General Observations on Mosquitos in relation to Yellow Fever in the Anglo-Egyptian Sudan

1947 ◽  
Vol 37 (4) ◽  
pp. 543-566 ◽  
Author(s):  
D. J. Lewis

1. Owing to the history of yellow fever in the Sudan and the lines of communication which traverse the country, a general survey of the mosquitos, particularly the Culicines, is of practical interest. The known potential vectors of yellow fever are listed.2. Observations on the man-biting or man-ignoring habits of some species are recorded and also notes on the bionomics of Taeniorhynchus africanus, T. uniformis, Aëdes aegypti and other species.3. For purposes of description the country is divided into sub-divisions of the recognized faunal areas and notes are given on the Culicines of each.4. Brief observations are made on mosquito control measures against yellow fever.

2020 ◽  
Vol 57 (6) ◽  
pp. 1992-1996
Author(s):  
Natalie P Cataldo ◽  
C Suzanne Lea ◽  
Timothy Kelley ◽  
Stephanie L Richards

Abstract Aedes aegypti (L.) is the primary vector of Zika, dengue, yellow fever, and chikungunya viruses. Insecticides used in mosquito control can help prevent the spread of vector-borne diseases. However, it is essential to determine insecticide resistance (IR) status before control measures are undertaken. Only the most effective insecticides should be used to avoid ineffective control and/or promotion of IR. Pyrethroids and organophosphates are the most commonly used insecticides for mosquito control. Here, the efficacy of two active ingredients (AIs; permethrin [pyrethroid], chlorpyrifos [organophosphate]), two formulated products (FPs; Biomist [AI: permethrin]) and (Mosquitomist [AI: chlorpyrifos]), and three synergists (piperonyl butoxide, diethyl maleate, S-S-S-tributyl phosphorotrithioate) was evaluated in two Ae. aegypti colonies (pyrethroid resistant and susceptible). Mosquitomist was most effective against the pyrethroid-resistant colony (100% mortality at diagnostic time). Pre-exposure to synergists did not increase the efficacy of AIs against the pyrethroid-resistant colony. Further research is needed to discover how synergists may affect the efficacy of insecticides when used on pyrethroid-resistant mosquitoes.


2005 ◽  
Vol 37 (6) ◽  
pp. 761-771 ◽  
Author(s):  
JOSEPH KEATING ◽  
KATE MACINTYRE ◽  
CHARLES M. MBOGO ◽  
JOHN I. GITHURE ◽  
JOHN C. BEIER

A geographically stratified cross-sectional survey was conducted in 2002 to investigate household-level factors associated with use of mosquito control measures and self-reported malaria in Malindi, Kenya. A total of 629 households were surveyed. Logistic regressions were used to analyse the data. Half of all households (51%) reported all occupants using an insecticide-treated bed net and at least one additional mosquito control measure such as insecticides or removal of standing water. Forty-nine per cent reported a history of malaria in the household. Of the thirteen household factors analysed, low (OR=0·23, CI 0·11, 0·48) and medium (OR=0·50, CI 0·29, 0·86) education, mud–wood–coral (OR=0·0·39, CI 0·24, 0·66) and mud block–plaster (OR=0·47, CI 0·25, 0·87) wall types, farming (OR=1·38, CI 1·01, 1·90) and travel to rural areas (OR=0·48, CI 0·26, 0·91) were significantly associated with the use of mosquito control, while controlling for other covariates in the model. History of reported malaria was not associated with the use of mosquito control (OR=1·22, CI 0·79, 1·88). Of the thirteen covariates analysed in the second model, only two household factors were associated with history of malaria: being located in the well-drained stratum (OR=0·49, CI 0·26, 0·96) and being bitten while in the house (OR=1·22, CI 0·19, 0·49). These results suggest that high socioeconomic status is associated with increased household-level mosquito control use, although household-level control may not be enough, as many people are exposed to biting mosquitoes while away from the house and in areas that are more likely to harbour mosquitoes.


