scholarly journals An assessment of mosquito collection techniques for xenomonitoring of anopheline-transmitted Lymphatic Filariasis in Ghana

Parasitology ◽  
2018 ◽  
Vol 145 (13) ◽  
pp. 1783-1791 ◽  
Author(s):  
Millicent Opoku ◽  
Corrado Minetti ◽  
Worlasi D. Kartey-Attipoe ◽  
Sampson Otoo ◽  
Joseph Otchere ◽  
...  

AbstractMonitoring 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.

2020 ◽  
Vol 4 (2) ◽  
pp. 207-216
Author(s):  
A. A. Aliyu ◽  
G. J. Sow ◽  
I. S. Ndams

Entomological survey of mosquito vectors was carried out to determine species abundance and identify those responsible for the transmission of lymphatic filariasis in Talatan-mafara and Tsafe Local Government Areas of Zamfara State, Nigeria. Houses were randomly selected for mosquito collection. Aerosol (Baygon) was sprayed in the rooms to knockdown indoor resting mosquitoes. A total of 5,230 mosquitoes comprising of 3,104 females and 2,126 males were collected and 1,182 engorged females were dissected to isolate filarial worm, Wuchereria bancrofti. The species of mosquitoes encountered include Culex quinquefasciatus (84%), Anopheles funestus (10%) and Anopheles gambiae sl. (6%). The overall infection and infectivity rates of the mosquitoes with Wuchereria bancrofti were 1.86% and 1.44% respectively. The infection/infectivity rates of Culex quinquefasciatus, Anopheles funestus and Anopheles gambiae sl. were 1.01%/0.51%, 2.97%/2.97% and 4.54%/4.14% respectively.


2019 ◽  
Vol 14 (1-2) ◽  
pp. 159-173
Author(s):  
Darya Yu. Vashchenko

The article discusses the inscriptions on funerary monuments from the Croatian villages of Cunovo and Jarovce, located in the South of Slovakia, near Bratislava. These inscriptions reflect the complicated sociocultural situation in the region, which is particularly specific due to the fact that this territory was included to Slovakia’s territory only after 1946, while earlier the village was part of Hungary. In addition, the local Croatian ethnic group was actively in close contact with the German and Hungarian communities. At the same time, the orthographic norms of the literary Croatian, German, Hungarian, and Slovak languages, which could potentially be owned by the authors of the inscriptions, differ in many ways, despite the Latin alphabet used on all the gravestones. All this is reflected in the tombstones, representing a high degree of mixing codes. The article identifies the main types of fusion on the monuments: separate orthograms, writing the maiden name of the deceased in the spelling of her native language, the traditional spelling of the family name. In addition, the mixing of codes can be associated with writing feminitives, also order of name and surname within the anthroponym. Moreover, the settlements themselves represent different ethnic groups coexistence within the village. Gravestones from the respective cemeteries also differ from each other in the nature of the prevailing trend of the mixing codes. In Jarovce, where the ethnic groups live compactly, fusion is often presented as a separate foreign language orthograms. In Cunovo, where the ethnic groups constitute a global conglomerate, more traditional presents for a specific family spelling of the names on the monument.


2020 ◽  
Vol 13 (Supplement_1) ◽  
pp. S33-S38
Author(s):  
Gilberto Fontes ◽  
Eliana Maria Mauricio da Rocha ◽  
Ronaldo Guilherme Carvalho Scholte ◽  
Rubén Santiago Nicholls

Abstract In South and Central America, lymphatic filariasis (LF) is caused by Wuchereria bancrofti, which is transmitted by Culex quinquefasciatus, the only vector species in this region. Of the seven countries considered endemic for LF in the Americas in the last decade, Costa Rica, Suriname and Trinidad and Tobago were removed from the World Health Organization list in 2011. The remaining countries, Brazil, Dominican Republic, Guyana and Haiti, have achieved important progress in recent years. Brazil was the first country in the Americas to stop mass drug administration (MDA) and to establish post-MDA surveillance. Dominican Republic stopped MDA in all LF-endemic foci: La Ciénaga and Southwest passed the third Transmission Assessment Survey (TAS) and the Eastern focus passed TAS-1 in 2018. Haiti passed the TAS and interrupted transmission in >80% of endemic communes, achieving effective drug coverage. Guyana implemented effective coverage in MDAs in 2017 and 2018 and in 2019 scaled up the treatment for 100% of the geographical region, introducing ivermectin in the MDA in order to achieve LF elimination by the year 2026. The Americas region is on its way to eliminating LF transmission. However, efforts should be made to improve morbidity management to prevent disability of the already affected populations.


