bims-mosdis 2023-04-23 papers

bims-mosdis

Biomed News

on Mosquito distribution and disease

Issue of 2023–04–23
ten papers selected by
Richard Halfpenny, Staffordshire University

Burden of mosquito-borne diseases across rural versus urban areas in Cameroon between 2002 and 2021: prospective for community-oriented vector management approaches.
Insecticide resistance status of Aedes aegypti and Aedes albopictus mosquitoes in southern Benin, West Africa.
Jamestown Canyon virus (Bunyavirales: Peribunyaviridae) vector ecology in a focus of human transmission in New Hampshire, USA.
Vector competence of Anopheles stephensi for O'nyong-nyong virus: a risk for global virus spread.
Insecticide resistance status of Aedes aegypti in southern and northern Ghana.
Ensemble species distribution modeling of Culex tarsalis (Diptera: Culicidae) in the continental United States.
Community perceptions on challenges and solutions to implement an Aedes aegypti control project in Ponce, Puerto Rico (USA).
Dengue and zika seropositivity, burden, endemicity, and cocirculation antibodies in Nigeria.
Phylogenetic Analysis of Transmission Dynamics of Dengue in Large and Small Population Centers, Northern Ecuador.
Malaria and environmental, socioeconomics and public health conditions in the municipality of São Félix do Xingu, Pará, Eastern Amazon, Brazil: An ecological and cross-sectional study.

Parasit Vectors. 2023 Apr 19. 16(1): 136

Burden of mosquito-borne diseases across rural versus urban areas in Cameroon between 2002 and 2021: prospective for community-oriented vector management approaches.

Leo Dilane Alenou, Philippe Nwane, Lili Ranaise Mbakop, Michael Piameu, Wolfgang Ekoko, Stanislas Mandeng, Elisabeth Ngo Bikoy, Jean Claude Toto, Hugues Onguina, Josiane Etang.

   BACKGROUND: Over the past two decades, Cameroon has recorded one of the highest rates of urban population growth in sub-Saharan Africa. It is estimated that more than 67% of Cameroon's urban population lives in slums, and the situation is far from improving as these neighbourhoods are growing at an annual rate of 5.5%. However, it is not known how this rapid and uncontrolled urbanization affects vector populations and disease transmission in urban versus rural areas. In this study, we analyse data from studies conducted on mosquito-borne diseases in Cameroon between 2002 and 2021 to determine the distribution of mosquito species and the prevalence of diseases they transmit with regards to urban areas versus rural areas.
METHODS: A search of various online databases, such as PubMed, Hinari, Google and Google Scholar, was conducted for relevant articles. A total of 85 publications/reports were identified and reviewed for entomological and epidemiological data from the ten regions of Cameroon.
RESULTS: Analysis of the findings from the reviewed articles revealed 10 diseases transmitted by mosquitoes to humans across the study regions. Most of these diseases were recorded in the Northwest Region, followed by the North, Far North and Eastern Regions. Data were collected from 37 urban and 28 rural sites. In the urban areas, dengue prevalence increased from 14.55% (95% confidence interval [CI] 5.2-23.9%) in 2002-2011 to 29.84% (95% CI 21-38.7%) in 2012-2021. In rural areas, diseases such as Lymphatic filariasis and Rift valley fever, which were not present in 2002-2011, appeared in 2012-2021, with a prevalence of 0.4% (95% CI 0.0- 2.4%) and 10% (95% CI 0.6-19.4%), respectively. Malaria prevalence remained the same in urban areas (67%; 95% CI 55.6-78.4%) between the two periods, while it significantly decreased in rural areas from 45.87% (95% CI 31.1-60.6%) in 2002-2011 to 39% (95% CI 23.7-54.3%) in the 2012-2021 period (*P = 0.04). Seventeen species of mosquitoes were identified as involved in the transmission of these diseases, of which 11 were involved in the transmission of malaria, five in the transmission of arboviruses and one in the transmission of malaria and lymphatic filariasis. The diversity of mosquito species was greater in rural areas than in urban areas during both periods. Of the articles reviewed for the 2012-2021 period, 56% reported the presence of Anopheles gambiae sensu lato in urban areas compared to 42% reported in 2002-2011. The presence of Aedes aegypti increased in urban areas in 2012-2021 but this species was absent in rural areas. Ownership of long-lasting insecticidal nets varied greatly from one setting to another.
CONCLUSIONS: The current findings suggest that, in addition to malaria control strategies, vector-borne disease control approaches in Cameroon should include strategies against lymphatic filariasis and Rift Valley fever in rural areas, and against dengue and Zika viruses in urban areas.

