bims-mosdis 2022-03-13 papers

bims-mosdis

Biomed News

on Mosquito distribution and disease

Issue of 2022–03–13
seventeen papers selected by
Richard Halfpenny, Staffordshire University

Surveillance and Control of Culex quinquefasciatus Using Autocidal Gravid Ovitraps.
Mosquito surveillance and the first record of morphological and molecular-based identification of invasive species Aedes (Stegomyia) aegypti (Diptera: Culicidae), southern Iran.
Insecticide Resistance in Aedes aegypti Varies Seasonally and Geographically in Texas/Mexico Border Cities.
The Early Warning and Response System (EWARS-TDR) for dengue outbreaks: can it also be applied to chikungunya and Zika outbreak warning?
Temperature, season, and latitude influence development-related phenotypes of Philippine Aedes aegypti (Linnaeus): Implications for dengue control amidst global warming.
Detection and molecular characterization of West Nile virus in Culex pipiens mosquitoes in Central Macedonia, Greece, 2019-2021.
West Nile Virus and Eastern Equine Encephalitis Virus High Probability Habitat Identification for the Selection of Sentinel Chicken Surveillance Sites in Florida.
The Potential to Address Disease Vectors in Favelas in Brazil Using Sustainable Drainage Systems: Zika, Drainage and Greywater Management.
Effects of land use and weather on the presence and abundance of mosquito-borne disease vectors in a urban and agricultural landscape in Eastern Ontario, Canada.
Population Genetic Analysis of Aedes aegypti Mosquitoes From Sudan Revealed Recent Independent Colonization Events by the Two Subspecies.
Evaluating malaria prevalence and land cover across varying transmission intensity in Tanzania using a cross-sectional survey of school-aged children.
Temporal Monitoring and Predicting of the Abundance of Malaria Vectors Using Time Series Analysis of Remote Sensing Data through Google Earth Engine.
Detection of temporal, spatial and spatiotemporal clustering of malaria incidence in northwest Ethiopia, 2012-2020.
Magnitude of urban malaria and its associated risk factors: the case of Batu town, Oromia Regional State, Ethiopia.
Author Correction: Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector.
Spatiotemporal analysis of dengue fever in Burkina Faso from 2016 to 2019.
Characterising spatial patterns of neglected tropical disease transmission using integrated sero-surveillance in Northern Ghana.

J Am Mosq Control Assoc. 2022 Mar 01. 38(1): 19-23

Surveillance and Control of Culex quinquefasciatus Using Autocidal Gravid Ovitraps.

Roberto Barrera, Veronica Acevedo, Manuel Amador.

  We monitored trap captures of Culex quinquefasciatus using an interrupted time-series study to determine if autocidal gravid ovitraps (AGO traps) were useful to control the population of this mosquito species in a community in southern Puerto Rico. Data for this report came from a previous study in which we used mass trapping to control Aedes aegypti, resulting in a significant 79% reduction in numbers of this species. The AGO traps used to monitor and control Ae. aegypti also captured numerous Cx. quinquefasciatus. Culex quinquefasciatus was monitored in surveillance AGO traps from October 2011 to February 2013, followed by a mosquito control intervention from February 2013 to June 2014. Optimal captures of this mosquito occurred on the 2nd wk after the traps were set or serviced, which happened every 8 wk. Changes in collection numbers of Cx. quinquefasciatus were positively correlated with rainfall and showed oscillations every 8 wk, as revealed by sample autocorrelation analyses. Culex quinquefasciatus was attracted to and captured by AGO traps, so mass trapping caused a significant but moderate reduction of the local population (31.2%) in comparison with previous results for Ae. aegypti, possibly resulting from female mosquitoes flying in from outside of the study area and decreased attraction to the traps past the 2nd wk of trap servicing. Because Ae. aegypti and Cx. quinquefasciatus are frequently established in urban areas, mass trapping to control the former has some impact on Cx. quinquefasciatus. Control of the latter could be improved by locating and treating its aquatic habitats within and around the community.

Keywords:   Aedes aegypti ; Culex quinquefasciatus ; Puerto Rico; mass trapping; mosquito control

DOI:  https://doi.org/10.2987/21-7046
Exp Parasitol. 2022 Mar 02. pii: S0014-4894(22)00029-7. [Epub ahead of print] 108235

Mosquito surveillance and the first record of morphological and molecular-based identification of invasive species Aedes (Stegomyia) aegypti (Diptera: Culicidae), southern Iran.

