Timing of host feeding drives rhythms in parasite replication

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the hosts' peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the hosts' peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new arena for studying host-parasite-vector coevolution and has broad implications for applied bioscience

Repeated doses of Praziquantel in Schistosomiasis Treatment (RePST) - single versus multiple praziquantel treatments in school-aged children in Côte d'Ivoire: a study protocol for an open-label, randomised controlled trial.

BACKGROUND: Large scale administration of the anthelminthic drug praziquantel (PZQ) to at-risk populations is the cornerstone of schistosomiasis control, although persisting high prevalence of infections in some areas and growing concerns of PZQ resistance have revealed the limitations of this strategy. Most studies assessing PZQ efficacy have used relatively insensitive parasitological diagnostics, such as the Kato-Katz (KK) and urine-filtration methods, thereby overestimating cure rates (CRs). This study aims to determine the efficacy of repeated PZQ treatments against Schistosoma mansoni infection in school-aged children in Côte d'Ivoire using the traditional KK technique, as well as more sensitive antigen- and DNA-detection methods. METHODS: An open-label, randomised controlled trial will be conducted in school-aged children (5 to 18 years) from the region of Taabo, Côte d'Ivoire, an area endemic for S. mansoni. This 8-week trial includes four two-weekly standard doses of PZQ in the "intense treatment" intervention group and one standard dose of PZQ in the "standard treatment" control group. The efficacy of PZQ will be evaluated in stool samples using the KK technique and real-time PCR as well as in urine using the point-of-care circulating cathodic antigen test and the up-converting phosphor, lateral flow, circulating anodic antigen assay. The primary outcome of the study will be the difference in CR of intense versus standard treatment with PZQ on individuals with a confirmed S. mansoni infection measured by KK. Secondary outcomes include the difference in CR and intensity reduction rate between the intense and standard treatment groups as measured by the other diagnostic tests, as well as the accuracy of the different diagnostic tests, and the safety of PZQ. DISCUSSION: This study will provide data on the efficacy of repeated PZQ treatment on the clearance of S. mansoni as measured by several diagnostic techniques. These findings will inform future mass drug administration policy and shed light on position of novel diagnostic tools to evaluate schistosomiasis control strategies. TRIAL REGISTRATION: The study is registered at EudraCT (2016-003017-10, date of registration: 22 July 2016) and ( NCT02868385 , date of registration: 16 August 2016)

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Supply of Compost and Arbuscular Mycorrhizal Fungi for Enhancing Quality of Ceiba pentandra (Kapok Tree) Seedlings

The success of reforestation depends on the production of quality seedlings in nurseries. Initial fertilization and mycorrhization are determinants that improve the growth of plants. The purpose of this study was to improve the quality of Ceiba pentandra seedlings using fertilization and mycorhization in nurseries. Seedlings of C. pentandra were subjected to various treatments (T1: Sterilized forest soil (100 %), T2: 90 % T1 + sterilized mycorrhizal inoculum (10 %); T3: 90 % T1 + mycorrhizal inoculum (10 %); T4: 90 % T1 + compost (10 %); T5: 80 % T1 + mycorrhizal inoculum (10 %) + compost (10 %)). The results showed an increase of 117.35 % in the dry stem weight of young Ceiba pentandra mycorrhizae (T3) seedlings compared to non-mycorrhizae (T2) seedlings. Growth parameters, roots, total leaf area were better with the treatment combining mycorrhization and compost application. Furthermore, the sturdiness quotient was identical for all substrates. Seedlings of Ceiba pentandra are highly dependent on mycorrhization. For rapid production of quality seedlings, fertilization could be coupled with mycorrhization

Community-based measles mortality surveillance in two districts of Katanga Province, Democratic Republic of Congo

Mortality due to measles is often under-reported. Traditional methods of measuring mortality can be time and resource-intensive. We describe the implementation of a community-based method to monitor measles mortality

Situation épidémiologique avant la mise en eau du barrage hydroagricole de cinq villages de Bouaké, centre Côte d'Ivoire

From June 2007 to June 2008, entomological, malacological and parasitological investigations were carried out in five villages in close proximity to a small dam of Raffierkro in Bouake, central Cote-d'Ivoire. The objective of the study was to identify vectors and intermediate host snails of parasitic diseases related to water, and to assess the prevalence of malaria, schistosomiasis and soil-transmitted helminthiasis before dam construction. Mosquitoes were caught by human landing catches, snails were collected in water bodies, and microscopic analyses of blood, stool and urine samples were carried out. Two malaria vector species were identified: Anopheles gambiae and Anopheles funestus. The average infective rate of An. gambiae ranged between 3.1 and 4.5 %. The infective rate of An. funestus was 1 % in all sites. The entomological inoculation rate ranged between 343.1 and 427.1 infective bites per person per year (ib/p/y) for An. gambiae and between 14.6 and 40.1 ib/p/y for An. funestus. Three species of were found: Plasmodium falciparum (predominant species), Plasmodium ovale and Plasmodium malariae. There were no intermediate host snails of schistosomiasis with the exception of Biomphalaria pfeifferi, intermediate host snail of Schistosoma mansoni in Ahougui. The prevalence of urinary and intestinal schistosomiasis and soil-transmitted helminthiasis was low. Our studies revealed important transmission of malaria, with the presence of three plasmodial species, whereas schistosomiasis and soil-transmitted helminthiasis were present, but only at low frequencie