bims-mosdis 2022-04-17 papers

bims-mosdis

Biomed News

on Mosquito distribution and disease

Issue of 2022–04–17
twenty-two papers selected by
Richard Halfpenny, Staffordshire University

Blood meal profile and positivity rate with malaria parasites among different malaria vectors in Sudan.
Dengue Fever in Mainland China, 2005-2020: A Descriptive Analysis of Dengue Cases and Aedes Data.
Mosquito surveillance in maritime entry ports in Miami-Dade County, Florida to increase preparedness and allow the early detection of invasive mosquito species.
A novel statistical framework for exploring the population dynamics and seasonality of mosquito populations.
Ad libitum consumption of protein- or peptide-sucrose solutions stimulates egg formation by prolonging the vitellogenic phase of oogenesis in anautogenous mosquitoes.
Mapping Yellow fever epidemics as a potential indicator of the historical range of Aedes aegypti in the United States.
Mosquito survey in Mauritania: Detection of Rift Valley fever virus and dengue virus and the determination of feeding patterns.
Effect of morphology on larvicidal activity of chemically synthesized zinc oxide nanoparticles against mosquito vectors.
Thermal biology of invasive Aedes mosquitoes in the context of climate change.
Has Zika Been Forgotten? Findings From Nationwide Survey on Knowledge, Attitudes, and Mosquito Preventive Practices in Malaysia.
Spatiotemporal Trends and Distributions of Malaria Incidence in the Northwest Ethiopia.
Spatial dynamics of dengue fever spreading for the coexistence of two serotypes with an application to the city of São Paulo, Brazil.
First case of Zika virus infection during an outbreak of chikungunya in a rural region of Maharashtra state, India.
Co-circulation of Chikungunya Virus during the 2015-2017 Zika Virus Outbreak in Pernambuco, Brazil: An Analysis of the Microcephaly Epidemic Research Group Pregnancy Cohort.
Duration of West Nile Virus Immunoglobulin M Antibodies up to 81 Months Following West Nile Virus Disease Onset.
The Emerging Threat of Plasmodium knowlesi Malaria Infection: A Concept Paper on the Vulnerable Factors in Human.
Socioeconomic risk markers of arthropod-borne virus (arbovirus) infections: a systematic literature review and meta-analysis.
Cross-border malaria drivers and risk factors on the Brazil-Venezuela border between 2016 and 2018.
Malaria in 2022: Challenges and Progress.
Geo-Climatic Factors of Malaria Morbidity in the Democratic Republic of Congo from 2001 to 2019.
Knowledge, Attitudes, Beliefs, and Practices Regarding Dengue in La Réunion Island, France.
Strengthening Management, Community Engagement, and Sustainability of the Subnational Response to Accelerate Malaria Elimination in Namibia.

Malar J. 2022 Apr 15. 21(1): 124

Blood meal profile and positivity rate with malaria parasites among different malaria vectors in Sudan.

Omnia Altahir, Hanadi AbdElbagi, Mustafa Abubakr, Emmanuel Edwar Siddig, Ayman Ahmed, Nouh Saad Mohamed.

   BACKGROUND: Malaria is a life-threatening public health problem globally with particularly heavy burden in the sub-Saharan Africa including Sudan. The understanding of feeding preference of malaria vectors on different hosts is a major challenge for hindering the transmission cycle of malaria. In this study, blood meals taken by blood-fed Anopheles mosquitoes collected from the field in malaria endemic areas of Sudan were analysed for source of blood meal and malaria parasite presence.
METHODS: Anopheles mosquitoes were collected from different regions in Sudan: Khartoum state, Sennar state, Northern state, and El Gedarif state between September 2020 and February 2021. Anopheles mosquitoes were collected using the standard pyrethrum spray catch and back-pack aspirator. Mosquito samples were sorted and morphologically identified to species level using international identification keys. Morphologically identified mosquito species were also confirmed using PCR. Genomic DNA was extracted from mosquitoes for molecular identification of blood meal source and parasite detection. The presence of Plasmodium species DNA in each mosquito sample was investigated using semi-nested PCR. Frequency of each blood meal source, Anopheles mosquito vector, and malaria parasite detected was calculated. Positivity rate of each fed female Anopheles mosquito was calculated for each species.
RESULTS: A total of 2132 Anopheles mosquitoes were collected. 571 (26.8%) were males and 1561 (73.2%) were females classified based on their abdominal status into 1048 (67.1%) gravid, 274 (17.6%) fed, and 239 (15.3%) unfed females. Among the blood fed Anopheles mosquitoes, 263 (96.0%) were morphologically identified and confirmed using PCR to Anopheles arabiensis, 9 (3.3%) to Anopheles stephensi, and 2 (0.7%) to Anopheles rufipes. Of 274 blood-fed An. arabiensis, 68 (25.9%) fed on mixed blood meals from human and cattle, 8 (3.0%) fed on cattle and goat, and 13 (4.8%) fed on human, cattle and goat. For single blood meal sources, 70 (26.6%) fed on human, 95 (36.1%) fed on cattle, 8 (3.0%) fed on goat, and 1 (0.4%) fed on dog. While An. rufipes and An. stephensi fed on dog (2; 0.75%) and cattle (9; 3.3%), respectively. Plasmodium parasite detection in the blood meals showed that 25/274 (9.1%) An. arabiensis meals were positive for Plasmodium vivax and 19/274 (6.9%) An. arabiensis meals were positive for Plasmodium falciparum. The rate of positivity of An. arabiensis with any Plasmodium species was 16.7%. However, the positivity rate with P. falciparum only was 7.2%, while P. vivax was 9.5%. Both An. rufipes and An. stephensi were having positivity rates of 0.0% each.
CONCLUSIONS: This study which was mainly on blood-fed Anopheles mosquitoes showed a diversity in the type of diet from human, cattle, and goat. Anopheles mosquitoes especially An. arabiensis in Sudan, are opportunistic blood feeders and can feed broadly on both human and cattle. The application of blood meal identification is not only important in malaria vector epidemiological surveillance but also is very useful in areas where arthropods exhibit zoophilic feeding behaviour for mammals.

