bims-mosdis 2022-12-11 papers

bims-mosdis

Biomed News

on Mosquito distribution and disease

Issue of 2022–12–11
nineteen papers selected by
Richard Halfpenny, Staffordshire University

Screening eaves of houses reduces indoor mosquito density in rural, western Kenya.
Dried out but alive: how mosquitoes survive 8 months.
Visual threats reduce blood-feeding and trigger escape responses in Aedes aegypti mosquitoes.
Genetic diversity of Aedes aegypti in the central-upper Paraná Cross-Border axis in Paraguay.
Meteorological indicators of dengue epidemics in non-endemic Northwest Argentina.
Biology, bionomics and life-table studies of Anopheles stephensi (Diptera: Culicidae) in Sri Lanka and estimating the vectorial potential using mathematical approximations.
Which trap is best? Alternatives to outdoor human landing catches for malaria vector surveillance: a meta-analysis.
Knowledge, attitudes, and practices regarding malaria control among communities living in the south Cameroon forest region.
Ownership and use of long-lasting insecticidal nets three months after a mass distribution campaign in Uganda, 2021.
Malaria and dengue outbreaks during a national disaster in Pakistan: A rising concern for public health.
Vaccination with a Zika virus envelope domain III protein induces neutralizing antibodies and partial protection against Asian genotype in immunocompetent mice.
Achievements of the national malaria control and elimination program in the People's Republic of China: the Atlas of Malaria Transmission in China.
Temporal and spatial analysis of municipal dengue cases in Paraná and social and environmental indicators, 2012 to 2021: ecological study.
Fast surveillance response reveals the introduction of a new yellow fever virus sub-lineage in 2021, in Minas Gerais, Brazil.
Mapping Dengue in children in a Colombian Caribbean Region: clinical and epidemiological analysis of more than 3500 cases.
Spatiotemporal analysis of malaria incidence in Côte d'Ivoire from 2015 to 2019.
Malaria Elimination: What Can Africa Learn from China?
A randomized controlled trial showing safety and efficacy of a whole sporozoite vaccine against endemic malaria.
Malaria Elimination in China and Sustainability Concerns in the Post-elimination Stage.

Malar J. 2022 Dec 09. 21(1): 377

Screening eaves of houses reduces indoor mosquito density in rural, western Kenya.

Bernard Abong'o, John E Gimnig, Diana Omoke, Eric Ochomo, Edward D Walker.

   BACKGROUND: Despite the scale-up of insecticide-treated nets and indoor residual spraying, the bulk of malaria transmission in western Kenya still occurs indoors, late at night. House improvement is a potential long-term solution to further reduce malaria transmission in the region.
METHODS: The impact of eave screening on mosquito densities was evaluated in two rural villages in western Kenya. One-hundred-and-twenty pairs of structurally similar, neighbouring houses were used in the study. In each pair, one house was randomly selected to receive eave screening at the beginning of the study while the other remained unscreened until the end of the sampling period. Mosquito sampling was performed monthly by motorized aspiration method for 4 months. The collected mosquitoes were analysed for species identification.
RESULTS: Compared to unscreened houses, significantly fewer female Anopheles funestus (RR = 0.40, 95% CI 0.29-0.55), Anopheles gambiae Complex (RR = 0.46, 95% CI 0.34-0.62) and Culex species (RR = 0.53, 95% CI 0.45-0.61) were collected in screened houses. No significant differences in the densities of the mosquitoes were detected in outdoor collections. Significantly fewer Anopheles funestus were collected indoors from houses with painted walls (RR = 0.05, 95% CI 0.01-0.38) while cooking in the house was associated with significantly lower numbers of Anopheles gambiae Complex indoors (RR = 0.60, 95% CI 0.45-0.79). Nearly all house owners (99.6%) wanted their houses permanently screened, including 97.7% that indicated a willingness to use their own resources. However, 99.2% required training on house screening. The cost of screening a single house was estimated at KES6,162.38 (US$61.62).
CONCLUSION: Simple house modification by eave screening has the potential to reduce the indoor occurrence of both Anopheles and Culex mosquito species. Community acceptance was very high although education and mobilization may be needed for community uptake of house modification for vector control. Intersectoral collaboration and favourable government policies on housing are important links towards the adoption of house improvements for malaria control.

