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Filarial lymphedema (LE) remains a significant global problem despite the progress made toward elimination of lymphatic filariasis (LF). In Ghana, the main approach to LF is preventive chemotherapy, but this has minimal impact on individuals who have already developed LE. In 2018-2020, a 24-month randomized, double-blind, placebo-controlled trial was conducted to evaluate the efficacy of stringent hygiene measures using the Essential Package of Care with or without additional administration of doxycycline (DOX) to improve filarial leg LE. This study enrolled 356 participants with LE stages 1-3 from two districts in the Upper East Region of Ghana. In addition to regular training on appropriate care for their affected legs, participants were randomized to receive 6 weeks of either 200 mg/day DOX (n = 117), 100 mg/day DOX (n = 120), or matching placebo (n = 119). Participants were seen every 2 months, with clinical measurements done at 6, 12, 18, and 24 months to assess the status of affected legs. There was a trend toward later appearance of acute attacks after DOX, but surprisingly, DOX showed no effect on LE stage progression. In all groups, leg LE improvement was more common (DOX 200 mg: n = 23 [20%]; DOX 100 mg: n = 23 [19.5%]; placebo: n = 32 [27.4%]) than LE worsening (DOX 200 mg: n = 2 [1.7%]; DOX 100 mg: n = 3 [2.5%]; placebo: n = 2 [1.7%]). Overall, these data show a strong benefit from adherence to a strict hygiene protocol, with some added potential benefit for DOX in preventing acute attacks.

Background: Mass drug administration (MDA) programmes for the control of lymphatic filariasis in Ghana, have been ongoing in some endemic districts for 16 years. The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana., Methods: The study was undertaken in two "hotspot" districts (Ahanta West and Kassena Nankana West) and two control districts (Mpohor and Bongo) in Ghana. Mosquitoes were collected and identified using morphological and molecular tools. A proportion of the cibarial armatures of each species was examined. Dissections were performed on Anopheles gambiae for filarial worm detection. A questionnaire was administered to obtain information on MDA compliance and vector control activities. Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis., Results: High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district (F = 16.09, P = 0.002). There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts (F = 2.16, P = 0.185). Mansonia species were predominant in Ahanta West district. An. coluzzii mosquitoes were prevalent in all districts. An. melas with infected and infective filarial worms was found only in Ahanta West district. No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts. Reported MDA coverage was high in all districts. The average use of bednet and indoor residual spraying was 82.4 and 66.2%, respectively. There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts, both considered hotspots of lymphatic filariasis transmission., Conclusions: The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis. Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities, ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates of An. gambiae and initial infection prevalence, coupled with high densities of An. melas and Mansonia vector species that have low or no teeth and exhibiting limitation.

Background: Despite the progress achieved in scaling-up mass drug administration (MDA) for lymphatic filariasis (LF) in Ghana, communities with persistent LF still exist even after 10 years of community treatment. To understand the reasons for persistence, we conducted a study to assess the status of disease elimination and understand the adherence to interventions including MDA and insecticide treated nets., Methodology and Principal Findings: We conducted a parasitological and epidemiological cross-sectional study in adults from eight villages still under MDA in the Northern Region savannah and the coastal Western Region of the country. Prevalence of filarial antigen ranged 0 to 32.4% and in five villages the prevalence of night blood microfilaria (mf) was above 1%, ranging from 0 to 5.7%. Median mf density was 67 mf/ml (range: 10-3,560). LF antigen positivity was positively associated with male sex but negatively associated with participating in MDA the previous year. Male sex was also associated with a decreased probability of participating in MDA. A stochastic model (TRANSFIL) was used to assess the expected microfilaria prevalence under different MDA coverage scenarios using historical data on one community in the Western Region. In this example, the model simulations suggested that the slow decline in mf prevalence is what we would expect given high baseline prevalence and a high correlation between MDA adherence from year to year, despite high MDA coverage., Conclusions: There is a need for an integrated quantitative and qualitative research approach to identify the variations in prevalence, associated risk factors and intervention coverage and use levels between and within regions and districts. Such knowledge will help target resources and enhance surveillance to the communities most at risk and to reach the 2020 LF elimination goals in Ghana., Competing Interests: The authors have declared that no competing interests exist.

