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Background and Objectives: Data on HIV drug resistance in Madagascar are rare and outdated. In this study, we assessed the prevalence of HIV drug resistance mutations to antiretrovirals (ARVs) and genetic diversity of circulating strains in treatment-naive people living with HIV (PLHIV) in Madagascar., Materials and Methods: We amplified the protease (PR), fragments of the Reverse Transcriptase (RT) and Integrase (IN) genes according to the French ANRS protocol. The amplicons were sequenced using next-generation sequencing technology on an Illumina platform (MiSeq). We determined HIV-1 subtypes through phylogenetic analysis using maximum likelihood in PhyML. Resistance interpretation was performed using the Stanford algorithm (version 9.5.1)., Results: We included 239 HIV-infected adults and children, sampled between January 2019 and November 2023, with a median age of 30 years and a mean plasma HIV viral load of 6.3 Log copies/mL. We sequenced at least one genomic fragment (PR or RT or IN) of the 239 samples, but 9 were excluded from analysis (mean depth < 10,000×). Phylogenetic analysis of 230 sequences revealed the presence of subtype C (33.91 %), A1 (11.30 %), B (11.30 %), CRF02&#95;AG (9.56 %), subtype G (3.04 %), subtype D (0.43 %), CRF01&#95;AE (0.43 %), and a significant proportion of unique recombinant forms (URFs) (30.30 %). The prevalence of transmitted drug resistance (TDR) was 4.95 % (10/202) among patients aged 15 years and older. When stratified by ARV class, this prevalence was 4.79 % for non-nucleoside reverse transcriptase inhibitors (NNRTIs), 0.59 % for Nucleoside Reverse Transcriptase inhibitors (NRTIs), and 0.50 % for integrase strand transfer inhibitors (INSTIs). Among children under 15 years old (n = 28), the prevalence of TDR was 14.28 % (4/28), with all mutations conferring resistance to NNRTIs. No mutation conferring resistance to protease inhibitors was found, neither in children nor in adults., Conclusion: Our results show a low prevalence of ARV resistance mutations among adult treatment-naive PLHIV in Madagascar. In children under 15 years old, 92 % were infants under two years old, the high resistance rate is likely related to mother-to-child transmission. No resistance mutation to dolutegravir was detected. We also observed high frequencies of subtypes C, B, A1 and a high proportion of URFs, highlighting an ongoing dynamic epidemic., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Antimicrobial resistance (AMR) is a major public health threat, affecting not only people but also animals and the environment. The One Health dimension of AMR is well known; however, data are lacking on the circulation of resistance-conferring genes, particularly in low-income countries. In 2017, WHO proposed a protocol called Tricycle, focusing on extended-spectrum β-lactamase (ESBL)-Escherichia coli surveillance in the three sectors (humans, animals, and the environment). We implemented Tricycle in Madagascar to assess ESBL-E coli prevalence and describe intrasector and intersector circulation of ESBL-E coli and plasmids., Methods: In this prospective study, we collected blood culture data from hospitalised patients with a suspected bloodstream infection processed from May 1, 2018, to April 30, 2019, and rectal swabs from healthy pregnant women from July 30, 2018, to April 27, 2019, both from three hospitals in Antananarivo, Madagascar; and caeca from farm chickens and surface waters from the Ikopa river, wastewater, and slaughterhouse effluents in the Antananarivo area, Madagascar, from April 9, 2018, to April 30, 2019. All samples were tested for ESBL-E coli. The genomes of all isolates were sequenced using a short-read method on NextSeq 500 and NovaSeq 6000 platforms (Illumina, San Diego, CA, USA) and those carrying plasmid replicons using an additional long-read method on a MinION platform (Oxford Nanopore Technologies, Oxford, UK). We characterised genomes of isolated strains (sequence type, resistance and virulence gene content, and plasmid replicons). We then compared isolates using the variant calling method (single-nucleotide polymorphism)., Findings: Data from 1056 blood cultures were collected and 289 pregnant women, 246 chickens, and 28 surface waters were sampled. Of the blood cultures, 18 contained E coli, of which seven (39%) were ESBL. ESBL-E coli was present in samples from 86 (30%) of 289 pregnant women, 140 (57%) of 246 chickens, and 28 (100%) of 28 surface water samples. The wet season (November to April) was associated with higher rates of carriage in humans (odds ratio 3·08 [1·81-5·27]) and chickens (2·79 [1·65-4·81]). Sequencing of 277 non-duplicated isolates (82 from pregnant women, 118 from chickens, and 77 from environmental samples) showed high genetic diversity (90 sequence types identified) with sector-specific genomic features. Single nucleotide polymorphism (SNP) analysis revealed that 169 (61%) of 277 isolates grouped into 44 clusters (two or more isolates) of closely related isolates (<40 SNPs), of which 24 clusters contained isolates from two sectors and five contained isolates from all three sectors. ESBL genes were all bla CTX-M variants (215 [78%] of 277 being bla CTX-M-15 ) and were located on a plasmid in 113 (41%) of 277 isolates. These ESBL-carrying plasmids were mainly IncF (63 [55%] of 114; one strain carried two plasmids) and IncY (42 [37%] of 114). The F31/36:A4:B1 (n=13) and F-:A-:B53 (n=8) pMLST subtypes, and the IncY plasmids, which were all highly conserved, were observed in isolates of differing genetic backgrounds from all sectors and were transferable in vitro by conjugation., Interpretation: Despite sector-specific population structures, both ESBL-E coli strains and plasmids are circulating among humans, chickens, and the environment in Antananarivo, Madagascar. The Tricycle protocol can be implemented in a low-income country and represents a powerful tool for investigating dissemination of AMR from a One Health perspective., Funding: Fondation Mérieux and INSERM, Université Paris Cité., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