Keywords:  Arbovirus diseases; Cameroon; Mosquitoes; Plasmodium spp.; Urban and rural areas

DOI:  https://doi.org/10.1186/s13071-023-05737-w
Trop Med Health. 2023 Apr 21. 51(1): 22

Insecticide resistance status of Aedes aegypti and Aedes albopictus mosquitoes in southern Benin, West Africa.

Alphonse Keller Konkon, Germain Gil Padonou, Razaki Osse, Albert Sourou Salako, David Mahouton Zoungbédji, Haziz Sina, Arthur Sovi, Filemon Tokponnon, Rock Aïkpon, Herbert Noukpo, Lamine Baba-Moussa, Martin Codjo Akogbéto.

   BACKGROUND: The emergence of insecticide resistance in Aedes mosquitoes could undermine efforts to control arboviruses. The present study aims to assess in some communes of Southern Benin, the susceptibility level of Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) to insecticides commonly used in public health, as well as mechanisms involved.
METHODS: Females Ae. albopictus and Ae. aegypti collected in Ifangni, Porto-Novo, Avrankou, Adjarra and Kétou from June 2021 to October 2022, were exposed to: deltamethrin 0.05%, permethrin 0.75%, alpha-cypermethrin 0.05%, pirimiphos methyl 0.25% and bendiocarb 0.1%, following the standard WHO susceptibility tube test protocol. In some sites, pre-exposure to the synergist PBO was used to verify if pyrethroid resistance of populations of Aedes was mediated by oxidases.
RESULTS: Full susceptibility to deltamethrin and permethrin was observed in all tested populations of Ae. albopictus. However, with alphacypermethrin, a suspected resistance was observed in Adjarra (94.67%), Ifangni (93%) and Porto-Novo (94%), and a resistance in Avrankou (83%). The PBO-alphacypermethrin tests performed, led to a full susceptibility (100%) in all four sites, which confirms the full involvement of oxidases in resistance of all tested populations of Ae. albopictus to alphacypermethrin. At the opposite, Aedes aegypti was either resistant or suspected of being resistant to all tested pyrethroids in all four sites, except in Ifangni where a full susceptibility to alphacypermethrin was observed. The full susceptibility of Ae. aegypti to bendiocarb and pirimiphos-methyl in all communes suggests that these two insecticides can be good candidates for an effective control of pyrethroid-resistant Aedes vector populations. Use of permethrin and deltamethrin could also be considered for controlling populations of Ae. albopictus.
CONCLUSION: Results of the present study will help guide strategy to implement for an effective control of Aedes vector populations in Benin.

Keywords:  Aedes aegypti; Aedes albopictus; Benin; Insecticide resistance diagnostics

DOI:  https://doi.org/10.1186/s41182-023-00514-y
J Med Entomol. 2023 Apr 18. pii: tjad046. [Epub ahead of print]

Jamestown Canyon virus (Bunyavirales: Peribunyaviridae) vector ecology in a focus of human transmission in New Hampshire, USA.

Joseph D Poggi, Colin Conery, Abigail Mathewson, Denise Bolton, Rebecca Lovell, Laura C Harrington, Marco Notarangelo.