Hedayat Dorzaban, Aboozar Soltani, Hamzeh Alipour, Jafar Hatami, Seyed Aghil Jaberhashemi, Marziae Shahriari-Namadi, Azim Paksa, Reza Safari, Asghar Talbalaghi, Kourosh Azizi.

  Ae. aegypti is an important vector for transmission of some dangerous arboviral diseases, including Dengue Fever. The present study was conducted (from August 2017 to January 2020) to survey the fauna of Culicine mosquitoes, emphasizing the existence of this invasive species in oriental parts of the country located near the Persian Gulf. Different sampling methods were used to collect all life stages of the mosquito. After morphological identification, a molecular study based on Cytochrome Oxidase (COI) gene-specific primers was performed. Then, the COI gene was sequenced via the Sanger method. A total of 4843 adults and 11,873 larvae were collected (8 species of Culex, one species of Culiseta, and 5 species of Aedes). Fifty-five Ae. aegypti specimens (8 adults and 47 larvae) were identified.Based on the biology and ecological requirements of Ae. aegypti, the possibility of the permanent establishment of this species in the tropical climate of the region is very likely. Considering the detection of this invasive vector mosquito species in Iran and the high incidence of some arboviral diseases in the neighboring countries, and continuous movements of the settlers of these areas, potential outbreaks of arboviral diseases can be predicted. Planning and implementing an immediate surveillance and control program of the vector mosquito is vital to prevent the permanent establishment of this invasive vector mosquito species in southern Iran.

Keywords:  Ae. aegypti; COI gene; Dengue fever; Iran; Vector surveillance

DOI:  https://doi.org/10.1016/j.exppara.2022.108235
J Am Mosq Control Assoc. 2022 Mar 01. 38(1): 59-69

Insecticide Resistance in Aedes aegypti Varies Seasonally and Geographically in Texas/Mexico Border Cities.

Heather M Hernandez, Flor A Martinez, Christopher J Vitek.

  Insecticide use is the primary method of attempting to reduce or control the spread of mosquito-borne diseases. Insecticide resistance is a major concern as resistance will limit the efficacy of vector-control efforts. The lower Rio Grande Valley region of South Texas has had autochthonous transmission of multiple mosquito-borne diseases including those caused by dengue virus, chikungunya virus, and Zika virus. However, the current status of mosquito resistance to commonly used pesticides in this region is unknown. In this study, we collected field samples from multiple municipalities in South Texas and assessed resistance using the Centers for Disease Control and Prevention bottle bioassay. All populations exhibited characteristics of resistance, and permethrin was the most effective insecticide with an average mortality rate of 44.78%. Deltamethrin and sumethrin had significantly lower mortality rates of 20.31% and 32.16%, respectively, although neither of these insecticides are commonly used for vector-control activities in this region. Depending on which insecticide was used, there was little significance between each of the 7 cities. Seasonal variation in resistance was observed among the collection sites. Both deltamethrin and sumethrin exhibited an increase in susceptibility over the course of 10 months, while permethrin exhibited a decrease in susceptibility. These data highlight the need for further studies to determine if variations in resistance observed are repeated. The data and future findings may be useful in determining the most effective strategies for pesticide use and rotation.

Keywords:  Insecticide resistance; South Texas; mortality rates; mosquitoes; seasonal variation

DOI:  https://doi.org/10.2987/21-21-7034
BMC Infect Dis. 2022 Mar 07. 22(1): 235

The Early Warning and Response System (EWARS-TDR) for dengue outbreaks: can it also be applied to chikungunya and Zika outbreak warning?

Rocio Cardenas, Laith Hussain-Alkhateeb, David Benitez-Valladares, Gustavo Sánchez-Tejeda, Axel Kroeger.