Keywords:  Blood meal source; Malaria parasites; Mosquito vectors; Sudan

DOI:  https://doi.org/10.1186/s12936-022-04157-y
Int J Environ Res Public Health. 2022 Mar 25. pii: 3910. [Epub ahead of print]19(7):

Dengue Fever in Mainland China, 2005-2020: A Descriptive Analysis of Dengue Cases and Aedes Data.

Yujuan Yue, Qiyong Liu, Xiaobo Liu, Ning Zhao, Wenwu Yin.

  Dengue fever occurs throughout mainland China, except in the Tibet Autonomous Region. During 2005-2020, there were 12,701 imported cases and 81,653 indigenous cases recorded. The indigenous cases were mainly clustered in Guangdong (74.0%) and Yunnan provinces (13.7%). Indigenous dengue fever is a seasonal illness in mainland China, manifesting predominantly in summer and autumn. Indigenous dengue fever cases tend to peak every 5years and have shown a substantial increase during the period 2005-2020. During the study period, indigenous dengue fever occurred more than ten times in each of the seven counties of Guangdong Province. Indigenous dengue fever has spread from low to high latitudes; that is, from the southwestern, southern, and southeastern areas to the central and northern regions, and from border ports and cities to rural areas. Aedes aegypti has become widespread in Yunnan Province but has diminished in Guangxi, Guangdong, and Hainan provinces in recent years. Aedes albopictus is distributed throughout mainland China, spanning 25 provinces and municipalities. To maintain effective public health prevention and control, it is important to monitor dengue occurrence, provide dengue classification guidance, and ensure sustainable vector management of Aedes.

Keywords:  Aedes aegypti; Aedes albopictus; dengue fever; spatial diffusion analyses; spatial occurrence frequency analyses; time-series analyses

DOI:  https://doi.org/10.3390/ijerph19073910
PLoS One. 2022 ;17(4): e0267224

Mosquito surveillance in maritime entry ports in Miami-Dade County, Florida to increase preparedness and allow the early detection of invasive mosquito species.

André B B Wilke, Chalmers Vasquez, Augusto Carvajal, Maday Moreno, William D Petrie, John C Beier.

Invasive mosquito vector species have been inadvertently transported to new areas by humans for decades. Strong evidence supports that monitoring maritime, terrestrial, and aerial points of entry is an essential part of the effort to curb the invasion and establishment of invasive vector mosquito species. Miami-Dade County, Florida is an important operational hub for the cruise ship industry and leisure boats that routinely visit nearby areas in the Caribbean, and freight cargo ships transporting goods from Miami-Dade to Caribbean countries and vice versa. To deal with the increasing public health concern, we hypothesized that mosquito surveillance in small- and medium-sized maritime ports of entry in Miami-Dade is crucial to allow the early detection of invasive mosquito species. Therefore, we have selected 12 small- and medium-sized maritime ports of entry in Miami-Dade County with an increased flow of people and commodities that were not covered by the current mosquito surveillance system. Collection sites were comprised of two distinct environments, four marinas with international traffic of leisure boats, and eight maintenance and commercial freight cargo ship ports. Mosquitoes were collected weekly at each of the 12 collection sites for 24 hours for 6 weeks in the Spring and then for 6 additional weeks in the Summer using BG-Sentinel traps. A total of 32,590 mosquitoes were collected, with Culex quinquefasciatus and Aedes aegypti being the most abundant species totaling 19,987 and 11,247 specimens collected, respectively. Our results show that important mosquito vector species were present in great numbers in all of the 12 maritime ports of entry surveyed during this study. The relative abundance of Cx. quinquefasciatus and Ae. aegypti was substantially higher in the commercial freight cargo ship ports than in the marinas. These results indicate that even though both areas are conducive for the proliferation of vector mosquitoes, the port area in the Miami River is especially suitable for the proliferation of vector mosquitoes. Therefore, this potentially allows the establishment of invasive mosquito species inadvertently brought in by cargo freights.

DOI: https://doi.org/10.1371/journal.pone.0267224
Proc Biol Sci. 2022 Apr 13. 289(1972): 20220089

A novel statistical framework for exploring the population dynamics and seasonality of mosquito populations.

Charles Whittaker, Peter Winskill, Marianne Sinka, Samuel Pironon, Claire Massey, Daniel J Weiss, Michele Nguyen, Peter W Gething, Ashwani Kumar, Azra Ghani, Samir Bhatt.

  Understanding the temporal dynamics of mosquito populations underlying vector-borne disease transmission is key to optimizing control strategies. Many questions remain surrounding the drivers of these dynamics and how they vary between species-questions rarely answerable from individual entomological studies (that typically focus on a single location or species). We develop a novel statistical framework enabling identification and classification of time series with similar temporal properties, and use this framework to systematically explore variation in population dynamics and seasonality in anopheline mosquito time series catch data spanning seven species, 40 years and 117 locations across mainland India. Our analyses reveal pronounced variation in dynamics across locations and between species in the extent of seasonality and timing of seasonal peaks. However, we show that these diverse dynamics can be clustered into four 'dynamical archetypes', each characterized by distinct temporal properties and associated with a largely unique set of environmental factors. Our results highlight that a range of environmental factors including rainfall, temperature, proximity to static water bodies and patterns of land use (particularly urbanicity) shape the dynamics and seasonality of mosquito populations, and provide a generically applicable framework to better identify and understand patterns of seasonal variation in vectors relevant to public health.