  Jamestown Canyon virus disease (JCVD) is a potentially neuroinvasive condition caused by the arbovirus Jamestown Canyon virus (JCV). Human cases of JCVD have increased in New Hampshire (NH) over the past decade, but vector surveillance is limited by funding and person power. We conducted mosquito surveillance with a focus on human JCVD cases south central NH during 2021. Routine surveillance with CDC miniature traps baited with CO2 (lights removed) was supplemented by a paired trapping design to test the collection efficiency of octenol, and New Jersey light traps. We performed virus testing, blood meal analysis, and compared morphological identification with DNA barcoding. Over 50,000 mosquitoes were collected representing 28 species. Twelve JCV-positive pools were derived from 6 species of more than 1,600 pools tested. Of those, Aedes excrucians/stimulans (MLE 4.95, Diptera: Culicidae, Walker, 1856, 1848), and Aedes sticticus (MLE 2.02, Meigen, 1838) had the highest JCV infection rates, and Aedes canadensis (MLE 0.13, Theobold, 1901) and Coquillettidia perturbans (0.10, Diptera: Culicidae, Walker, 1856) had the lowest infection rates. One hundred and fifty-one blood meals were matched to a vertebrate host. All putative vectors fed on the amplifying host of JCV, white-tailed deer (36-100% of bloodmeals). Putative vectors that fed on human hosts included Aedes excrucians (8%), Anopheles punctipennis (25%, Diptera: Culicidae, Say, 1823), and Coquillettidia perturbans (51%). CDC traps baited with CO2 were effective for collecting putative vectors. DNA barcoding enhanced morphological identifications of damaged specimens. We present the first ecological overview of JCV vectors in NH.

Keywords:  arbovirus; culicidae; ecology; jamestown canyon virus

DOI:  https://doi.org/10.1093/jme/tjad046
Parasit Vectors. 2023 Apr 17. 16(1): 133

Vector competence of Anopheles stephensi for O'nyong-nyong virus: a risk for global virus spread.

Maud Mutsaers, Cecilia Springer Engdahl, Lukas Wilkman, Clas Ahlm, Magnus Evander, Olivia Wesula Lwande.

   BACKGROUND: O'nyong-nyong virus (ONNV) is a mosquito-borne alphavirus causing sporadic outbreaks of febrile illness with rash and polyarthralgia. Up to now, ONNV has been restricted to Africa and only two competent vectors have been found, Anopheles gambiae and An. funestus, which are also known malaria vectors. With globalization and invasive mosquito species migrating to ONNV endemic areas, there is a possible risk of introduction of the virus to other countries and continents. Anopheles stephensi, is closely related to An. gambiae and one of the invasive mosquito species of Asian origin that is now present in the Horn of Africa and spreading further east. We hypothesize that An. stephensi, a known primary urban malaria vector, may also serve as a new possible vector for ONNV.
METHODS: One-week-old female adult An. stephensi were exposed to ONNV-infected blood, and the vector competence for ONNV, i.e. infection rates (IRs), dissemination rates (DRs), transmission rates (TRs), dissemination efficiency (DEs) and transmission efficiency (TEs), were evaluated. Infection (IRs), dissemination efficiency (DEs) and transmission efficiency (TEs) were determined. Detection of ONNV RNA was analysed by RT-qPCR in the thorax and abdomen, head, wings, legs and saliva of the infected mosquitoes at four different time points, day 7, 14, 21 and 28 after blood meal. Infectious virus in saliva was assessed by infection of Vero B4 cells.
RESULTS: The mean mortality across all sampling times was 27.3% (95 confidence interval [CI] 14.7-44.2%). The mean rate of infection across all sampling periods was 89.5% (95% CI 70.6-95.9). The mean dissemination rate across sampling intervals was 43.4% (95% CI 24.3-64.2%). The mean TR and TE across all mosquito sampling time intervals were 65.3 (95% CI 28.6-93.5) and 74.6 (95% CI 52.1-89.4). The IR was 100%, 79.3%, 78.6% and 100% respectively at 7, 14, 21 and 28 dpi. The DR was the highest at 7 dpi with 76.0%, followed by 28 dpi at 57.1%, 21 dpi at 27.3% and 14 dpi at the lowest DR of 13.04%. DE was 76%, 13.8%, 25%, 57.1% and TR was 79%, 50%, 57.1% and 75% at 7, 14, 21 and 28 dpi respectively. The TE was the highest at 28 dpi, with a proportion of 85.7%. For 7, 14 and 21 dpi the transmission efficiency was 72.0%, 65.5% and 75.0% respectively.
CONCLUSION: Anopheles stephensi is a competent vector for ONNV and being an invasive species spreading to different parts of the world will likely spread the virus to other regions.

