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French Guiana experienced an unprecedented dengue epidemic during 2023–2024. Prior to the 2023–2024 outbreak in French Guiana, DENV-3 had not circulated in an epidemic manner since 2005. We therefore studied retrospectively the strains circulating in the French Territories of the Americas (FTA)—French Guiana, Guadeloupe, and Martinique—from the 2000s to the current epidemic. To this end, DENV-3 samples from the collection of the National Reference Center for Arboviruses in French Guiana (NRCA-FG) were selected and sequenced using next-generation sequencing (NGS) based on Oxford Nanopore Technologies, ONT. Phylogenetic analysis showed that (i) the 97 FTA sequences obtained all belonged to genotype III (GIII); (ii) between the 2000s and 2013, the regional circulation of the GIII American-I lineage was the source of the FTA cases through local extinctions and re-introductions; (iii) multiple introductions of lineages of Asian origin appear to be the source of the 2019–2021 epidemic in Martinique and the 2023–2024 epidemic in French Guiana. Genomic surveillance is a key factor in identifying circulating DENV genotypes, monitoring strain evolution, and identifying import events. [ABSTRACT FROM AUTHOR]

Abstract This study reports the dissemination of multidrug-resistant (MDR) OXA-23-producing Acinetobacter baumannii clones in hospitals in Antananarivo, Madagascar. A total of 53 carbapenem-resistant A. baumannii isolates were obtained from September 2006 to March 2009 in five hospitals. These resistant strains represent 44% of all A. baumannii isolates. The double disk synergy test was performed to screen for production of metallo-beta-lactamases. Polymerase chain reaction (PCR) and DNA sequencing were performed for the detection of bla(AmpC), bla(OXA-51),bla(OXA-23), bla(OXA-24), bla(IMP), bla(VIM). The presence of the insertion sequence ISAba1 relative to blaOXA-23 and blaOXA-51 was assessed by PCR. Isolates were typed by Rep-PCR. All the isolates were MDR and produced the OXA-23 carbapenemase, which was confirmed by sequencing. PCR analysis for AmpC and OXA-51 gave positive results for all strains studied. No isolates produced metallo-beta-lactamases. In all isolates ISAba1 laid upstream of blaOXA-23. The A. baumannii isolates were separated into two genotypes; genotype A had a higher prevalence (41 strains) than genotype B (12 strains). Genotype A was present in four hospitals, whilst genotype B had spread in two hospitals. The high frequency of MDR OXA-23-producing A. baumannii in various hospitals in Antananarivo is curious since carbapenems are not available in Madagascar, but it emphasises the need for infection control procedures and strict adherence to them to prevent the spread of these resistant organisms in Antananarivo and also the need to control the use of carbapenems in the future.

In French Guiana, most snakebites are caused by crotalids, with the main signs being tissue damage and bleeding due to venom-induced coagulopathy. Since December 2014 the Western Guiana Hospital (WGH) has used Antivipmyn TriTM, a Mexican polyvalent antivenom. The aim of the study was to assess its benefit on the correction of snakebite-related coagulopathy. This retrospective study included patients hospitalized at the WGH with snakebite and a coagulopathy defined by: a prothrombin rate (PR) lower than 45%, an activated partial thromboplastin time ratio (aPTTr) greater than 2 or a fibrinogen lower than 100 mg.dL−1. The antivenom group included patients receiving Antivipmyn TriTM from December 2014 to September 2017. The control group included patients admitted between January 2013 and November 2014 (when antivenom was unavailable) or admitted between December 2014 and September 2017 during times of antivenom shortage. We graphically compared the time courses of PR, aPTTr and fibrinogen between groups. Other endpoints were the length of hospital stay and the need for surgery or dialysis. 84 patients were included: 42 in the antivenom group, 42 in the control group. Both groups were similar for age, sex-ratio, proportion of bleedings, necrosis, and severity. Most patients in the antivenom group received 3 vials. There were no significant differences in recovery of PR, aPTTr and fibrinogen through the first 24 h. Fibrinogen declined again in the control group at 30 h and showed a slower rise to normal concentration. There were no significant differences in any secondary endpoint. Antivipmyn TriTM as currently used did not show any benefit in recovery from coagulopathy. [ABSTRACT FROM AUTHOR]