Keywords:  Anopheles funestus; Anopheles gambiae; Eave screening

DOI:  https://doi.org/10.1186/s12936-022-04397-y
Trends Parasitol. 2022 Dec 02. pii: S1471-4922(22)00279-3. [Epub ahead of print]

Dried out but alive: how mosquitoes survive 8 months.

Francesco Baldini, Mafalda Viana.

  How malaria mosquitoes persist during the dry season in the Sahel and rapidly rebound at the onset of rains is unclear. Recently, Faiman and colleagues demonstrated that aestivation, a summer dormancy mechanism, is a major persistence strategy of Anopheles mosquitoes, which could be targeted by vector control.

Keywords:  Anopheles mosquito; aestivation; isotopic labelling; long-distance migration; malaria

DOI:  https://doi.org/10.1016/j.pt.2022.11.006
Sci Rep. 2022 Dec 09. 12(1): 21354

Visual threats reduce blood-feeding and trigger escape responses in Aedes aegypti mosquitoes.

Nicole E Wynne, Karthikeyan Chandrasegaran, Lauren Fryzlewicz, Clément Vinauger.

The diurnal mosquitoes Aedes aegypti are vectors of several arboviruses, including dengue, yellow fever, and Zika viruses. To find a host to feed on, they rely on the sophisticated integration of olfactory, visual, thermal, and gustatory cues emitted by the hosts. If detected by their target, this latter may display defensive behaviors that mosquitoes need to be able to detect and escape in order to survive. In humans, a typical response is a swat of the hand, which generates both mechanical and visual perturbations aimed at a mosquito. Here, we used programmable visual displays to generate expanding objects sharing characteristics with the visual component of an approaching hand and quantified the behavioral response of female mosquitoes. Results show that Ae. aegypti is capable of using visual information to decide whether to feed on an artificial host mimic. Stimulations delivered in a LED flight arena further reveal that landed Ae. aegypti females display a stereotypical escape strategy by taking off at an angle that is a function of the direction of stimulus introduction. Altogether, this study demonstrates that mosquitoes landed on a host mimic can use isolated visual cues to detect and avoid a potential threat.

DOI: https://doi.org/10.1038/s41598-022-25461-2
Rev Peru Med Exp Salud Publica. 2022 Apr-Jun;39(2):39(2): 170-177

Genetic diversity of Aedes aegypti in the central-upper Paraná Cross-Border axis in Paraguay.

Sady C Britez, Leidi Herrera, María C Ferreira, Leticia M Rolón, Vanessa Ruiz, Nilsa González-Brítez.

OBJECTIVE: To determine the genetic diversity of Aedes aegypti in the Central-Alto Paraná cross-border road corridor of Paraguay, an area that has reports of dengue cases.
MATERIALS AND METHODS: Twenty adult females were selected from hatching Ae. aegypti eggs from households geolocated in the departments of Alto Paraná, Caaguazú, Cordillera and Central, between 2018 and 2019. DNA was extracted from the tissue of females for amplifying their polymorphic patterns by random amplification of polymorphic DNA by PCR (RAPD-PCR), using primers H3 and B03 in order to identify genetic parameters of population diversity. The relationships between mosquito populations according to locality were observed by unpaired arithmetic mean analysis. We used DIVA-GIS 7.3.0 and MAXENT to analyze the suitable areas of actual and potential geographic distribution of these Ae. aegypti populations.
RESULTS: Forty loci were identified by RAPD-PCR profiling, with moderate gene differentiation (Gst = 0.12). The cross-border corridor presented bioclimatic conditions for the presence of variant populations of Ae. aegypti, with precipitation in the warmest quarter and mean temperature in the driest quarter being determinant in the distribution.
CONCLUSIONS: There is evidence of moderate genetic diversity in Ae. aegypti populations from areas that have reported dengue cases in the cross-border road corridor linking the Central and Alto Paraná departments of Paraguay. The study of genetic variability of Ae. aegypti is very useful for entomo-epidemiological surveillance and evaluation of possible resistance to chemical control.

