Predictors of Visceral Leishmaniasis Relapse in HIV-Infected Patients: A Systematic Review

Visceral leishmaniasis (VL) is the most serious form of an insect-transmitted parasitic disease prevalent in 70 countries. The disease is caused by species of the L. donovani complex found in different geographical regions. These parasites have substantially different clinical, drug susceptibility and epidemiological characteristics. According to data from the World Health Organization, the areas where HIV-Leishmania co-infection is distributed are extensive. HIV infection increases the risk of developing VL, reduces the likelihood of a therapeutic response, and greatly increases the probability of relapse. A better understanding of the factors promoting relapses is essential; therefore we performed a systematic review of articles involving all articles assessing the predictors of VL relapse in HIV-infected individuals older than 14 years of age. Out of 178 relevant articles, 18 met the inclusion criteria and in total, data from 1017 patients were analyzed. We identified previous episodes of VL relapse, CD4+ lymphocyte count fewer than 100 cells/mL at VL diagnosis, and the absence of an increase in CD4+ counts at follow-up as major factors associated with VL relapse. Knowledge of relapse predictors can help to identify patients with different degrees of risk, facilitate and direct prophylaxis choices, and aid in patient counseling

Shoreline change and sea level rise at the Muni-Pomadze coastal wetland (Ramsar site), Ghana

Lagoon-wetland systems are common along low-lying coastlines. They provide rich species habitats, multiple ecosystem services and socio-economic activities. They are particularly susceptible to the impacts of sea level rise (SLR), especially in less developed countries (LDCs) where economic and development constraints limit adaptation. The Muni-Pomadze lagoon is one of five coastal Ramsar sites in Ghana and one of many along the country’s coastline. It is an intermittently closed lagoon with extreme seasonal hydrological and physico-chemical variation. Field observation, digital mapping and GIS analysis of the shoreline has enabled an understanding of coastal change and SLR at the lagoon. From 1972 to 2014 the high water mark has shifted landwards with an average retreat rate of 0.22 m/year. Evidence of erosion and sediment washover indicate loss of and a shift landward of the sand barrier separating the lagoon from the ocean. Creation of an inundation map for a one-meter rise of sea level reveals fragementation and breaching of the barrier and an increasingly permanent connection to the ocean. A more open lagoon system stabilises hydrological and physico-chemical conditions, leading to increases in biodiversity and aquatic productivity. The lagoon currently has no consideration of SLR in its management plan. The results of this analysis and the limited development of the Muni-Pomadze lagoon support a no intervention approach to coastal management that allows SLR to transform the closed lagoon to an open estuary. A similar approach at comparable coastal wetland systems in Ghana and in other LDCs could prove an effective management option.Sheffield Hallam University Department of Natural and Built Environment professional development funds. University of Virginia

Sediment supply as a driver of river meandering and floodplain evolution in the Amazon Basin

The role of externally imposed sediment supplies on the evolution of meandering rivers and their floodplains is poorly understood, despite analytical advances in our physical understanding of river meandering1, 2. The Amazon river basin hosts tributaries that are largely unaffected by engineering controls and hold a range of sediment loads, allowing us to explore the influence that sediment supply has on river evolution. Here we calculate average annual rates of meander migration within 20 reaches in the Amazon Basin from Landsat imagery spanning 1985–2013. We find that rivers with high sediment loads experience annual migration rates that are higher than those of rivers with lower sediment loads. Meander cutoff also occurs more frequently along rivers with higher sediment loads. Differences in meander migration and cutoff rates between the study reaches are not explained by differences in channel slope or river discharge. Because faster meander migration and higher cutoff rates lead to increased sediment-storage space in the resulting oxbows, we suggest that sediment supply modulates the reshaping of floodplain environments by meandering rivers. We conclude that imposed sediment loads influence planform changes in lowland rivers across the Amazon