   BACKGROUND: In the Americas, endemic countries for Aedes-borne diseases such as dengue, chikungunya, and Zika face great challenges particularly since the recent outbreaks of CHIKV and ZIKV, all transmitted by the same insect vectors Aedes aegypti and Ae. albopictus. The Special Program for Research and Training in Tropical Diseases (TDR-WHO) has developed together with partners an Early Warning and Response System (EWARS) for dengue outbreaks based on a variety of alarm signals with a high sensitivity and positive predictive value (PPV). The question is if this tool can also be used for the prediction of Zika and chikungunya outbreaks.
METHODOLOGY: We conducted in nine districts of Mexico and one large city in Colombia a retrospective analysis of epidemiological data (for the outbreak definition) and of climate and entomological data (as potential alarm indicators) produced by the national surveillance systems for dengue, chikungunya and Zika outbreak prediction covering the following outbreak years: for dengue 2012-2016, for Zika 2015-2017, for chikungunya 2014-2016. This period was divided into a "run in period" (to establish the "historical" pattern of the disease) and an "analysis period" (to identify sensitivity and PPV of outbreak prediction).
RESULTS: In Mexico, the sensitivity of alarm signals for correctly predicting an outbreak was 100% for dengue, and 97% for Zika (chikungunya data could not be obtained in Mexico); the PPV was 83% for dengue and 100% for Zika. The time period between alarm and start of the outbreak (i.e. the time available for early response activities) was for Zika 4-5 weeks. In Colombia the sensitivity of the outbreak prediction was 92% for dengue, 93% for chikungunya and 100% for Zika; the PPV was 68% for dengue, 92% for chikungunya and 54% for Zika; the prediction distance was for dengue 3-5 weeks, for chikungunya 10-13 weeks and for Zika 6-10 weeks.
CONCLUSION: EWARS demonstrated promising capability of timely disease outbreak prediction with an operational design likely to improve the coordination among stakeholders. However, the prediction validity varied substantially across different types of diseases and appeared less optimal in low endemic settings.

Keywords:  Chikungunya; Colombia; Dengue outbreak; Early warning; Mexico; Zika

DOI:  https://doi.org/10.1186/s12879-022-07197-6
Parasit Vectors. 2022 Mar 05. 15(1): 74

Temperature, season, and latitude influence development-related phenotypes of Philippine Aedes aegypti (Linnaeus): Implications for dengue control amidst global warming.

Frances Edillo, Rhoniel Ryan Ymbong, Alyssa Angel Bolneo, Ric Jacob Hernandez, Bianca Louise Fuentes, Garren Cortes, Joseph Cabrera, Jose Enrico Lazaro, Anavaj Sakuntabhai.

   BACKGROUND: Dengue is endemic in the Philippines. Aedes aegypti is the primary vector. This study aimed to determine the hatching behavior and viability of Ae. aegypti first-generation (F1) eggs when exposed to temperature and photoperiod regimes under laboratory conditions.
METHODS: Parental eggs were collected from selected highland and lowland sites in the Philippine big islands (Luzon, Visayas, and Mindanao) during the wet (2017-2018) and dry (2018) seasons. F1 egg cohorts were exposed separately in environmental chambers at 18, 25, and 38 °C with respective photoperiods for 6 weeks. Phenotypes (percent pharate larvae [PPL], hatch rates [HRs], and reproductive outputs [ROs]) were determined.
RESULTS: Results of multivariate analyses of variance (MANOVA) between seasons showed significant main effects of temperature, season, and big island on all phenotypes across all sites. Significant interaction effects between seasons on all phenotypes across sites were shown between or among (1) season and big island, (2) season and temperature, (3) big island and temperature, (4) season, big island, and temperature, (5) big island, altitude, and temperature, and (6) season, big island, altitude, and temperature. Factors associated with the big islands might include their ecology, available breeding sites, and day lengths due to latitudinal differences, although they were not measured in the field. MANOVA results within each season on all phenotypes across sites showed (1) significant main effects of big island and temperature, and (2) significant interaction effects between big island and temperature within the wet season and (3) between temperature and photoperiod within the dry season. PPL were highest at 18 °C and were formed even at 38 °C in both seasons. Pharate larvae might play an adaptive role in global warming, expanded distribution to highlands, and preponderance to transmit human diseases. HRs in both seasons were highest at 25 °C and lowest at 38 °C. ROs were highest at 25 °C in the wet season and at 18 °C in the dry season.
CONCLUSIONS: Temperature and latitude of Philippine big islands influenced the development-related phenotypes of Ae. aegypti in both seasons. The two seasons influenced the phenotypes and their interaction effects with big island and/or temperature and/or altitude. Recommendations include year-round enhanced 4S control strategies for mosquito vectors and water pipeline installation in rural highlands.

