Molecular epidemiology of Candida africana isolates collected from vagina swabs in French Guiana.

Previous molecular studies have shown that Candida africana corresponds to the clade 13 of Candia albicans. It has been mostly involved in vulvovaginal candidiasis worldwide but few data exist in South America. The aim of our study was to investigate the prevalence of C. africana in women living in French Guiana. For this, we first set up a fluorescent-intercalating-dye-real time Polymerase Chain Reaction (PCR) targeting the hyphal wall protein 1 gene. The test was applied to 212 C. albicans isolates collected from May to August 2019 from vaginal swabs, allowing the identification of six women harboring C. africana (eight isolates). The in vitro susceptibility of these eight isolates to six antifungal drugs was also evaluated. No demographics or clinical-specific features could be demonstrated. Genetic diversity of those isolates was analyzed through multilocus sequence typing and showed that diploid sequence type 182 was predominant (n = 6) and allowed the report of a new diploid sequence type.

Candida africana, the clade 13 of C. albicans, is characterized by specific genetic and phenotypic traits. Using a new molecular technique, we report a high prevalence of C. africana in vaginal swabs from patients living in French Guiana. The worldwide predominant genotype was detected in all but one patient.

Pulmonary Histoplasmosis in People Living with Human Immunodeficiency Virus in French Guiana: Clinical Epidemiology, Medical Imaging and Prognostic.

BACKGROUND: Histoplasmosis is mainly described as a disseminated disease in people living with HIV (PLHIV). Compared to historical descriptions in immunocompetent individuals, knowledge is lacking on the detailed clinical and radiological findings and outcomes of pulmonary histoplasmosis (PH). Overlooked or misdiagnosed with other AIDS-defining condition, prognostic of PLHIV may be at risk because of inappropriate care. METHODS: A retrospective multicentric study was conducted in PLHIV from French Guiana between January 1988 and October 2019. Proven PH were documented through mycological direct examination, culture, or histology. Patients with concomitant respiratory infections were excluded. RESULTS: Among 65 patients, sex ratio M:F was 2.4 with a median age of 39 years [IQR 25-75%: 34-44]. Median CD4 count was 24 cells/mm3 [11-71], with histoplasmosis as the AIDS-defining condition in 88% and concomitant AIDS-defining conditions in 29%. Clinical findings were fever (89%), cough (58%), dyspnea (35%), expectoration (14%), and hemoptysis (5%). Sixty-one X-rays and 24 CT-scans were performed. On X-rays, an interstitial lung disease was mainly found (77%). On CT-scans, a nodular pattern was predominant (83%): mostly miliary disease (63%), but also excavated nodules (35%). Consolidations were present in 46%, associated with miliary disease in 21%. Thoracic lymphadenopathies were found in 58%, mainly hilar and symmetric (33%). Despite antifungal treatment, case-fatality rate at one month was 22%. CONCLUSION: When faced with an interstitial lung disease on X-rays or a miliary pattern on CT-scans in advanced PLHIV, physicians in endemic areas, apart from tuberculosis or pneumocystosis, should include histoplasmosis as part of their differential diagnoses.

Morphological and Molecular Characterizations of Cochliomyia hominivorax (Diptera: Calliphoridae) Larvae Responsible for Wound Myiasis in French Guiana.

Myiasis is an ectoparasitic infection caused by the larvae of true flies (Diptera). We came across a rather rare case of myiasis in an immunocompetent 34-year-old man from French Guiana with advanced wound myiasis masquerading as cavitary myiasis and a history of cholesteatoma surgery in the left ear. The Diptera larvae responsible for the disease were isolated and identified using morphological and molecular approaches as Cochliomyia hominivorax. We underline the importance of this parasitosis as the second case of myiasis caused by C. hominivorax and the first case of wound myiasis in this overseas department of France and its incidence in pre-urban areas of the capital, Cayenne, in South America.

Case Report: Acute Brucellosis Due to Brucella suis in a Brazilian Gold Miner Diagnosed in French Guiana.