2021 ◽  
Vol 9 (8) ◽  
pp. 1630
Author(s):  
Min-Goo Seo ◽  
Byung-Eon Noh ◽  
Hak Seon Lee ◽  
Tae-Kyu Kim ◽  
Bong-Goo Song ◽  
...  

Since 2010, the Korea Disease Control and Prevention Agency has established centers at 16 locations to monitor disease vectors and pathogens. Here, we examined tick populations to understand the geographical and temporal distribution of severe fever with thrombocytopenia syndrome virus (SFTSV) vectors in 2020. From April to November, 63,376 ticks were collected from traps to monitor tick populations, with a trap index of 41.3. Tick incidence varied from April to October, with population peaks observed for nymphs in May, adults in July, and larvae in September. The predominant tick species were Haemaphysalis longicornis, Haemaphysalis spp., H. flava, Ixodes spp., Amblyomma testudinarium, and Ixodes nipponensis. Approximately 50% of the collected ticks were pooled into 2973 groups to detect the rate of SFTSV infection in ticks. The minimum infection rate (MIR) of SFTSV was 0.2%, and Andong had the highest MIR for SFTSV (4.0%). The B3 genotype was the most prevalent (52.2%) followed by B2 (28.6%), B5 (15.9%), B4 (1.6%), and B6 (1.6%). We identified widely distributed tick species and a high degree of diversity in SFTSV strains in ticks from different geographical regions. The results may provide a basis for future epidemiological studies and risk assessments for tick-borne diseases.


Author(s):  
Allassane F Ouattara ◽  
Catherine M Bjerum ◽  
Méité Aboulaye ◽  
Olivier Kouadio ◽  
Vanga K Marius ◽  
...  

Abstract Background Ivermectin (IVM) plus albendazole (ALB), or IA, is widely used in mass drug administration (MDA) programs that aim to eliminate lymphatic filariasis (LF) in Africa. However, IVM can cause severe adverse events in persons with heavy Loa loa infections that are common in Central Africa. ALB is safe in loiasis, but more information is needed on its efficacy for LF. This study compared the efficacy and safety of three years of semiannual treatment with ALB to annual IA in persons with bancroftian filariasis. Methods Adults with Wuchereria bancrofti microfilaremia (Mf) were randomized to receive either three annual doses of IA (N=52), six semiannual doses of ALB 400mg (N=45), or six semiannual doses of ALB 800mg (N=47). The primary outcome amicrofilaremia at 36 months. Findings IA was more effective for completely clearing Mf than ALB 400mg or ALB 800mg (79%, CI 67-91; vs. 48%, CI 32-66 and 57%, CI 41-73, respectively). Mean % reductions in Mf counts at 36 months relative to baseline tended to be greater after IA (98%, CI 88-100) than after ALB 400mg (88%, CI 78-98) and ALB 800mg (89%, CI 79-99) (P=0.07 and P=0.06, respectively). Adult worm nest numbers (assessed by ultrasound) were reduced in all treatment groups. Treatments were well tolerated. Interpretation Repeated semiannual treatment with ALB is macrofilaricidal for W. bancrofti and leads to sustained reductions in Mf counts. This is a safe and effective regimen that could be used as MDA to eliminate LF in areas ivermectin cannot be used.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Eliza Lupenza ◽  
Dinah B. Gasarasi ◽  
Omary M. Minzi

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.


Parasitology ◽  
2000 ◽  
Vol 121 (S1) ◽  
pp. S147-S160 ◽  
Author(s):  
J. HORTON ◽  
C. WITT ◽  
E.A. OTTESEN ◽  
J.K. LAZDINS ◽  
D.G. ADDISS ◽  
...  

