scholarly journals Rapid Point-of-Contact Tool for Mapping and Integrated Surveillance of Wuchereria bancrofti and Onchocerca volvulus Infection

2015 ◽  
Vol 22 (8) ◽  
pp. 896-901 ◽  
Author(s):  
Cathy Steel ◽  
Allison Golden ◽  
Eric Stevens ◽  
Lindsay Yokobe ◽  
Gonzalo J. Domingo ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Wuchereria Bancrofti ◽  
Lateral Flow ◽  
Onchocerca Volvulus ◽  
Buffer Strips ◽  
Predictive Values ◽  
Content Type ◽  
Single Antigen ◽  
Lateral Flow Strips

ABSTRACTElimination programs forWuchereria bancroftiandOnchocerca volvulusare in critical need of sensitive, specific, and point-of-contact (POC) tools that can be used for surveillance years beyond cessation of mass drug administration when infection intensities are low. Previously, Wb123 and Ov16 were identified individually as potential filarial antigens for an antibody-based POC test. The present study compares single-antigen Wb123- and Ov16-based POC tests with an integrated configuration to detect antibodies to Wb123 and Ov16 simultaneously. Wb123 and Ov16 isolates were striped onto lateral flow strips containing anti-IgG4. Sera fromW. bancrofti-,O. volvulus-, and other helminth-infected or -uninfected individuals were added to the strips with buffer. Strips were read for the appearance of a positive or negative test line for both antigens at 20 min and following drying. Sensitivity, specificity, and predictive values were calculated for the single-antigen and biplex strips. Single and biplex lateral flow strips showed nearly identical results, with >90% sensitivity for Ov16 and >92% sensitivity for Wb123. Overall specificities for the single and biplex tests were 98% and 96% for Ov16 and Wb123, respectively. Biplex tests performed as well as the single-antigen tests regardless of the intensity of patient IgG4 response. The high sensitivity and specificity make these new biplex tests extremely useful for POC long-term surveillance following mass drug administration in Africa that should reduce time and cost in areas where bancroftian filariasis and onchocerciasis are coendemic.

scholarly journals Rapid Wuchereria bancrofti-Specific Antigen Wb123-Based IgG4 Immunoassays as Tools for Surveillance following Mass Drug Administration Programs on Lymphatic Filariasis

2013 ◽  
Vol 20 (8) ◽  
pp. 1155-1161 ◽  
Author(s):  
Cathy Steel ◽  
Allison Golden ◽  
Joseph Kubofcik ◽  
Nicole LaRue ◽  
Tala de los Santos ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Wuchereria Bancrofti ◽  
Lateral Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Predictive Values ◽  
Content Type ◽  
Helminth Infections ◽  
Highly Sensitive

ABSTRACTThe Global Programme to Eliminate Lymphatic Filariasis has an urgent need for rapid assays to detect ongoing transmission of lymphatic filariasis (LF) following multiple rounds of mass drug administration (MDA). Current WHO guidelines support using the antigen card immunochromatographic test (ICT), which detects active filarial infection but does not detect early exposure to LF. Recent studies found that antibody-based assays better serve this function. In the present study, two tests, a rapid IgG4 enzyme-linked immunosorbent assay (ELISA) and a lateral-flow strip immunoassay, were developed based on the highly sensitive and specificWuchereria bancroftiantigen Wb123. A comparison ofW. bancrofti-infected and -uninfected patients (with or without other helminth infections) demonstrated that both tests had high sensitivities and specificities (93 and 97% [ELISA] and 92 and 96% [strips], respectively). When theW. bancrofti-uninfected group was separated into those with other filarial/helminth infections (i.e., onchocerciasis, loiasis, and strongyloidiasis) and those who were parasite uninfected, the specificities of the assays varied between 91 and 100%. In addition, the geometric mean response by ELISA ofW. bancrofti-infected patients was significantly higher than the response of those withoutW. bancroftiinfection (P< 0.0001). Furthermore, the Wb123 ELISA and the lateral-flow strips had high positive and negative predictive values, giving valuable information on the size of survey population needed to be reasonably certain whether or not transmission is ongoing. These highly sensitive and specific IgG4 tests to theW. bancroftiWb123 protein give every indication that they will serve as useful tools for post-MDA monitoring.

scholarly journals Lymphatic filariasis, infection status in Culex quinquefasciatus and Anopheles species after six rounds of mass drug administration in Masasi District, Tanzania

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Eliza Lupenza ◽  
Dinah B. Gasarasi ◽  
Omary M. Minzi
Keyword(s):  
Vector Control ◽  
Lymphatic Filariasis ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Wuchereria Bancrofti ◽  
Elimination Phase ◽  
Anopheles Species ◽  
The Status ◽  
Household Environment ◽  
Indoor And Outdoor

