Unexpected mould diversity in clinical isolates from French Guiana and associated identification difficulties.

New mold species are increasingly reported in invasive fungal infections. However, these fungi are often misdiagnosed or undiagnosed due to the use of inappropriate laboratory diagnostic tools. Tropical countries, such as French Guiana, harbor a vast diversity of environmental fungi representing a potential source of emerging pathogens. To assess the impact of this diversity on the accuracy of mold-infection diagnoses, we identified mold clinical isolates in French Guiana during a five-month follow-up using both microscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. In total, 38.8% of the 98 obtained molds isolates could not be identified and required a DNA-based identification. Fungal diversity was high, including 46 species, 26 genera, and 13 orders. Fungal ecology was unusual, as Aspergillus species accounted for only 27% of all isolates, and the Nigri section was the most abundant out of the six detected Aspergillus sections. Macromycetes (orders Agaricales, Polyporales, and Russulales) and endophytic fungi accounted for respectively 11% and 14% of all isolates. Thus, in tropical areas with high fungal diversity, such as French Guiana, routine mold identification tools are inadequate. Molecular identifications, as well as morphological descriptions, are necessary for the construction of region-specific mass spectrum databases. These advances will improve the diagnosis and clinical management of new fungal infections. LAY SUMMARY: In French Guiana, environmental fungal diversity may be a source of emerging pathogens. We evaluated microscopy and mass spectrometry to identify mold clinical isolates. With 39% of unidentified isolates, a region-specific mass spectrum database would improve the diagnosis of new fungal infections.

Predictors of antimalarial self-medication in illegal gold miners in French Guiana: a pathway towards artemisinin resistance.

BACKGROUND: Malaria is endemic in French Guiana (FG), South America. Despite the decrease in cases in the local population, illegal gold miners are very affected by malaria (22.3% of them carried Plasmodium spp.). Self-medication seems to be very common, but its modalities and associated factors have not been studied. The aim of this study was to evaluate parasite susceptibility to drugs and to document behaviours that could contribute to resistance selection in illegal gold miners. METHODS: This multicentric cross-sectional study was conducted in resting sites along the FG-Surinamese border. Participating gold miners working in FG completed a questionnaire and provided a blood sample. RESULTS: From January to June 2015, 421 illegal gold miners were included. Most were Brazilian (93.8%) and 70.5% were male. During the most recent malaria attack, 45.5% reported having been tested for malaria and 52.4% self-medicated, mainly with artemisinin derivatives (90%). Being in FG during the last malaria attack was the main factor associated with self-medication (adjusted OR = 22.1). This suggests that access to malaria diagnosis in FG is particularly difficult for Brazilian illegal gold miners. Treatment adherence was better for persons who reported being tested. None of the 32 samples with Plasmodium falciparum presented any mutation on the pfK13 gene, but one isolate showed a resistance profile to artemisinin derivatives in vitro. CONCLUSIONS: The risk factors for the selection of resistance are well known and this study showed that they are present in FG with persons who self-medicated with poor adherence. Interventions should be implemented among this specific population to avoid the emergence of artemisinin resistance.

Histoplasma capsulatum causing sinusitis: a case report in French Guiana and review of the literature.

BACKGROUND: American histoplasmosis is a mycosis caused by Histoplasma capsulatum. A variety of clinical features of histoplasmosis have been commonly described ranging from asymptomatic infections to severe pulmonary infections. In immunocompromised individuals, progressive disseminated forms are frequent, leading to fatal outcome if untreated. However, H. capsulatum sinusitis is unusual with a few cases documented over the last three decades and may be underdiagnosed or confused with other fungal aetiologies, especially outside endemic regions. CASE PRESENTATION: In this study, we report an atypical case of Histoplasma capsulatum sinus fungus ball-like in a patient with Acquired Immunodeficiency Syndrome due to Human Immunodeficiency Virus complicated by a disseminated histoplasmosis with a death ending. Diagnosis relied on CT-Scan imaging and on both direct examination of H. capsulatum yeast forms (Gomory methenamine Grocott) in the sinus specimen (aspirate, biopsy) and on positivity of the culture further confirmed by qPCR. CONCLUSIONS: Since last few decades, among the eight reviewed patients, H. capsulatum sinusitis occurred mostly in HIV-immunocompromised patients and for three cases as a sinusitis with disseminated histoplasmosis. Even if this is a rare clinical presentation, its diagnosis is crucial as it could represent an early expression of an Histoplasma capsulatum exposure that can evolve into a disseminated fatal infection when immunity decreases.

