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Parasitic filarial nematodes infect more than 200 million individuals worldwide, causing debilitating inflammatory diseases such as river blindness and lymphatic filariasis. Using a murine model for river blindness in which soluble extracts of filarial nematodes were injected into the corneal stroma, we demonstrated that the predominant inflammatory response in the cornea was due to species of endosymbioticWolbachiabacteria. In addition, the inflammatory response induced by these bacteria was dependent on expression of functional Toll-like receptor 4 (TLR4) on host cells.

This paper describes the introduction of 3D blade designs into the core compressors of the Rolls-Royce Trent engine series with particular emphasis on the use of sweep and dihedral in the rotor designs. It follows the development of the basic ideas in a university research project, through multistage low-speed model testing, to their application to the high pressure engine compressor. An essential element of the project was the use of multistage CFD and some of the development of the method to allow the designs to take place is also discussed. Part I of the paper concentrated on the fundamental university-based research and the methods development. Part II describes additional low-speed multistage design and testing and the high-speed engine compressor designs and tests.

This paper describes the introduction of 3D blade designs into the core compressors for the Rolls-Royce Trent engine with particular emphasis on the use of sweep and dihedral in the rotor designs. It follows the development of the basic ideas in a university research project, through multistage low-speed model testing, to the application to high pressure engine compressors. An essential element of the project was the use of multistage CFD and some of the development of the method to allow the designs to take place is also discussed. The first part of the paper concentrates on the university-based research and the methods development. The second part describes additional low-speed multistage design and testing and the high-speed engine compressor design and test.

Background\ud \ud Interactions of the Th2 cytokine IL-33 with its receptor ST2 lead to amplified Type 2 immune responses. As Type 2 immune responses are known to mediate protection against helminth infections we hypothesized that the lack of ST2 would lead to an increased susceptibility to filarial infections.\ud \ud Methodology/Principal Finding\ud \ud ST2 deficient and immunocompetent BALB/c mice were infected with the filarial nematode Litomosoides sigmodontis. At different time points after infection mice were analyzed for worm burden and their immune responses were examined within the thoracic cavity, the site of infection, and systemically using spleen cells and plasma. Absence of ST2 led to significantly increased levels of peripheral blood microfilariae, the filarial progeny, whereas L. sigmodontis adult worm burden was not affected. Development of local and systemic Type 2 immune responses were not impaired in ST2 deficient mice after the onset of microfilaremia, but L. sigmodontis infected ST2-ko mice had significantly reduced total numbers of cells within the thoracic cavity and spleen compared to infected immunocompetent controls. Pronounced microfilaremia in ST2-ko mice did not result from an increased microfilariae release by adult female worms, but an impaired splenic clearance of microfilariae.\ud \ud Conclusions/Significance\ud \ud Our findings suggest that the absence of ST2 does not impair the establishment of adult L. sigmodontis worms, but is important for the splenic clearance of microfilariae from peripheral blood. Thus, ST2 interactions may be important for therapies that intend to block the transmission of filarial disease.

Onchocerciasis is a debilitating parasitic infection caused by the filarial nematodeOnchocerca volvulus. Infections are chronic, and persistence of the parasites for several years argues for highly adapted mechanisms of immune evasion. Due to the restricted host repertoire ofO. volvulus, we have used the cattle parasiteOnchocerca ochengito investigate the nature of immunomodulation underpinning these long-term infections. Cattle were infected with a single inoculation of 350 infective-stage larvae under laboratory conditions (n= 6). Intradermal nodules containing immature adult worms were detected from 110 days postinfection, and microfilariae in skin were detected from day 280 postinfection. Parasite-specific responses during early infection were nonpolarized with respect to the major Th cytokines (interleukin-4 [IL-4], IL-2, and gamma interferon [IFN-γ]) produced by antigen-stimulated peripheral blood mononuclear cells (PBMC) or serum antibody isotypes. Antigen-induced proliferation of PBMC peaked shortly after exposure and remained high during the prepatent infection. As the parasites matured and animals developed patent infections, there was a profound down-regulation of lymphoproliferation, accompanied by sharp falls in the expression of both IL-4 and IFN-γ and a gradual decline in IL-2. Levels of immunoglobulin G2 (IgG2) fell, while those of IgG1 remained high. We conclude that neither a classical Th2 response nor a simple Th1-to-Th2 switch is sufficient to explain the immunomodulation associated with patentOnchocercainfections. Instead, there is an initial Th0 response, which matures into a response with some, but not all of the features of a Th2 response. The natural host-parasite relationship ofO. ochengiin cattle may be useful as both a descriptive and predictive tool to test more refined models of immunomodulation in onchocerciasis.