Abstract Background Lymphatic filariasis (LF) elimination program in Tanzania started in 2000 in response to the Global program for the elimination of LF by 2020. Evidence shows a persistent LF transmission despite more than a decade of mass drug administration (MDA). It is advocated that, regular monitoring should be conducted in endemic areas to evaluate the progress towards elimination and detect resurgence of the disease timely. This study was therefore designed to assess the status of Wuchereria bancrofti infection in Culex quinqefasciatus and Anopheles species after six rounds of MDA in Masasi District, South Eastern Tanzania. Methods Mosquitoes were collected between June and July 2019 using Center for Diseases Control (CDC) light traps and gravid traps for indoor and outdoor respectively. The collected mosquitoes were morphologically identified into respective species. Dissections and PCR were carried out to detect W. bancrofti infection. Questionnaire survey and checklist were used to assess vector control interventions and household environment respectively. A Poisson regression model was run to determine the effects of household environment on filarial vector density. Results Overall, 12 452 mosquitoes were collected of which 10 545 (84.7%) were filarial vectors. Of these, Anopheles gambiae complex, An. funestus group and Cx. quinquefasciatus accounted for 0.1%, 0.7% and 99.2% respectively. A total of 365 pools of Cx. quinquefasciatus (each with 20 mosquitoes) and 46 individual samples of Anopheles species were analyzed by PCR. For Cx. quinquefasciatus pools, 33 were positive for W. bancrofti, giving an infection rate of 0.5%, while the 46 samples of Anopheles species were all negative. All 1859 dissected mosquitoes analyzed by microscopy were also negative. Households with modern latrines had less mosquitoes than those with pit latrines [odds ratio (OR) = 0.407, P < 0.05]. Houses with unscreened windows had more mosquitoes as compared to those with screened windows (OR = 2.125, P < 0.05). More than 80% of the participants own bednets while 16.5% had no protection. Conclusions LF low transmission is still ongoing in Masasi District after six rounds of MDA and vector control interventions. The findings also suggest that molecular tools may be essential for xenomonitoring LF transmission during elimination phase.

EVALUATION OF LYMPHATIC FILARIASIS AFTER TWO ROUNDS OF MASS DRUG ADMINISTRATION IN LAU LOCAL GOVERNMENT AREA OF TARABA STATE NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 513-519
Author(s):  
D. E. Akafyi ◽  
I. S. Ndams ◽  
S. A. Luka ◽  
F. S. Ojeleye ◽  
S. O. Elkanah ◽  
...  
Keyword(s):  
Local Government ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Clinical Manifestations ◽  
Wuchereria Bancrofti ◽  
Local Government Area ◽  
Filarial Antigen ◽  
Physical Examinations ◽  
The Impact ◽  
Card Test

This study was undertaken to evaluate the effects of Mass Drug Administration (MDA) on Wuchereria bancrofti (microfilariae) after two rounds of combined Ivermectin and Albendazole distribution. A total of 221 participants were recruited in three communities in Lau Local Government Area of Taraba State by convenience sampling method. Questionnaires and physical examinations were used to assess clinical manifestations associated with the infection. Blood samples were collected by finger prick method and stained with Giemsa stain for examination to establish the presence of W. bancrofti while immunochromatographic card test was performed to determine the presence of filarial antigen in serum. Previous data were used to determine the pre-drug prevalence of the parasite. The results showed that the drug did not significantly reduce the clinical manifestations reported among the patients. The microfilariae prevalence and microfilaria mean density after two rounds of drug administration was 19.5% and 1.49%, while the pre- MDA prevalence and microfilaria mean density was 27.8% and 2.44% respectively. There was a statistically significant decrease of microfilaria prevalence (P<0.05) after two rounds of MDA. There was no significant effect of MDA by age, sex and occupation-related microfilariae prevalence in the study area.  In conclusion, the study reveals that microfilaria prevalence and load decreased after two rounds of MDA of combined Ivermectin and Albendazole distribution amongst the studied populations. Routine evaluation of the MDA is required to assess the impact of the drug for the eventual elimination of the infection.

scholarly journals Wuchereria bancrofti transmission pattern in southern Mali prior to and following the institution of mass drug administration

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Yaya Ibrahim Coulibaly ◽  
Benoit Dembele ◽  
Abdallah Amadou Diallo ◽  
Sibylle Kristensen ◽  
Siaka Konate ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Wuchereria Bancrofti ◽  
Transmission Pattern

scholarly journals Molecular Characterization and Phylogenetic analysis ofWuchereria bancroftiin human blood samples from Malindi and Tana River Delta, endemic regions in Kenya

2019 ◽  
Author(s):  
Kinyatta Nancy ◽  
Wambua Lillian ◽  
Mutahi Wilkinson ◽  
Mugasa Claire ◽  
Kamau Luna ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Drug Administration ◽  
Human Blood ◽  
Mass Drug Administration ◽  
Wuchereria Bancrofti ◽  
River Delta ◽  
Blood Samples ◽  
Tana River ◽  
Human Blood Samples ◽  
Tajima’S D