Keywords:  Anopheles mosquitoes; epidemiology; malaria ecology; population dynamics; seasonality

DOI:  https://doi.org/10.1098/rspb.2022.0089
Parasit Vectors. 2022 Apr 12. 15(1): 127

Ad libitum consumption of protein- or peptide-sucrose solutions stimulates egg formation by prolonging the vitellogenic phase of oogenesis in anautogenous mosquitoes.

Ruby E Harrison, Kangkang Chen, Lilith South, Ange Lorenzi, Mark R Brown, Michael R Strand.

   BACKGROUND: Anautogenous mosquitoes commonly consume nectars and other solutions containing sugar but are thought to only produce eggs in discrete gonadotrophic cycles after blood-feeding on a vertebrate host. However, some anautogenous species are known to produce eggs if amino acids in the form of protein are added to a sugar solution. Unclear is how different sources of amino acids in sugar solutions affect the processes that regulate egg formation and whether responses vary among species. In this study, we addressed these questions by focusing on Aedes aegypti and conducting some comparative assays with Aedes albopictus, Anopheles gambiae, Anopheles stephensi and Culex quinquefasciatus.
METHODS: Adult female mosquitoes were fed sugar solutions containing amino acids, peptides or protein. Markers for activation of a gonadotrophic cycle including yolk deposition into oocytes, oviposition, ovary ecdysteroidogenesis, expression of juvenile hormone and 20-hydroxyecdysone-responsive genes, and adult blood-feeding behavior were then measured.
RESULTS: The five anautogenous species we studied produced eggs when fed two proteins (bovine serum albumin, hemoglobin) or a mixture of peptides (tryptone) in 10% sucrose but deposited only small amounts of yolk into oocytes when fed amino acids in 10% sucrose. Focusing on Ae. aegypti, cultures were maintained for multiple generations by feeding adult females protein- or tryptone-sugar meals. Ad libitum access to protein- or tryptone-sugar solutions protracted production of ecdysteroids by the ovaries, vitellogenin by the fat body and protease activity by the midgut albeit at levels that were lower than in blood-fed females. Females also exhibited semi-continual oogenesis and repressed host-seeking behavior.
CONCLUSIONS: Several anautogenous mosquitoes produce eggs when provided ad libitum access to protein- or peptide-sugar meals, but several aspects of oogenesis also differ from females that blood-feed.

Keywords:  Diet; Endocrinology; Mosquito; Oogenesis; Reproduction

DOI:  https://doi.org/10.1186/s13071-022-05252-4
Mem Inst Oswaldo Cruz. 2022 ;pii: S0074-02762022000101100. [Epub ahead of print]117 e220306

Mapping Yellow fever epidemics as a potential indicator of the historical range of Aedes aegypti in the United States.

Nicole S Fijman, Donald A Yee.

BACKGROUND: Yellow fever (YF) plagued the United States from the 1690s until 1905, resulting in thousands of deaths. Within the US, Aedes aegypti is the only YF vector and almost no data exists for the location of this species prior to the early 1900s.
OBJECTIVES: To determine the historical range of Ae. aegypti we examined the occurrence of YF epidemics across time and space. We hypothesized that historically Ae. aegypti was driven by human population density, like its contemporary range suggests.
METHODS: To test this hypothesis, we compiled a list of YF cases in the US, human population density, location, and the number of people infected. This data was mapped using ArcGIS and was analyzed using linear regression models to determine the relationship among variables.
FINDINGS: The historic range was generally south of 40º latitude, from Texas in the west to Florida in the east, with concentrations along major waterways like the Mississippi River. Infected individuals and human population density were strongly correlated across the whole dataset as well as by decade.
MAIN CONCLUSIONS: Although other factors likely affected the range of Ae. aegypti, we found that human population density was related to the number of people infected with historic YF infections.

DOI: https://doi.org/10.1590/0074-02760220306
PLoS Negl Trop Dis. 2022 Apr 15. 16(4): e0010203

Mosquito survey in Mauritania: Detection of Rift Valley fever virus and dengue virus and the determination of feeding patterns.

Franziska Stoek, Yahya Barry, Aliou Ba, Ansgar Schulz, Melanie Rissmann, Claudia Wylezich, Balal Sadeghi, Abdellahi Diambar Beyit, Albert Eisenbarth, Fatimetou Bounene N'diaye, Mohamed Lemine Haki, Baba Abdellahi Doumbia, Mohamed Baba Gueya, Mohamed Yahya Bah, Martin Eiden, Martin H Groschup.