DOI: https://doi.org/10.17843/rpmesp.2022.392.10709
Infect Dis Model. 2022 Dec;7(4): 823-834

Meteorological indicators of dengue epidemics in non-endemic Northwest Argentina.

Javier Armando Gutierrez, Karina Laneri, Juan Pablo Aparicio, Gustavo Javier Sibona.

  In the last two decades dengue cases increased significantly throughout the world, giving place to more frequent outbreaks in Latin America. In the non-endemic city of San Ramón de la Nueva Orán, located in Northwest Argentina, large dengue outbreaks alternate with several years of smaller ones. This pattern, as well as the understanding of the underlying mechanisms, could be essential to design proper strategies to reduce epidemic size. We develop a stochastic model that includes climate variables, social structure, and mobility between a non-endemic city and an endemic area. Climatic variables were input of a mosquito population ecological model, which in turn was coupled to a meta-population, spatially explicit, epidemiological model. Human mobility was included into the model given the high border crossing to the northern country of Bolivia, where dengue transmission is sustained during the whole year. We tested different hypotheses regarding people mobility as well as climate variability by fitting numerical simulations to weekly clinical data reported from 2009 to 2016. After assessing the number of imported cases that triggered the observed outbreaks, our model allows to explain the observed epidemic pattern. We found that the number of vectors per host and the effective reproductive number are proxies for large epidemics. Both proxies are related with climate variability such as rainfall and temperature, opening the possibility to test these meteorological variables for forecast purposes.

Keywords:  Dengue; Mathematical modelling; Mosquitoes population; Outbreak

DOI:  https://doi.org/10.1016/j.idm.2022.10.004
Parasitol Int. 2022 Dec 02. pii: S1383-5769(22)00179-9. [Epub ahead of print]93 102715

Biology, bionomics and life-table studies of Anopheles stephensi (Diptera: Culicidae) in Sri Lanka and estimating the vectorial potential using mathematical approximations.

Justin Jude, Nayana Gunathilaka, Lahiru Udayanaga, Deepika Fernando, Prasad Premarathne, Rajitha Wickremasinghe, Wimaladharma Abeyewickreme.

   BACKGROUND: Anopheles stephensi is an invasive mosquito in Sri Lanka that can potentially transmit malaria. The transmission intensity is linked with biology, bionomic and behavioral aspects of a vector that are associated with the Vectorial Capacity (VC). However, the influence of larval conditions eventually affects the vectorial potential of An. stephensi are not well understood.
METHODS: A colony of An. stephensi was established at the Regional Centre of the Open University of Sri Lanka, Jaffna District. The colony was maintained under confined conditions according to standard protocols. Biotypes of An. stephensi were characterized by referring to the number of egg ridges. Information on (a) biological aspects of eggs (duration for egg hatching, egg development and hatchability), (b) larval development time, larval survivorship pupation success, resting depth of larvae), (c) pupae (adult emergence rate, average time for adult emergence) and (d) adults (biting frequency, mating success gonotrophic cycle, fecundity, duration for egg-laying, percentage of sexes, adult survival/longevity) were evaluated under life-table analysis. Further, selected morphometric characters of each life cycle stage were recorded from the eggs (length and breadth), larvae (head length, width of head, length of thorax, width of thorax, length of abdomen, width of abdomen, and the total length of larvae), pupae (cephalothoracic length and width) and adults (length & width of wing, thorax and abdomen). The VC was calculated using a mathematical-based approach. Descriptive statistics, General Linear Model (GLM) and independent-sample t-test were used for the statistical analysis.
RESULTS: All three biotypes were identified based on egg morphology. Mysorensis biotype (47%; n = 470) was predominant followed by type (38.1%; n = 381) and intermediate (14.9%; n = 149). The mean egg length (F(2,997) = 3.56; P = 0.029) and breadth (F(2,997) = 4.57; P = 0.011) denoted significant differences among the three biotypes. The mating success of females observed was 80.7 ± 4.45%. The mean hatching period was 1.9 ± 0.03 days, with a hatching rate of 86.2 ± 0.77%. Overall, 8.0 ± 0.14 days were required for larval development and 30.3 ± 0.14 h were spent in the pupal stage. The pupation success was 94.5 ± 0.37%, and the majority were males (53.1 ± 0.73%). The mean fecundity was 106.5 ± 6.38 eggs and a gonotrophic cycle of 3.4 ± 0.06 days. The female survival rate was 43.2 ± 2.4%, with a mean biting frequency of 66.6 ± 3.5%. The average VC of adult An. stephensi was estimated to be 18.7.
CONCLUSIONS: The type biotype, which is an effective vector in the Indian subcontinent is present in Sri Lanka. According to the mathematical approximation, An. stephensi found locally has a vectorial capacity of over 18. Therefore, this study warrants the health authorities and vector control programmes to continue the entomological surveys, monitoring of vector densities and implementing appropriate vector control interventions based on biology and bionomic information of vectors.