Keywords:  Aedes aegypti; Dengue; Development-related phenotype; Global warming; Hatching rate; Pharate larvae; Reproductive output

DOI:  https://doi.org/10.1186/s13071-022-05186-x
Acta Trop. 2022 Mar 07. pii: S0001-706X(22)00089-4. [Epub ahead of print] 106391

Detection and molecular characterization of West Nile virus in Culex pipiens mosquitoes in Central Macedonia, Greece, 2019-2021.

Katerina Tsioka, Sandra Gewehr, Stella Kalaitzopoulou, Styliani Pappa, Konstantina Stoikou, Spiros Mourelatos, Anna Papa.

  Since 2010 when West Nile virus (WNV) emerged in Greece, it causes seasonal outbreaks of human infections almost every year. During May-October of 2019-2021 a total number of 51,504 Culex pipiens mosquitoes were trapped in all seven regional units of Central Macedonia in northern Greece. They were grouped into 1099 pools and tested for WNV. The virus was detected in 5% of the mosquito pools (1.5%, 3.6% and 9.6% pools in 2019, 2020, and 2021, respectively), with significant rate differences among the regional units and years. The highest maximum likelihood estimation for WNV infection rates calculated per 1000 mosquitoes for 2019 and 2020 were 1.89 and 3.84 in Serres, and 7.08 for 2021 in Pella regional unit. Sixteen whole genome sequences were taken by applying a recently described PCR-based next generation sequencing protocol. Phylogenetic analysis showed that the sequences belonged to the Central European clade of WNV lineage 2, and that a virus strain introduced in Greece in 2019 continued to circulate and spread further during 2020-2021. The data are useful for public health and mosquito control programs' operational scheduling, while the whole genome sequences are an added value for molecular epidemiology and evolutionary studies.

Keywords:  Culex pipiens; Greece; West Nile virus; lineage 2, mosquito control

DOI:  https://doi.org/10.1016/j.actatropica.2022.106391
J Am Mosq Control Assoc. 2022 Mar 01. 38(1): 1-6

West Nile Virus and Eastern Equine Encephalitis Virus High Probability Habitat Identification for the Selection of Sentinel Chicken Surveillance Sites in Florida.

Sean P Beeman, Joni A Downs, Thomas R Unnasch, Robert S Unnasch.

  To mitigate the effects of West Nile virus (WNV) and eastern equine encephalitis virus (EEEV), the state of Florida conducts a serosurveillance program that uses sentinel chickens operated by mosquito control programs at numerous locations throughout the state. Coop locations were initially established to detect St. Louis encephalitis virus (SLEV), and coop placement was determined based on the location of human SLEV infections that occurred between 1959 and 1977. Since the introduction of WNV into Florida in 2001, WNV has surpassed SLEV as the primary arbovirus in Florida. Identifying high probability locations for WNV and EEEV transmission and relocating coops to areas of higher arbovirus activity would improve the sensitivity of the sentinel chicken surveillance program. Using 2 existing models, this study conducted an overlay analysis to identify areas with high probability habitats for both WNV and EEEV activity. This analysis identified approximately 7,800 km2 (about 4.5% of the state) as high probability habitat for supporting both WNV and EEEV transmission. Mosquito control programs can use the map resulting from this analysis to improve their sentinel chicken surveillance programs, increase the probability of virus detection, reduce operational costs, and allow for a faster, targeted response to virus detection.

Keywords:  Eastern equine encephalitis virus; West Nile virus; model; risk; surveillance

DOI:  https://doi.org/10.2987/21-7049
Int J Environ Res Public Health. 2022 Mar 01. pii: 2860. [Epub ahead of print]19(5):

The Potential to Address Disease Vectors in Favelas in Brazil Using Sustainable Drainage Systems: Zika, Drainage and Greywater Management.

Susanne M Charlesworth, Debora C Kligerman, Matthew Blackett, Frank Warwick.