1942 ◽  
Vol 33 (4) ◽  
pp. 227-228
Author(s):  
D. J. Lewis

Outbreaks of yellow fever in the Anglo-Egyptian Sudan and Uganda in 1940 emphasised the necessity for the mosquito control measures which are in force to prevent the disease from reaching Egypt or the East African ports. Edwards (1941, Mosquitoes of the Ethiopian Region, III, p. 3), referring to yellow fever, states that “ it would seem that most of the common biting mosquitoes of West Africa are to be regarded as potentially dangerous.” This statement applies also to north-east Africa. For the further planning of control measures, more information is required as to which mosquitos can act as vectors. Transmission experiments can usually be carried out only in a few specially equipped laboratories, so that mosquitos must sometimes be transported over great distances. A convenient method of doing this is to carry several thousands of living larvae which can provide a supply of adults for experiments. The writer has, for several years, used the simple method described below and found it effective in the hot dry climate of the northern Sudan. Recently it proved useful for sending larvae of species of Aëdes to the Yellow Fever Reseaich Institute at Entebbe.Larvae are stranded on a wet surface in a cool damp atmosphere and can be carried under these conditions for many hours or even several days. Perforated trays are made from the metal of petrol tins as shown in Fig. 1. A piece of cloth 44 cm. square is laid over each tray and tied underneath it. Water containing the larvae is poured into the tray and drains away, leaving the larvae stranded. A metal cross-piece laid on the tray serves to support another tray above it. Eight trays can be placed in a four gallon petrol tin which is then closed with a lid. In hot weather a wet towel may be wrapped round the tin.


2021 ◽  
Vol 45 ◽  
Author(s):  
Jacina Walker ◽  
Alyssa Pyke ◽  
Paul Florian ◽  
Fred Moore ◽  
Nicolas Smoll ◽  
...  

Objective(s): To describe an autochthonous dengue virus type 2 (DENV-2) outbreak in Central Queensland from May 2019 and subsequent public health actions. Design and setting: Public health outbreak investigation of locally acquired DENV-2 cases in Rockhampton, Central Queensland. This included laboratory investigations, associated mosquito vector surveillance, and control measures implemented in response to the outbreak. Results: Twenty-one locally-acquired DENV-2 cases were identified during the Rockhampton outbreak (from 23 May to 7 October 2019): 13 laboratory-confirmed and eight probable cases. Clinical symptoms included lethargy (100%); fever (95%); headache (95%); and aches and pains (90%). Inspections of premises demonstrated that <i>Aedes aegypti</i> was present in 9.5% of those investigated which was more than half of the premises identified as containing mosquitoes. Nucleotide sequencing of a DENV-2 isolate recovered from the first confirmed case and DENV-2 RNA from an additional 5 patients indicated a single DENV-2 strain was responsible for the outbreak which was most closely related to DENV-2 strains from Southeast Asia. Conclusions: The 2019 DENV-2 outbreak in Rockhampton, Central Queensland, Australia, likely resulted from the importation of a strain, most closely related to DENV-2 strains from Southeast Asia and is the first reported outbreak in the region specifically implicating DENV-2. Given the presence of <i>Aedes aegypti</i> in Rockhampton, appropriate medical and mosquito avoidance advice; ongoing surveillance; and deployment of mosquito control strategies for the prevention of dengue and other mosquito-borne diseases should be priorities for this region.


1998 ◽  
Vol 37 (01) ◽  
pp. 97-108 ◽  
Author(s):  
S. Subramanian ◽  
P. K. Das ◽  
W. Souza ◽  
T. Lapa ◽  
A. F. Furtado ◽  
...  

Abstract:The LYMFASIM modeling framework for the transmission and control of the tropical parasitic disease lymphatic filariasis is described and its use in the context of an endemic community in north-eastern Brazil is illustrated. Lymphatic filariasis is a disease with a complex natural history with many unknowns. This complicates decision making with respect to control strategies. With LYMFASIM, a variety of hypotheses can be tested about the life history of the parasite Wuchereria bancrofti, its transmission from man to man through mosquitoes, the role of the immune system in regulating parasite numbers, the development of disease symptoms, and the effects of control measures (drug treatment or mosquito control). The implications of alternative assumptions and uncertainty about the quantification of parameters for the effectiveness of control strategies can be investigated. Thanks to the use of stochastic microsimulation, LYMFASIM is highly flexible and can be adapted and extended as new knowledge emerges.


2008 ◽  
Vol 33 (1) ◽  
pp. 76-88 ◽  
Author(s):  
Adriana Troyo ◽  
Olger Calderón-Arguedas ◽  
Douglas O. Fuller ◽  
Mayra E. Solano ◽  
Adrian Avendaño ◽  
...  

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 575 ◽  
Author(s):  
Rosilainy S. Fernandes ◽  
Olivia O’Connor ◽  
Maria Ignez L. Bersot ◽  
Dominique Girault ◽  
Marguerite R. Dokunengo ◽  
...  