[Paracoccidioidomycosis of the external ear]. / Paracoccidioïdomycose localisée au pavillon d'une oreille.

BACKGROUND: Paracoccidioidomycosis is a systemic fungal infection common in Latin America. Cutaneous involvement is frequent and usually affects multiple sites, being most frequently associated with lesions of the oropharyngeal mucosa. The cutaneous form on its own is rare. PATIENTS AND METHODS: We report a case of paracoccidioidomycosis isolated from the ear of a 43-year-old immunocompetent man. The lesion consisted of a partially ulcerated plaque on the auricle of the left ear. Direct examination, histopathological examination and PCR revealed the presence in the skin lesion of yeasts identified as Paracoccidioides brasiliensis. DISCUSSION: The sites of paracoccidioidomycosis on the ear can be confused with other tropical diseases frequently found in the Amazon region such as leishmaniasis, leprosy and lobomycosis. The absence of any other cutaneous sites in this case raised the question of whether the lesion was of primary or secondary origin.

Actinomycetoma caused by Gordonia westfalica: first reported case of human infection.

Bacteria of the genus Gordonia are rarely involved in human infections. We report here the case of a 30-year-old man from Guinea Buissau with mycetoma of the foot. 16S DNA sequencing after surgical biopsy identified Gordonia westfalica. To our knowledge, this is the first report of human infection caused by G. westfalica.

An atypical keloid in a Brazilian man.

Case report from French Guiana of an atypical keloid in a Brazilian man: Lobomycosis. Lobomycosis is a rare fungal skin infection, endemic to the Amazon basin. Its clinical manifestations are slow-growing keloid-like nodules, with a granulomatous reaction on histopathology. The etiological agent, Lacazia loboi, has never been isolated in the environment or cultured in a laboratory. Diagnosis is based on the typical appearance on microscopy. Treatment is disappointing, with a high recurrence rate. We report a new case in French Guiana and review the literature. Only 10 cases have been reported outside of the endemic area, 2 involving no travel; the mean time to diagnosis was 21 years. Phylogenetic analysis has recently proved that lobomycosis in dolphins is caused by a fungus more closely related to Paracoccidioides brasiliensis than to L. loboi (two very closely related species). Molecular diagnosis is possible in a few centers. Climate change may result in spreading lobomycosis to currently disease-free areas of the world.

[Mucocutaneous leishmaniasis due to Leishmania guyanensis: a case report in an HIV-infected patient]. / Leishmaniose cutanéo-muqueuse à Leishmania guyanensis: une observation chez un patient infecté par le VIH.

In French Guiana cutaneous leishmaniasis occurs mainly in the localized form with L. guyanensis accounting for more than 90% of cases. Mucocutaneous leishmaniasis is uncommon (less than 2% of cases) with L. braziliensis accounting for all previously reported cases. The purpose of this report is to describe a case of mucocutaneous leishmaniasis due to L. guyanensis that led to diagnosis of HIV infection in a patient living in French Guiana.

[Cardiac troponin I and CK-MB mass after cardiac surgery with cardiopulmonary bypass]. / Troponine Ic et CK-MB masse en chirurgie cardiaque sous circulation extracorporelle.

