Global and local environmental changes as drivers of Buruli ulcer emergence

International audienceMany emerging infectious diseases are caused by generalist pathogens that infect and transmit via multiple host species with multiple dissemination routes, thus confounding the understanding of pathogen transmission pathways from wildlife reservoirs to humans. The emergence of these pathogens in human populations has frequently been associated with global changes, such as socio-economic, climate or biodiversity modifications, by allowing generalist pathogens to invade and persist in new ecological niches, infect new host species, and thus change the nature of transmission pathways. Using the case of Buruli ulcer disease, we review how land-use changes, climatic patterns and biodiversity alterations contribute to disease emergence in many parts of the world. Here we clearly show that Mycobacterium ulcerans is an environmental pathogen characterized by multi-host transmission dynamics and that its infectious pathways to humans rely on the local effects of global environmental changes. We show that the interplay between habitat changes (for example, deforestation and agricultural land-use changes) and climatic patterns (for example, rainfall events), applied in a local context, can lead to abiotic environmental changes and functional changes in local biodiversity that favor the pathogen’s prevalence in the environment and may explain disease emergence

Resipientundersøkelser i Ballangfjorden 1997. Vannkvalitet, bunnsedimenter, bløtbunnsfauna og metaller i tang

Resipientundersøkelser er utført i Ballangfjorden i august 1997 etter 8 års gruvedrift ved Nikkel Olivin A/S. Undersøkelsene har omfattet analyse av metaller i vann, sediment og grisetang samt undersøkelser av bløtbunnsfauna. Den indre del av fjorden er meget sterk (overflatevann) til sterkt forurenset (sediment) med metaller og det er bly (Pb) og kobber (Cu) og nikkel (Ni) som bidrar mest til den dårlige miljøtilstanden. I vann, sediment og blæretang ses en avtagende forurensningsgrad fra deponiet på Ballangsleira innerst i fjorden og ut i Ofotfjorden. Overflatevannet innerst i fjorden (<3 km fra deponiet) inneholdt i 1997 vesentlig mere Ni og Cu enn de øvrige år og medførte en forverring av områdets miljøtilstand. Dette skyldes i hovedsak deponeringen av gruveslam på Ballangsleira, men også pågående anleggsarbeider under prøvetakingen kan ha medvirket. Sedimentet på de innerste stasjoner inneholdt vesentlig mer Ni i 1997 enn i 1989. Konsentrasjonen av Cu. Pb, sink (Zn) og kadmium (Cd) i sedimentet var derimot i 1997 lavere eller i samme nivå som i 1989. For Ni og kobolt (Co) i sediment ble det observert en lokal konsentrasjonsøkning ca. 3 km ut i fjorden. En økning i NI konsentrasjonen (og andre metaller) ble også observert i bunnvann ca. 3 km ut i fjorden. Deponiet ved Fornes framstår som en sekundær kilde til metall påvirkning av sediment. Sammensetningen av bløtbunnsfaunaen kan tyde på en øket geografisk utbredelse av belastningseffektene mot Ofotfjorden siden 1989, men kan ikke knyttes direkte til endringer i metallbelastningen. Innholdet av metallene arsen (As), Cd, Cr, Pb og Zn i grisetang var i 1997 lavt, som ved tidligere undersøkelser. Innholdet av metallene Co, Ni og Cu i tang var lavt på stasjoner ytterst i fjorden mens stasjoner innerst hadde noe høyere konsentrasjoner (moderat til markert forurenset). Analysene av grisetang tyder på svakt økende metallkonsentrasjoner, sannsynligvis forårsaket av påvirkning fra begge deponier (Ballangleira, Fornes). Samlet tyder undersøkelsene i 1997 på en økende effekt på miljøet fra gruvedrift til Nikkel og Olivin A/S mens effekter knyttet til tidligere utslipp fra Bjørkåsen gruve er noe redusert

Performance of a nurse-led paediatric point of care service for respiratory syncytial virus testing in secondary care

Objectives: To evaluate respiratory syncytial virus (RSV)-point-of-care-testing (POCT) performance among paediatric patients with respiratory symptoms, using the BinaxNOW (R) RSV assay performed by trained nurses on the paediatric ward, and compare results with those obtained by real-time polymerase chain reaction (PCR). Methods: Four paediatric nurses were trained and certified in using RSV-POCT. Between October 2008 and March 2009, all hospitalised children below 5 years of age presenting with a suspected RSV infection had nasopharyngeal swabs (NPS) tested by RSV-POCT by the nurses and a real-time PCR targeting common respiratory viruses by laboratory staff. Results: Among 159 NPS, 21 (13.2%) were RSV-POCT positive and 138 (86.8%) negative. All 21 RSV-POCT positive samples were positive by PCR, yielding a specificity of 100% (95% CI 95.7%, 100.0%). Of 138 RSV-POCT negative samples, 30 (21.7%) were RSV positive by PCR (sensitivity 41.2%; 95% CI: 27.9%, 55.8%). The positive and negative predictive values for RSV-POCT were 100% (95% CI 80.8%, 100.0%) and 78.3% (95% CI 70.3%, 84.6%) respectively. Other respiratory viruses were detected in 52/138 (39.9%) NPS. Conclusions: A POCT for RSV run by trained nurses can be used reliably as a first screening step in symptomatic children. Negative samples should be analysed for RSV and other respiratory pathogens by real-time PCR. (C) 2010 The British Infection Association. Published by Elsevier Ltd. All rights reserved