To estimate the prevalence of IgG antibodies against six arboviruses in people living with HIV-1 (PLWHIV) in Madagascar, we tested samples collected between January 2018 and June 2021. We used a Luminex-based serological assay to detect IgG antibodies against antigens from Dengue virus serotypes 1-4 (DENV1-4), Zika virus (ZIKV), West Nile virus (WNV), Usutu virus (USUV), Chikungunya virus (CHIKV), and O'nyong nyong virus (ONNV). Of the 1036 samples tested, IgG antibody prevalence was highest for ONNV (28.4%), CHIKV (26.7%), WNV-NS1 (27.1%), DENV1 (12.4%), USUV (9.9%), and DENV3 (8.9%). ZIKV (4.9%), DENV2 (4.6%), WNV-D3 (5.1%), and DENV4 (1.4%) were lower. These rates varied by province of origin, with the highest rates observed in Toamasina, on the eastern coast (50.5% and 56.8%, for CHIKV and ONNV, respectively). The seroprevalence increased with age for DENV1 and 3 ( p = 0.006 and 0.038, respectively) and WNV DIII ( p = 0.041). The prevalence of IgG antibodies against any given arborvirus varied over the year and significantly correlated with rainfalls in the different areas (r = 0.61, p = 0.036). Finally, we found a significant correlation between the seroprevalence of antibodies against CHIKV and ONNV and the HIV-1 RNA plasma viral load. Thus, PLWHIV in Madagascar are highly exposed to various arboviruses. Further studies are needed to explain some of our findings.

Chromoblastomycosis is an implantation fungal infection. Twenty years ago, Madagascar was recognized as the leading focus of this disease. We recruited patients in Madagascar who had chronic subcutaneous lesions suggestive of dermatomycosis during March 2013-June 2017. Chromoblastomycosis was diagnosed in 50 (33.8%) of 148 patients. The highest prevalence was in northeastern (1.47 cases/100,000 persons) and southern (0.8 cases/100,000 persons) Madagascar. Patients with chromoblastomycosis were older (47.9 years) than those without (37.5 years) (p = 0.0005). Chromoblastomycosis was 3 times more likely to consist of leg lesions (p = 0.003). Molecular analysis identified Fonsecaea nubica in 23 cases and Cladophialophora carrionii in 7 cases. Of 27 patients who underwent follow-up testing, none were completely cured. We highlight the persistence of a high level of chromoblastomycosis endemicity, which was even greater at some locations than 20 years ago. We used molecular tools to identify the Fonsecaea sp. strains isolated from patients as F. nubica.

Human settlement of Madagascar traces back to the beginning of the first millennium with the arrival of Austronesians from Southeast Asia, followed by migrations from Africa and the Middle East. Remains of these different cultural, genetic, and linguistic legacies are still present in Madagascar and other islands of the Indian Ocean. The close relationship between human migration and the introduction and spread of infectious diseases, a well-documented phenomenon, is particularly evident for the causative agent of leprosy, Mycobacterium leprae . In this study, we used whole-genome sequencing (WGS) and molecular dating to characterize the genetic background and retrace the origin of the M. leprae strains circulating in Madagascar ( n = 30) and the Comoros ( n = 3), two islands where leprosy is still considered a public health problem and monitored as part of a drug resistance surveillance program. Most M. leprae strains (97%) from Madagascar and Comoros belonged to a new genotype as part of branch 1, closely related to single nucleotide polymorphism (SNP) type 1D, named 1D-Malagasy. Other strains belonged to the genotype 1A (3%). We sequenced 39 strains from nine other countries, which, together with previously published genomes, amounted to 242 genomes that were used for molecular dating. Specific SNP markers for the new 1D-Malagasy genotype were used to screen samples from 11 countries and revealed this genotype to be restricted to Madagascar, with the sole exception being a strain from Malawi. The overall analysis thus ruled out a possible introduction of leprosy by the Austronesian settlers and suggests a later origin from East Africa, the Middle East, or South Asia., (Copyright © 2020 Avanzi, Lécorché, Rakotomalala, Benjak, Rapelanoro Rabenja, Ramarozatovo, Cauchoix, Rakoto-Andrianarivelo, Tió-Coma, Leal-Calvo, Busso, Boy-Röttger, Chauffour, Rasamoelina, Andrianarison, Sendrasoa, Spencer, Singh, Dashatwar, Narang, Berland, Jarlier, Salgado, Moraes, Geluk, Randrianantoandro, Cambau and Cole.)

