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Journal of Vector Borne Diseases Apr 2024Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. A study was conducted to identify the...
BACKGROUND OBJECTIVES
Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. A study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence.
METHODS
Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version.
RESULTS
83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the remaining were Culex and Ar-migeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1%, respectively. 54.5% of the bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean=11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps.
INTERPRETATION CONCLUSION
Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.
Topics: Animals; Bangladesh; Dengue; Aedes; Mosquito Control; Mosquito Vectors; Chikungunya Fever; Larva; Pupa; Sasa; Culex; Humans
PubMed: 38922657
DOI: 10.4103/jvbd.jvbd_152_23 -
Journal of Vector Borne Diseases Apr 2024In Port Blair, the capital of Andaman & Nicobar Islands, in the Bay of Bengal, India, there was a sudden increase in fever cases resembling the symptoms of dengue in the...
BACKGROUND OBJECTIVES
In Port Blair, the capital of Andaman & Nicobar Islands, in the Bay of Bengal, India, there was a sudden increase in fever cases resembling the symptoms of dengue in the monsoon period of 2022. Hence, an investigation was carried out to find out epidemiological and entomological reasons behind the outbreak.
METHODS
An entomological survey was carried out in 24 wards of Port Blair Municipal Council (PBMC) area, epidemiological data of last six years (January-December 2017-2021 and January-October 2022) and patient details of the year 2022 were collected. Both the epidemiological and entomological data were analyzed concerning time and place.
RESULTS
During this outbreak period tyres (22.4%) came out as a major breeding habitat followed by small discarded materials (17.5%), metal drums (15.3%), and plastic drums (11.7%). In rainy season, peri-domestic breeding (55%) was more than the domestic breeding (45%) habitat. Ae. aegypti had a high preference for indoor large containers (100-1000 L) like plastic tank, metal drum and cement tank whereasAe. albopictus prefers to breed in medium sized plastic container (20-100 L) and outdoor water receptacles like tyres, flower pots, and domestic discarded materials.
INTERPRETATION CONCLUSION
By source reduction, indoor space spray and outdoor fogging, vector density was controlled which curtailed the transmission and within eight weeks a decreasing trend of dengue cases was noticed. A regular entomological survey is crucial to know the seasonality and key breeding habitats of the vector for proper planning of vector control.
Topics: India; Dengue; Animals; Humans; Disease Outbreaks; Aedes; Mosquito Vectors; Seasons; Ecosystem; Female; Male; Adult; Adolescent; Young Adult; Child; Middle Aged; Islands; Dengue Virus; Child, Preschool
PubMed: 38922656
DOI: 10.4103/jvbd.jvbd_144_23 -
Journal of Vector Borne Diseases Apr 2024Malaria remains a major public health concern in Nigeria and the vector (Anopheles species) can only be controlled effectively by having good knowledge of its...
BACKGROUND OBJECTIVES
Malaria remains a major public health concern in Nigeria and the vector (Anopheles species) can only be controlled effectively by having good knowledge of its composition and potential for disease transmission. This work aimed at surveying indoor malaria vectors and, Knowledge, Attitudes, and Practices (KAP) in relation to disease transmission in Toro LGA, Bauchi State, Nigeria.
METHODS
Mosquitoes were collected by Pyrethrum Spray Catch (PSC) between October and December 2019 and were morphologically identified using standard keys. Blood samples were collected from individuals who slept in the rooms where PSC was conducted. Thick and thin blood smears were made for malaria parasite examination. Questionnaires were administered to 120 participants for the KAP studies.
RESULTS
Ninety-seven Anopheles mosquitoes were collected and identified as Anopheles gambiae 76 (78.35%), An. funestus 20 (20.62%) and An. coustani 1(1.03%). The overall malaria prevalence was 15.8%. KAP studies revealed that measures and treatment-seeking behaviours against malaria varied significantly (P<0.05) among the respondents. Sleeping under a net 55 (45.8%) and use of insecticides 24 (20.0%) were some of the preventive measures highlighted while the treatment-seeking behaviours included visit to a pharmacy 74 (61.7%) and use of local herbs 11 (9.2%).
INTERPRETATION CONCLUSION
This work revealed that An. gambiae and An. funestus are predominant malaria vectors in the area. The KAP information demonstrated fair knowledge about the disease by the respondents. Therefore, public enlightenment about malaria prevention, control and treatment is recommended to address the few but highly negative impact knowledge gaps about malaria.