Keywords:  An. stephensi; Bionomics; Life-table; Vectorial capacity

DOI:  https://doi.org/10.1016/j.parint.2022.102715
Malar J. 2022 Dec 09. 21(1): 378

Which trap is best? Alternatives to outdoor human landing catches for malaria vector surveillance: a meta-analysis.

Jordan Eckert, Seun Oladipupo, Yifan Wang, Shanshan Jiang, Vivek Patil, Benjamin A McKenzie, Neil F Lobo, Sarah Zohdy.

   BACKGROUND: Human landing catches (HLC) are an entomological collection technique in which humans are used as attractants to capture medically relevant host-seeking mosquitoes. The use of this method has been a topic of extensive debate for decades mainly due to ethical concerns. Many alternatives to HLC have been proposed; however, no quantitative review and meta-analysis comparing HLC to outdoor alternative trapping methods has been conducted.
METHODS: A total of 58 comparisons across 12 countries were identified. We conducted a meta-analysis comparing the standardized mean difference of Anopheles captured by HLC and alternative traps. To explain heterogeneity, three moderators were chosen for analysis: trap type, location of study, and species captured. A meta-regression was fit to understand how the linear combination of moderators helped in explaining heterogeneity. The possibility of biased results due to publication bias was also explored.
RESULTS: Random-effects meta-analysis showed no statistically significant difference in the mean difference of Anopheles collected. Moderator analysis was conducted to determine the effects of trap type, geographical location of study, and the species of Anopheles captured. On average, tent-based traps captured significantly more Anopheles than outdoor HLC (95% CI: [- .9065, - 0.0544]), alternative traps in Africa captured on average more mosquitoes than outdoor HLC (95% CI: [- 2.8750, - 0.0294]), and alternative traps overall captured significantly more Anopheles gambiae s.l. than outdoor HLC (95% CI: [- 4.4613, - 0.2473]) on average. Meta-regression showed that up to 55.77% of the total heterogeneity found can be explained by a linear combination of the three moderators and the interaction between trap type and species. Subset analysis on An. gambiae s.l. showed that light traps specifically captured on average more of this species than HLC (95% CI: [- 18.3751, - 1.0629]). Publication bias likely exists. With 59.65% of studies reporting p-values less than 0.025, we believe there is an over representation in the literature of results indicating that alternative traps are superior to outdoor HLC.
CONCLUSIONS: Currently, there is no consensus on a single "magic bullet" alternative to outdoor HLC. The diversity of many alternative trap comparisons restricts potential metrics for comparisons to outdoor HLC. Further standardization and specific question-driven trap evaluations that consider target vector species and the vector control landscape are needed to allow for robust meta-analyses with less heterogeneity and to develop data-driven decision-making tools for malaria vector surveillance and control.

Keywords:  Anopheles; Collection; HLC; Meta-analysis; Mosquito

DOI:  https://doi.org/10.1186/s12936-022-04332-1
IJID Reg. 2022 Dec;5 169-176

Knowledge, attitudes, and practices regarding malaria control among communities living in the south Cameroon forest region.

Roland Bamou, Timoléon Tchuinkam, Edmond Kopya, Parfait Awono-Ambene, Flobert Njiokou, Joseph Mwangangi, Christophe Antonio-Nkondjio.