A 29-year-old Brazilian illegal gold miner developed intermittent fever. Blood cultures were positive for Gram-negative coccobacilli and, after an initial misidentification by an automated identification system, the diagnosis of brucellosis caused by Brucella suis was confirmed. We hypothesize an association with domestic or wild swine exposure. The patient responded well to standard antibiotic therapy of brucellosis. We report the first case of human brucellosis on the Guiana Shield. This report underlines the importance of considering brucellosis in the presence of a fever of unknown origin, even in the Amazonian rainforest area, where several zoonotic diseases might be considered in the differential diagnosis of unexplained fever.

Dynamics of SARS-CoV-2 lineages in French Guiana in 2020-2021: 4 epidemic waves with cross-influences from Europe and South America.

Since the first cases of SARS-CoV-2 infection in Wuhan in December 2019, this RNA virus gave rise to different viral lineages with different virological, epidemiological and immunological properties. Here we describe the dynamics of circulation of SARS-CoV-2 lineages in an Amazonian South American French overseas territory, French Guiana (FG). The data analyzed are based on the general epidemic course, and genomic surveillance data come from whole genome sequencing (WGS) as well as typing PCRs. From March 2020 to October 2021, four COVID-19 epidemic waves were observed in FG with an evolution of viral lineages influenced by virus introductions from continental France and above all by land-based introductions from neighbouring countries. The third epidemic wave from March to June 2021 was driven by a predominant Gamma introduced from Brazil and a less frequent Alpha introduced from France. This coexistence was completely substituted by Delta that initiated the fourth epidemic wave.

Novel Chronic Anaplasmosis in Splenectomized Patient, Amazon Rainforest.

We report a case of unusual human anaplasmosis in the Amazon rainforest of French Guiana. Molecular typing demonstrated that the pathogen is a novel Anaplasma species, distinct to all known species, and more genetically related to recently described Anaplasma spp. causing infections in rainforest wild fauna of Brazil.

Case Report: Invasive Cryptococcosis in French Guiana: Immune and Genetic Investigation in Six Non-HIV Patients.

Objectives: We describe the clinical, mycological, immunological, and genetic characteristics of six HIV-negative patients presenting with invasive cryptococcosis. Methods: Patients with cryptococcosis without any of the classical risk factors, such as HIV infection, followed at Cayenne Hospital, were prospectively included. An immunologic and genetic assessment was performed. Results: Five male patients and one female patient, 5 adults and one child, were investigated. All presented a neuromeningeal localization. Cryptococcus neoformans var. gattii and C. neoformans var. grubii were isolated in two and three patients, respectively, whereas one patient could not be investigated. Overall, we did not observe any global leukocyte defect. Two patients were found with high levels of circulating autoantibodies against Granulocyte macrophage-colony stimulating factor (GM-CSF), and none had detectable levels of autoantibodies against Interferon gamma (IFN-γ) Sequencing of STAT1 exons and flanking regions performed for four patients was wild type. Conclusion: To better understand cryptococcosis in patients with cryptococcosis but otherwise healthy, further explorations are needed with repeated immune checkups and strain virulence studies.

Cryptosporidiosis outbreak in Amazonia, French Guiana, 2018.

BACKGROUND: Cryptosporidiosis outbreaks in South America are poorly documented. In March 2018, 51 cases of cryptosporidiosis were reported in Maripasoula, a village located in a remote forest area along the border between Surinam and French Guiana. METHOD: To identify the origin of the epidemic, we performed epidemiological, microbiological, and environmental investigations. Only the cases involving diarrhoea and Cryptosporidium-positive stool were considered as bona fide, while cases involving diarrhoea and close contact with a confirmed case were classified as "possible". RESULTS: We identified 16 confirmed cases and 35 possible ones. Confirmed cases comprised nine children (median age of 18 months, range: 6-21), one immunocompromised adult and six soldiers. One child required a hospitalisation for rehydration. All 16 Cryptosporidium stools were PCR positive, and sequencing of the gp60 gene confirmed only one Cryptosporidium hominis subtype IbA10G2. Tap water consumption was the only common risk factor identified. Contamination of the water network with Cryptosporidium parvum subtype IIdA19G2 was found. CONCLUSION: Water quality is a major public health issue in Amazonian French Guiana, especially for population at risk (children, people with comorbidity, travelers). For them, alternative water supply or treatment should be implemented.

