scholarly journals Filariasis Control in Coastal Nigeria: Predictive Significance of Baseline Entomological Indices of Anopheles gambiae s.l. (Diptera: Culicidae)

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Dominic Ibe ◽  
Gloria N. Wokem
Keyword(s):  
Anopheles Gambiae ◽  
Rainy Season ◽  
Light Trap ◽  
Control Programme ◽  
Dry Season ◽  
Human Landing Catch ◽  
Transmission Potential ◽  
Biting Rate ◽  
Human Landing ◽  
Anopheles Gambiae S.L

This work aimed at collecting filariasis transmission data of Anopheles gambiae to be used in predicting future trends in filariasis transmission and control programme outcomes. Collection of the mosquitoes was made by human landing catch and light trap methods. In all, 5,813 females were caught from September 2005 to August 2006. Mosquito population started to expand at the onset of the rains. The highest density was found after peak temperature. The A. gambiae s.l. biting peaked around midnight; 39.7% were parous and 0.3% were infective. The highest percentage of parous females caught was near midnight, ranging between 42.0% and 47.5% from 22.00 to 03.00 hours. Biting rate in the rainy season was 2.6 times higher than it in the dry season. Transmission potential was 3.6 times higher during the rains than during the dry season. The percentage infectivity was relatively high (13.2%) in June, corresponding to 8.8 infective bites per person per month. All infective A. gambiae, were caught between 22.00 and 03.00 hours. The average load of L3 larvae per infective A. gambiae was 1.4 L3/mosquito. The monthly transmission potential calculated for each month indicated that transmission was ongoing for most of the months of the year, especially in the rainy season.

scholarly journals The Abundance and Biting Patterns of Culex quinquefasciatus Say (Culicidae) in the Coastal Region of Nigeria

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Gloria N. Wokem ◽  
Christiana Okonofua
Keyword(s):  
Culex Quinquefasciatus ◽  
Rainy Season ◽  
Coastal Region ◽  
Dry Season ◽  
Human Landing Catch ◽  
Light Traps ◽  
Transmission Potential ◽  
Human Landing ◽  
The Mean

This study was aimed at determining the abundance and biting patterns of Culex quinquefasciatus in the coastal region of Nigeria. Collections were done by human landing catch and by CDC miniature light traps from September 2005 to August 2006. A total of 3798 C. quinquefasciatus females were collected. The highest number of females was caught in the month of August and it represented nearly a quarter (24.0%) of the total females collected. In all, 38.8% of females dissected were parous. The abundance of C. quinquefasciatus followed the pattern of rainfall with the population starting to expand at the onset of the rains. The highest increase was found after the temperature had peaked. The mean of biting was 3.2 times more in the rainy season than in the dry season, whereas the transmission potential was higher in the dry season. C. quinquefasciatus is presently regarded as a biting nuisance having no significant epidemiological importance yet. Efforts at its control should be intensified before it is too late.

Seasonal Transmitting Potential of Malaria Vectors in Six Communities in Ekiti State, Nigeria

2021 ◽  
Vol 42 (1) ◽  
pp. 107-117
Author(s):  
O.F. Olorunniyi ◽  
O.A. Idowu ◽  
A.B. Idowu ◽  
O.R. Pitan ◽  
T.S. Oyeniyi ◽  
...  
Keyword(s):  
Rainy Season ◽  
Strong Relationship ◽  
Control Programme ◽  
Dry Season ◽  
Malaria Vectors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chain Reactions ◽  
Anopheles Mosquitoes ◽  
Polymerase Chain Reactions ◽  
Multistage Sampling

Malaria vectors are found virtually in all communities of Nigeria. Understanding the transmitting potential of these vectors in  relationship with the malaria parasite (MP) infection is essential to design a sustainable community base control programme. This study aimed at determining this relationship in six communities in Ekiti State, Nigeria. The communities were randomly selected through a multistage sampling. Blood samples were screened for MPinfection among human volunteers during dry and rainy seasons in each community. Adult mosquitoes were collected indoors for twelve months in the communities using light traps. Female  Anopheles mosquitoes collected were characterized by Polymerase Chain Reactions and circumsporozoite proteins of the infected mosquitoes were detected by Enzyme-Linked Immunosorbent Assay. Prevalence of MP infection, human biting rates (HBR), sporozoite rates and entomological inoculation rates (EIRs) were determined using appropriate formulae. Overall prevalence of MPinfection was 26% in dry season and 38% in rainy season (P=0.001). Female Anopheles mosquitoes collected were 428. Strong relationship existed between HBR and MP infection in rainy  season (R2 = 0.671) but the relationship was weak (R2 = 0.209) in dry season. Sporozoites were detected in 2.3% of the female Anopheles mosquitoes collected. EIRs were between 0.100 - 0.252 infective bites/person/night.  Transmission of malaria parasites occurred throughout the year particularly during rainy season when there were recorded EIRs. Malaria control interventions will be more appropriate during raining season in this region. Keywords: Anophelesmosquitoes, Nigeria, transmission, malaria, season

scholarly journals Seasonality, parity rates and transmission indices of Mansonella ozzardi (Manson) (Nematoda: Onchocercidae) by Cerqueirellum argentiscutum (Shelley & Luna Dias) (Diptera: Simulidae) in a lower Solimões River community, Amazonas, Brazil