Monitoring vectors is relevant to ascertain transmission of lymphatic filariasis (LF). This may require the best sampling method that can capture high numbers of specific species to give indication of transmission. Gravid anophelines are good indicators for assessing transmission due to close contact with humans through blood meals. This study compared the efficiency of an Anopheles gravid trap (AGT) with other mosquito collection methods including the box and the Centres for Disease Control and Prevention gravid, light, exit and BioGent-sentinel traps, indoor resting collection (IRC) and pyrethrum spray catches across two endemic regions of Ghana. The AGT showed high trapping efficiency by collecting the highest mean number of anophelines per night in the Western (4.6) and Northern (7.3) regions compared with the outdoor collection methods. Additionally, IRC was similarly efficient in the Northern region (8.9) where vectors exhibit a high degree of endophily. AGT also showed good trapping potential for collecting Anopheles melas which is usually difficult to catch with existing methods. Screening of mosquitoes for infection showed a 0.80-3.01% Wuchereria bancrofti and 2.15-3.27% Plasmodium spp. in Anopheles gambiae. The AGT has shown to be appropriate for surveying Anopheles populations and can be useful for xenomonitoring for both LF and malaria.

Introduction: Lymphatic filariasis is a debilitating disease caused by the filarial worm Wuchereria bancrofti. It is earmarked for elimination by the year 2020 through the Global Program for the Elimination of LF (GPELF). In Ghana, mass treatment has been on-going since the year 2000. Earlier studies have revealed differing epidemiology of LF in the North and South of Ghana. This study was therefore aimed at understanding the possible impacts of W. bancrofti diversity on the epidemiology and control of LF in Ghana., Methods: The Mitochondrial, Cytochrome C Oxidase I gene of W. bancrofti samples was sequenced and analyzed. The test sequences were grouped into infrapopulations, and pairwise differences (π) and mutation rates (θ) were computed. The amount of variance within and among populations was also computed using the AMOVA. The evolutionary history was inferred using the Maximum Parsimony method., Results: Seven samples from the South and 15 samples from the North were sequenced, and submitted to GenBank with accession numbers GQ479497- GQ479518. The results revealed higher mutation frequencies in the southern population, compared to the northern population. Haplotype analyses revealed a total of 11 haplotypes (Hap) in all the 22 DNA sequences, with high genetic variation and polymorphisms within the southern samples., Conclusion: This study showed that there is considerable genetic variability within W. bancrofti populations in Ghana, differences that might explain the observed epidemiology of LF. Further studies are however required for an in-depth understanding of LF epidemiology and control.

The ability of vector mosquitoes to transmit the microfilariae (mff) of Wuchereria bancrofti, especially when the levels of microfilaraemia in the humans on which the mosquitoes are feeding are very low, is very important for understanding the transmission dynamics of lymphatic filariasis. Data on the correlation between vector competence and the microfilarial load in the human host are also relevant to those trying to improve transmission models for this disease. The majority of the relevant studies have involved culicine rather than anopheline vectors. The competence of populations of Anopheles mosquitoes to transmit W. bancrofti in a district in the Upper East region of Ghana has now been investigated. The wild mosquitoes that fed on 20 volunteers under natural conditions were collected hourly during the night, from 21.00 hours on one day to 06.00 hours on the next. Overall, 1348 fed female mosquitoes--665 Anopheles, 662 Culex and 21 Aedes--were collected. Approximately 50% of the mosquitoes caught were killed immediately post-collection and dissected so that the number of W. bancrofti mff each had ingested could be counted. The remaining mosquitoes where dissected when they died (if this was within 12 days of collection) or when they were killed on day 12 post-collection. With the exception of one Culex mosquito that harboured one microfilaria, none of the Culex and Aedes mosquitoes were found infected with W. bancrofti. All of the other mosquitoes found infected were An. gambiae s.l. or An. funestus. When fingerprick samples of blood, collected hourly from the volunteers during the mosquito infection, were used to estimate the microfilaraemias in the blood on which these mosquitoes had fed, microfilarial uptake and the number of developing larvae were found to vary considerably even when the microfilaraemias in the bloodmeal source were similar. The results of a regression analysis on the pooled data for the Anopheles mosquitoes indicated the process of limitation, although larger samples need to be investigated to determine whether this process occurs only in An. gambiae s.l. or An. funestus or in both of these taxa., (Copyright 2004 The Liverpool School of Tropical Medicine)