Diagnostic accuracy and acceptability of molecular diagnosis of COVID-19 on saliva samples relative to nasopharyngeal swabs in tropical hospital and extra-hospital contexts: The COVISAL study.

A prospective study was conducted among different intra and extra-hospital populations of French Guiana to evaluate the performance of saliva testing compared to nasopharyngeal swabs. Persons aged 3 years and older with mild symptoms suggestive of COVID-19 and asymptomatic persons with a testing indication were prospectively enrolled. Nasopharyngeal and salivary samples were stored at 4°C before analysis. Both samples were analyzed with the same Real-time PCR amplification of E gene, N gene, and RdRp gene. Between July 22th and October 28th, 1159 persons were included, of which 1028 were analyzed. When only considering as positives those with 2 target genes with Ct values <35, the sensitivity of RT-PCR on saliva samples was 100% relative to nasopharyngeal samples. Specificity positive and negative predictive values were above 90%. Across a variety of cultures and socioeconomic conditions, saliva tests were generally much preferred to nasopharyngeal tests and persons seemed largely confident that they could self-sample. For positive patients defined as those with the amplification of 2 specific target genes with Ct values below 35, the sensitivity and specificity of RT-PCR on saliva samples was similar to nasopharyngeal samples despite the broad range of challenging circumstances in a tropical environment.

Accuracy of SD Malaria Ag P.f/Pan® as a rapid diagnostic test in French Amazonia.

BACKGROUND: French Guiana (FG) is a French overseas territory where malaria is endemic. The current incidence rate is 0.74‰ inhabitants, and Plasmodium vivax is widely predominating even though Plasmodium falciparum is still present due to imported cases mainly from Africa. In FG, rapid diagnostic test (SD Malaria Ag P.f/Pan®) is based on the detection of pan-pLDH, PfHRP2, and PfHRP3 antigens, while in South America, the share of deletion of PfHRP2 gene is significantly increasing. Accordingly, the study questions the reliability of RDTs in the Amazonian context. METHODS: The study is retrospective. It is conducted over 4 years and analysed 12,880 rapid diagnostic tests (RDTs) compared to concomitant Blood Film Tests (BFTs) sampled for malaria diagnosis. RESULTS: The global assessment of the accuracy of SD Malaria Ag P.f/Pan® in the diagnostic of malaria shows both Positive and Negative Predictive Values (PPV and NPV) higher than 95%, except for PPV in the diagnosis of malaria to P. falciparum (88%). Overall, the concordance rate between RDT and BFT (positive/positive; negative/negative) was 99.5%. The PPV of the RDT in the follow-up of patients diagnosed with P. falciparum was the lowest during the first 28 days. The PPV of the RDT in the follow-up of patients diagnosed with P. vivax was the lowest during the first 21 days. The global sensitivity of SD Malaria Ag P.f/Pan® test was, on average, 96% (88.2-100) for P. falciparum and 93% (90.6-94.2) for P. vivax. The global specificity was 99.8% (99.5-100) for all included species. CONCLUSION: SD Malaria Ag P.f/Pan® is a reliable rapid test used for the first-line diagnosis in remote healthcare centres. The test results should be interpreted in the light of patient's recent medical history and the date of arrival to FG.

Cytological Spectrum of Pulmonary Histoplasmosis Diagnosed by Bronchoalveolar Lavage: 12 Years of Experience in French Guiana.

