Hepatitis C Virus Infection May Lead to Slower Emergence of P. falciparum in Blood

International audienceBACKGROUND: Areas endemic for Plasmodium falciparum, hepatitis B virus (HBV) and hepatitis C virus (HCV) overlap in many parts of sub-Saharan Africa. HBV and HCV infections develop in the liver, where takes place the first development stage of P. falciparum before its further spread in blood. The complex mechanisms involved in the development of hepatitis may potentially influence the development of the liver stage of malaria parasites. Understanding the molecular mechanisms of these interactions could provide new pathophysiological insights for treatment strategies in Malaria. METHODOLOGY: We studied a cohort of 319 individuals living in a village where the three infections are prevalent. The patients were initially given a curative antimalarial treatment and were then monitored for the emergence of asexual P. falciparum forms in blood, fortnightly for one year, by microscopy and polymerase chain reaction. PRINCIPAL FINDINGS: At inclusion, 65 (20.4%) subjects had detectable malaria parasites in blood, 36 (11.3%) were HBV chronic carriers, and 61 (18.9%) were HCV chronic carriers. During follow-up, asexual P. falciparum forms were detected in the blood of 203 patients. The median time to P. falciparum emergence in blood was respectively 140 and 120 days in HBV- and HBV+ individuals, and 135 and 224 days in HCV- and HCV+ individuals. HCV carriage was associated with delayed emergence of asexual P. falciparum forms in blood relative to patients without HCV infection. CONCLUSIONS: This pilot study represents first tentative evidence of a potential epidemiological interaction between HBV, HCV and P. falciparum infections. Age is an important confounding factor in this setting however multivariate analysis points to an interaction between P. falciparum and HCV at the hepatic level with a slower emergence of P. falciparum in HCV chronic carriers. More in depth analysis are necessary to unravel the basis of hepatic interactions between these two pathogens, which could help in identifying new therapeutic approaches against malaria

The Impact of Delayed Treatment of Uncomplicated \u3ci\u3eP. falciparum\u3c/i\u3e Malaria on Progression to Severe Malaria: A Systematic Review and a Pooled Multicentre Individual-Patient Meta-Analysis

BACKGROUND: Delay in receiving treatment for uncomplicated malaria (UM) is often reported to increase the risk of developing severe malaria (SM), but access to treatment remains low in most high-burden areas. Understanding the contribution of treatment delay on progression to severe disease is critical to determine how quickly patients need to receive treatment and to quantify the impact of widely implemented treatment interventions, such as \u27test-and-treat\u27 policies administered by community health workers (CHWs). We conducted a pooled individual-participant meta-analysis to estimate the association between treatment delay and presenting with SM. METHODS AND FINDINGS: A search using Ovid MEDLINE and Embase was initially conducted to identify studies on severe Plasmodium falciparum malaria that included information on treatment delay, such as fever duration (inception to 22nd September 2017). Studies identified included 5 case-control and 8 other observational clinical studies of SM and UM cases. Risk of bias was assessed using the Newcastle-Ottawa scale, and all studies were ranked as \u27Good\u27, scoring ≥7/10. Individual-patient data (IPD) were pooled from 13 studies of 3,989 (94.1% aged \u3c15 years) SM patients and 5,780 (79.6% aged \u3c15 years) UM cases in Benin, Malaysia, Mozambique, Tanzania, The Gambia, Uganda, Yemen, and Zambia. Definitions of SM were standardised across studies to compare treatment delay in patients with UM and different SM phenotypes using age-adjusted mixed-effects regression. The odds of any SM phenotype were significantly higher in children with longer delays between initial symptoms and arrival at the health facility (odds ratio [OR] = 1.33, 95% CI: 1.07-1.64 for a delay of \u3e24 hours versus ≤24 hours; p = 0.009). Reported illness duration was a strong predictor of presenting with severe malarial anaemia (SMA) in children, with an OR of 2.79 (95% CI:1.92-4.06; p \u3c 0.001) for a delay of 2-3 days and 5.46 (95% CI: 3.49-8.53; p \u3c 0.001) for a delay of \u3e7 days, compared with receiving treatment within 24 hours from symptom onset. We estimate that 42.8% of childhood SMA cases and 48.5% of adult SMA cases in the study areas would have been averted if all individuals were able to access treatment within the first day of symptom onset, if the association is fully causal. In studies specifically recording onset of nonsevere symptoms, long treatment delay was moderately associated with other SM phenotypes (OR [95% CI] \u3e3 to ≤4 days versus ≤24 hours: cerebral malaria [CM] = 2.42 [1.24-4.72], p = 0.01; respiratory distress syndrome [RDS] = 4.09 [1.70-9.82], p = 0.002). In addition to unmeasured confounding, which is commonly present in observational studies, a key limitation is that many severe cases and deaths occur outside healthcare facilities in endemic countries, where the effect of delayed or no treatment is difficult to quantify. CONCLUSIONS: Our results quantify the relationship between rapid access to treatment and reduced risk of severe disease, which was particularly strong for SMA. There was some evidence to suggest that progression to other severe phenotypes may also be prevented by prompt treatment, though the association was not as strong, which may be explained by potential selection bias, sample size issues, or a difference in underlying pathology. These findings may help assess the impact of interventions that improve access to treatment

Elements de biologie des populations de goelands argentes Larus argentatus Pont. en Bretagne : approche demographique

CNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Dynamique de population du goéland argenté en Bretagne application à la gestion de l’espèce

The population dynamics of the Herring Gull population of Brittany is briefly summarized. Following its steady increase between 1955 and 1978, the population started levelling off, but began colonizing new sites further south. The number of fledglings per pair was 1.3 ± 0.2 in 1983-84. The yearly survival rate of adult breeders was 0.91 ± 0.02, and the survival rate of birds during their first year of life was 0.71 ± 0.10.Migot Pierre. Dynamique de population du goéland argenté en Bretagne application à la gestion de l’espèce . In: Revue d'Écologie. Supplément n°4, 1987. pp. 183-187

La réintroduction du castor en (Castor fiber) France: Essai de synthèse et réflexions

Rouland Patrick, Migot Pierre. La réintroduction du castor en (Castor fiber) France: Essai de synthèse et réflexions. In: Revue d'Écologie. Supplément n°5, 1990. pp. 145-158

Conflict between grey partridge Perdix perdix hunting and hen harrier Circus cyaneus protection in France: a review

The recovery of protected predators raises tensions and divisions within society when their prey are of socio-economic value. For instance, conflicts may arise when hunters perceive protected predators as a threat for declining game populations, and cull them. These conflicts can have a strong impact on the status of the affected predator species. In this paper we review a conflict between hunters and raptor protectionists related to grey partridge Perdix perdix - hen harrier Circus cyaneus relationships in central northern France. We compiled all available information from scientific journals as well as hunting or protectionist journals, in order to present the polarised views of the problem and to analyse the social, political, legal and scientific aspects of the conflict. The results of existing studies suggest that in some circumstances hen harrier predation may have an impact on grey partridge populations. However, these studies also suggest that the problem is currently restricted to certain areas. The impact of hen harrier predation on grey partridge populations is not fully understood. Further research is therefore needed to better understand the ecological basis of the conflict. We also present and discuss potential solutions to alleviate predation that might help to reduce the conflict