Cardiac troponin I (cTnI) assay is used in the diagnosis of myocardial infarction after cardiac surgery. Variations in the cut-off value have been reported even with the same assay method. The aim of this work is to investigate the release profile of cTnI and CK-MB mass after cardiac surgery and to determine the cut-off value of cTnI and CK-MB mass allowing the diagnosis of perioperative myocardial infarction. In patients without postoperative cardiac complication, the cTnI peak was observed 24 hours after surgery both in coronary artery bypass grafting and in valve replacement. Moreover, the amount of cTnI released within the three hours after surgery is 2.5 fold higher in valve replacement than in coronary artery bypass grafting. The CK-MB peak was observed 3 hours after surgery in the two surgical procedures. In these patients, cTnI and CK-MB concentrations increased with the cross clamp time duration. In patients with postoperative myocardial infarction, the cTnI and CK-MB peaks were observed 24 hours after surgery. Diagnosis of perioperative myocardial infarction can be performed with a sensitivity of 100% at 24 hours with cut-off values of 32 and 7 microg/L for CK-MB and cTnI, respectively, both with Stratus (Dade Behring) and Immulite (DPC) analysers.

A stochastic version of the Malthusian Trap Model: consequences for the empirical relationship between economic growth and population growth in LDC's.

A stochastic version of the Malthusian trap model relating the growth rate of income per capita to the population growth rate of a given country is described. This model is applied to the a priori evaluation of the cross-sectional correlation between these 2 growth rates under 2 additional assumptions: 1) the relations in the model at national levels include country-specific and time-invariant random components, and 2) these growth rates are measured with a certain degree of temporal aggregation. It is shown that these 2 assumptions can explain near-0 correlations between the 2 growth rates even if there exist a strongly negative effect of population growth on economic growth. However, it is not clear whether these assumptions fully explain such insignificant correlations. Indeed, the implementation of the model is complicated by the structural shifts which are likely to occur in the equations over the course of the demographic transition.

Fatal histoplasmosis in a non-HIV patient in French Guiana.

Histoplasmosis is an endemic fungal infection that causes no symptoms or minor self-limited illnesses in most cases. Severe forms are commonly reported in patients with immunodeficiency disorders; histoplasmosis is considered to be an opportunistic infection in patients with AIDS. We report a case of disseminated histoplasmosis in a patient with no induced active suppression of the immune response. The infection was fulminant, and antifungal treatment was delayed because of a misdiagnosis of tuberculosis.

[Chagas disease (American trypanosomiasis) in France]. / La maladie de Chagas (ou trypanosomose américaine) en France.

Chagas disease is an anthropozoonotic infection caused by Trypanosoma cruzi, transmitted by a hematophagous triatomine insect vector belonging to the Reduviidae family, while taking a blood meal. There is a large reservoir of wild and domestic mammals. Human contamination may come via vectorial, transplacental, and digestive routes, blood transfusion, organ or tissue transplantation, and by accident. The disease has two phases. The acute phase, oligosymptomatic, is frequently undiagnosed. It is followed by a chronic phase. Most of the infected patients remain asymptomatic all life-long. But 10 or 25 years later, one third of infected patients present with cardiac or digestive complications. Chagas disease is endemic in Latin America, from Mexico to Argentina. In French Guyana, the prevalence of the infection was estimated at 0.25% and 0.5% (from 500 to 1000 infected patients) on blood samples collected from 1992 to 1998. In 2000 and 2009, 192 cases were diagnosed. In this district, there is no established domestic vector and the transmission risk is low. The vector is very easily found in forest habitats and even in the peridomestic persistent forest, with an infection rate of 46 to 86%. Vectorial eradication is impossible. Fighting against Chagas disease in French Guyana relies more on individual protection, control of blood transfusion, prevention of mother-to-child transmission, diagnosis, and treatment of infected patients than on vectorial control.

Eumycetoma caused by Diaporthe phaseolorum (Phomopsis phaseoli): a case report and a mini-review of Diaporthe/Phomopsis spp invasive infections in humans.

Diaporthe phaseolorum (syn. Phomopsis phaseoli) is a frequent fungal parasite of plants, present on all continents around the world. It has rarely been involved in human diseases. We report a case of eumycetoma with osteomyelitis of the forefoot caused by this fungus and diagnosed by molecular biology. The patient had positive HTLV-1 serology and was a farmer from French Guiana who walked barefoot. He was successfully treated with long-term oral itraconazole (400 mg/day). A review of the literature underlines the essential roles of plants and host immunosuppression in this infection and the favourable outcome with a triazole antifungal treatment.

Human impact on genetic diversity of Toxoplasma gondii: example of the anthropized environment from French Guiana.

