Molecular xenomonitoring of diurnally subperiodic Wuchereria bancrofti infection in Aedes (Downsiomyia) niveus (Ludlow, 1903) after nine rounds of Mass Drug Administration in Nancowry Islands, Andaman and Nicobar Islands, India

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.

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

FUDMA Journal of Sciences ◽

10.33003/fjs-2020-0404-511 ◽

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.

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Elimination of diurnally sub-periodic Wuchereria bancrofti in Andaman and Nicobar Islands, India, using mass DEC-fortified salt as a supplementary intervention to MDA

Parasitology Research ◽

10.1007/s00436-020-06659-7 ◽

2020 ◽

Vol 119 (5) ◽

pp. 1467-1483 ◽

Cited By ~ 3

Author(s):

A. N. Shriram ◽

Addepalli Premkumar ◽

K. Krishnamoorthy ◽

Amitabha De ◽

S. K. Paul ◽

...

Keyword(s):

Wuchereria Bancrofti ◽

Andaman And Nicobar Islands ◽

Nicobar Islands

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Genetic variability of diurnally sub-periodic Wuchereria bancrofti in Nicobarese tribe of Nicobar group of Islands, Andaman and Nicobar Islands, India

Parasitology Research ◽

10.1007/s00436-008-0927-2 ◽

2008 ◽

Vol 103 (1) ◽

pp. 59-66 ◽

Cited By ~ 9

Author(s):

R. Dhamodharan ◽

M. K. Das ◽

S. L. Hoti ◽

P. K. Das ◽

A. P. Dash

Keyword(s):

Genetic Variability ◽

Wuchereria Bancrofti ◽

Andaman And Nicobar Islands ◽

Nicobar Islands

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

Parasites & Vectors ◽

10.1186/1756-3305-6-247 ◽

2013 ◽

Vol 6 (1) ◽

Cited By ~ 15

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

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

10.1101/648220 ◽

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.

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