Keywords:  Alphavirus; Anopheles stephensi; Arthritis; O’nyong-nyong virus; Vector competence

DOI:  https://doi.org/10.1186/s13071-023-05725-0
Parasit Vectors. 2023 Apr 18. 16(1): 135

Insecticide resistance status of Aedes aegypti in southern and northern Ghana.

Anisa Abdulai, Christopher Mfum Owusu-Asenso, Gabriel Akosah-Brempong, Abdul Rahim Mohammed, Isaac Kwame Sraku, Simon Kwaku Attah, Akua Obeng Forson, David Weetman, Yaw Asare Afrane.

   BACKGROUND: Outbreaks of Aedes-borne arboviral diseases are becoming rampant in Africa. In Ghana, there is no organized arboviral control programme with interventions restricted to mitigate outbreaks. Insecticide application is a crucial part of outbreak responses and future preventative control measures. Thus, knowledge of the resistance status and underlying mechanisms of Aedes populations is required to ensure optimal insecticide choices. The present study assessed the insecticide resistance status of Aedes aegypti populations from southern Ghana (Accra, Tema and Ada Foah) and northern Ghana (Navrongo) respectively.
METHODS: Phenotypic resistance was determined with WHO susceptibility tests using Ae. aegypti collected as larvae and reared into adults. Knockdown resistance (kdr) mutations were detected using allele-specific PCR. Synergist assays were performed with piperonyl butoxide (PBO) to investigate the possible involvement of metabolic mechanisms in resistance phenotypes.
RESULTS: Resistance to DDT was moderate to high across sites (11.3 to 75.8%) and, for the pyrethroids deltamethrin and permethrin, moderate resistance was detected (62.5 to 88.8%). The 1534C kdr and 1016I kdr alleles were common in all sites (0.65 to 1) and may be on a trajectory toward fixation. In addition, a third kdr mutant, V410L, was detected at lower frequencies (0.03 to 0.31). Pre-exposure to PBO significantly increased the susceptibility of Ae. aegypti to deltamethrin and permethrin (P < 0.001). This indicates that in addition to kdr mutants, metabolic enzymes (monooxygenases) may be involved in the resistance phenotypes observed in the Ae. aegypti populations in these sites.
CONCLUSION: Insecticide resistance underpinned by multiple mechanisms in Ae. aegypti indicates the need for surveillance to assist in developing appropriate vector control strategies for arboviral disease control in Ghana.

Keywords:  Aedes aegypti; Ghana; Insecticide resistance; Knockdown resistance; Piperonyl butoxide synergist; Target-site mutations

DOI:  https://doi.org/10.1186/s13071-023-05752-x
J Med Entomol. 2023 Apr 15. pii: tjad027. [Epub ahead of print]

Ensemble species distribution modeling of Culex tarsalis (Diptera: Culicidae) in the continental United States.

Charlotte G Rhodes, Luis F Chaves, Luke R Bergmann, Gabriel L Hamer.

  West Nile virus (WNV) is the primary mosquito-borne disease in the United States and has had case reports every year since its introduction in 1999. As such, it is critical that we characterize the distribution of WNV vectors. Estimates of Culex tarsalis Coquillett species distribution, a major WNV vector, are scarce. We used ensemble distribution modeling to estimate habitat suitability for this species across the contiguous United States by consolidating presence data from four publicly available mosquito trapping data servers. The central plains region and much of the western US were estimated to have high habitat suitability. We identified multiple metrics of temperature and precipitation to be important in predicting the occurrence of Cx. tarsalis in a given geographic area. Furthermore, we observed habitat suitability for Cx. tarsalis to be significantly higher in areas with a high incidence of West Nile neuroinvasive disease compared to areas with low WN disease incidence, suggesting that Cx. tarsalis is present in regions with a high incidence of disease.

Keywords:   Culex tarsalis ; NDVI; West Nile virus; google earth engine; machine learning

DOI:  https://doi.org/10.1093/jme/tjad027
PLoS One. 2023 ;18(4): e0284430

Community perceptions on challenges and solutions to implement an Aedes aegypti control project in Ponce, Puerto Rico (USA).