  Residents of informal settlements, the world over, suffer consequences due to the lack of drainage and greywater management, impacting human and environmental health. In Brazil, the presence of the Aedes aegypti mosquito in urban areas promotes infections of the Zika virus as well as companion viruses, such as dengue, chikungunya and yellow fever. By using observation and interviews with the community, this paper shows how a simple sustainable drainage system approach could prevent the accumulation of on-street standing water, and thus reduce opportunities for the mosquito to breed and reduce infection rates. During the interview phase, it became apparent that underlying misinformation and misunderstandings prevail related to existing environmental conditions in favelas and the role of the mosquito in infecting residents. This inhibits recommendations made by professionals to reduce breeding opportunities for the disease vector. Whilst unrest is an issue in favelas, it is not the only issue preventing the human right to reliable, safe sanitation, including drainage. In "pacified" favelas which may be considered safe(r), the infrastructure is still poor and is not connected to the city-wide sanitation/treatment networks.

Keywords:  Brazil; Zika; favela; greywater; sustainable drainage systems (SuDS)

DOI:  https://doi.org/10.3390/ijerph19052860
PLoS One. 2022 ;17(3): e0262376

Effects of land use and weather on the presence and abundance of mosquito-borne disease vectors in a urban and agricultural landscape in Eastern Ontario, Canada.

Miarisoa Rindra Rakotoarinia, F Guillaume Blanchet, Dominique Gravel, David R Lapen, Patrick A Leighton, Nicholas H Ogden, Antoinette Ludwig.

Weather and land use can significantly impact mosquito abundance and presence, and by consequence, mosquito-borne disease (MBD) dynamics. Knowledge of vector ecology and mosquito species response to these drivers will help us better predict risk from MBD. In this study, we evaluated and compared the independent and combined effects of weather and land use on mosquito species occurrence and abundance in Eastern Ontario, Canada. Data on occurrence and abundance (245,591 individuals) of 30 mosquito species were obtained from mosquito capture at 85 field sites in 2017 and 2018. Environmental variables were extracted from weather and land use datasets in a 1-km buffer around trapping sites. The relative importance of weather and land use on mosquito abundance (for common species) or occurrence (for all species) was evaluated using multivariate hierarchical statistical models. Models incorporating both weather and land use performed better than models that include weather only for approximately half of species (59% for occurrence model and 50% for abundance model). Mosquito occurrence was mainly associated with temperature whereas abundance was associated with precipitation and temperature combined. Land use was more often associated with abundance than occurrence. For most species, occurrence and abundance were positively associated with forest cover but for some there was a negative association. Occurrence and abundance of some species (47% for occurrence model and 88% for abundance model) were positively associated with wetlands, but negatively associated with urban (Culiseta melanura and Anopheles walkeri) and agriculture (An. quadrimaculatus, Cs. minnesotae and An. walkeri) environments. This study provides predictive relationships between weather, land use and mosquito occurrence and abundance for a wide range of species including those that are currently uncommon, yet known as arboviruses vectors. Elucidation of these relationships has the potential to contribute to better prediction of MBD risk, and thus more efficiently targeted prevention and control measures.

DOI: https://doi.org/10.1371/journal.pone.0262376
Front Genet. 2022 ;13 825652

Population Genetic Analysis of Aedes aegypti Mosquitoes From Sudan Revealed Recent Independent Colonization Events by the Two Subspecies.

Mohammed-Ahmed B Elnour, Andrea Gloria-Soria, Rasha S Azrag, Abeer M Alkhaibari, Jeffrey R Powell, Bashir Salim.

  Increases in arbovirus outbreaks in Sudan are vectored by Aedes aegypti, raising the medical importance of this mosquito. We genotyped 12 microsatellite loci in four populations of Ae. aegypti from Sudan, two from the East and two from the West, and analyzed them together with a previously published database of 31 worldwide populations to infer population structure and investigate the demographic history of this species in Sudan. Our results revealed the presence of two genetically distinct subspecies of Ae. aegypti in Sudan. These are Ae. aegypti aegypti in Eastern Sudan and Ae. aegypti formosus in Western Sudan. Clustering analysis showed that mosquitoes from East Sudan are genetically homogeneous, while we found population substructure in West Sudan. In the global context our results indicate that Eastern Sudan populations are genetically closer to Asian and American populations, while Western Sudan populations are related to East and West African populations. Approximate Bayesian Computation Analysis supports a scenario in which Ae. aegypti entered Sudan in at least two independent occasions nearly 70-80 years ago. This study provides a baseline database that can be used to determine the likely origin of new introductions for this invasive species into Sudan. The presence of the two subspecies in the country should be consider when designing interventions, since they display different behaviors regarding epidemiologically relevant parameters, such as blood feeding preferences and ability to transmit disease.