In Mauritania, several mosquito-borne viruses have been reported that can cause devastating diseases in animals and humans. However, monitoring data on their occurrence and local distribution are limited. Rift Valley fever virus (RVFV) is an arthropod-borne virus that causes major outbreaks throughout the African continent and the Arabian Peninsula. The first Rift Valley fever (RVF) epidemic in Mauritania occurred in 1987 and since then the country has been affected by recurrent outbreaks of the disease. To gain information on the occurrence of RVFV as well as other mosquito-borne viruses and their vectors in Mauritania, we collected and examined 4,950 mosquitoes, belonging to four genera and 14 species. The mosquitoes were captured during 2018 in the capital Nouakchott and in southern parts of Mauritania. Evidence of RVFV was found in a mosquito pool of female Anopheles pharoensis mosquitoes collected in December on a farm near the Senegal River. At that time, 37.5% of 16 tested Montbéliarde cattle on the farm showed RVFV-specific IgM antibodies. Additionally, we detected IgM antibodies in 10.7% of 28 indigenous cattle that had been sampled on the same farm one month earlier. To obtain information on potential RVFV reservoir hosts, blood meals captured engorged mosquitoes were analyzed. The mosquitoes mainly fed on humans (urban areas) and cattle (rural areas), but also on small ruminants, donkeys, cats, dogs and straw-colored fruit bats. Results of this study demonstrate the circulation of RVFV in Mauritania and thus the need for further research to investigate the distribution of the virus and its vectors. Furthermore, factors that may contribute to its maintenance should be analyzed more closely. In addition, two mosquito pools containing Aedes aegypti and Culex quinquefasciatus mosquitoes showed evidence of dengue virus (DENV) 2 circulation in the city of Rosso. Further studies are therefore needed to also examine DENV circulation in Mauritania.

DOI: https://doi.org/10.1371/journal.pntd.0010203
RSC Adv. 2021 Feb 23. 11(15): 8857-8866

Effect of morphology on larvicidal activity of chemically synthesized zinc oxide nanoparticles against mosquito vectors.

U M T M Gunathilaka, W A P P de Silva, S P Dunuweera, R M G Rajapakse.

We report the larvicidal effects of four different morphologies of zinc oxide nanoparticles (ZnO NPs) [star-shaped (S), needle-like (N), plate-like (P) and cubical (C)] on larvae of Aedes albopictus and Anopheles vagus; the mosquitoes causing dengue fever and malaria, respectively. The nanoparticles were characterized by several analytical techniques, and their sizes and shapes were determined. Second instar larvae of the two types of mosquitoes were exposed to several concentrations of nanoparticles (25 mg L-1, 50 mg L-1, 75 mg L-1, 100 mg L-1) at 25 ± 2 °C and 84 ± 5% R.H, separately, for each morphology. Larval mortality was reported at 24 h intervals up to 21 days. The resulting LC50 for Aedes albopictus were, respectively, 38.90 mg L-1, 47.53 mg L-1, 68.38 mg L-1, 50.24 mg L-1 for S-, N-, P- and C-shaped nanoparticles. The LC50 of Anopheles vagus is lower (LC50 4.78 mg L-1, 6.51 mg L-1, 13.64 mg L-1, 10.47 mg L -1 ), respectively, for S-, N-, P- and C-shaped nanoparticles indicating that the nanoparticles are more toxic to Anopheles vagus larvae. The highest larvicidal effect was obtained from star-shaped nanoparticles [Aedes albopictus (38.90 mg L-1) on Anopheles vagus (4.78 mg L-1)], and the lowest was shown by the plate-like nanoparticles [Aedes albopictus (68.38 mg L-1), Anopheles vagus (13.64 mg L-1)]. The rate of development of surviving mosquito larvae was retarded when exposed to ZnO nanoparticles suggesting the possibility for these nanoparticles to kill and delay the growth of Aedes albopictus and Anopheles vagus larvae.

DOI: https://doi.org/10.1039/d1ra00014d
Curr Opin Insect Sci. 2022 Apr 11. pii: S2214-5745(22)00055-4. [Epub ahead of print] 100920

Thermal biology of invasive Aedes mosquitoes in the context of climate change.

Chloé Lahondère, Mariangela Bonizzoni.

The increasing incidence of arboviral diseases in tropical endemic areas and their emergence in new temperate countries is one of the most important challenges that Public Health agencies are currently facing. Because mosquitoes are poikilotherms, shifts in temperature influence physiological functions besides egg viability. These traits impact not only vector density, but also their interaction with their hosts and arboviruses. As such the relationship among mosquitoes, arboviral diseases and temperature is complex. Here we summarize current knowledge on the thermal biology of Aedes invasive mosquitoes, highlighting differences among species. We also emphasise the need to expand knowledge on the variability in thermal sensitivity across populations within a species, especially in light of climate change that encompasses increase not only in mean environmental temperature but also in the frequency of hot and cold snaps. Finally, we suggest a novel experimental approach to investigate the molecular architecture of thermal adaptation in mosquitoes. KEYWORDS.

DOI: https://doi.org/10.1016/j.cois.2022.100920
Disaster Med Public Health Prep. 2022 Apr 11. 1-8

Has Zika Been Forgotten? Findings From Nationwide Survey on Knowledge, Attitudes, and Mosquito Preventive Practices in Malaysia.

Li Ping Wong, Haridah Alias, Hai Yen Lee, Sazaly AbuBakar.

   OBJECTIVE: The aim of this study is to assess knowledge and attitudes toward Zika virus disease (ZVD) as well as mosquito prevention practices in Malaysia at a nationwide level.
METHODS: Computer-assisted telephone interviews (CATI) were conducted between June 2019 and February 2020.
RESULTS: There are gaps in knowledge about the symptoms, mode of transmission, and risk of microcephaly. The mean for the Zika-related knowledge score was 5.9 (SD ± 4.4) out of a possible score of 14. The majority perceived little or no risk of getting ZVD (75.0%) and 75.5% were a little or not at all worried about ZVD. A high proportion reported the use of insect sprays or mosquito coils to prevent mosquito bites; however, a relatively lower proportion of people reported fixing mosquito netting on doors and windows, and using mosquito bed nets. The mean for the mosquito prevention practices score was 11.9 (SD ± 4.7) out of a possible score of 27. Important factors influencing mosquito prevention practices include household income, environment factors, risk perception, and Zika-related knowledge.
CONCLUSION: Zika prevention measures should be targeted in priority toward residents in lower socioeconomic neighborhoods. Campaigns should focus on messages highlighting the high risk of getting dengue.