Carmen L Pérez-Guerra, Coral Rosado-Santiago, Sue A Ramos, Karla M Marrero, Gladys González-Zeno, Julieanne Miranda-Bermúdez, Marianyoly Ortíz-Ortíz, Vanessa Rivera-Amill, Stephen Waterman, Gabriela Paz-Bailey, Liliana Sánchez-González.

This study characterizes community perceptions on a large-scale project seeking to reduce the population of Aedes aegypti mosquitoes and prevent arboviral disease transmission in Ponce, Puerto Rico; and to leverage on these perceptions to make modifications to ensure effective project implementation. In 2017-2018 the team conducted informal interviews, focus groups, and in-depth interviews with leaders and residents of the communities, focusing on challenges and potential solutions to the project implementation. Possible challenges to the project implementation included the lack of geographic consistency between clusters defined by researchers and the participants' description of the communities' geographic boundaries. Few children living in the communities could affect the ability of the project to adequately measure arboviral disease incidence. Also, population attrition due to out-migration, and lack of community leaders and communication channels after Hurricane Maria could affect participation in project activities. Lack of trust on strangers was an important challenge due to criminal activity involving violence and drug use in some community areas. Solutions to the identified challenges included identifying emerging leaders and implementing community meetings to promote project activities. The information that community members provided helped us to understand the natural disasters' impact on population attrition in these communities with a disproportionate impact in younger groups, resulting in an aging population. We identified lack of community organization and leadership and increasing number of abandoned houses that could turn into Aedes aegypti breeding sites. The formative work helped to better define the geographic areas that the study would cover, evaluate the acceptability of innovative vector control methods, and identify communication methods used by residents. With this information, challenges and potential solutions in recruiting participants were anticipated, and the community engagement and communications plans were developed. We recommend selecting clusters before research, because opinions towards mosquito control technologies could vary in added clusters.

DOI: https://doi.org/10.1371/journal.pone.0284430
Ann Med. 2023 12;55(1): 652-662

Dengue and zika seropositivity, burden, endemicity, and cocirculation antibodies in Nigeria.

Peter Asaga Mac, Markos Tadele, Philomena E Airiohuodion, Thilini Nisansala, Shaistha Zubair, Jude Aigohbahi, Chukwuma Anyaike, Raman Velayudha, Axel Kroeger, Marcus Panning.

   INTRODUCTION: Mosquito-borne infections are of global health concern because of their rapid spread and upsurge, which creates a risk for coinfections. DENV and ZIKV are transmitted by Aedes aegypti and A. albopictus and are prevalent in Nigeria and neighbouring countries. However, their seroprevalence, burden, hidden endemicity and possible cocirculation are poorly understood in Nigeria.
METHODS: We conducted a cross-sectional study of 871 participants from three regions of Nigeria. All serum samples were analysed using malaria RDT and the immunoblot molecular diagnostic assay recomLine Tropical Fever for the presence of arboviral antibody serological marker IgG (Mikrogen Diagnostik, Neuried, Germany) with DENV and ZIKV Nonstructural protein 1 (NS 1), DENV and ZIKV Equad (variant of the envelope protein with designated mutations to increase specificity), according to the manufacturer's instructions.
RESULTS: The overall IgG antibody seropositivity against DENV-flavivirus was 44.7% (389/871); 95% CI (41.41-47.99), while ZIKV-flavivirus was 19.2% (167/871); 95% CI (0.16-0.21), and DENV-ZIKV-flavivirus cocirculation antibody seropositivity was 6.2%5 (54/871); 95% CI (0.6-0.7) in the three study regions of Nigeria. The study cohort presented similar clinical signs and symptoms of flaviviruses (DENV and ZIKV) in all three study regions.
CONCLUSION: This study highlighted an unexpectedly high antibody seropositivity, burden, hidden endemicity, and regional spread of mono- and co-circulating flaviviruses (DENV and ZIKV) in Nigeria.Key messagesDengue flavivirus sero-cross-reactivity drives antibody-dependent enhancement of ZIKV infection.Both viruses share common hosts (humans) and vectors (primarily Aedes aegypti), and are thus influenced by similar biological, ecological, and economic factors, resulting in epidemiological synergy.Additionally, the actual burden in epidemic and interepidemic periods is grossly or chronically unknown and underreported. Despite this trend and the potential public health threat, there are no reliable data, and little is known about these arboviral co-circulation infections.

