Progress towards elimination of onchocerciasis in the Region du Sud-Ouest of Burkina Faso which was previously subject to a recrudescence event after vector control.

Background: The Sud-Ouest region of Burkina Faso (especially the Bougouriba valley) has been historically problematic with respect to onchocerciasis control, with a recrudescence of infections after vector control carried out the WHO Onchocerciasis Control Programme was halted in 1989. After 1996, mass drug administration of ivermectin was instigated to control the recrudescence so that it would no longer constitute a public health problem. However, in 2010 WHO changed its recommended policy from control to elimination, and in 2013 biannual Community-Directed Treatment with Ivermectin (CDTI) was instigated.

Cytotaxonomic characterization and estimation of migration patterns of onchocerciasis vectors (Simulium damnosum sensu lato) in northwestern Ethiopia based on RADSeq data.

Background: While much progress has been made in the control and elimination of onchocerciasis across Africa, the extent to which vector migration might confound progress towards elimination or result in re-establishment of endemism in areas where transmission has been eliminated remains unclear. In Northern Ethiopia, Metema and Metekel-two foci located near the Sudan border-exhibit continuing transmission. While progress towards elimination has been faster in Metema, there remains a problematic hotspot of transmission.

Seasonal variations and other changes in the geographical distributions of different cytospecies of the Simulium damnosum complex (Diptera: Simuliidae) in Togo and Benin.

Simulium damnosum s.l., the most important vector of onchocerciasis in Africa, is a complex of sibling species described on the basis of differences in their larval polytene chromosomes.

Identification of the onchocerciasis vector in the Kakoi-Koda focus of the Democratic Republic of Congo.

Background: The objective of this study was to characterise the vector in a small hyper-endemic focus of onchocerciasis (the Kakoi-Koda focus) which has recently been discovered on the western slopes of the rift valley above Lake Albert.

Methodology/principal Findings: Aquatic stages of blackflies were collected by hand from streams and rivers, and anthropophilic adult females were collected by human landing catches. Using a combination of morphotaxonomy and DNA barcoding, the blackflies collected biting humans within the focus were identified as Simulium dentulosum and Simulium vorax, which were also found breeding in local streams and rivers.

"Slash and Clear", a Community-Based Vector Control Method to Reduce Onchocerciasis Transmission by in Maridi, South Sudan: A Prospective Study.

Background: High ongoing transmission was recently documented in Maridi County, South Sudan. To complement community-directed treatment with ivermectin (CDTI) as the main onchocerciasis control strategy, we initiated a community-based vector control method "slash and clear" at the Maridi dam, a s.l.

The impact of ivermectin on onchocerciasis in villages co-endemic for lymphatic filariasis in an area of onchocerciasis recrudescence in Burkina Faso.

In Burkina Faso, onchocerciasis was no longer a public health problem when the WHO Onchocerciasis Control Programme in West Africa closed at the end in 2002. However, epidemiological surveillance carried out from November 2010 to February of 2011, showed a recrudescence of infection in the Cascades Region. This finding was made at a time when ivermectin, a drug recommended for the treatment of both onchocerciasis and lymphatic filariasis, had been distributed in this area since 2004 for the elimination of lymphatic filariasis.

Mansonellosis: current perspectives.

Mansonellosis is a filarial disease caused by three species of filarial (nematode) parasites (, , and ) that use humans as their main definitive hosts. These parasites are transmitted from person to person by bloodsucking females from two families of flies (Diptera). Biting midges (Ceratopogonidae) transmit all three species of , but blackflies (Simuliidae) are also known to play a role in the transmission of in parts of Latin America.

Onchocerciasis prevalence, human migration and risks for onchocerciasis elimination in the Upper Mouhoun, Nakambé and Nazinon river basins in Burkina Faso.

Historically, the whole of Burkina Faso was considered to be endemic for onchocerciasis (except a small area in the far north of the country) with prevalence rates 60-80%, but all endemic areas were included in the World Health Organisation Onchocerciasis Control Programme, which operated a system of vector control by larviciding beginning in 1974. In Burkina Faso larviciding had been phased out by 1989 when it was considered that onchocerciasis had been reduced to levels below the transmission breakpoint (and any residual infections would disappear without further intervention). There was never any mass drug administration against onchocerciasis in Burkina Faso, except in the Bougouriba and Comoé river basins (from 1996 and 2011 to present respectively) because in each of these two areas there was a resurgence of infection, and in parts of the Nakambé River basin and Sissili River basin from 1992 to 1998.

From river blindness control to elimination: bridge over troubled water.

Background: An estimated 25 million people are currently infected with onchocerciasis (a parasitic infection caused by the filarial nematode Onchocerca volvulus and transmitted by Simulium vectors), and 99% of these are in sub-Saharan Africa. The African Programme for Onchocerciasis Control closed in December 2015 and the World Health Organization has established a new structure, the Expanded Special Project for the Elimination of Neglected Tropical Diseases for the coordination of technical support for activities focused on five neglected tropical diseases in Africa, including onchocerciasis elimination.

Aims: In this paper we argue that despite the delineation of a reasonably well-defined elimination strategy, its implementation will present particular difficulties in practice.

Report of the first international workshop on onchocerciasis-associated epilepsy.

Background: Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where onchocerciasis is still endemic.