Keywords:  Aedes aegypti; Sudan; genetic diversity; microsatellites; population genetics

DOI:  https://doi.org/10.3389/fgene.2022.825652
Malar J. 2022 Mar 09. 21(1): 80

Evaluating malaria prevalence and land cover across varying transmission intensity in Tanzania using a cross-sectional survey of school-aged children.

Cedar L Mitchell, Billy Ngasala, Mark M Janko, Frank Chacky, Jessie K Edwards, Brian W Pence, Ally Mohamed, Lwidiko E Mhamilawa, Twilumba Makene, Thwai Kyaw, Fabrizio Molteni, Humphrey Mkali, Ssanyu Nyinondi, Bilali Kabula, Naomi Serbantez, Erin L Eckert, Chonge Kitojo, Erik Reaves, Michael Emch, Jonathan J Juliano.

   BACKGROUND: Transmission of malaria in sub-Saharan Africa has become increasingly stratified following decades of malaria control interventions. The extent to which environmental and land cover risk factors for malaria may differ across distinct strata of transmission intensity is not well known and could provide actionable targets to maximize the success of malaria control efforts.
METHODS: This study used cross-sectional malaria survey data from a nationally representative cohort of school-aged children in Tanzania, and satellite-derived measures for environmental features and land cover. Hierarchical logistic regression models were applied to evaluate associations between land cover and malaria prevalence within three distinct strata of transmission intensity: low and unstable, moderate and seasonal, and high and perennial.
RESULTS: In areas with low malaria transmission, each 10-percentage point increase in cropland cover was associated with an increase in malaria prevalence odds of 2.44 (95% UI: 1.27, 5.11). However, at moderate and higher levels of transmission intensity, no association between cropland cover and malaria prevalence was detected. Small associations were observed between greater grassland cover and greater malaria prevalence in high intensity settings (prevalence odds ratio (POR): 1.10, 95% UI: 1.00, 1.21), and between greater forest cover and reduced malaria prevalence in low transmission areas (POR: 0.74, 95% UI: 0.51, 1.03), however the uncertainty intervals of both estimates included the null.
CONCLUSIONS: The intensity of malaria transmission appears to modify relationships between land cover and malaria prevalence among school-aged children in Tanzania. In particular, greater cropland cover was positively associated with increased malaria prevalence in areas with low transmission intensity and presents an actionable target for environmental vector control interventions to complement current malaria control activities. As areas are nearing malaria elimination, it is important to re-evaluate environmental risk factors and employ appropriate interventions to effectively address low-level malaria transmission.

Keywords:  Land cover; Malaria; Transmission intensity

DOI:  https://doi.org/10.1186/s12936-022-04107-8
Sensors (Basel). 2022 Mar 02. pii: 1942. [Epub ahead of print]22(5):

Temporal Monitoring and Predicting of the Abundance of Malaria Vectors Using Time Series Analysis of Remote Sensing Data through Google Earth Engine.

Fahimeh Youssefi, Mohammad Javad Valadan Zoej, Ahmad Ali Hanafi-Bojd, Alireza Borhani Dariane, Mehdi Khaki, Alireza Safdarinezhad, Ebrahim Ghaderpour.

  In many studies regarding the field of malaria, environmental factors have been acquired in single-time, multi-time or a short-time series using remote sensing and meteorological data. Selecting the best periods of the year to monitor the habitats of Anopheles larvae can be effective in better and faster control of malaria outbreaks. In this article, high-risk times for three regions in Iran, including Qaleh-Ganj, Sarbaz and Bashagard counties with a history of malaria prevalence were estimated. For this purpose, a series of environmental factors affecting the growth and survival of Anopheles were used over a seven-year period through the Google Earth Engine. The results of this study indicated two high-risk times for Qaleh-Ganj and Bashagard counties and three high-risk times for Sarbaz county over the course of a year observing an increase in the abundance of Anopheles mosquitoes. Further evaluation of the results against the entomological data available in previous studies showed that the high-risk times predicted in this study were consistent with an increase in the abundance of Anopheles mosquitoes in the study areas. The proposed method is extremely useful for temporal prediction of the increase in abundance of Anopheles mosquitoes in addition to the use of optimal data aimed at monitoring the exact location of Anopheles habitats.