2004 ◽  
Vol 34 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Jansen Fernandes de Medeiros ◽  
Victor Py-Daniel
Keyword(s):  
Infection Rate ◽  
Rainy Season ◽  
Parasitic Infection ◽  
Black Flies ◽  
Transmission Potential ◽  
Biting Rate ◽  
Solimões River

Mansonella ozzardi is transmitted by two dipterian families, Ceratopogonidae (midges) and Simuliidae (black flies). In Brazil, black flies are vectors for this filariasis until now. In this paper, we determined the seasonality, parity capacity and parasitic infection rate of Cerqueirellum argentiscutum. The work was carried out in the Porto Japão community, Lower Solimões River, Amazonas, Brazil. Results show that the black flies were more abundant during the rainy season (from December to May). The number of parous flies was higher in every sampling during the course of year. Monthly Biting Rate (MBR1 123742.00, MBR2 86701.50) was high, although Parasitic Infection Rate (PIR1 0.06, PIR2 0.08) and Annual Transmission Potential (ATP 7.25) were low in numbers.

scholarly journals Morphological changes in the spiracles of Anopheles gambiae s.l (Diptera) as a response to the dry season conditions in Burkina Faso (West Africa)

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Wadaka Mamai ◽  
Karine Mouline ◽  
Jean-Philippe Parvy ◽  
Jo Le Lannic ◽  
Kounbobr Roch Dabiré ◽  
...  
Keyword(s):  
West Africa ◽  
Burkina Faso ◽  
Anopheles Gambiae ◽  
Morphological Changes ◽  
Dry Season ◽  
Anopheles Gambiae S.L

scholarly journals The Epidemiological Implications of Deer Fly Nuisance Biting and Transmission of Loiasis in an Endemic Area in Southeastern Nigeria

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Emmanuel Chukwunenye Uttah
Keyword(s):  
Endemic Area ◽  
Southeastern Nigeria ◽  
Transmission Potential ◽  
Biting Rate ◽  
Human Landing ◽  
Two Peaks

This work was aimed at determining the epidemiological implications of deer fly biting in Southeastern Nigeria and ascertaining the circadian and monthly biting pattern and the transmission potential of Chrysops in the area. Human-landing catches were carried out for 52 weeks by a catching team of four. A total of 930 female Chrysops sp. was caught; biting peaked during the months of June through August. The highest monthly biting rate (MBR) was 353 bites per person per month in July 2006. The annual biting rate (ABR) was 3,317 bites per person per year. The overall infective rate was 3.8%. A total of 314 L3s was recorded with a mean of 9.8 L3s per infective Chrysops. The highest monthly transmission potential (MTP) was 389 infective bites per month observed in July 2006. The annual transmission potential (ATP) was 1,265 infective bites per person per year. Parous rate was 29.3% and was higher during dry months of October through February. The circadian biting activities showed two peaks: between 07:00 and 10:00 hours and between 15:00 and 17:00 hours. The epidemiological implications of deer fly biting in the area are multifaceted. Resources must not be spared in bringing an end to their menace.

scholarly journals Comparative Human Landing Catch and CDC Light Trap in Mosquito Sampling in Knowlesi Malaria Endemic Areas in Peninsula Malaysia

2016 ◽  
Vol 04 (01) ◽  
pp. 1-10 ◽  
Author(s):  
Ahmad Rohani ◽  
Abd Rahman Aidil Azahary ◽  
Mohamed Nor Zurainee ◽  
Wan Mohd Ali Wan Najdah ◽  
Ismail Zamree ◽  
...  
Keyword(s):  
Light Trap ◽  
Human Landing Catch ◽  
Cdc Light Trap ◽  
Mosquito Sampling ◽  
Human Landing ◽  
Endemic Areas

The Centres for Disease Control Light Trap (CDC LT) and The Human Decoy Trap (HDT) Compared to The Human Landing Catch (HLC) for Measuring Anopheles Biting in Rural Tanzania

2021 ◽  
Author(s):  
Isaac Haggai Namango ◽  
Carly Marshall ◽  
Adam Saddler ◽  
Amanda Ross ◽  
David Kaftan ◽  
...  
Keyword(s):  
Disease Control ◽  
Large Scale ◽  
Geometric Mean ◽  
Light Trap ◽  
Malaria Vectors ◽  
Human Landing Catch ◽  
Mosquito Abundance ◽  
Rural Tanzania ◽  
Human Landing ◽  
Control Light