Cryptococcal meningoencephalitis (CM) remains the most prevalent invasive fungal infection worldwide. The main objective of this study was to describe the prevalence of CM and cryptococcal infection in HIV-infected patients in Madagascar. The secondary objectives were to assess the adjusted prevalence of CM according to clinical presentation and patient characteristics, to determine crude 90-day survival according to cryptococcal antigen (CrAg) status and CM, and to identify the genotypes of Cryptococcus clinical isolates. This cross-sectional study was carried out at two urban hospitals in Antananarivo (central highlands) and Toamasina (east coast) between November 2014 and December 2016. Consecutive HIV-infected adults presenting with CD4 cell counts ≤200/μl were enrolled. Lateral flow immunoassays of CrAg were performed on serum for all patients, and on cerebrospinal fluid for patients with CM symptoms. MALDI-ToF MS, ITS sequencing, and determinations of the molecular and mating types of the isolates were performed. Fluconazole is the only drug for CM treatment available in Madagascar. Patients were treated orally, with high doses (1200 mg/day) for 10-12 weeks and then with 200 mg/day. Minimum inhibitory concentrations were determined for amphotericin B, flucytosine, voriconazole and fluconazole in E-tests. Overall prevalence was 13.2% (95% CI 7.9-20.3) for cryptococcal infection and 10.9% (95% CI 6.1-17.5) for CM, among the 129 HIV-infected patients studied. The 90-day mortality rate was 58.8% (10/17) in CrAg-positive patients and 17.9% (20/112) in CrAg-negative patients (p<0.001). The 13 Cryptococcus strains obtained at baseline were all Cryptococcus neoformans var. grubii, genotypes VNI-αA (3 isolates), VNII-αA (4 isolates) or hybrid VNI/VNII-αAAα (6 isolates), suggesting high diversity. Two strains acquired fluconazole resistance after four and five months of exposure, respectively. The prevalence of cryptococcosis is high in Madagascar and this serious condition is life-threatening in HIV-infected patients. These findings will be used to raise the awareness of national authorities to strengthen the national HIV/AIDS control program., Competing Interests: The authors have declared that no competing interests exist.

Sporotrichosis is a saprozoonotic fungal infection found mostly in tropical and subtropical areas. Few case reports in Madagascar have been published. To document sporotrichosis epidemiology in Madagascar, we conducted a cross-sectional study. During March 2013-June 2017, we recruited from select hospitals in Madagascar patients with chronic cutaneous lesions suggestive of dermatomycosis. Sporotrichosis was diagnosed for 63 (42.5%) of 148 patients. All but 1 patient came from the central highlands, where the prevalence was 0.21 cases/100,000 inhabitants. Frequency was high (64.7%) among patients <18 years of age. Sporotrichosis was diagnosed for 73.8% of patients with arm lesions, 32.3% with leg lesions, and 15.4% with lesions at other sites. Molecular identification identified 53 Sporothrix schenckii isolates. Among the 32 patients who were followed up, response to itraconazole was complete or major for 15 and minor for 17. Overall, endemicity of sporotrichosis in Madagascar was high, concentrated in the highlands.

Chromoblastomycosis and sporotrichosis are endemic fungal infections of tropical and subtropical regions, including Madagascar. The causal fungi develop in the soil or on plants and infect humans through wounds, either directly (wounding by the plant, through thorns, for example), or through the contact of an existing wound with contaminated soil. For this reason, the lesions predominantly occur on the limbs, and these fungi principally infect people working outside with bare hands and/or feet. The subcutaneous lesions of chromoblastomycosis are initially nodular, subsequently becoming warty, tumoral, cauliflower-like and pruriginous, which promotes dissemination. The chronic nature of the infection and its progression over long periods lead to highly disabling lesions in essentially rural and agricultural populations. The lesions of sporotrichosis are also nodular, but more ulcerous, and they form an extended chain following the route of the lymph vessels. Pus, squamous or skin biopsy specimens are used for the mycological examination of these mycoses. Treatment depends on the severity and form of the lesions and is based on antifungal drugs sometimes combined with physical methods. There has been no study of these infections for more than two decades in Madagascar, despite the large numbers of cases seen by doctors in all parts of the island. The nature, diversity and distribution of the plants responsible for contamination have not been described in Madagascar. In this review, we described these two endemic mycoses in terms of their epidemiological, mycological, clinical and therapeutic characteristics, focusing particularly on Madagascar, which is one of the leading foci of these two infections worldwide., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)