Global and local environmental changes as drivers of Buruli ulcer emergence &#91;+ erratum in Emerging Microbes and Infections.2017,6, e34&#93;

Many emerging infectious diseases are caused by generalist pathogens that infect and transmit via multiple host species with multiple dissemination routes, thus confounding the understanding of pathogen transmission pathways from wildlife reservoirs to humans. The emergence of these pathogens in human populations has frequently been associated with global changes, such as socio-economic, climate or biodiversity modifications, by allowing generalist pathogens to invade and persist in new ecological niches, infect new host species, and thus change the nature of transmission pathways. Using the case of Buruli ulcer disease, we review how land-use changes, climatic patterns and biodiversity alterations contribute to disease emergence in many parts of the world. Here we clearly show that Mycobacterium ulcerans is an environmental pathogen characterized by multi-host transmission dynamics and that its infectious pathways to humans rely on the local effects of global environmental changes. We show that the interplay between habitat changes (for example, deforestation and agricultural land-use changes) and climatic patterns (for example, rainfall events), applied in a local context, can lead to abiotic environmental changes and functional changes in local biodiversity that favor the pathogen's prevalence in the environment and may explain disease emergence

Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969-2013: an epidemiological study

Background Mycobacterium ulcerans infection is the third most common mycobacterial disease in the world after tuberculosis and leprosy. To date, transmission pathways from its environmental reservoir to humans are still unknown. In South America, French Guiana has the highest reported number of M ulcerans infections across the continent. This empirical study aimed to characterise the epidemiology of M ulcerans infection in French Guiana between 1969 and 2013. Methods Data were collected prospectively mainly by two dermatologists at Cayenne Hospital's dermatology department between Jan 1, 1969, and Dec 31, 2013, for age, date of diagnosis, sex, residence, location of the lesion, type of lesion, associated symptoms, and diagnostic method (smear, culture, PCR, or histology) for all confirmed and suspected cases of M ulcerans. We obtained population data from censuses. We calculated mean M ulcerans infection incidences, presented as the number of cases per 100 000 person-years. Findings 245 patients with M ulcerans infections were reported at Cayenne Hospital's dermatology department during the study period. M ulcerans infection incidence decreased over time, from 6.07 infections per 100 000 person-years (95% CI 4.46-7.67) in 1969-83 to 4.77 infections per 100 000 person-years (3.75-5.79) in 1984-98 and to 3.49 infections per 100 000 person-years (2.83-4.16) in 1999-2013. The proportion of children with infections also declined with time, from 42 (76%) of 55 patients in 1969-83 to 26 (31%) of 84 in 1984-98 and to 22 (21%) of 106 in 1999-2013. Most cases occurred in coastal areas surrounded by marshy savannah (incidence of 21.08 per 100 000 person-years in Sinnamary and 21.18 per 100 000 person-years in Mana). Lesions mainly affected limbs (lower limbs 161 [66%] patients; upper limbs 60 [24%] patients). We diagnosed no bone infections. Interpretation The decrease of M ulcerans infection incidence and the proportion of children with infections over a 45 year period in this ultra-peripheral French territory might have been mostly driven by improving living conditions, prophylactic recommendations, and access to health care. Copyright (C) The Author(s). Published by Elsevier Ltd

Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969–2013: an epidemiological study

Background: Mycobacterium ulcerans infection is the third most common mycobacterial disease in the world after tuberculosis and leprosy. To date, transmission pathways from its environmental reservoir to humans are still unknown. In South America, French Guiana has the highest reported number of M ulcerans infections across the continent. This empirical study aimed to characterise the epidemiology of M ulcerans infection in French Guiana between 1969 and 2013. Methods: Data were collected prospectively mainly by two dermatologists at Cayenne Hospital's dermatology department between Jan 1, 1969, and Dec 31, 2013, for age, date of diagnosis, sex, residence, location of the lesion, type of lesion, associated symptoms, and diagnostic method (smear, culture, PCR, or histology) for all confirmed and suspected cases of M ulcerans. We obtained population data from censuses. We calculated mean M ulcerans infection incidences, presented as the number of cases per 100 000 person-years. Findings: 245 patients with M ulcerans infections were reported at Cayenne Hospital's dermatology department during the study period. M ulcerans infection incidence decreased over time, from 6·07 infections per 100 000 person-years (95% CI 4·46–7·67) in 1969–83 to 4·77 infections per 100 000 person-years (3·75–5·79) in 1984–98 and to 3·49 infections per 100 000 person-years (2·83–4·16) in 1999–2013. The proportion of children with infections also declined with time, from 42 (76%) of 55 patients in 1969–83 to 26 (31%) of 84 in 1984–98 and to 22 (21%) of 106 in 1999–2013. Most cases occurred in coastal areas surrounded by marshy savannah (incidence of 21·08 per 100 000 person-years in Sinnamary and 21·18 per 100 000 person-years in Mana). Lesions mainly affected limbs (lower limbs 161 [66%] patients; upper limbs 60 [24%] patients). We diagnosed no bone infections. Interpretation: The decrease of M ulcerans infection incidence and the proportion of children with infections over a 45 year period in this ultra-peripheral French territory might have been mostly driven by improving living conditions, prophylactic recommendations, and access to health care. Funding: Agence Nationale de la Recherche