Keywords:  Zika; knowledge; post-pandemic; prevention

DOI:  https://doi.org/10.1017/dmp.2022.40
J Trop Med. 2022 ;2022 6355481

Spatiotemporal Trends and Distributions of Malaria Incidence in the Northwest Ethiopia.

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

Understanding and extracting noticeable patterns of malaria surveillance data at the district level are crucial for malaria prevention, control, and elimination progress. This study aimed to analyze spatiotemporal trends and nonparametric dynamics of malaria incidences in northwest Ethiopia, considering spatial and temporal correlations. The data were analyzed using count regression spatiotemporal models under the Bayesian setups, and parameters were estimated using integrated nested Laplace approximations (INLA). The region had a declining linear trend, and the average annual malaria incidence rate was 24.8 per 1,000 persons between 2012 and 2020. The malaria incidence rate was decreased by 0.984 (95% CI: 0.983, 0.986) per unit increase in months between July 2012 and June 2020. Districts found in the western and northwestern parts of the region had a steeper trend, while districts in the eastern and southern parts had a less steep trend than the average trend of the region. Compared to the regional level trend, the decreasing rate of malaria incidence trends was lower in most town administrations. The nonparametric dynamics showed that the monthly malaria incidence had a sinusoidal wave shape that varied throughout study periods. Malaria incidence had a decreasing linear trend changed across districts of the study region, and the steepness of trends of districts might not depend on incidences. Thus, an intervention and controlling mechanism that considers malaria incidences and district-specific differential trends would be indispensable to mitigate malaria transmission in the region.

DOI: https://doi.org/10.1155/2022/6355481
Comput Methods Programs Biomed. 2022 Mar 26. pii: S0169-2607(22)00144-4. [Epub ahead of print]219 106758

Spatial dynamics of dengue fever spreading for the coexistence of two serotypes with an application to the city of São Paulo, Brazil.

F M M Pereira, P H T Schimit.

   BACKGROUND AND OBJECTIVE: Dengue fever is a disease in which individuals' spatial distribution and Aedes aegypti mosquitoes breeding places are important factors for the disease dynamics. Typically urban, dengue is a problem for least developed countries due to the ineffectiveness in controlling the vector and disorderly urbanization processes. The result is a composition of urban sanitation problems and areas with high demographic densities and intense flows of people. This paper explores the spatial distribution of vector breeding places to evaluate introducing a new dengue serotype to a population at equilibrium for a pre-existing serotype. The paper's objective is to analyze the spatial dynamics of dengue using variations of the basic reproduction number.
METHODS: A model based on probabilistic cellular automata is proposed to permitting the necessary flexibility to consider some spatial distributions of vector breeding places. Then, ordinary differential equations are used as a mean-field approach of the model, and the basic reproduction number (R0) is derived considering the next-generation matrix method. A spatial approach for R0 is also proposed, and the model is tested in a neighbourhood from the city of São Paulo, Brazil, to examine the potential risks of vector breeding cells distribution.
RESULTS: The results indicated that the more spread out these places, the higher are the values of R0. When the model is applied to a neighbourhood in São Paulo, residential areas may boost the infections and must be under public vigilance to combat vector breeding sites.
CONCLUSIONS: Considering the mean-field approximation of the cellular automata model by ordinary differential equations, the basic reproduction number derived returned an estimative of the disease dynamics in the population. However, the spatial basic reproduction number was more assertive in showing areas with a higher disease incidence. Moreover, the model could be easily adapted to be used in real maps enabling simulations closer to real problems.

Keywords:  Basic reproduction number; Dengue; Probabilistic cellular automata; Spatial basic reproduction number; Spatial dynamics

DOI:  https://doi.org/10.1016/j.cmpb.2022.106758
Trans R Soc Trop Med Hyg. 2022 Apr 12. pii: trac022. [Epub ahead of print]

First case of Zika virus infection during an outbreak of chikungunya in a rural region of Maharashtra state, India.

Yogesh K Gurav, Kalichamy Alagarasu, Pragya D Yadav, Gajanan Sapkal, Mangesh Gokhale, Deepti Parashar, Ujwala Jadhav, Minal Bote, Mahadeo Kakade, Dimpal Nyayanit, Abhinendra Kumar, Gururaj Rao Deshpande, Sarah Cherian, Pradip S Awate, Priya Abraham.

   BACKGROUND: In July 2021, an outbreak of chikungunya virus (CHIKV) was reported in a rural region of Maharashtra state, India.
METHODS: Serum samples of symptomatic cases (n=33) were screened for dengue virus (DENV), CHIKV and Zika virus (ZIKV) by molecular and serological assays.
RESULTS: The first case of ZIKV infection from Maharashtra was detected and confirmed by molecular and serological assays. Complete genome sequencing revealed that the ZIKV sequence belongs to the Asian genotype and had a closer homology with pre-epidemic strains present before 2007.
CONCLUSIONS: ZIKV surveillance needs to be strengthened in the regions experiencing dengue and chikungunya outbreaks.