Topics: Nigeria; Health Knowledge, Attitudes, Practice; Animals; Humans; Malaria; Anopheles; Mosquito Vectors; Female; Male; Adult; Young Adult; Surveys and Questionnaires; Mosquito Control; Middle Aged; Adolescent; Prevalence
PubMed: 38922651
DOI: 10.4103/jvbd.jvbd_66_23 -
Journal of Vector Borne Diseases Apr 2024The incidence of Dengue Hemorrhagic Fever (DHF) continues to increase over time in the world, including Indonesia. One of the prevention efforts against dengue virus...
BACKGROUND OBJECTIVES
The incidence of Dengue Hemorrhagic Fever (DHF) continues to increase over time in the world, including Indonesia. One of the prevention efforts against dengue virus transmission is to avoid vector mosquito bites by the use of repellants. Using repellents can reduce exposure to mosquito bites that may cause infection with the dengue virus. This study aimed to determine the effectiveness of repellent lotion composed of patchouli batik extract (Pogostemon cablin) from Southeast Sulawesi varieties against Aedes aegypti mosquitoes.
METHODS
The research subjects were Aedes aegypti adult mosquitoes. The research consisted of three stages. The first stage was a phytochemical test (qualitative method), the second stage was the analysis of patchouli essential oil (GC-MS method) and the third stage was a test of the effectiveness of lotions made from patchouli extract in lotion preparations against Aedes aegypti.
RESULTS
The results of the effectiveness test of patchouli leaf repellent (Pogestemon cablin) lotion preparations were as follows: for a concentration of 2.5%, protective power 81.5%; concentration 5%, protection power 83.67%; concentration 7.5%, protection power 88.64 %; the concentration of 10%, protection power 90.44%, and the concentration of 12.5% had protection power 90.89%. Probit analysis and linear regression showed the value of ProbitLc 50 was 6.631.
INTERPRETATION CONCLUSION
The results of the effectiveness test of Pogestemon cablin repellent lotion preparations with the most effective concentrations were 10% and 12.5%. The results of ANOVA test indicated there was no difference in the average value of the protection power in patchouli leaves.
Topics: Animals; Aedes; Insect Repellents; Pogostemon; Indonesia; Plant Extracts; Oils, Volatile; Female; Mosquito Vectors; Plant Leaves; Gas Chromatography-Mass Spectrometry
PubMed: 38922650
DOI: 10.4103/jvbd.jvbd_38_22 -
Journal of Vector Borne Diseases Apr 2024Despite significant progress in malaria control throughout India, Chhattisgarh state continues to be a significant contributor to both malaria morbidity and mortality.... (Review)
Review
BACKGROUND OBJECTIVES
Despite significant progress in malaria control throughout India, Chhattisgarh state continues to be a significant contributor to both malaria morbidity and mortality. This study aims to identify key factors associated with malaria endemicity, with a goal of focusing on these factors for malaria elimination by 2030.
METHODS
We employed an analysis and narrative review methodology to summarize the existing evidence on malaria epidemiology in Chhattisgarh. Data encompassing environmental conditions, dominant malaria vectors and their distribution, and the impact of previous interventions on malaria control, were extracted from published literature using PubMed and Google Scholar. This information was subsequently correlated with malaria incidence data using appropriate statistical and geographical methods.
RESULTS
Much of the malaria burden in Chhattisgarh state is concentrated in a few specific districts. The primary malaria vectors in these regions are Anopheles culicifacies and An. fluviatilis. High transmission areas are found in tribal belts which are challenging to access and are characterized by densely forested areas that provide a conducive habitat for malaria vectors.
INTERPRETATION CONCLUSION
Conducive environmental conditions characterized by high forest cover, community behavior, and insurgency, contribute to high malaria endemicity in the area. Challenges include insecticide resistance in malaria vectors and asymptomatic malaria. Allocating additional resources to high-endemic districts is crucial. Innovative and focused malaria control programs of the country, such as DAMAN and Malaria Mukt Abhiyan, hold immense importance.
Topics: India; Humans; Malaria; Animals; Anopheles; Mosquito Vectors; Mosquito Control; Disease Eradication; Incidence; Insecticide Resistance
PubMed: 38922649
DOI: 10.4103/jvbd.jvbd_167_23 -
Anais Da Academia Brasileira de Ciencias 2024The genus Flavivirus comprises approximately 80 different viruses. Phylogenetic relationships among its members indicate a clear ecological separation between those...