Disseminated histoplasmosis is a major cause of mortality in HIV-infected patients. Rapid and efficient diagnosis of Histoplasma capsulatum is crucial. Cytopathology is available in most hospitals and represents a rapid diagnostic alternative. In this study, we reviewed 12 years of experience to describe the cytology of histoplasmosis diagnosed by bronchoalveolar lavage (BAL) in relation to patient characteristics. BAL-diagnosed pulmonary histoplasmosis concerned 17 patients (14 HIV+). BAL cellularity ranged from 76,000 to 125,000 cells/mL in HIV patients, and 117,000 to 160,000 cells/mL in non-HIV patients. Macrophages predominated in all HIV patients (from 60% to 88%), lymphocytic infiltrates ranged from 5% to 15%, and neutrophils were very heterogeneous (from 2% to 32%). The number of H. capsulatum at hot spots seemed greater in HIV-infected than in immunocompetent patients (9 to 375 vs. 4 to 10) and were inversely proportional to the CD4 counts. Yeasts were both intracellular and extracellular in 85.7% of the HIV patients. This is the most comprehensive series detailing the cytological aspects of BAL in the diagnosis of H. capsulatum, focusing on the number of yeasts and their clustering pattern. The cytological examination of the Gomori-Grocott-stained BAL allows a reliable diagnosis of histoplasmosis.

Review of diagnostic methods and results for HIV-associated disseminated histoplasmosis: Pathologists are not sufficiently involved.

OBJECTIVES: Disseminated histoplasmosis is a major killer of HIV-infected persons in Latin America. Antigen detection, fungal culture and Polymerase Chain Reaction are often not available, but cytology and histology are present in most hospitals and may offer a diagnostic alternative. In this study, we review 34 years of clinical experience to describe the roles of cytology and histology in diagnosing disseminated histoplasmosis. METHODS: Retrospective multicentric study of 349 patients between 1 January 1981 and 1 October 2014 with confirmed disseminated histoplasmosis. RESULTS: Around 32/214 (14.9%) of samples were screened using cytopathology, as were 10/101 (9.9%) bronchoalveolar lavage samples and 5/61 (8.2%) of spinal fluid samples. The samples most commonly sent to pathology were liver biopsies, lower digestive tract and lymphnode biopsies; the greatest proportion of positive results were found in lower digestive tract (43/59 (72.9%) positives), lymph node (39/63 (66.1%)), and liver (38/75 (50.7%)) samples. Overall, 97.2% of bone marrow and 97% of bronchoalveolar lavage samples were directly examined by a mycologist. Positive direct examination was independently associated with death (aHR = 1.5 (95%CI = 1-2.2)). CONCLUSIONS: Opportunities for a rapid diagnosis were regularly missed, notably for bone marrow samples, which could have been examined using staining methods complementary to those of the mycologist.

Breakthrough Infections of SARS-CoV-2 Gamma Variant in Fully Vaccinated Gold Miners, French Guiana, 2021.

An outbreak of severe acute respiratory syndrome coronavirus 2 caused by the Gamma variant of concern infected 24/44 (55%) employees of a gold mine in French Guiana (87% symptomatic, no severe forms). The attack rate was 60% (15/25) among fully vaccinated miners and 75% (3/4) among unvaccinated miners without a history of infection.

Invasive Fungal Infections in Persons Living with HIV in an Amazonian Context: French Guiana, 2009-2019.

Although the burden of histoplasmosis in patients with advanced HIV has been the focus of detailed estimations, knowledge about invasive fungal infections in patients living with HIV in an Amazonian context is somewhat scattered. Our goal was thus to adopt a broader view integrating all invasive fungal infections diagnosed over a decade in French Guiana. All patients hospitalized at Cayenne hospital from 1 January 2009 to 31 December 2018 with a proven diagnosis of invasive fungal infection were included (N = 227). Histoplasmosis was the most common (48.2%), followed by Cryptococcus infection (26.3%), and pneumocystosis (12.5%). For cryptococcal infection, there was a discordance between the actual diagnosis of cryptococcal meningitis n = (26) and the isolated presence of antigen in the serum (n = 46). Among the latter when the information was available (n = 34), 21(65.6%) were treated with antifungals but not coded as cryptococcocosis. Most fungal infections were simultaneous to the discovery of HIV (38%) and were the AIDS-defining event (66%). The proportion of major invasive fungal infections appeared to remain stable over the course of the study, with a clear predominance of documented H. capsulatum infections. Until now, the focus of attention has been histoplasmosis, but such attention should not overshadow other less-studied invasive fungal infections.