   Objective: This study assessed knowledge, attitudes, and practices (KAP) regarding malaria among communities living in the equatorial forest region of south Cameroon.
Methods: The study was conducted in Olama and Nyabessan. Interviews were undertaken using a semi-structured questionnaire for data collection on KAP, while malaria rapid diagnostic testing, using SD BIOLINE kits, was employed for malaria parasite detection.
Results: In total, 186 heads of households (HoH), comprising 105 (56.45%) males and 81 (43.45%) females, were interviewed. The majority of HoH demonstrated good knowledge of malaria (86.56%; n = 161) and control measures, with a high proportion of long-lasting insecticidal net (LLIN) ownership (96.8%; n = 180). More than two-thirds (81.1%; n = 151) of households owned at least one LLIN for two people. The majority of HoH (85.40%) declared visiting hospitals or clinics in cases of suspected malaria. Malaria parasite prevalence was high in the two study sites (63.9% in Nyabessan and 48.65% in Olama), and varied according to age, house type, and sleeping time.
Conclusion: The study indicated that despite good knowledge of malaria, high possession and utilization of control measures by population, transmission of malaria still persist in the area. The study stress the need for implementing additional control measures to improve the fight against malaria in the area.

Keywords:  Cameroon; HoH, head of household; IRS, indoor residual spraying; KAP; KAP, knowledge, attitude, and practice; LLIN, long-lasting insecticidal net; MoH, Ministry of Health. PBO, piperonyl butoxide; NMCP, National Malaria Control Program; WHO, World Health Organization; forested area; mRDT, malaria rapid diagnostic test; malaria determinants; malaria prevalence

DOI:  https://doi.org/10.1016/j.ijregi.2022.11.003
Malar J. 2022 Dec 03. 21(1): 367

Ownership and use of long-lasting insecticidal nets three months after a mass distribution campaign in Uganda, 2021.

Andrew Kwiringira, Carol Nanziri, Edirisa Juniour Nsubuga, Stella Martha Migamba, Vivian Ntono, Immaculate Atuhaire, Sherry Rita Ahirirwe, Alice Asio, Shaban Senyange, Petranilla Nakamya, Veronicah Masanja, Sarah Elayeete, Allan Komakech, Hildah T Nansikombi, Patience Mwine, Rose Nampeera, Alex Ndyabakira, Paul Okello, Richard Migisha, Lilian Bulage, Benon Kwesiga, Daniel Kadobera, Damian Rutazaana, Julie R Harris, Alex R Ario.

   BACKGROUND: Uganda conducted its third mass long-lasting insecticidal net (LLIN) distribution campaign in 2021. The target of the campaign was to ensure that 100% of households own at least one LLIN per two persons and to achieve 85% use of distributed LLINs. LLIN ownership, use and associated factors were assessed 3 months after the campaign.
METHODS: A cross-sectional household survey was conducted in 14 districts from 13 to 30 April, 2021. Households were selected using multistage sampling. Each was asked about LLIN ownership, use, duration since received to the time of interview, and the presence of LLINs was visually verified. Outcomes were having at least one LLIN per two household members, and individual LLIN use. Modified Poisson regression was used to assess associations between exposures and outcomes.
RESULTS: In total, 5529 households with 27,585 residents and 15,426 LLINs were included in the analysis. Overall, 95% of households owned ≥ 1 LLIN, 92% of the households owned ≥ 1 LLIN < 3 months old, 64% of households owned ≥ 1 LLIN per two persons in the household. Eighty-seven per cent could sleep under an LLIN if every LLIN in the household were used by two people, but only 69% slept under an LLIN the night before the survey. Factors associated with LLIN ownership included believing that LLINs are protective against malaria (aPR = 1.13; 95% CI 1.04-1.24). Reported use of mosquito repellents was negatively associated with ownership of LLINs (aPR = 0.96; 95% CI 0.95-0.98). The prevalence of LLIN use was 9% higher among persons who had LLINs 3-12 months old (aPR = 1.09; 95% CI 1.06-1.11) and 10% higher among those who had LLINs 13-24 months old (aPR = 1.10; 95% CI 1.06-1.14) than those who had LLINs < 3 months old. Of 3,859 LLINs identified in the households but not used for sleeping the previous night, 3250 (84%) were < 3 months old. Among these 3250, 41% were not used because owners were using old LLINs; 16% were not used because of lack of space for hanging them; 11% were not used because of fear of chemicals in the net; 5% were not used because of dislike of the smell of the nets; and, 27% were not used for other reasons.
CONCLUSION: The substantial difference between the population that had access to LLINs and the population that slept under LLINs indicates that the National Malaria Control Programme (NMCP) may need to focus on addressing the main drivers or barriers to LLIN use. NMCP and/or other stakeholders could consider designing and conducting targeted behaviour change communication during subsequent mass distribution of LLINs after the mass distribution campaign to counter misconceptions about new LLINs.