Approximately 50 million people in Egypt and sub-Saharan Africa have bancroftian filariasis and together they represent about a third of all cases of lymphatic filariasis (LF) world-wide. Currently, the Global Programme to Eliminate Lymphatic Filariasis, which was launched by the World Health Organization (WHO) in 1998, is largely based on repeated annual cycles of mass drug administration (MDA) to endemic populations. Also, some countries, including Egypt, are taking steps to improve LF vector-control interventions, to break the transmission cycle more effectively than is achievable with MDA alone. New tools and strategies for monitoring and evaluating elimination campaigns are needed. The last 20 years have witnessed dramatic advances in the diagnosis of LF for epidemiological purposes. The recent introduction and development of molecular technologies have moved parasite-detection systems from traditional methods (that are labour-intensive, tedious and often impractical) to improved PCR-based assays that have considerable potential for field use. The present article highlights the strengths and limitations of the PCR-based assays when used to detect filarial infections in mosquitoes (particularly for the xenomonitoring of elimination campaigns).

We conducted an entomological study to document the effect of irrigation on the vectors and transmission dynamics of lymphatic filariasis in the Upper East Region of Ghana. Mosquitoes were collected by indoor spraying of houses in a cluster of communities located around irrigation projects (Tono and Vea) and others without reservoirs (Azoka). Anopheles gambiae s.s. was the dominant species and major vector, followed by An. funestus. Anopheles arabiensis constituted 9--14% of the An. gambiae complex but none were infective. Culex quinquefasciatus was also not infective in these communities. Chromosomal examinations showed that >60% (n=280--386) of the An. gambiae s.s. in irrigated communities were Mopti forms whilst 73% (n=224) in the non-irrigated area were Savannah forms. Infectivity rates (2.3--2.8 vs. 0.25), worm load (1.62--2.04 vs. 1.0), annual bites per person (6.50--8.83 vs. 0.47) and annual transmission potential (13.26--14.30 vs. 0.47) were significantly higher in irrigated communities.

A qualitative study to investigate lymphatic filariasis related perceptions and practices that may be relevant for the design of appropriate health education and control programmes was conducted in four endemic villages in coastal Ghana. The villagers were aware of the common manifestations of filariasis, such as adenolymphangitis (ADL), lymphoedema, elephantiasis and hydrocele, which were specifically described with local terminology. ADL attacks were identified as the most dreaded health problem in the communities, and elephantiasis and hydrocele also ranked high in importance among reported diseases. Generally the respondents did not accept the mosquito theory of transmission, but they believed in other physical, and in spiritual and hereditary causes. Hydrocele was considered to have no link to the other disease manifestations. The manifestations were most often treated with herbal preparations which were used orally, smeared on affected parts or given as enema. In some cases the affected parts were scarified before herbal preparations were applied. The manifestations affected the work output of its victims and subjected them to hardships such as teasing, unsuitability for marriage, sexual dysfunction and divorce. Although the etiology was seen as different, the local perception of the developmental process of elephantiasis closely paralleled that of the biomedical understanding. It is suggested that this coincidence is used as an entry point for health education, to advance a broader biomedical knowledge on etiology, transmission and treatment options, and thereby to ensure co-operation of the target populations in the control of this complex disease.

A reconnaissance survey for the presence of lymphatic filariasis is made in 41 chiefdoms of north east Ghana. Four disease levels are identified culminating in hyperendemic disease foci associated with two Government-introduced rice irrigation projects. Attention is also drawn to the disease effects of small village dams. Multiple concurrent infections are noted. Within the most stricken irrigation villages, aspects of concealment, stigma and marriage are considered. Failure to control lymphatic filariasis has led to hospital avoidance and neglect of the disease jointly by patients, physicians and nurses. Culpability rests with the irrigation authority and Government health services. An outline is given of possible measures for disease control. A multisectoral policy of 'prevention before development' is strongly advocated.