In French Guiana, severe cases of toxoplasmosis in immunocompetent patients are associated with atypical strains of Toxoplasma gondii linked to a wild neotropical rainforest cycle and a higher genetic diversity than usually observed for T. gondii isolates from anthropized environment. This raises the question of the impact of anthropization of the natural environment, on genetic diversity and on the population structure of T. gondii. However, few data are available on strains circulating in the anthropized areas from French Guiana. Seropositive animals originating mainly from anthropized sub-urban areas and punctually from wild environment in French Guiana were analyzed for T. gondii isolation and genotyping. Thirty-three strains were obtained by bioassay in mice and compared with 18 previously reported isolates chiefly originating from the Amazon rainforest. The genotyping analysis performed with 15 microsatellite markers located on 12 different chromosomes revealed a lower genetic diversity in the anthropized environment. Results were analyzed in terms of population structure by clustering methods, Neighbor-joining trees reconstruction based on genetic distances, F(ST,) Mantel's tests and linkage disequilibrium. They clearly showed a genetic differentiation between strains associated to the anthropized environment and those associated to the wild, but with some inbreeding between them. The majority of strains from the anthropized environment were clustered into additional lineages of T. gondii that are common in the Caribbean. In conclusion the two environmental populations "wild" and "anthropized" were genetically well differentiated. The anthropization of the environment seems to be accompanied with a decreased diversity of T. gondii associated with a greater structure of the populations. We detected potential interpenetration and genetic exchanges between these two environmental populations. As a higher pathogenicity in human of "wild" genotypes has been described, the interpenetration of both environments leads to hybridization between strains that may be at risk for human health.

Age structure and capital dilution effects in neo-classical growth models.

PIP: Economists often over estimate capital dilution effects when applying neoclassical growth models which use age structured population and depreciation of capital stock. This occurs because capital stock is improperly characterized. A standard model which assumes a constant depreciation of capital intimates that a population growth rate equal to a negative constant savings ratio is preferable to any higher growth rate. Growth rates which are lower than a negative constant savings ratio suggest an ever growing capital/labor ratio and an ever growing standard of living, even if people do not save. This is suggested because the natural reduction of the capital stock through depreciation is slower than the population decrease which is simply unrealistic. This model overlooks the fact that low or negative growth rates result in an ageing of the capital stock, and this ageing subsequently results in an increase of the overall rate of capital depreciation. In that overly simplistic model, depreciation was assumed independent of the age of the captial stock. Incorporating depreciation as a variable into a model allows a more symmetric treatment of capital. Using models with heterogenous capital, this article explores what occurs when more than 1 kind of capital good is involved in production and when these various captial goods have different lengths of life. Applying economic models, it also examines what occurs when the length of life of capital may vary. These variations correct the negative impact that population growth can have on per capital production and consumption.^ieng

[Demographic factors in the evolution of unemployment]. / Facteurs demographiques de l'evolution du chomage

PIP: The contribution of demographic factors, such as the baby boom, to changes in unemployment in France during the post-World War II period is assessed. Trends in the size of the working-age population are described, fluctuations in unemployment are analyzed, and some comparisons are also made with data for other developed countries.^ieng

[Are the retired threatened by the decline in fertility?]. / Les retraites menacees par la denatalite?

PIP: The implications of current fertility trends in France for the funding of retirement costs are reviewed. Consideration is given to changes in the capital aspects of the current system, changes in the retirement age, and more efficient use of the existing labor force.^ieng

Population growth and income growth during the demographic transition: does a Malthusian model help explain their relationship?

PIP: This paper examines the potential links between growth of income/head and population growth during demographic transition. In so doing, both malthusian and neo-Boserupian views are considered with a view to determining which of the 2 paradigms is most useful in explaining the current situation in developing countries. The relationship between demographic and economic progress in the Malthusian system when it is initiated by an exogenous technical progress is discussed. Attention is also called to the recent disappearance of a negative correlation between economic and demographic growth. Finally, the neo-Boseupian model is compared to the Malthusian view, and implications of the analysis as they relate to the desirability of population policies are presented.^ieng