AbstractIntroductionLymphatic filariasis is a debilitating disease caused by filarial worms;Wuchereria bancrofti, Brugia MalayiandB. Timori. It is earmarked for elimination by the year 2020 through the Global Program for the Elimination of Lymphatic Filariasis (GPELF). In Kenya, mass treatment has been ongoing since the year 2002 though it has not been consistent as recommended by World health organization (WHO). Taking this into account, the emergence ofW. bancroftiresistance strains against the current choice of drugs cannot be ruled out. Information on genetic structure and variations is important in assessment of Program’s success. Data on genetic characterization ofW. bancroftiin Kenya is lacking. This study, therefore reports the first genetic diversity of W.bancroftiin two Kenyan endemic regions.MethodologyGenomic DNA was extracted from 100 human blood samples obtained from Mpirani district in Malindi and Kipini district in Tana River Delta. They were then amplified by PCR and detected through gel electrophoresis. Seventeen PCR products positive forWuchereriaPCRbancroftiwere purified and then DNA quantified for Sanger sequencing. Chromas version 2.6.5 and BioEdit softwares were used for sequence alignment and editing. Fourteen sequences were selected for analysis by MEGA7 and six more related sequences retrieved from the Gene Bank for further analysis with the study sequences. Intrapopulation, interpopulation diversity and pair wise distance were determined and the phylogenetic trees constructed. Tajima’s D-test of neutrality was also determined and Statistical evolutionary rate was done using Chi-square (X2) test.Results and DiscussionThe mean diversity of Malindi and Tana River Delta isolates was 1.42 and the overall mean distance was 0.99. Tajima’s (D) test for test of Neutrality was 4.149 and nucleotide diversity(π) was 0.603. These results revealed high genetic variations ofW. bancroftiin Kenyan endemic regions. This variation could be attributed to prolonged use of the mass drug administration (MDA) and the long period of parasite circulation in these populations.Author SummaryElephantiasis is a disabling disease that causes severe swellings to the affected limbs. It is caused by parasites ofWuchereria bancrofti, Brugia TimoriandB. malayiwhich are transmitted by mosquito vectors. The disease is under the control by the Global Programme to eliminate filariasis and due to the effect of continued treatment through mass drug administration there have been changes in the genetic makeup of the parasite. This may result to resistant strains which may have negative impact on the treatment interventions. We therefore aimed at characterizing the genetic sequences of theWuchereria bancroftiparasite found in Kenya. Through analyzing parasites obtained in different years after treatment, we were able to track any genetic variations since the start of mass drug administration in Kenya. These variations would be due to the effect of drug pressure, human population movements or mosquito vector movement. This kind of study is important for drug developments and for evaluating the progress of the control programmes.

scholarly journals Differential susceptibility of Onchocerca volvulus microfilaria to ivermectin in two areas of contrasting history of mass drug administration in Cameroon: Relevance of microscopy and molecular techniques for the monitoring of skin microfilarial repopulation within six months of direct observed treatment

2020 ◽  
Author(s):  
Raphael Awah Abong ◽  
Glory N. Amambo ◽  
Patrick W. Chounna Ndongmo ◽  
Abdel Jelil Njouendou ◽  
Ritter Manuel ◽  
...  
Keyword(s):  
Real Time ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Real Time Pcr ◽  
Differential Susceptibility ◽  
Diagnostic Techniques ◽  
Molecular Techniques ◽  
Onchocerca Volvulus ◽  
Density Reduction ◽  
Low Sensitivity

Abstract Background. Ivermectin is an excellent microfilaricide against Onchocerca volvulus. However, in some regions, long term use of ivermectin has resulted in sub-optimal responses to the treatment. More data to properly document the phenomenon in various contexts of ivermectin mass drug administration (IVM-MDA) is needed. Also, there is a need to accurately monitor a possible repopulation of skin by microfilariae following treatment. Skin snip microscopy is known to have a low sensitivity in individuals with light infections, which can be the case following treatment. This study was designed with two complementary objectives: (i) to assess the susceptibility of O. volvulus microfilariae to ivermectin in two areas undergoing IVM-MDA for different lengths of time, and (ii) to document the repopulation of skin by the O. volvulus microfilariae following treatment, using 3 independent diagnostic techniques. Method. Identified microfilaridermic individuals were treated with ivermectin and re-examined after 1, 3, and 6 months using microscopy, actin real-time PCR (actinqPCR) and O-150 LAMP assays. Susceptibility to ivermectin and trends in detecting reappearance of skin microfilariae were determined using three techniques. Microscopy was used as an imperfect gold standard to determine the performance of actin-qPCR and LAMP. Results. In Bafia with over 20 years of IVM-MDA, 11/51 (21.6%) direct observe treated microfilaridemic participants were still positive for skin microfilariae after 1 month. In Melong, with 10 years of IVM-MDA, 2/29 (6.9%) treated participants were still positive. The microfilarial density reduction per skin biopsy within one month following treatment was significantly lower in participants from Bafia. In both study sites, the molecular techniques detected higher proportions of infected individuals than microscopy at all monitoring time points. LAMP demonstrated the highest levels of sensitivity and real-time PCR was found to have the highest specificity. Conclusion. Patterns in skin mirofilariae clearance and repopulation were established. O. volvulus worms from Bafia with higher number of annual MDA displayed a lower clearance and higher repopulation rate after treatment with ivermectin. Molecular assays displayed higher sensitivity in monitoring O. volvulus microfilaridemia within six months following treatment.

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