A cDNA from adult femaleOnchocerca volvulusencoding the C-terminal portion of a tropomyosin isoform (termed MOv-14) has been shown previously to confer protective immunity in rodent models of onchocerciasis. The full-length sequence (designatedOv-tmy-1) obtained by PCR amplification, codes for a protein of 33 kDa and shares 91% identity with tropomyosins from other nematodes, falling to 57% identity with human α-tropomyosin.Ov-TMY-1 migrates with an apparent molecular mass of 42 kDa on SDS/PAGE and is present in all life-cycle stages, as determined by immunoblotting. Immunogold electron microscopy identified antigenic sites within muscle blocks and the cuticle of microfilariae and infective larvae. Anti-MOv14 antibodies were abundant in mice exhibiting serum-transferable protection against microfilariae conferred by vaccination with a PBS-soluble parasite extract. In contrast, little or no MOv14-specific antibody was present in mice inoculated with live microfilariae, in which resistance is mediated by antibody-independent mechanisms. In human infections, there was an inverse correlation between anti-tropomyosin IgG levels and densities of microfilariae in the skin. Seropositivity varied with the relative endemicity of infection. An immunodominant B cell epitope withinOv-TMY-1 (AQLLAEEADRKYD) was mapped to the N terminus of the MOv14 protein by using sera from protectively vaccinated mice. Intriguingly, the sequence coincides with an IgE-binding epitope within shrimp tropomyosin, believed to be responsible for hypersensitivity in individuals exhibiting allergy to shellfish. IgG and IgE antibodies reacting with theO. volvulusepitope were detected in human infections. It is concluded that antibody responses to tropomyosin may be important in limiting microfilarial densities in a proportion of individuals with onchocerciasis and have the potential to mediate hypersensitivity reactions to dead microfilariae, raising the possibility of a link with the immunopathology of infection.

Inoculation of severe combined immunodeficient (SCID) mice with microfilariae of Onchocerca lienalis results in a sustained infection of the skin, extending for months beyond the point at which the parasites are eliminated from immunocompetent BALB/c controls. Reconstitution of SCID mice with spleen cells, thymocytes, or CD4+-cell-enriched splenocytes from naive BALB/c donors confers the ability to mount a protective immune response, leading to the rapid elimination of microfilariae. High levels of interleukin-5 and low levels of gamma interferon in the sera of reconstituted SCID mice during the destruction of microfilariae suggest that this protective immune response is directed by Th2 lymphocytes, mirroring that observed in immunocompetent controls. Unexpectedly, abbreviation of primary infections of unreconstituted SCID mice with the drug ivermectin induces resistance to reinfection with microfilariae at a level equivalent to that induced in secondarily infected, immunocompetent controls. In contrast to protection mediated by adoptive reconstitution, resistance induced by ivermectin-abbreviated infection occurs in the absence of T cells and in association with negligible levels of serum interleukin-5 and gamma interferon. This points to the activation of some alternative host defense mechanism that operates after the clearance of therapeutic levels of drug. Such a response could have important implications for the treatment of human onchocerciasis and may go some way in explaining the long-term suppression of microfilariae observed in patients after treatment with ivermectin.

This paper presents a system for performing real-time vehicular self-location through a combination of triangulation of target sightings and low-cost auxiliary sensor information (e.g. accelerometer, compass, etc.). The system primarily relies on the use of three video cameras to monitor a dynamic 1 80° field of view. Machine vision algorithms process the imagery from this field of view searching for targets placed at known locations. Triangulation results are then combined with the past video processing results and auxiliary sensor information to arrive at real-time vehicle location update rates in excess of 10 Hz on a single low-cost conventional CPU. To supply both extended operating range and nighttime operational capabilities, the system also possesses an active illumination mode that utilizes multiple, inexpensive infrared LED's to act as the illuminating source for reflective targets. This paper presents the design methodology used to arrive at the system, explains the overall system concept and process flow, and will briefly discuss actual results of implementing the system on a standard commercial vehicle. Keywords: Machine Vision, Self-Location, Autonomous Vehicles, Infrared Sensing, Position Determination