Zika virus (ZIKV) has caused severe epidemics in South America beginning in 2015, following its spread through the Pacific. We comparatively assessed the vector competence of ten populations of Aedes aegypti and Ae. albopictus from Brazil and two of Ae. aegypti and one of Culex quinquefasciatus from New Caledonia to transmit three ZIKV isolates belonging to African, Asian and American lineages. Recently colonized mosquitoes from eight distinct sites from both countries were orally challenged with the same viral load (107 TCID50/mL) and examined after 7, 14 and 21 days. Cx. quinquefasciatus was refractory to infection with all virus strains. In contrast, although competence varied with geographical origin, Brazilian and New Caledonian Ae. aegypti could transmit the three ZIKV lineages, with a strong advantage for the African lineage (the only one reaching saliva one-week after challenge). Brazilian Ae. albopictus populations were less competent than Ae. aegypti populations. Ae. albopictus generally exhibited almost no transmission for Asian and American lineages, but was efficient in transmitting the African ZIKV. Viral surveillance and mosquito control measures must be strengthened to avoid the spread of new ZIKV lineages and minimize the transmission of viruses currently circulating.


2019 ◽  
Vol 20 (2) ◽  
pp. 468-473
Author(s):  
TANAWAT CHAIPHONGPACHARA

Abstract. Chaiphongpachara T. 2019. Short Communication: A checklist of the mosquito species (Diptera: Culicidae) in the Suan Phueng District, Ratchaburi Province, Thailand. Biodiversitas 20: 468-473. Mosquito is a medically important insect, which is a vector to transmit pathogens to humans. There are several methods to reduce the numbers mosquitoes, which requires entomological knowledge. It is critical to know the species of mosquitoes in the area to choose the most suitable method to provide vector control, specifically, to target mosquito species. In this study, we investigated the species of mosquito vectors in the Huay Nam Nak Village in the Suan Phueng District, Ratchaburi Province, Thailand, which is an endemic area of mosquito-borne diseases, especially malaria and dengue fever. Mosquito species were collected by the Mosquito Magnet® Independence trap from the Huay Nam Nak Village. A total of 1,002 mosquitoes, divided into eight species in four genera, including Anopheles barbirostris s.l. van der Wulp (118 individuals), An. subpictus s.l. Grassi (127 individuals), Culex quinquefasciatus Say (186 individuals), Cx. vishnui Theobald (204 individuals), Cx. whitmorei Giles (198 individuals), Aedes aegypti Linnaeus (45 individuals), Ae. albopictus Skuse (78 individuals), and Armigeres subalbatus Coquillett (46 individuals). This checklist of the mosquito species is very important information to set mosquito control measures that suit each area.


2020 ◽  
Vol 14 (11) ◽  
pp. e0008846
Author(s):  
Abdullah A. Alomar ◽  
Bradley H. Eastmond ◽  
Barry W. Alto

Zika virus (ZIKV) is an emerging mosquito-borne pathogen that can cause global public health threats. In the absence of effective antiviral medications, prevention measures rely largely on reducing the number of adult mosquito vectors by targeting juvenile stages. Despite the importance of juvenile mosquito control measures in reducing adult population size, a full understanding of the effects of these measures in determining mosquito phenotypic traits and in mosquito-arbovirus interactions is poorly understood. Pyriproxyfen is a juvenile hormone analog that primarily blocks adult emergence, but does not cause mortality in larvae. This mechanism has the potential to work in combination with other juvenile sources of mortality in nature such as predation to affect mosquito populations. Here, we experimentally evaluated the effects of juvenile exposure to pyriproxyfen and predatory mosquito Toxorhynchites rutilus on Aedes aegypti phenotypes including susceptibility to ZIKV infection and transmission. We discovered that combined effects of pyriproxyfen and Tx. rutilus led to higher inhibition of adult emergence in Ae. aegypti than observed in pyriproxyfen or Tx. rutilus treatments alone. Adult body size was larger in treatments containing Tx. rutilus and in treatments mimicking the daily mortality of predation compared to control or pyriproxyfen treatments. Susceptibility to infection with ZIKV in Ae. aegypti was reduced in predator treatment relative to those exposed to pyriproxyfen. Disseminated infection, transmission, and titers of ZIKV in Ae. aegypti were similar in all treatments relative to controls. Our data suggest that the combination of pyriproxyfen and Tx. rutilus can inhibit adult Ae. aegypti emergence but may confer a fitness advantage in survivors and does not inhibit their vector competence for ZIKV relative to controls. Understanding the ultimate consequences of juvenile mosquito control measures on subsequent adults’ ability to transmit pathogens is critical to fully understand their overall impacts.


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