The genus Flavivirus comprises approximately 80 different viruses. Phylogenetic relationships among its members indicate a clear ecological separation between those viruses transmitted by mosquitoes, ticks, with no known vector, and insect-specific Flaviviruses. The diversity and phylogenetic relationships among insect-specific flaviviruses circulating in the central and northern regions of Argentina were studied by performing molecular detection and characterization of the NS5 protein gene in mosquitoes collected in Córdoba, Chaco and Tucumán provinces. Overall, 68 out of 1776 pools were positive. CxFV, KRV and CFAV circulate in the 3 studied provinces. Several mosquito species (Aedes aegypti, Culex bidens, Cx. dolosus, Cx. interfor, Cx. quinquefasciatus, Cx. saltanensis, Haemagogus spegazzini) were found infected. A wide circulation of CxFV was observed in the central-northern region of Argentina. CxFV strains detected in our study clustered with strains circulating in Santa Fe and Buenos Aires provinces (Argentina), and other countries such as Indonesia, Mexico, Uganda and Taiwan. The presence of these viruses in mosquitoes could play an important role from the public health perspective, because it has been shown that previous CxFV infection can increase or block the infection of the mosquito by other pathogenic flaviviruses.
Topics: Animals; Argentina; Flavivirus; Culicidae; Phylogeny; Mosquito Vectors
PubMed: 38922274
DOI: 10.1590/0001-3765202420230452 -
Pathogens (Basel, Switzerland) Jun 2024Rift Valley fever virus (RVFV) is an adaptable arbovirus that can be transmitted by a wide variety of arthropods. Widespread urban transmission of RVFV has not yet...
Rift Valley fever virus (RVFV) is an adaptable arbovirus that can be transmitted by a wide variety of arthropods. Widespread urban transmission of RVFV has not yet occurred, but peri-urban outbreaks of RVFV have recently been documented in East Africa. We previously reported low-level exposure in urban communities and highlighted the risk of introduction via live animal influx. We deployed a slaughtered animal testing framework in response to an early warning system at two urban slaughterhouses and tested animals entering the meat value chain for anti-RVFV IgG and IgM antibodies. We simultaneously trapped mosquitoes for RVFV and bloodmeal testing. Out of 923 animals tested, an 8.5% IgG seroprevalence was identified but no evidence of recent livestock exposure was detected. Mosquito species abundance varied greatly by slaughterhouse site, which explained 52% of the variance in blood meals. We captured many spp., a known RVFV amplifying vector, at one of the sites ( < 0.001), and this species had the most diverse blood meals. No mosquito pools tested positive for RVFV antigen using a rapid VecTOR test. These results expand understanding of potential RVF urban disease ecology, and highlight that slaughterhouses are key locations for future surveillance, modelling, and monitoring efforts.
PubMed: 38921786
DOI: 10.3390/pathogens13060488 -
Insects Jun 2024Arthropod vectors are responsible for a multitude of human and animal diseases affecting poor communities in sub-Saharan Africa. Their control still relies on chemical...
Arthropod vectors are responsible for a multitude of human and animal diseases affecting poor communities in sub-Saharan Africa. Their control still relies on chemical agents, despite growing evidence of insecticide resistance and environmental health concerns. Biorational agents, such as the entomopathogenic fungus , might be an alternative for vector control. Recently, the isolate ICIPE 7 has been developed into a commercial product in Kenya for control of ticks on cattle. We were interested in assessing the potential of controlling not only ticks but also disease-transmitting mosquitoes and tsetse flies using cattle as blood hosts, with the aim of developing a product for integrated vector management. Laboratory bioassays were carried out with , isolate ICIPE 7 and isolate ICIPE 30, to compare efficacy against laboratory-reared . ICIPE 7 was further tested against wild and spp. Dose-response tests were implemented, period of mosquito exposure was evaluated for effects on time to death, and the number of spores attached to exposed vectors was assessed. Exposure to 10 spores/mL of ICIPE 7 for 10 min resulted in a similar mortality of as exposure to ICIPE 30, albeit at a slower rate (12 vs. 8 days). The same ICIPE 7 concentration also resulted in mortalities of tsetse flies (LT: 16 days), tick nymphs (LT: 11 days), and adult ticks (LT: 20 days). Mosquito mortality was dose-dependent, with decreasing LT of 8 days at a concentration of 10 spores/mL to 6 days at 10 spores/mL. Exposure period did not modulate the outcome, 1 min of exposure still resulted in mortality, and spore attachment to vectors was dose-dependent. The laboratory bioassays confirmed that ICIPE 7 has the potential to infect and cause mortality to the three exposed arthropods, though at slower rate, thus requiring further validation under field conditions.