Keywords:  Endemicity; Nigeria; burden; chikungunya; dengue; seroprevalence

DOI:  https://doi.org/10.1080/07853890.2023.2175903
Emerg Infect Dis. 2023 May;29(5): 888-897

Phylogenetic Analysis of Transmission Dynamics of Dengue in Large and Small Population Centers, Northern Ecuador.

Sully Márquez, Gwenyth Lee, Bernardo Gutiérrez, Shannon Bennett, Josefina Coloma, Joseph N S Eisenberg, Gabriel Trueba.

  Although dengue is typically considered an urban disease, rural communities are also at high risk. To clarify dynamics of dengue virus (DENV) transmission in settings with characteristics generally considered rural (e.g., lower population density, remoteness), we conducted a phylogenetic analysis in 6 communities in northwestern Ecuador. DENV RNA was detected by PCR in 121/488 serum samples collected from febrile case-patients during 2019-2021. Phylogenetic analysis of 27 samples from Ecuador and other countries in South America confirmed that DENV-1 circulated during May 2019-March 2020 and DENV-2 circulated during December 2020-July 2021. Combining locality and isolation dates, we found strong evidence that DENV entered Ecuador through the northern province of Esmeraldas. Phylogenetic patterns suggest that, within this province, communities with larger populations and commercial centers were more often the source of DENV but that smaller, remote communities also play a role in regional transmission dynamics.

Keywords:  Dengue; Ecuador; dengue virus; phylogenetics; remoteness; transmission; urban; vector-borne infections; viruses; whole-genome sequencing

DOI:  https://doi.org/10.3201/eid2905.221226
Rev Soc Bras Med Trop. 2023 ;pii: S0037-86822023000100315. [Epub ahead of print]56 e0502

Malaria and environmental, socioeconomics and public health conditions in the municipality of São Félix do Xingu, Pará, Eastern Amazon, Brazil: An ecological and cross-sectional study.

Nelson Veiga Gonçalves, Bruna Costa de Souza, Marília de Souza Araújo, Emerson Cordeiro Morais, Bruma Gouveia de Melo, Silvana Rossy de Brito, Maria de Fátima Pinheiro Carrera, Simone Beverly Nascimento da Costa, Taiana Moita Koury Alves, Thalita da Rocha Bastos, João Simão de Melo Neto, Claudia do Socorro Carvalho Miranda.

BACKGROUND: Malaria is a parasitosis conditioned by several factors. This study sought to analyze the spatial distribution of malaria considering environmental, socioeconomic, and political variables in São Félix do Xingu, Pará, Brazil, from 2014 to 2020.
METHODS: Epidemiological, cartographic, and environmental data were obtained from the Ministry of Health, Brazilian Geographical and Statistical Institute, and National Space Research Institute. Statistical and spatial distribution analyses were performed using chi-squared tests of expected equal proportions and the kernel and bivariate global Moran's techniques with Bioestat 5.0 and ArcGIS 10.5.1.
RESULTS: The highest percentage of cases occurred in adult males with brown skin color, mainly placer miners, with a primary education level, living in rural areas, who were infected with Plasmodium vivax and with parasitemia of two or three crosses as diagnosed by the thick drop/smear test. The disease had a non-homogeneous distribution, with distinct annual parasite indices associated with administrative districts and clusters of cases in locations with deforestation, mining, and pastures close to Conservation Units and Indigenous Lands. Thus, a direct relationship between areas with cases and environmental degradation associated with land use was demonstrated, along with the precarious availability of health services. Pressure on protected areas and epidemiological silence in Indigenous Lands were also noted.
CONCLUSIONS: Environmental and socioeconomic circuits were identified for development of diseases associated with precarious health services in the municipality. These findings highlight the need to intensify malaria surveillance and contribute to the systematic knowledge of malaria's epidemiology by considering the complexity of its conditioning factors.

DOI: https://doi.org/10.1590/0037-8682-0502-2022