Abstract BackgroundThe intensity of vector mosquito biting is an important measure for malaria epidemiology and control. The human landing catch (HLC) is an effective entomological surveillance tool, but is labour-intensive, expensive and raises safety issues. The Centres for Disease Control light trap (CDC LT) and the human decoy trap (HDT) are less costly and exposure-free alternatives. This study compared the CDC LT and HDT against the HLC for measuring Anopheles (An.) biting in rural Tanzania and assessed their suitability as HLC proxies.MethodsIndoor mosquito surveys using HLC and CDC LT and outdoor surveys using HLC and HDT were conducted in 2017 and in 2019 in Ulanga, Tanzania in 19 villages, with one trap per house per night. Species composition, sporozoite rates and the numbers of mosquitoes caught by different trap types were compared. Aggregating the data by village and month, the Bland-Altman approach was used to assess agreement. ResultsOverall, 66,807 Anopheles funestus and 14,606 An. arabiensis adult females were caught from 6,013 CDC LT, 339 indoor HLC, 136 HDT and 195 outdoor HLC collections. Overall, the CDC LT caught fewer malaria vectors than indoor HLC: An. arabiensis (Adjusted rate ratio (Adj.RR) =0.35 (95% confidence interval (CI):0.27-0.46)) and An. funestus (Adj.RR=0.63(95%CI:0.51-0.79)). HDT caught fewer malaria vectors than outdoor HLC: An. arabiensis (Adj.RR=0.04(95%CI:0.01-0.14)) and An. funestus (Adj.RR=0.10(95%CI:0.07-0.15)). The bias and variability of the ratios of geometric mean mosquitoes caught by CDC LT and HDT relative to HLC collections for the same village-month were dependent on mosquito densities. The relative efficacies of both CDC LT and HDT declined with mosquito abundance. The variability in the ratios was substantial for low HLC counts and decreased as mosquito abundance increased. CDCLT caught a higher proportion of infected An. arabiensis and An. funestus than HLC, and HDT caught no infected mosquitoes.ConclusionsIf caution is taken in appreciation of its limitations, the CDC LT is suitable for use in routine entomological surveys and may be preferable for measuring sporozoite rates for Afrotropical mosquitoes. Use of HLC is useful to estimate human exposure to mosquitoes for estimating Entomological Inoculation Rate (EIR). The present design of the HDT is not amenable for use to conduct large-scale entomological surveys.

scholarly journals Anopheles gambiae (s.l.) is found where few are looking: assessing mosquito diversity and density outside inhabited areas using diverse sampling methods

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Patric Stephane Epopa ◽  
Abdoul Azize Millogo ◽  
Catherine Matilda Collins ◽  
Ace R. North ◽  
Mark Quentin Benedict ◽  
...  
Keyword(s):  
Gene Flow ◽  
Anopheles Gambiae ◽  
Adult Mosquito ◽  
The Road ◽  
Resting Sites ◽  
Relative Evaluation ◽  
Host Seeking ◽  
Human Landing ◽  
Anopheles Gambiae S.L ◽  
To Come

Abstract Background One of the promising current approaches to curb malaria lies in genetic vector control, the implementation of which will require an improved understanding of the movement of genetic constructs among mosquito populations. To predict potential gene flow from one area to another, it is important to begin to understand mosquito dynamics outside of the commonly-sampled village areas, and thus how genes may move between villages. This study assessed the presence and relative abundance of mosquitoes in a 6-km corridor between two villages in western Burkina Faso. Methods The area surrounding the villages was mapped and the road between them was used as the basis of a transect along which to sample. Five collection points were placed along this transect. To investigate both larval and adult mosquito presence, multiple sampling approaches were used surrounding each point: searching for larval sites in an area of 500 m radius, swarm sampling, human landing catches (HLC), CDC light traps and backpack aspiration catches of potential resting sites. Sampling took place twice: in September and October 2015. Results Adult mosquitoes from six species of Anopheles and three other genera were found along the whole transect. Anopheles gambiae (s.l.) was the most abundant followed by Anopheles nili and Anopheles coustani. Larvae of Anopheles spp. were found in small pools of surface water along the whole transect, though their presence increased with human proximity. HLC and aspiration were the most efficient methods of collecting adult mosquitoes along the whole transect, indicating that there are both host-seeking and resting mosquitoes well away from core village areas. In contrast, swarms of male mosquitoes, thought to be the principle mating locations of Anopheles spp. mosquitoes in West Africa, were only found close to the core village areas. Conclusions This preliminary study indicates that Anopheles spp. mosquitoes are both present and breeding in low human-density areas along transit axes and provides both a relative evaluation of methods for use in these areas and evidence that gene flow between Sahelian population centres is likely. More robust and structured studies are nevertheless needed to come with stronger conclusions.

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