Keywords:  Anopheles; Google Earth Engine; climate; hydro-climate time series; malaria; remote sensing; trend analysis

DOI:  https://doi.org/10.3390/s22051942
Sci Rep. 2022 Mar 07. 12(1): 3635

Detection of temporal, spatial and spatiotemporal clustering of malaria incidence in northwest Ethiopia, 2012-2020.

Teshager Zerihun Nigussie, Temesgen T Zewotir, Essey Kebede Muluneh.

Malaria is one of Ethiopia's most targeted communicable diseases for elimination. Malaria transmission varies significantly across space and time; and Ethiopia had space-time disparity in its transmission intensities. Considering heterogeneity and transmission intensity at the district level could play a crucial role in malaria prevention and elimination. This study aimed to explore temporal, spatial, and spatiotemporal clusters of malaria incidence in northwest Ethiopia. The analysis is based on monthly malaria surveillance data of districts and collected from the Amhara public health institute. The Kulldorff's retrospective space-time scan statistics using a discrete Poisson model were used to detect temporal, spatial, and space-time clusters of malaria incidence with and without adjusting the altitude + LLIN arm. Monthly malaria incidence had seasonal variations, and higher seasonal indices occurred in October and November. The temporal cluster occurred in the higher transmission season between September and December annually. The higher malaria incidence risk occurred between July 2012 and December 2013 (LLR = 414,013.41, RR = 2.54, P < 0.05). The purely spatial clustering result revealed that the most likely cluster occurred in the north and northwest parts of the region while secondary clusters varied in years. The space-time clusters were detected with and without considering altitude + LLIN arm. The most likely space-time cluster was concentrated in northwestern and western parts of the region with a high-risk period between July 2012 and December 2013 (LLR = 880,088.3, RR = 5.5, P < 0.001). We found eight significant space-time clusters using the altitude + LLIN arm. The most likely space-time cluster occurred in the western and northwestern parts of the region in July 2012-December 2013 (LLR = 886,097.7, RR = 5.55, P < 0.05). However, secondary clusters were located in eastern, northwestern, western parts of regions, which had different cases and relative risks in each cluster. Malaria transmission had temporal, spatial, and space-time variation in the region at the district level. Hence, considering these variations and factors contributing to malaria stratification would play an indispensable role in preventing and controlling practices that ultimately leads to malaria eliminations.

DOI: https://doi.org/10.1038/s41598-022-07713-3
J Int Med Res. 2022 Mar;50(3): 3000605221080686

Magnitude of urban malaria and its associated risk factors: the case of Batu town, Oromia Regional State, Ethiopia.

Jifar Hassen, Hunduma Dinka.

   OBJECTIVE: This study aimed to assess the magnitude of malaria and its associated risk factors in urban, Batu town, Oromia Regional State, Ethiopia.
METHODS: This health-facility based prospective cross-sectional study enrolled 356 febrile malaria patients to assess risk factors associated with malaria infection.
RESULTS: An overall positivity rate of 17.13% (61/356) for malaria infection was observed. Among the malaria-positive patients, 50.8% (31/61) of them were positive for Plasmodium vivax, 45.90% (28/61) were positive for Plasmodium falciparum, and 3.3% (2/61) had mixed infections of P. falciparum and P. vivax. Logistic regression analysis revealed that individuals who possessed insecticide-treated net (Odds ratio [OR] = 0.38, 95% confidence interval [CI] [0.194, 0.743]) and whose houses were sprayed with insecticides (OR = 0.18, 95% CI [0.097, 0.34]) were significantly less likely to have a malaria infection. Individuals living closer to stagnant water had a significantly greater chance of malaria infection than those who lived a distance from stagnant water (OR = 0.34, 95% CI [0.19, 0.59]).
CONCLUSION: The present study revealed that malaria remains a public health problem in the urban area of Batu town, which suggests that the same might be true for other urban areas in the country.