A cDNA clone of Onchocerca volvulus, designated MOv14, and encoding 136 amino-acid residues from the C-terminus of O. volvulus tropomyosin, was evaluated as a protective immunogen in two complimentary rodent models of onchocerciasis. Vaccination of BALB/c mice with the recombinant fusion of MOv14 coupled to Maltose-Binding Protein (MBP) induced significant reductions (48-62%) in the recovery of Onchocerca lienalis microfilariae from the skin, compared to control groups immunized with MBP alone. The predominant antibody response generated to MOv14 by vaccination was of IgG1. Following a similar vaccination protocol in Mongolian jirds, two independent experiments demonstrated that 16 weeks after infection with Acanthocheilonema viteae there was a 46% reduction in the recovery of adult worms in vaccinated animals compared to control groups. Antibodies generated by vaccination recognized a product released during culture of A. viteae infective larvae which migrated at a distinct molecular mass from native tropomyosin from somatic tissues.

SUMMARYMice inoculated with microfilariae of the filarial nematodeOnchocerca lienalisclear their parasites over a period of 3–4 months and are highly resistant to re-infection. We have investigated the comparative roles of the eosinophil, macrophage and neutrophil in effecting this parasite clearance, employing agents specifically to perturb cell functionin vivo. Using the anti-IL-5 monoclonal antibody TRFK-5, we show that eosinophils are of primary importance in effecting resistance to re-infection. Ablation of macrophages (with carbon) and neutrophils (with the monoclonal antibody NIMP-R14) had no effect on parasite clearance following re-infection. Neutralization of these 3 cell types during a primary infection showed that while the removal of both eosinophils and macrophages caused a small but significant delay in parasite clearance, the depletion of neutrophils had no effect. This report describes the first direct evidence for eosinophil-mediated killing of microfilariaein vivo, and is consistent with Th-2 cell responses previously described in this model.

SUMMARYThe susceptibility ofBrugia malayiandOnchocerca lienalismicrofilariae to H2O2and NO either in cell-free culture or from IFNγ-activated macrophages was examined. In cell-free culture,O. lienalismicrofilariae were highly susceptible to H2O2induced toxicity, exhibiting rapid reductions in motility and viability. The addition of exogenous catalase abrogated H2O2-induced killing. In contrast,B. malayimicrofilariae were relatively resistant to H2O2, with concentrations as high as 50 μM having no effect on motility or viability. On exposure to NO, both species showed reductions in motility within 5–30 min, but longer was required to see effects on the viability of microfilariae. Parasites incubated with IFNγ-activated macrophages also exhibited marked reductions in motility and viability. In cultures withB. malayiand activated macrophages, inhibition of these effects was achieved by the addition of eitherL-NMMA, to abolish NO production, or neutralizing anti-TNFα antibodies. Attempts to inhibit parasite killing by the addition of catalase to macrophage cultures were ineffective. The results of this study show thatB. malayiandO. lienalismicrofilariae have different susceptibility to H2O2, but are equally affected by exposure to NO. Moreover both species are killed by IFNγ-activated macrophages and in the case ofB. malayi, killing is dependent on the generation of NO via TNFα.

A cDNA designated MOv2 was isolated from an Onchocerca volvulus library on the basis of its product's recognition by an antiserum raised against the infective stage. Immunogold electron microscopy revealed a high density of antigenic sites associated with the annulae of the L3 cuticle and with the uterine wall of the adult female: a general, low density of labell ing occurred in all developmental forms. Western blotting confirmed the presence of the antigen throughout the life cycle and the existence of an immunologically cross-reactive homologue in the related filaria, Acanthocheilonema viteae. The antigen was shown to be secreted by infective larvae and adult females of A. viteae. Sequence comparisons revealed two homologues of MOv2 (Ov-20, Ov-9) which had been selected independently by other laboratories on the basis of their specific recognition by human onchocerciasis infection sera. The IgG antibody response against MOv2 in cattle experimentally infected with O. lienalis revealed the induction of a response during the prepatent period that was strongly boosted at the onset of patency. However, only a proportion of infected cattle responded with a detectable level of anti-MOv2 antibodies. The appearance of MOv2 in larval cuticle and secretions prompted us to evaluate it as a candidate molecule for prophylactic immunization. Trials performed in the A. viteae/Mongolian jird model of filariasis revealed that recombinant MOv2 induced a host-protective response, reducing worm recoveries by 36–55% following a challenge infection.