This review of the safety of the co-administration regimens to be used in programmes to eliminate lymphatic filariasis (albendazole+ivermectin or albendazole+diethylcarbamazine [DEC]) is based on 17 studies conducted in Sri Lanka, India, Haiti, Ghana, Tanzania, Kenya, Ecuador, the Philippines, Gabon, Papua New Guinea, and Bangladesh. The total data set comprises 90635 subject exposures and includes individuals of all ages and both genders. Results are presented for hospital-based studies, laboratory studies, active surveillance of microfilaria-positive and microfilaria-negative individuals, and passive monitoring in both community-based studies and mass treatment programmes of individuals treated with albendazole (n=1538), ivermectin (9822), DEC (576), albendazole+ivermectin (7470), albendazole+DEC (69020), or placebo (1144). The most rigorous monitoring, which includes haematological and biochemical laboratory parameters pre- and post-treatment, provides no evidence that consistent changes are induced by any treatment; the majority of abnormalities appear to be sporadic, and the addition of albendazole to either ivermectin or DEC does not increase the frequency of abnormalities. Both DEC and ivermectin show, as expected, an adverse event profile compatible with the destruction of microfilariae. The addition of albendazole to either single-drug treatment regimen does not appear to increase the frequency or intensity of events seen with these microfilaricidal drugs when used alone. Direct observations indicated that the level of adverse events, both frequency and intensity, was correlated with the level of microfilaraemia. In non microfilaraemic individuals, who form 80–90% of the ‘at risk’ populations to be treated in most national public health programmes to eliminate lymphatic filariasis (LF), the event profile with the compounds alone or in combination does not differ significantly from that of placebo. Data on the use of ivermectin+albendazole in areas either of double infection (onchocerciasis and LF), or of loiais (with or without concurrent LF) are still inadequate and further studies are needed. Additional data are also recommended for populations infected with Brugia malayi, since most data thus far derive from populations infected with Wuchereria bancrofti.


2020 ◽  
Author(s):  
Triwibowo Ambar Garjito ◽  
Lulus Susanti ◽  
Mujiyono Mujiyono ◽  
Mega Tyas Prihatin ◽  
Dwi Susilo ◽  
...  

Abstract BackgroundSeveral methods exist to collect and assess the abundance of dengue vector mosquitoes, i.e. morning adult collection using an aspirator, pupal collection, various ovitraps, whole night collection using human landing methods, and larval collection. This diversity of methods might be a source of variability and lack of statistical significance when trying to correlate mosquito density and risk of dengue outbreak. There is also a lack of published data regarding the effectiveness of these methods MethodsA mosquito survey was conducted in 39 locations corresponding to 15 dengue endemic provinces in Indonesia. The larval surveys were performed by collecting at least a single Aedes larva from each container, and then reared up until hatching. Three adult mosquito sampling methods were also used, including morning resting collection, human landing collection, animal baited trap. All field samples were tested for dengue. Factor Analysis of Mixed Data (FAMD) was conducted to analyze the effectiveness of the collection methods against mosquito species and dengue incidence.ResultsA total of 44,675 mosquitoes were collected. The single larva method was the most efficient method. Out of a total of 89 dengue-positive pools, the most frequently encountered virus was DENV2, which made up half of the positive samples, followed by DENV3 and DENV1, respectively. FAMD showed that no correlation could be found between any methods and the presence of dengue virus in mosquitoes. Moreover, no correlation could be found between either any methods or the incidence.ConclusionsThere was no concistency in the efficacy of a given method and the incidence of dengue in the human population. There was no correlation between any of the parameters considered, i.e. method, incidence of dengue, location and presence of dengue virus in mosquitoes. This indicates that entomological factors are not reliable indicators.


2020 ◽  
Vol 83 ◽  
pp. 106431
Author(s):  
Nazeer Yasin ◽  
Hoti Sugerappa Laxmanappa ◽  
Uday M. Muddapur ◽  
Jennifer Cheruvathur ◽  
S.M. Uday Prakash ◽  
...  

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