Keywords:  Batu town; magnitude of malaria; plasmodium falciparum; plasmodium vivax; risk factor; urban.

DOI:  https://doi.org/10.1177/03000605221080686
Nat Microbiol. 2022 Mar 07.

Author Correction: Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector.

Kelsey L Adams, Daniel G Abernathy, Bailey C Willett, Emily K Selland, Maurice A Itoe, Flaminia Catteruccia.

DOI: https://doi.org/10.1038/s41564-022-01098-9
BMC Public Health. 2022 Mar 08. 22(1): 462

Spatiotemporal analysis of dengue fever in Burkina Faso from 2016 to 2019.

Cheick Ahmed Ouattara, Seydou Traore, Ibrahim Sangare, Tiandiogo Isidore Traore, Ziemlé Clément Meda, Léon G Blaise Savadogo.

   BACKGROUND: Burkina Faso experienced an epidemic resurgence of dengue in 2016, which led to the implementation of several control strategies. In order to allow a better adaptation of these strategies, we studied the spatio-temporal distribution of dengue.
METHODS: Monthly dengue cases from 2016 to 2019, aggregated at the health district level, were used to map the crude incidence, excess risk, and smoothed incidence of dengue in Burkina Faso with GeoDa software. A Kulldoff scan on Satscan software was then used to identify spatio-temporal clustering of cases.
RESULTS: The results show that the distribution of dengue fever across the health districts of Burkina Faso is heterogeneous. Dengue was considered non-endemic in 9 out of the 70 health districts, minimally endemic in 45 districts (< 10 incidences), moderately endemic (10-100 incidences) in 12 districts, and highly endemic (> 100 incidences) in 4 districts. The main cluster covered the health districts of Baskuy, Nongr-massom, Sig-noghin, Boulmiougou, and Bogodogo. The months of October and November corresponded to the peak of cases and a significant temporal cluster in 2017.
CONCLUSION: This study identified the spatial and temporal clustering of dengue cases in Burkina Faso. These results may help to develop better preventive strategies.

Keywords:  Burkina Faso; Cluster; Dengue; Excess risk; Incidence

DOI:  https://doi.org/10.1186/s12889-022-12820-x
PLoS Negl Trop Dis. 2022 Mar 08. 16(3): e0010227

Characterising spatial patterns of neglected tropical disease transmission using integrated sero-surveillance in Northern Ghana.

Kimberly M Fornace, Laura Senyonjo, Diana L Martin, Sarah Gwyn, Elena Schmidt, David Agyemang, Benjamin Marfo, James Addy, Ernest Mensah, Anthony W Solomon, Robin Bailey, Chris J Drakeley, Rachel L Pullan.

BACKGROUND: As prevalence decreases in pre-elimination settings, identifying the spatial distribution of remaining infections to target control measures becomes increasingly challenging. By measuring multiple antibody responses indicative of past exposure to different pathogens, integrated serological surveys enable simultaneous characterisation of residual transmission of multiple pathogens.
METHODOLOGY/PRINCIPAL FINDINGS: Here, we combine integrated serological surveys with geostatistical modelling and remote sensing-derived environmental data to estimate the spatial distribution of exposure to multiple diseases in children in Northern Ghana. The study utilised the trachoma surveillance survey platform (cross-sectional two-stage cluster-sampled surveys) to collect information on additional identified diseases at different stages of elimination with minimal additional cost. Geostatistical modelling of serological data allowed identification of areas with high probabilities of recent exposure to diseases of interest, including areas previously unknown to control programmes. We additionally demonstrate how serological surveys can be used to identify areas with exposure to multiple diseases and to prioritise areas with high uncertainty for future surveys. Modelled estimates of cluster-level prevalence were strongly correlated with more operationally feasible metrics of antibody responses.
CONCLUSIONS/SIGNIFICANCE: This study demonstrates the potential of integrated serological surveillance to characterise spatial distributions of exposure to multiple pathogens in low transmission and elimination settings when the probability of detecting infections is low.

DOI: https://doi.org/10.1371/journal.pntd.0010227