Keywords:  India; Zika virus; chikungunya virus; dengue virus; outbreaks; rural population

DOI:  https://doi.org/10.1093/trstmh/trac022
Am J Trop Med Hyg. 2022 Apr 11. pii: tpmd210449. [Epub ahead of print]

Co-circulation of Chikungunya Virus during the 2015-2017 Zika Virus Outbreak in Pernambuco, Brazil: An Analysis of the Microcephaly Epidemic Research Group Pregnancy Cohort.

Microcephaly Epidemic Research Group

Co-circulation of arthropod-borne viruses, particularly those with shared mosquito vectors like Zika (ZIKV) and Chikungunya (CHIKV), is increasingly reported. An accurate differential diagnosis between ZIKV and CHIKV is of high clinical importance, especially in the context of pregnancy, but remains challenging due to limitations in the availability of specialized laboratory testing facilities. Using data collected from the prospective pregnancy cohort study of the Microcephaly Epidemic Research Group, which followed up pregnant persons with rash during the peak and decline of the 2015-2017 ZIKV epidemic in Recife, Pernambuco, Brazil, this study aims to describe the geographic and temporal distribution of ZIKV and CHIKV infections and to investigate the extent to which ZIKV and CHIKV infections may be clinically differentiable. Between December 2015 and June 2017, we observed evidence of co-circulation with laboratory confirmation of 213 ZIKV mono-infections, 55 CHIKV mono-infections, and 58 sequential ZIKV/CHIKV infections (i.e., cases with evidence of acute ZIKV infection with concomitant serological evidence of recent CHIKV infection). In logistic regressions with adjustment for maternal age, ZIKV mono-infected cases had lower odds than CHIKV mono-infected cases of presenting with arthralgia (aOR, 99% CI: 0.33, 0.15-0.74), arthritis (0.35, 0.14-0.85), fatigue (0.40, 0.17-0.96), and headache (0.44, 0.19-1.90). However, sequential ZIKV/CHIKV infections complicated discrimination, as they did not significantly differ in clinical presentation from CHIKV mono-infections. These findings suggest clinical symptoms alone may be insufficient for differentiating between ZIKV and CHIKV infections during pregnancy and therefore laboratory diagnostics continue to be a valuable tool for tailoring care in the event of arboviral co-circulation.

DOI: https://doi.org/10.4269/ajtmh.21-0449
Am J Trop Med Hyg. 2022 Apr 11. pii: tpmd211234. [Epub ahead of print]

Duration of West Nile Virus Immunoglobulin M Antibodies up to 81 Months Following West Nile Virus Disease Onset.

J Erin Staples, Katherine B Gibney, Amanda J Panella, Harry E Prince, Alison J Basile, Janeen Laven, James J Sejvar, Marc Fischer.

West Nile virus (WNV) IgM antibodies typically indicate a recent infection. However, WNV IgM antibodies can remain detectable for months to years following illness onset. We found that 23% (11/47) of samples tested with a WNV ELISA and 43% (20/47) of samples tested with WNV microsphere immunoassay (MIA) at 16-19 months following WNV illness onset were positive for IgM antibodies. The proportion of samples testing positive for WNV IgM by ELISA decreased over time, but 5% (2/44) of individuals remained positive at 60-63 months after their acute illness and 4% (2/50) were WNV IgM equivocal at 72-81 months. Testing by MIA showed the same general trend of decreased proportion positive over time though the rates of positivity were higher at most time points compared with the ELISA, including 6% (3/50) of participant's samples identified as IgM positive by MIA at 72-81 months post their acute illness. With the MIA, there also was a high proportion of samples with nonspecific results at each time point; average of 23% across all time points. Clinicians and public health officials should consider these findings along with clinical and epidemiologic data when interpreting WNV IgM antibody test results.

DOI: https://doi.org/10.4269/ajtmh.21-1234
Int J Environ Res Public Health. 2022 Apr 06. pii: 4419. [Epub ahead of print]19(7):

The Emerging Threat of Plasmodium knowlesi Malaria Infection: A Concept Paper on the Vulnerable Factors in Human.

Nurul Athirah Naserrudin, Rozita Hod, Mohammad Saffree Jeffree, Kamruddin Ahmed, Mohd Rohaizat Hassan.

  In South-East Asia (SEA), there has been an increase in the trend of detected and reported cases of Plasmodium knowlesi malaria in the last few decades. This higher transmission rate within SEA countries is attributed to the distribution of the Macaque, banded leaf monkeys, and Anopheles mosquito in this region. This study aims to propose a concept that highlights the integration of vulnerability factors to P. knowlesi malaria infection. The relevant literature on the vulnerability factors of P. knowlesi was reviewed. Any theories and models that could be integrated to support the factors were also explored throughout this study. Exposure to P. knowlesi malaria was found to be influenced by sociodemographic, socioeconomic, environmental, social context, belief, and human behaviour factors. However, these factors were commonly discussed separately in existing studies. For better disease prevention and control, all these factors should be explored collectively, to facilitate research aimed at generating a deeper understanding of the vulnerability factors to P. knowlesi malaria from various perspectives, including the genetic, sociodemographic, socioeconomic, environmental, sociocultural beliefs, and human behaviour of the population.

Keywords:  Plasmodium knowlesi; malaria; malaria exposure; vulnerability factors; zoonotic malaria

DOI:  https://doi.org/10.3390/ijerph19074419
BMJ Glob Health. 2022 Apr;pii: e007735. [Epub ahead of print]7(4):

Socioeconomic risk markers of arthropod-borne virus (arbovirus) infections: a systematic literature review and meta-analysis.

Grace M Power, Aisling M Vaughan, Luxi Qiao, Nuria Sanchez Clemente, Julia M Pescarini, Enny S Paixão, Ludmila Lobkowicz, Amber I Raja, André Portela Souza, Mauricio Lima Barreto, Elizabeth B Brickley.