OvB20 is an antigen of Onchocerca volvulus preferentially recognized by sera from cattle vaccinated with irradiated infective larvae of Onchocerca lienalis. Antibodies raised against the recombinant protein were used to characterize the expression of the native protein in different developmental stages of O. volvulus and the rodent filaria Acanthocheilonema viteae. In O. volvulus, antibodies reacted to a polypeptide of 42 kDa in microfilariae and with proteins of 52 and 65 kDa in third-stage larvae. No products were detected in adult stages. Immunogold electron microscopy localized the native protein to discrete patches of the hypodermis and cuticle of infective larvae. Characterization of a homologous protein in A. viteae confirmed the stage-specific expression in infective larvae of the 65-kDa protein, which was secreted during in vitro culture. Vaccination of rodents against A. viteae with a B20-maltose-binding-protein fusion protein resulted in a 49 to 60% reduction in adult worm recoveries with a corresponding 97% reduction in microfilaremia.

New generations of military unmanned systems on the ground, at sea, and in the air will be driven by man-portable command units. In past efforts we implemented several prototypes of such units which provided display and capture of up to four video input channels, provided 4 color LCD screens and a larger status display LCD screen, provided drive input through two joysticks, and, through software, supported a flexible 'virtual' driver's interface. We have also performed additional trade analysis of prototype systems incorporating force feedback and extensive image-oriented processing facilities applied to man-controlled robotic control systems. This prior work has resulted in a database of practical design guidelines and a new generation of hardened compact robotic command center which is being designed and built to provide more advanced video capture, display, and interfacing features, supercomputer level computational performance, and ergonomic features for hard field use. In this paper we will summarize some past work and will project current performance to features likely to be common across most unmanned systems command, control, and communications subsystems of the near future.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Photoconductive detectors (PCDs) are routinely used alongside vacuum x-ray diodes (XRDs) to provide an alternative x-ray flux measurement at laser facilities such as HELEN at AWE Aldermaston, UK, and Omega at the Laboratory for Laser Energetics. To evaluate diamond PCDs as an alternative to XRD arrays, calibration measurements made at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory are used to accurately calculate the x-ray flux from a laser-heated target. This is compared to a flux measurement using the Dante XRD diagnostic. Estimates indicate that the photoinduced conductivity from measurements made at Omega are too large, and calculations using the radiometric calibrations made at the NSLS agree with this hypothesis. High-purity, single-crystal, chemical vapor deposited (CVD) diamond samples are compared to natural type-IIa PCDs and show promising high resistivity effects, the corollary of which preliminary results show is a slower response time.

The majority of filarial nematodes harbour Wolbachia endobacteria, including the major pathogenic species in humans, Onchocerca volvulus, Brugia malayi and Wuchereria bancrofti. These obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. However, a recent report described the detection by PCR of Wolbachia in the metastrongylid nematode, Angiostrongylus cantonensis (rat lungworm), a leading cause of eosinophilic meningitis in humans. To address the intriguing possibility of Wolbachia infection in nematode species distinct from the Family Onchocercidae, we used both PCR and immunohistochemistry to screen samples of A. cantonensis and A. costaricensis for the presence of this endosymbiont. We were unable to detect Wolbachia in either species using these methodologies. In addition, bioinformatic and phylogenetic analyses of the Wolbachia gene sequences reported previously from A. cantonensis indicate that they most likely result from contamination with DNA from arthropods and filarial nematodes. This study demonstrates the need for caution in relying solely on PCR for identification of new endosymbiont strains from invertebrate DNA samples.

Rats were trained to run towards a lighted target following either bilateral lesions of the superior colliculus (SC) or control lesions of the overlying cortex. At 4 months post-surgery, the animals were tested for the disruptive effects of an auditory tone. An increase in running times was found in both groups, attributable to frequent freezing reactions in all animals. However, only the control rats made orienting reactions to the tones. It is argued that the freezing responses show that the SC lesions did not impair sensory detection; consequently, the orienting failure cannot be attributed to a sensory deficit.

