wandered the Cape of Good Hope to transfer the riches of the east to the west caused the western powers to turn their attention to this geography in the sixteenth century. In our article, we draw attention to the formation of the Islamic civilization of the coasts of East Africa and the Red Sea and the development phase of this cultural texture called the Swahili civilization. We tried to focus on the Harar sultanates and the Abyssinian State of the Ottoman Empire. It is preferred to give point to the strategic location of the cities of Suakin, Masawa and Zeila, which are the administrative centers of the Abyssinian state. We observe that the Ottoman navy, which dominated the Red Sea for three centuries and prevented the Portuguese invasion, organized voyages in the Indian Ocean in the direction of Yemen, Basra and the Indian through the Bosporus of Bâbü'l-Mendeb, as well as voyages along the coast of East Africa to the lands of today's Somalia, Kenya and Tanzania. In our article, it will be clarified that how East African Muslims had a bond of affection with the Ottoman Empire until the First World War.

Detection of SARS-CoV-2 variant 501Y.V2 in Comoros Islands in January 2021.

Background. Genomic data is key in understanding the spread and evolution of SARS-CoV-2 pandemic and informing the design and evaluation of interventions. However, SARS-CoV-2 genomic data remains scarce across Africa, with no reports yet from the Indian Ocean islands. Methods. We genome sequenced six SARS-CoV-2 positive samples from the first major infection wave in the Union of Comoros in January 2021 and undertook detailed phylogenetic analysis. Results. All the recovered six genomes classified within the 501Y.V2 variant of concern (also known as lineage B.1.351) and appeared to be from 2 sub-clusters with the most recent common ancestor dated 30 th Oct-2020 (95% Credibility Interval: 06 th Sep-2020 to 10 th Dec-2020). Comparison of the Comoros genomes with those of 501Y.V2 variant of concern from other countries deposited into the GISAID database revealed their close association with viruses identified in France and Mayotte (part of the Comoros archipelago and a France, Overseas Department). Conclusions. The recovered genomes, albeit few, confirmed local transmission following probably multiple introductions of the SARS-CoV-2 501Y.V2 variant of concern during the Comoros's first major COVID-19 wave. These findings demonstrate the importance of genomic surveillance and have implications for ongoing control strategies on the islands.

A diagnosis of progressive myoclonic ataxia guided by blood biomarkers

A 21-year-old woman from the Comoro Islands of Eastern Africa, born to consanguineous (first cousins) parents, presented abnormal movements and gait ataxia. At age 17 years, she had a miscarriage of unknown etiology after the 5th month of pregnancy, and at 18 years, she gave birth to a stillborn child. Her elder sister died at the age of 24 years from a similar, but undiagnosed neurological disorder that appeared 6 years before her death.

Graceful Exits: Spirit Possession as Personal Performance in Mayotte

In what ways can spirit possession among the Malagasy speakers of Mayotte (Comoro Islands, East Africa) be said to be a creative performance? Situating trance episodes in the broader life context of the performer enables us to see that style is in large part a product of frame management. A good performer provides a clear and resonant articulation of her identities as character, medium, and person. Such an articulation is examined at two problematic moments—the closing of a possession ceremony and the closing of a career in old age. The focus on exits marks a departure from the epidemiological slant characteristic of much of the literature and provides a novel way of dealing with trance practice in a non-deterministic framework.

Taxonomic Studies of Diospyros (Ebenaceae) from the Malagasy Region. VII. Revision of Diospyros sect. Forbesia in Madagascar and the Comoro Islands

A recent molecular phylogenetic study revealed that Diospyros L. sect. Forbesia F. White, originally circumscribed to encompass two species from Africa and several from the Mascarene Islands (White, 1980), also includes a group of species endemic to Madagascar. The taxonomy of the Malagasy members of the section has not been examined since Perrier de la Bâthie’s 1952 treatment in the Flore de Madagascar et des Comores, and in the intervening seven decades, numerous specimens have been collected that cannot be identified based on the key provided. This revision presents a significantly updated taxonomy of Diospyros sect. Forbesia in the Malagasy region in which 18 species are recognized, 14 of which are newly described and illustrated, including one new species restricted to Mayotte Island in the Comoro archipelago. An identification key is provided as well as IUCN risk of extinction assessments, which indicate that two species are Critically Endangered, four are Endangered, and seven are Vulnerable, while one is Near Threatened and four are Least Concern. A full description is provided for each species, along with color photos; each of the new species is also illustrated with a line drawing.