PubMed: 38921163
DOI: 10.3390/insects15060449 -
Parasites & Vectors Jun 2024The sand fly Nyssomyia neivai is one of the most abundant species in Southern Brazil. It is frequently found in areas that are foci of visceral leishmaniasis in the...
BACKGROUND
The sand fly Nyssomyia neivai is one of the most abundant species in Southern Brazil. It is frequently found in areas that are foci of visceral leishmaniasis in the state of Santa Catarina, caused by Leishmania infantum. In this region, the main vector of L. infantum, Lutzomyia longipalpis, has not been detected. In the absence of L. longipalpis, this study aimed to identify the sand fly fauna and diagnose any potential Leishmania spp. infection in sand flies and in dogs in a region of Southern Brazil that experienced a recent canine visceral leishmaniasis outbreak.
METHODS
This report includes a survey of the sand fly fauna at the Zoonosis Control Center of the Municipality of Tubarão (Santa Catarina, Brazil). Molecular tests were conducted to investigate Leishmania spp. natural infection in sand flies using polymerase chain reaction (PCR). In positive females, in addition to morphological identification, molecular analysis through DNA barcoding was performed to determine the sand fly species. Additionally, the dogs were tested for the presence of Leishmania spp. using a non-invasive technique for the collection of biological material, to be assessed by PCR.
RESULTS
A total of 3419 sand flies, belonging to five genera, were collected. Nyssomyia neivai was the most abundant species (85.8%), followed by Migonemyia migonei (13.3%), Pintomyia fischeri (0.8%), Evandromyia edwardsi (< 0.1%), and species of the genus Brumptomyia. (0.1%). Out of the 509 non-engorged females analyzed by PCR, two (0.4%) carried L. infantum DNA. The naturally infected females were identified as Ny. neivai, in both morphological and molecular analysis. In addition, two out of 47 conjunctival swabs from dogs tested positive for L. infantum, yielding an infection rate of 4.2%.
CONCLUSIONS
These results confirm the presence of Ny. neivai naturally infected with L. infantum in an area where dogs were also infected by the parasite, suggesting its potential role as a vector in Southern Brazil.
Topics: Animals; Dogs; Leishmania infantum; Brazil; Psychodidae; Dog Diseases; Leishmaniasis, Visceral; Female; Insect Vectors; Polymerase Chain Reaction; Male
PubMed: 38918858
DOI: 10.1186/s13071-024-06336-z -
Parasites & Vectors Jun 2024Past findings demonstrate that arthropods can egest midgut microbiota into the host skin leading to dual colonization of the vertebrate host with pathogens and saliva...
BACKGROUND
Past findings demonstrate that arthropods can egest midgut microbiota into the host skin leading to dual colonization of the vertebrate host with pathogens and saliva microbiome. A knowledge gap exists on how the saliva microbiome interacts with the pathogen in the saliva. To fill this gap, we need to first define the microbial composition of mosquito saliva.
METHODS
The current study aimed at analyzing and comparing the microbial profile of Aedes albopictus saliva and midgut as well as assessing the impact of Zika virus (ZIKV) infection on the midgut and saliva microbial composition. Colony-reared Ae. albopictus strains were either exposed to ZIKV infectious or noninfectious bloodmeal. At 14 ays postinfection, the 16S V3-V4 hypervariable rRNA region was amplified from midgut and saliva samples and sequenced on an Illumina MiSeq platform. The relative abundance and diversity of midgut and saliva microbial taxa were assessed.
RESULTS
We observed a richer microbial community in the saliva compared with the midgut, yet some of the microbial taxa were common in the midgut and saliva. ZIKV infection did not impact the microbial diversity of midgut or saliva. Further, we identified Elizabethkingia spp. in the Ae. albopictus saliva.
CONCLUSIONS
This study provides insights into the microbial community of the Ae. albopictus saliva as well as the influence of ZIKV infection on the microbial composition of its midgut and saliva. The identification of Elizabethkingia spp., an emerging pathogen of global health significance, in Ae. albopictus saliva is of medical importance. Future studies to assess the interactions between Ae. albopictus saliva microbiome and ZIKV could lead to novel strategies for developing transmission barrier tools.
Topics: Animals; Saliva; Aedes; Zika Virus; Mosquito Vectors; Microbiota; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Female; Zika Virus Infection; Gastrointestinal Tract
PubMed: 38918848
DOI: 10.1186/s13071-024-06334-1