Bali.. Indonesia equivalent to pre-contro! estimates, folJuly 1996 lowing the termination of control programmes. "(his raised the question of This workshop represents the first how long control programmes need to annual meeting designed to bring tobe maintainea in order to eliminate gether people involved in several as!ymphatic fi!=fi=ois as a pu!qic health peers of control, including health o~cials, probJem. E~imates for this vary from clinicians, epidemioiogists and laboratory five to ten years, although it was based scientists, with a view ~c monitor acknowledged that sustaining such a and develop the recent initiative o the programme becomes increasingly diffiWHO to eliminate lymphatic filanasis cult with respect to compliance, political as a major public health problemk The support and fundlng (J.P. Moulia-Peiat, meeting was structured into a series of Institut Malarde, French Polynesia). short reports fi'om countries in th~ Asia/Pacific region and scientific sessions covering; control, epidemiology and pathogenesis.

Background Diethylcarbamazine (DEC) has been used for many years in the treatment of human lymphatic filariasis. Its mode of action is not well understood, but it is known to interact with the arachidonic acid pathway. Here we have investigated the contribution of the nitric oxide and cyclooxygenase (COX) pathways to the activity of DEC against B. malayi microfilariae in mice.

Background Individuals with high microfilarial loads of Loa loa are at increased risk of neurologic serious adverse (SAE) events following ivermectin treatment against onchocerciasis. RAPLOA (Rapid Assessment Procedure for loiasis), a newly developed rapid assessment procedure for loiasis that relates the prevalence of key clinical manifestation of loiasis (history of eye worm) to the level of endemicity of the infection (prevalence of high intensity), is a very useful tool to identify areas at potential risk of L. loa post ivermectin treatment encephalopathy. In a perspective of treatment decision making in areas of co-endemicity of loiasis/onchocerciasis, it would be advantageous (both in time and cost savings) for national onchocerciasis control programmes to use RAPLOA and the Rapid epidemiologic assessment for onchocerciasis (REA), in combination in given surveys. Since each of the two rapid assessment tools have their own specificities, the workability of combining the two methods needed to be tested.

Background The majority of filarial nematode species are host to Wolbachia bacterial endosymbionts, although a few including Acanthocheilonema viteae, Onchocerca flexuosa and Setaria equina have been shown to be free of infection. Comparisons of species with and without symbionts can provide important information on the role of Wolbachia symbiosis in the biology of the nematode hosts and the contribution of the bacteria to the development of disease. Previous studies by electron microscopy and PCR have failed to detect intracellular bacterial infection in Loa loa. Here we use molecular and immunohistological techniques to confirm this finding.

In order to use a combination of ivermectin and albendazole for the elimination of lymphatic filariasis, it is important to assess the potential risk of increased adverse events in individuals infected with both lymphatic filariasis and onchocerciasis. We compared the safety and efficacy of albendazole (400 mg) in combination with ivermectin (150 micrograms/kg), for the treatment of co-infections of Wuchereria bancrofti and Onchocerca volvulus with single infection of W. bancrofti. The safety study on co-infections was a crossover, double blind design, while for the single infection of bancroftian filariasis an open design comparing two treatments was used. For co-infection, one group was allocated a single dose of ivermectin (150 micrograms/kg) plus albendazole (400 mg) (Group A). The other group received placebo (Group B). Five days later the treatment regime was reversed, with the Group A receiving placebo and Group B receiving treatment. For the single bancroftian filariasis infection, one group received a single dose of albendazole (400 mg) plus ivermectin (150 μg/kg) (Group C) while the other group received a single dose of albendazole (400 mg) alone (Group D). Blood and skin specimens were collected on admission day, day 0, and on days 2, 3, and 7 to assess drug safety and efficacy. Thereafter, blood and skin specimens were collected during the 12 months follow up for the assessment of drug efficacy. Study individuals were clinically monitored every six hours during the first 48 hours following treatment, and routine clinical examinations were performed during the hospitalisation period and follow-up. In individuals co-infected with bancroftian filariasis and onchocerciasis, treatment with ivermectin and albendazole was safe and tolerable. Physiological indices showed no differences between groups with co-infection (W. bancrofti and O. volvulus) or single infection (W. bancrofti). The frequency of adverse events in co-infected individuals was 63% (5/8, Group A, albendazole + ivermectin) and 57% (4/7, Group B, placebo) and of mild or moderate intensity. In single W. bancrofti infection the frequency of adverse events was 50% (6/12, Group C, albendazole + ivermectin) and 38% (5/13, Group D, albendazole) and of a similar intensity to those experienced with co-infection. There were no differences in adverse events between treatment groups. There was no significant difference in the reduction of microfilaraemia following treatment with albendazole and ivermectin in groups with single or co-infection. Our findings suggest that ivermectin plus albendazole is a safe and tolerable treatment for co-infection of bancroftian filariasis and onchocerciasis.