Immunoblot for the Diagnosis of Cutaneous Leishmaniasis in French Guiana.

Cutaneous leishmaniasis (CL) is firmly established in South America. We aimed to assess the detection of IgG antibodies against 14 and/or 16 kDa antigens by immunoblot (IB) for CL serological diagnosis in French Guiana, an area where many endemic pathogens could interfere with it. This study was performed retrospectively on sera from 141 patients at the Cayenne tertiary hospital: 30 were patients with confirmed CL, 71 were diagnosed with various other endemic pathogens, 11 were diagnosed with an autoimmune disease, and 29 controls had no history of CL. Antibodies bound to the 14 and/or 16 kDa antigens in 27 of the 30 CL patients' sera and in 39 of the 111 non-CL patients' sera (26 from the infectious diseases group, four from the autoimmune diseases group, and nine from the dermatology department). The method tested showed a high sensitivity (90%) and a low specificity (66%), and a diagnosis odds ratio of 17.5 (95% CI [4.6-78.0]). This IB may be helpful to exclude the diagnosis of CL, prompting physicians to look for another diagnosis in the case of a negative IB.

Histoplasmosis of the Central Nervous System: A Case Series between 1990 and 2019 in French Guiana.

Disseminated histoplasmosis is the most frequent acquired immunodeficiency syndrome-defining illness in French Guiana. Paradoxically, central nervous system (CNS) involvement has been scarcely described. We aimed to identify CNS histoplasmosis in our territory. We conducted an observational, multicentric, descriptive, and retrospective study including patients with proven or probable CNS histoplasmosis according to the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MGS). The study population consisted of patients admitted in one of the hospitals of French Guiana between January 1, 1990 and December 31, 2019. During the study period, 390 cases of HIV-associated histoplasmosis were recorded, in which six of them had CNS infections with Histoplasma capsulatum. The male to female sex ratio was 0.25, and the median age at diagnosis was 37.5 years. The median CD4 count was 42 cells/mm3 ([IQR: 29-60]). All patients had disseminated histoplasmosis. Usual signs of meningitis were observed in three patients and focal signs in four patients. One patient had no neurological signs. The median time between the first cerebral symptoms and diagnosis was 22.4 days (IQR 9.5-36.2). Two patients died within a month after diagnosis. In conclusion, few proven CNS localizations of histoplasmosis were observed on 30-year study in French Guiana. This low proportion suggests that the documentation of CNS involvement is often not ascertained for lack of awareness of this particular presentation, and for lack of rapid and sensitive diagnostic tools.

HIV-Associated Disseminated Histoplasmosis and Rare Adrenal Involvement: Evidence of Absence or Absence of Evidence.

Adrenal histoplasmosis and primary adrenal insufficiency are mostly described in immunocompetent patients. This particular tropism is attributed to the presence of cortisol within the adrenal gland, a privileged niche for Histoplasma growth. In French Guiana, disseminated histoplasmosis is the main opportunistic infection in HIV patients. Our objective was to search in our HIV-histoplasmosis cohorts to determine how frequent adrenal insufficiency was among these patients. Between January 1, 1981 and October 1, 2014, a multicentric retrospective, observational study of histoplasmosis was conducted. Patients co-infected by HIV and histoplasmosis were enrolled in French Guiana's histoplasmosis and HIV database. Among 349 cases of disseminated histoplasmosis between 1981 and 2014, only 3 had adrenal insufficiency (0.85%). Their respective CD4 counts were 10, 14 and 43 per mm3. All patients had regular electrolyte measurements and 234/349 (67%) had abdominal ultrasonography and 98/349 (28%) had abdominopelvic CT scans. None of these explorations reported adrenal enlargement. Overall, these numbers are far from the 10% reports among living patients and 80-90% among histoplasmosis autopsy series. This suggests 2 conflicting hypotheses: First, apart from acute adrenal failure with high potassium and low sodium, less advanced functional deficiencies, which require specific explorations, may have remained undiagnosed. The second hypothesis is that immunosuppression leads to different tissular responses that are less likely to incapacitate the adrenal function. Furthermore, given the general immunosuppression, the adrenal glands no longer represent a particular niche for Histoplasma proliferation.

