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Improvement of a tissue maceration technique for the determination of placental involvement in schistosomiasis

PLoS Neglected Tropical Diseases News - 24 April 2017 - 9:00pm

by Martha Charlotte Holtfreter, Heinrich Neubauer, Tanja Groten, Hosny El-Adawy, Jana Pastuschek, Joachim Richter, Dieter Häussinger, Mathias Wilhelm Pletz, Benjamin Thomas Schleenvoigt

Schistosomiasis in pregnancy may cause low birth weight, prematurity and stillbirth of the offspring. The placenta of pregnant women might be involved when schistosome ova are trapped in placental tissue. Standard histopathological methods only allow the examination of a limited amount of placental tissue and are therefore not sufficiently sensitive. Thus, placental schistosomiasis remains underdiagnosed and its role in contributing to schistosomiasis-associated pregnancy outcomes remains unclear. Here we investigated an advanced maceration method in order to recover a maximum number of schistosome ova from the placenta. We examined the effect of different potassium hydroxide (KOH) concentrations and different tissue fixatives with respect to maceration success and egg morphology. Placental tissue was kept either in 0.9% saline, 5% formalin or 70% ethanol and was macerated together with Schistosoma mansoni infested mouse livers and KOH 4% or 10%, respectively. We found that placenta maceration using 4% KOH at 37°C for 24 h was the most effective method: placental tissue was completely digested, egg morphology was well preserved and alkaline concentration was the lowest. Ethanol proved to be the best fixative for this method. Here we propose an improved maceration technique in terms of sensitivity, safety and required skills, which may enable its wider use also in endemic areas. This technique may contribute to clarifying the role of placental involvement in pregnant women with schistosomiasis.

Serological evidence for transmission of multiple dengue virus serotypes in Papua New Guinea and West Papua prior to 1963

PLoS Neglected Tropical Diseases News - 24 April 2017 - 9:00pm

by Dagwin Luang-Suarkia, Timo Ernst, Michael P. Alpers, Ralph Garruto, David Smith, Allison Imrie

Little is known about the natural history of dengue in Papua New Guinea (PNG). We assessed dengue virus (DENV)-specific neutralizing antibody profiles in serum samples collected from northern and southern coastal areas and the highland region of New Guinea between 1959 and 1963. Neutralizing antibodies were demonstrated in sera from the northern coast of New Guinea: from Sabron in Dutch New Guinea (now known as West Papua) and from four villages in East Sepik in what is now PNG. Previous monotypic infection with DENV-1, DENV-2, and DENV-4 was identified, with a predominance of anti-DENV-2 neutralizing antibody. The majority of positive sera demonstrated evidence of multiple previous DENV infections and neutralizing activity against all four serotypes was detected, with anti-DENV-2 responses being most frequent and of greatest magnitude. No evidence of previous DENV infection was identified in the Asmat villages of the southern coast and a single anti-DENV-positive sample was identified in the Eastern Highlands of PNG. These findings indicate that multiple DENV serotypes circulated along the northern coast of New Guinea at different times in the decades prior to 1963 and support the notion that dengue has been a significant yet neglected tropical infection in PNG for many decades.

Cystic and alveolar echinococcosis: Successes and continuing challenges

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Christine M. Budke, Adriano Casulli, Peter Kern, Dominique A. Vuitton

The role of 'omics' in the quest to eliminate human filariasis

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Sara Lustigman, Alexandra Grote, Elodie Ghedin

Parasite genomics—Time to think bigger

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Carlos Talavera-López, Björn Andersson

How to determine if a model is right for neglected tropical disease decision making

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Bruce Y. Lee, Sarah M. Bartsch

Mathematical and computational modeling can transform decision making for neglected tropical diseases (NTDs) if the right model is used for the right question. Modeling can help better understand and address the complex systems involved in making decisions for NTD prevention and control. However, all models, modelers, and modeling are not the same. Thus, decision makers need to better understand if a particular model actually fits their needs. Here are a series of questions that a decision maker can ask when determining whether a model is right for him or her.

Human African trypanosomiasis control: Achievements and challenges

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Serap Aksoy, Phillipe Buscher, Mike Lehane, Philippe Solano, Jan Van Den Abbeele

Sleeping sickness, also known as human African trypanosomiasis (HAT), is a neglected disease that impacts 70 million people living in 1.55 million km2 in sub-Saharan Africa. Since the beginning of the 20th century, there have been multiple HAT epidemics in sub-Saharan Africa, with the most recent epidemic in the 1990s resulting in about half a million HAT cases reported between 1990 and 2015. Here we review the status of HAT disease at the current time and the toolbox available for its control. We also highlight future opportunities under development towards novel or improved interventions.

Progress and projections in the program to eliminate trachoma

PLoS Neglected Tropical Diseases News - 20 April 2017 - 9:00pm

by Paul M. Emerson, Pamela J. Hooper, Virginia Sarah