Main Text: On October 12-14 2017, the first international workshop on onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries.

The Genomic Architecture of Novel Prophage Sequence Elements and Implications for Onchocerciasis Epidemiology.

Research interest in is growing as new discoveries and technical advancements reveal the public health importance of both naturally occurring and artificial infections. Improved understanding of the bacteriophages (WOs) WOcauB2 and WOcauB3 [belonging to a sub-group of four WOs encoding serine recombinases group 1 (sr1WOs)], has enhanced the prospect of novel tools for the genetic manipulation of . The basic biology of sr1WOs, including host range and mode of genomic integration is, however, still poorly understood.

Sequence and organization of the complete mitochondrial genome of the blackfly (Diptera: Simuliidae).

The complete mitochondrial genome of the European blackfly, Meigen, 1818 was sequenced using a combined Illumina and Sanger sequencing approach. Using the known sequence of Skuse, 1889 (Chironomidae) homologous NGS reads were identified and assembled. The genome is 15,367 bp in length and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region.

Recrudescence of onchocerciasis in the Comoé valley in Southwest Burkina Faso.

Onchocerciasis control by vector control was instigated in southwest Burkina Faso in January 1969 by ORSTOM/OCCGE, and continued until operations were taken over by the WHO Onchocerciasis Control Programme (OCP) in February 1975, which itself ceased operations in the area in 1989 when onchocerciasis was judged to have been reduced to insignificant levels. Initially (1969-1975) vector immigration maintained unacceptably high levels of transmission, but OCP was much larger than the preceding campaign and in 1975 the Annual Transmission Potential (ATP) dropped below 100 at all sites in the Comoé river valley except Folonzo, which continued to be subject to reinvasion, along with the whole of the Léraba river valley. However, after the southern extension of the OCP in 1979, ATPs dropped below 100 everywhere in the Comoé basin (including the Léraba valley), and further dropped to insignificant levels after the western extension of the OCP in 1985.

Onchocerciasis transmission in Ghana: the human blood index of sibling species of the Simulium damnosum complex.

Background: Vector-biting behaviour is important for vector-borne disease (VBD) epidemiology. The proportion of blood meals taken on humans (the human blood index, HBI), is a component of the biting rate per vector on humans in VBD transmission models. Humans are the definitive host of Onchocerca volvulus, but the simuliid vectors feed on a range of animals and HBI is a key indicator of the potential for human onchocerciasis transmission.

Onchocerciasis transmission in Ghana: persistence under different control strategies and the role of the simuliid vectors.

Background: The World Health Organization (WHO) aims at eliminating onchocerciasis by 2020 in selected African countries. Current control focuses on community-directed treatment with ivermectin (CDTI). In Ghana, persistent transmission has been reported despite long-term control.

Onchocerciasis transmission in Ghana: biting and parous rates of host-seeking sibling species of the Simulium damnosum complex.

Background: Ghana is renowned for its sibling species diversity of the Simulium damnosum complex, vectors of Onchocerca volvulus. Detailed entomological knowledge becomes a priority as onchocerciasis control policy has shifted from morbidity reduction to elimination of infection. To date, understanding of transmission dynamics of O.

Repeated landmass reformation limits diversification in the widespread littoral zone mosquito Anopheles sundaicus sensu lato in the Indo-Oriental Region.

Southeast Asia harbours abundant biodiversity, hypothesized to have been generated by Pliocene and Pleistocene climatic and environmental change. Vicariance between the island of Borneo, the remaining Indonesian archipelago and mainland Southeast Asia caused by elevated sea levels during interglacial periods has been proposed to lead to diversification in the littoral zone mosquito Anopheles (Cellia) sundaicus (Rodenwaldt) sensu lato. To test this biogeographical hypothesis, we inferred the population history and assessed gene flow of A.

Stability and change in the distribution of cytospecies of the Simulium damnosum complex (Diptera: Simuliidae) in southern Ghana from 1971 to 2011.

Background: Simulium damnosum s.l., the most important vector of onchocerciasis in Africa, is a complex of sibling species that have been described on the basis of differences in their larval polytene chromosomes.

Evolution, epidemiology, and population genetics of black flies (Diptera: Simuliidae).

More than 2000 species of black flies feed on vertebrate blood; 1.5% of all species are vectors of pathogens that cause human diseases. Of nine simuliid-borne animal diseases, only two, mansonellosis and onchocerciasis, afflict humans.

A preliminary analysis of the population genetics and molecular phylogenetics of Onchocerca volvulus (Nematoda: Filarioidea) using nuclear ribosomal second internal transcribed spacer sequences.

Nuclear internal transcribed spacer 2 (ITS2) rDNA sequences were used for a molecular phylogenetics analysis of five Onchocerca species. The sister species of the human parasite O. volvulus was found to be the cattle parasite O.

Detection of Onchocerca volvulus (Nematoda: Onchocercidae) infection in vectors from Amazonian Brazil following mass Mectizan distribution.

Detection of Onchocerca volvulus in Simulium populations is of primary importance in the assessment of the effectiveness of onchocerciasis control programs. In Brazil, the main focus of onchocerciasis is in the Amazon region, in a Yanomami reserve. The main onchocerciasis control strategy in Brazil is the semi-annually mass distribution of the microfilaricide ivermectin.