England and Wales are moving toward a model of ‘opt out’ for use of personal confidential data in health research. Existing research does not make clear how acceptable this move is to the public. While people are typically supportive of health research, when asked to describe the ideal level of control there is a marked lack of consensus over the preferred model of consent (e.g. explicit consent, opt out etc.).\ud This study sought to investigate a relatively unexplored difference between the consent model that people prefer and that which they are willing to accept. It also sought to explore any reasons for such acceptance. A mixed methods approach was used to gather data, incorporating a structured questionnaire and in-depth focus group discussions led by an external facilitator. The sampling strategy was designed to recruit people with different involvement in the NHS but typically with experience of NHS services. Three separate focus groups were carried out over three consecutive days. The central finding is that people are typically willing to accept models of consent other than that which they would prefer. Such acceptance is typically conditional upon a number of factors, including: security and confidentiality, no inappropriate commercialisation or detrimental use, transparency, independent overview, the ability to object to any processing considered to be inappropriate or particularly sensitive. This study suggests that most people would find research use without the possibility of objection to be unacceptable. However, the study also suggests that people who would prefer to be asked explicitly before data were used for purposes beyond direct care may be willing to accept an opt out model of consent if the reasons for not seeking explicit consent are accessible to them and they trust that data is only going to be used under conditions, and with safeguards, that they would consider to be acceptable even if not preferable.

Background Lipoproteins are the major agonists of Wolbachia-dependent inflammatory pathogenesis in filariasis and a validated target for drug discovery. Here we characterise the abundance, localisation and serology of the Wolbachia lipoproteins: Wolbachia peptidoglycan associated lipoprotein and the Type IV Secretion System component, VirB6. Methods We used proteomics to confirm lipoprotein presence and relative abundance; fractionation, immunoblotting and confocal and electron immuno-microscopy for localisation and ELISA for serological analysis. Results Proteomic analysis of Brugia malayi adult female protein extracts confirmed the presence of two lipoproteins, previously predicted through bioinformatics: Wolbachia peptidoglycan associated lipoprotein (wBmPAL) and the Type IV Secretion System component, VirB6 (wBmVirB6). wBmPAL was among the most abundant Wolbachia proteins present in an extract of adult female worms with wBmVirB6 only detected at a much lower abundance. This differential abundance was reflected in the immunogold-labelling, which showed wBmPAL localised at numerous sites within the bacterial membranes, whereas wBmVirB6 was present as a single cluster on each bacterial cell and also located within the bacterial membranes. Immunoblotting of fractionated extracts confirmed the localisation of wBmPAL to membranes and its absence from cytosolic fractions of C6/36 mosquito cells infected with wAlbB. In whole worm mounts, antibody labelling of both lipoproteins were associated with Wolbachia. Serological analysis showed that both proteins were immunogenic and raised antibody responses in the majority of individuals infected with Wuchereria bancrofti. Conclusions Two Wolbachia lipoproteins, wBmPAL and wBmVirB6, are present in extracts of Brugia malayi with wBmPAL among the most abundant of Wolbachia proteins. Both lipoproteins localised to bacterial membranes with wBmVirB6 present as a single cluster suggesting a single Type IV Secretory System on each Wolbachia cell.