   INTRODUCTION: Arthropod-borne viruses (arboviruses) are of notable public health importance worldwide, owing to their potential to cause explosive outbreaks and induce debilitating and potentially life-threatening disease manifestations. This systematic review and meta-analysis aims to assess the relationship between markers of socioeconomic position (SEP) and infection due to arboviruses with mosquito vectors.
METHODS: We conducted a systematic search on PubMed, Embase, and LILACS databases to identify studies published between 1980 and 2020 that measured the association of SEP markers with arbovirus infection. We included observational studies without geographic location or age restrictions. We excluded studies from grey literature, reviews and ecological studies. Study findings were extracted and summarised, and pooled estimates were obtained using random-effects meta-analyses.
RESULTS: We identified 36 observational studies using data pertaining to 106 524 study participants in 23 geographic locations that empirically examined the relationship between socioeconomic factors and infections caused by seven arboviruses (dengue, chikungunya, Japanese encephalitis, Rift Valley fever, Sindbis, West Nile and Zika viruses). While results were varied, descriptive synthesis pointed to a higher risk of arbovirus infection associated with markers of lower SEP, including lower education, income poverty, low healthcare coverage, poor housing materials, interrupted water supply, marital status (married, divorced or widowed), non-white ethnicities and migration status. Pooled crude estimates indicated an increased risk of arboviral infection associated with lower education (risk ratio, RR 1.5 95% CI 1.3 to 1.9); I2=83.1%), interruption of water supply (RR 1.2; 95% CI 1.1 to 1.3; I2=0.0%) and having been married (RR 1.5 95% CI 1.1 to 2.1; I2=85.2%).
CONCLUSION: Evidence from this systematic review suggests that lower SEP increases the risk of acquiring arboviral infection; however, there was large heterogeneity across studies. Further studies are required to delineate the relationship between specific individual, household and community-level SEP indicators and arbovirus infection risks to help inform targeted public health interventions.
PROSPERO REGISTRATION NUMBER: CRD42019158572.

Keywords:  arboviruses; epidemiology; public health; systematic review

DOI:  https://doi.org/10.1136/bmjgh-2021-007735
Sci Rep. 2022 Apr 11. 12(1): 6058

Cross-border malaria drivers and risk factors on the Brazil-Venezuela border between 2016 and 2018.

Kinley Wangdi, Erica Wetzler, Paola Marchesini, Leopoldo Villegas, Sara Canavati.

Globally, cross-border importation of malaria has become a challenge to malaria elimination. The border areas between Brazil and Venezuela have experienced high numbers of imported cases due to increased population movement and migration out of Venezuela. This study aimed to identify risk factors for imported malaria and delineate imported malaria hotspots in Roraima, Brazil and Bolivar, Venezuela between 2016 and 2018. Data on malaria surveillance cases from Roraima, Brazil and Bolivar, Venezuela from 2016 to 2018 were obtained from national surveillance systems: the Brazilian Malaria Epidemiology Surveillance Information System (SIVEP-Malaria), the Venezuelan Ministry of Health and other non-government organizations. A multivariable logistic regression model was used to identify the risk factors for imported malaria. Spatial autocorrelation in malaria incidence was explored using Getis-Ord (Gi*) statistics. During the study period, there were 11,270 (24.3%) and 4072 (0.7%) imported malaria cases in Roraima, Brazil and Bolivar, Venezuela, respectively. In the multivariable logistic regression for Roraima, men were 28% less likely to be an imported case compared to women (Adjusted Odds Ratio [AOR] = 0.72; 95% confidence interval [CI] 0.665, 0.781). Ages 20-29 and 30-39 were 90% (AOR = 1.90; 95% CI 1.649, 2.181) and 54% (AOR = 1.54; 95% CI 1.331, 1.782) more likely to be an imported case compared to the 0-9 year age group, respectively. Imported cases were 197 times (AOR = 197.03; 95% CI 175.094, 221.712) more likely to occur in miners than those working in agriculture and domestic work. In Bolivar, cases aged 10-19 (AOR = 1.75; 95% CI 1.389, 2.192), 20-29 (AOR = 2.48; 95% CI 1.957, 3.144), and 30-39 (AOR = 2.29; 95% CI 1.803, 2.913) were at higher risk of being an imported case than those in the 0-9 year old group, with older age groups having a slightly higher risk compared to Roraima. Compared to agriculture and domestic workers, tourism, timber and fishing workers (AOR = 6.38; 95% CI 4.393, 9.254) and miners (AOR = 7.03; 95% CI 4.903, 10.092) were between six and seven times more likely to be an imported case. Spatial analysis showed the risk was higher along the international border in the municipalities of Roraima, Brazil. To achieve malaria elimination, cross-border populations in the hotspot municipalities will need targeted intervention strategies tailored to occupation, age and mobility status. Furthermore, all stakeholders, including implementers, policymakers, and donors, should support and explore the introduction of novel approaches to address these hard-to-reach populations with the most cost-effective interventions.

DOI: https://doi.org/10.1038/s41598-022-09819-0
Am J Trop Med Hyg. 2022 Apr 12. pii: tpmd220128. [Epub ahead of print]

Malaria in 2022: Challenges and Progress.

Philip J Rosenthal.

DOI: https://doi.org/10.4269/ajtmh.22-0128
Int J Environ Res Public Health. 2022 Mar 23. pii: 3811. [Epub ahead of print]19(7):

Geo-Climatic Factors of Malaria Morbidity in the Democratic Republic of Congo from 2001 to 2019.