Prospective Comparison of Saliva and Nasopharyngeal Swab Sampling for Mass Screening for COVID-19.

Current testing for COVID-19 relies on reverse-transcriptase polymerase chain reaction from a nasopharyngeal swab specimen. Saliva samples have advantages regarding ease and painlessness of collection, which does not require trained staff and may allow self-sampling. We enrolled 776 persons at various field-testing sites and collected nasopharyngeal and pooled saliva samples. One hundred sixty two had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples vs. nasopharygeal swabs varied depending on the patient groups considered or on Ct thresholds. There were 10 (6.2%) patients with a positive saliva sample and a negative nasopharyngeal swab, all of whom had Ct values <25 for three genes. For symptomatic patients for whom the interval between symptoms onset and sampling was <10 days sensitivity was 77% but when excluding persons with isolated N gene positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts <30, sensitivity was 83 or 88.9% when considering two genes. The relatively good performance for patients with low Cts suggests that Saliva testing could be a useful and acceptable tool to identify infectious persons in mass screening contexts, a strategically important task for contact tracing and isolation in the community.

Prevalence of intestinal parasite among patients attending two hospitals in French Guiana: A 6-year retrospective study.

INTRODUCTION: Intestinal parasitic diseases are a global health problem. Due to its equatorial climate, vast territory with isolated areas and the precariousness of its population, intestinal parasitosis is considered to be a major issue in French Guiana but only few data are available and these mainly focus on specific population. We aimed at determining the parasitic index and at describing the characteristics of these infections in order to develop preventive strategies. MATERIAL AND METHODS: We retrospectively analysed all the parasitological samples recorded in the register of the two main laboratories of French Guiana between 2011 and 2016. The parasitic index was the percentage of parasitised patients in comparison with the total number of subjects studied. A patient who underwent several positive parasitological examinations was considered only once in the analysis at the time of the first sampling. RESULTS: A total of 15,220 parasitological samples of 9,555 patients were analysed and 2,916 were positive in 1,521 patients. The average infestation rate and parasitic index were 19.2% and 16.0%, respectively. The parasitic index remained stable between 2011 (18.2%) and 2016 (18.3%). The patients were mainly men (66.4%), with a median age of 33.0 years (26.3% of patients were under 18 years of age) and lived mainly in the Central Agglomeration (48.2%) and in West Guiana (37.4%). Hookworms were the most common parasite (25.2%) followed by Entamoeba coli (13.3%), Strongyloides stercoralis (10.9%) and Giardia intestinalis (10.8%). Among the infected patients, 31.0% presented mixed infections and 67.5% of them had at least one pathogenic parasite. The patients aged from 0 to 18 years presented significantly more polyparasitism (30.9%) than monoparasitism (24.3%, p<0.001). Ancylostoma sp and Strongyloides stercoralis were mainly diagnosed during the rainy season (59.5% and 64.7% respectively), in men (78.6% and 81.1% respectively) and in patients aged from 18 to 65 years (86.6% and 76.6% respectively) whereas, Giardia intestinalis infected mostly children under 5 years (59.5%) of age. CONCLUSION: Although it may not be representative of the entire Guyanese population, the parasitic index remained high and stable from 2011 and 2016 and it justifies the need for an active prevention program as it was already done in the other French overseas departments such as Martinique and Guadeloupe.