Abstract Background Hepatitis A virus (HAV) is an enteric, viral, infectious disease endemic in many developing countries such as Madagascar. Infection is often subclinical or asymptomatic in children; however, symptomatic acute infections become more common with increasing age. In some developing countries, improvements in living conditions have led to changes in the epidemiological pattern of HAV infection. There are very few reports on the prevalence of HAV in Madagascar. This study was to determine the seroprevalence of hepatitis A virus antibodies in relation to age in the city of Antananarivo, Madagascar. Methods Serum samples collected in 2004 during a cross-sectional survey of individuals aged between two and 24 years from Antananarivo were tested for anti-HAV antibody using a commercial enzyme immunoassay kit. Subjects were investigated using a standardized social and medical history questionnaire. Results 926 subjects were enrolled including 406 males and 520 females. There were 251 children under 10 years old and 675 subjects between 10 and 24 years old. Of the 926 serum samples tested, 854 (92.2%) were positive for anti-HAV antibodies. The number of seropositive samples was similar for males and females. The overall seroprevalence was 83.7% (210/251) for children under 10 years old and 95.5% (644/675) for subjects aged between 10 and 24 years (p < 0.001). Conclusion Despite improvements in sanitary conditions and hygiene over the last few years, the prevalence of HAV in Antananarivo is high. Only children under five years old remain susceptible to HAV infection. Immunization against HAV is not needed at the present time in the Madagascan population, but should be recommended for travellers.

Abstract Background Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. In developed countries, as methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become limited. In developing countries and especially African countries very little is known concerning the resistance of S. aureus to antibiotics. In Madagascar no data exist concerning this resistance. Objective To update the current status of antibiotic resistance of S. aureus in Antananarivo, Madagascar. Methods Clinical S. aureus isolates were collected from patients at the Institut Pasteur of Madagascar from January 2001 to December 2005. Susceptibility tests with 18 antibiotics were performed by the disk diffusion method. Results Among a total of 574 isolates, 506 were from community-acquired infections and 68 from nosocomial infections. There was no significant difference in the methicillin resistance rate between community-acquired strains (33 of 506; 6.5%) and nosocomial strains (3 of 68, 4.4%). Many MRSA isolates were resistant to multiple classes of antibiotics. Resistance to tetracyclin, trimethoprim-sulfamethoxazole and erythromycin was more common. Among MRSA isolates resistance rates to rifampicin, fusidic acid, gentamicin and ciprofloxacin were lower than that observed with other drugs easily available in Madagascar. No isolates were resistant to glycopeptides. Conclusion The rate of methicillin-resistant S. aureus is not different between community-acquired and nosocomial infections and is still rather low in Madagascar.

Neglected, unknown, misdiagnosed, fungal infections are highly prevalent in tropical areas due to climate conditions and living habits. Migration of infected individuals to temperate latitudes changes the epidemiological patterns. In developing countries, mycoses cause major public health and economic problems. Their morbidity is most profound among children. Even though fungal resistance seems to be limited for the common tropical fungi, most antifungal agents, including those recently approved, remain expensive or require medical and laboratory monitoring that is not easily accessible. Furthermore, treatment recommendations are based on case series and non-comparative studies because to date there have been few or no randomized controlled trials. These infections remain a challenge for surgical intervention for the most devastating of these subcutaneous fungal infections. Thus, recognition of the clinical symptoms and the pathogens, is critical in diagnosis of the tropical mycoses. Clinical decision trees or flow charts can aid physicians practicing in resource-limited tropical environments. [ABSTRACT FROM AUTHOR]

Helicobacter pylori has probably infected the human stomach since our origins and subsequently diversified in parallel with their human hosts. The genetic population history of H. pylori can therefore be used as a marker for human migration. We analysed seven housekeeping gene sequences of H. pylori strains isolated from 78 Senegalese and 24 Malagasy patients and compared them with the sequences of strains from other geographical locations. H. pylori from Senegal and Madagascar can be placed in the previously described HpAfrica1 genetic population, subpopulations hspWAfrica and hspSAfrica, respectively. These 2 subpopulations correspond to the distribution of Niger-Congo speakers in West and most of subequatorial Africa (due to Bantu migrations), respectively. H. pylori appears as a single population in Senegal, indicating a long common history between ethnicities as well as frequent local admixtures. The lack of differentiation between these isolates and an increasing genetic differentiation with geographical distance between sampling locations in Africa was evidence for genetic isolation by distance. The Austronesian expansion that started from Taiwan 5000 years ago dispersed one of the 10 subgroups of the Austronesian language family via insular Southeast Asia into the Pacific and Madagascar, and hspMaori is a marker for the entire Austronesian expansion. Strain competition and replacement of hspMaori by hpAfrica1 strains from Bantu migrants are the probable reasons for the presence of hspSAfrica strains in Malagasy of Southeast Asian descent. hpAfrica1 strains appear to be generalist strains that have the necessary genetic diversity to efficiently colonise a wide host spectrum. [ABSTRACT FROM AUTHOR]