Eric Kalunda Panzi, Léon Ngongo Okenge, Eugénie Hamuli Kabali, Félicien Tshimungu, Angèle Keti Dilu, Felix Mulangu, Ngianga-Bakwin Kandala.

   BACKGROUND: Environmentally related morbidity and mortality still remain high worldwide, although they have decreased significantly in recent decades. This study aims to forecast malaria epidemics taking into account climatic and spatio-temporal variations and therefore identify geo-climatic factors predictive of malaria prevalence from 2001 to 2019 in the Democratic Republic of Congo.
METHODS: This is a retrospective longitudinal ecological study. The database of the Directorate of Epidemiological Surveillance including all malaria cases registered in the surveillance system based on positive blood test results, either by microscopy or by a rapid diagnostic test for malaria was used to estimate malaria morbidity and mortality by province of the DRC from 2001 to 2019. The impact of climatic factors on malaria morbidity was modeled using the Generalized Poisson Regression, a predictive model with the dependent variable Y the count of the number of occurrences of malaria cases during a period of time adjusting for risk factors.
RESULTS: Our results show that the average prevalence rate of malaria in the last 19 years is 13,246 (1,178,383-1,417,483) cases per 100,000 people at risk. This prevalence increases significantly during the whole study period (p < 0.0001). The year 2002 was the most morbid with 2,913,799 (120,9451-3,830,456) cases per 100,000 persons at risk. Adjusting for other factors, a one-day in rainfall resulted in a 7% statistically significant increase in malaria cases (p < 0.0001). Malaria morbidity was also significantly associated with geographic location (western, central and northeastern region of the country), total evaporation under shelter, maximum daily temperature at a two-meter altitude and malaria morbidity (p < 0.0001).
CONCLUSIONS: In this study, we have established the association between malaria morbidity and geo-climatic predictors such as geographical location, total evaporation under shelter and maximum daily temperature at a two-meter altitude. We show that the average number of malaria cases increased positively as a function of the average number of rainy days, the total quantity of rainfall and the average daily temperature. These findings are important building blocks to help the government of DRC to set up a warning system integrating the monitoring of rainfall and temperature trends and the early detection of anomalies in weather patterns in order to forecast potential large malaria morbidity events.

Keywords:  DRC; geo-climatic factors; malaria cases; morbidity; poisson generalized linear model

DOI:  https://doi.org/10.3390/ijerph19073811
Int J Environ Res Public Health. 2022 Apr 06. pii: 4390. [Epub ahead of print]19(7):

Knowledge, Attitudes, Beliefs, and Practices Regarding Dengue in La Réunion Island, France.

Florence Lamaurt, Olga De Santis, Julie Ramis, Cédric Schultz, Ana Rivadeneyra, Mathias Waelli, Antoine Flahault.

  Since 2017, La Réunion island has been facing a major epidemic of dengue. Despite actions carried out by the anti-vector control department, public authorities have failed to contain this epidemic. As individual involvement is key to success in vector control, we carried out a mixed-methods study on population knowledge, attitudes, beliefs, and practices (KABP) regarding dengue infection risk in La Réunion. The study combined quantitative data collected through a questionnaire administered to a representative sample of 622 people to assess the use of protective measures and the perception of severity and risk of dengue, and a sample of 336 people to assess the level of knowledge and concern about dengue, as well as qualitative data collected through semi-structured interviews among 11 individuals who had previously completed the questionnaire. The study results show that 63% of the surveyed population had a good level of knowledge associated with age, education, and socio-professional category variables-78% considered dengue to be a serious threat, and concern was estimated at 6/10, while 71% were likely to use protective measures. The interviews revealed contradictory behaviors in the implementation of recommended actions, in conflict with personal beliefs regarding respect of human body and nature. The study also revealed a loss of confidence in public authorities.

Keywords:  KABP; La Reunion; dengue; mixed-methods study

DOI:  https://doi.org/10.3390/ijerph19074390
Am J Trop Med Hyg. 2022 Apr 11. pii: tpmd211195. [Epub ahead of print]

Strengthening Management, Community Engagement, and Sustainability of the Subnational Response to Accelerate Malaria Elimination in Namibia.

Amanda Marr Chung, Eliza Love, Julie Neidel, Idah Mendai, Sakeus Nairenge, Lesley-Anne van Wyk, Sara Rossi, Erika Larson, Peter Case, Jonathan Gosling, Greyling Viljoen, Macdonald Hove, Bruce Agins, Jerobeam Hamanyela, Roland Gosling.

Leadership and management skills are critical for health programs to deliver high-quality interventions in complex systems. In malaria-eliminating countries, national and subnational health teams are reorienting strategies to address focal transmission while preventing new cases and adapting to decentralization and declines in external financing. A capacity-strengthening program in two regions in Namibia helped malaria program implementers identify and address key operational, political, and financial challenges. The program focused on developing skills and techniques in problem-solving and teamwork, engaging decision-makers, and using financial evidence to prioritize domestic resources for malaria through participatory approaches. Results of the program included an observed 40% increase in malaria case reporting, 32% increase in reporting and tracing of imported malaria cases, 10% increase in malaria case management, integration of malaria activities into local operational plans, and an increase in subnational resources for malaria teams. To promote program sustainability beyond the implementation period, key program aspects were institutionalized into existing health system structures, program staff were trained in change leadership, and participants integrated the skills and approaches into their professional roles. A capacity -strengthening program with joint focus on leadership, management, and advocacy has potential for application to other health issues and geographies.

DOI: https://doi.org/10.4269/ajtmh.21-1195