Background Severe side effects following ivermectin treatment of onchocerciasis in areas of co-endemicity with loaisis have been an impediment for the work of the African Programme for Onchocerciasis Control (APOC) in forested regions of several countries. Doxycycline has been shown to be effective in the treatment of onchocerciasis and has the added advantages of killing adult Onchocerca volvulus but neither adult Loa loa nor their microfilariae. This drug therefore offers great potential for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The limitation of use of this drug is the duration of treatment that may pose a potential problem with therapeutic coverage and compliance with treatment. To benefit from the advantages that doxycycline offers in the treatment of onchocerciasis, it will be necessary to establish an effective distribution system that can access remote communities. This study assessed the feasibility of a large-scale distribution of doxycycline for the treatment of onchocerciasis in areas of co-endemicity with loiasis using a community-directed approach. Methods The study was carried out in 5 health areas co-endemic for Onchocerca volvulus and Loa loa which had no prior experience of the Community Directed Treatment with Ivermectin (CDTI). The community-directed delivery process was introduced using a cascade mechanism from the central health system that passed through the regional health delegation, health district and the health areas. Community health implementers (CHIs) were trained to deliver doxycycline to community members and, under the supervision of the health system, to monitor and document drug intake and side effects. Results The community members adhered massively to the process. Of the 21355 individuals counted, 17519 were eligible for treatment and 12936 were treated with doxycycline; giving a therapeutic coverage of eligible population of 73.8%. Of the 12936 who started the treatment, 97.5% complied by the end of six weeks. No serious side effect was registered during the six week treatment. Conclusion This study indicates that when empowered the community health implementers can successfully deliver doxycycline for six weeks for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The therapeutic coverage and the compliance treatment rate achieved in this study coupled to the known efficacy of doxycycline on O. volvulus, are indicators that the strategy involving the mass administration of doxycycline can be used to control onchocerciasis in those areas of co-endemicity with loiasis where ivermectin may be contraindicated.

Background\ud \ud Wolbachia endosymbionts are a proven target for control of human disease caused by filarial nematodes. However, little is known about the occurrence of Wolbachia in taxa closely related to the superfamily Filarioidea. Our study addressed the status of Wolbachia presence in members of the superfamily Dracunculoidea by screening the human parasite Dracunculus medinensis and related species from wildlife for Wolbachia.\ud \ud Findings\ud \ud D. medinensis, D. lutrae and D. insignis specimens were all negative for Wolbachia colonization by PCR screening for the Wolbachia ftsZ, 16S rRNA and Wolbachia surface protein (wsp) sequences. The quality and purity of the DNA preparations was confirmed by amplification of nematode 18S rRNA and cytochrome c oxidase subunit I sequences. Furthermore, Wolbachia endobacteria were not detected by whole mount fluorescence staining, or by immunohistochemistry using a Wolbachia-specific antiserum. In contrast, positive control Brugia malayi worms were shown to harbour Wolbachia by PCR, fluorescence staining and immunohistochemistry.\ud \ud Conclusions\ud \ud Three examined species of Dracunculus showed no evidence of Wolbachia endobacteria. This supports that members of the superfamily Dracunculoidea are free of Wolbachia. Within the order Spirurida, these endosymbionts appear restricted to the Filarioidea.

Background Lymphatic filariasis and onchocerciasis are debilitating diseases caused by filarial nematodes. Disease pathogenesis is induced by inflammatory responses following the death of the parasite. Wolbachia endosymbionts of filariae are potent inducers of innate and adaptive inflammation and bacterial lipoproteins have been identified as the ligands that bind toll-like receptors (TLR) 2 and TLR6. Lipoproteins are important structural and functional components of bacteria and therefore enzymes involved in Wolbachia lipoprotein biosynthesis are potential chemotherapeutic targets. Results Globomycin, a signal peptidase II (LspA) inhibitor, has activity against Gram-negative bacteria and a putative lspA gene has been identified from the Wolbachia genome of Brugia malayi (w Bm). The amino acids required for function are strictly conserved and functionality was verified by complementation tests in a temperature-sensitive Escherichia coli lspA mutant. Also, transformation of wild type E. coli with Wolbachia lspA conferred significant globomycin resistance. A cell-based screen has been developed utilizing a Wolbachia-containing Aedes albopictus cell line to assay novel compounds active against Wolbachia. Globomycin was screened using this assay, which resulted in a dose-dependent reduction in Wolbachia load. Furthermore, globomycin was also effective in reducing the motility and viability of adult B. malayi in vitro. Conclusions These studies validate lipoprotein biosynthesis as a target in an organism for which no genetic tools are available. Further studies to evaluate drugs targeting this pathway are underway as part of the A-WOL drug discovery and development program.