Keywords:  Long-lasting insecticidal nets; Malaria; Mass campaigns; Ownership and use; Uganda

DOI:  https://doi.org/10.1186/s12936-022-04401-5
J Glob Health. 2022 12 03. 12 03076

Malaria and dengue outbreaks during a national disaster in Pakistan: A rising concern for public health.

Talal Arshad, Ali Wajahat, Adina Jabeen, Syed Hasan Ali.

DOI: https://doi.org/10.7189/jogh.12.03076
Trop Med Health. 2022 Dec 05. 50(1): 91

Vaccination with a Zika virus envelope domain III protein induces neutralizing antibodies and partial protection against Asian genotype in immunocompetent mice.

Minna Shin, Kiju Kim, Hyo-Ji Lee, Yu-Jin Jung, Jeongho Park, Tae-Wook Hahn.

   BACKGROUND: Zika virus (ZIKV) is a mosquito-borne flavivirus classified in Flaviviridae family such as dengue (DENV), yellow fever, and West Nile virus. An outbreak of ZIKV infection can pose a major public health risk because the contagion is unpredictable and induces severe pathology such as Guillan-Barre syndrome and neonatal microcephaly. However, an authorized ZIKV vaccine is not yet available, while several vaccine candidates are under development.
METHODS: In this study, we constructed a recombinant ZIKV vaccine (Z_EDIII) that includes ZIKV envelope protein domain III using E. coli expression system. Then both humoral and cellular immunity were examined in C57BL/6 (female, 8-weeks-old) mice via Indirect ELISA assay, PRNT, ELISpot and cytokine detection for IFN-γ, TNF-α, and IL-12. In addition, the cross protection against DENV was evaluated in pups from Z_EDIII vaccinated and infected dam.
RESULTS: Mice immunized by Z_EDIII produced a significant amount of ZIKV EDIII-specific and neutralizing antibodies. Together with antibodies, effector cytokines, such as IFN-γ, TNF-α, and IL-12 were induced. Moreover, vaccinated females delivered the adaptive immunity to neonates who are protective against ZIKV and DENV challenge.
CONCLUSIONS: This study observed Z-EDIII-induced humoral and cellular immunity that protected hosts from both ZIKV and DENV challenges. The result suggests that our ZIKV EDIII recombinant vaccine has potential to provide a new preventive strategy against ZIKV infection.

Keywords:  Disease prevention; Infectious diseases; Zika virus

DOI:  https://doi.org/10.1186/s41182-022-00485-6
Front Med. 2022 Dec 05.

Achievements of the national malaria control and elimination program in the People's Republic of China: the Atlas of Malaria Transmission in China.

Jun Feng, Li Zhang, Zhigui Xia, Shuisen Zhou, Ning Xiao, Xiao-Nong Zhou.

  In 2017, China achieved the target of zero indigenous malaria case for the first time, and has been certified as malaria free by World Health Organization in 2021. To further summarize the historical achievements and technical experiences of the elimination program, a project on the Roadmap Analysis and Verification for Malaria Elimination in China was carried out. Results of the project were compiled and published as the Atlas of Malaria Transmission in China (The Atlas). The Atlas using modern digital information technologies, has been supported by various data from 24 malaria endemic provinces of China since 1950, to assess the changes in malaria epidemic patterns from 1950 to 2019 at national and provincial levels. The Atlas is designed as two volumes, including a total of 1850 thematic maps and more than 130 charts, consisting of introductory maps, thematic maps of malaria epidemic and control at national and provincial levels. It objectively and directly shows the epidemic history, evolution process, and great achievements of the national malaria control and elimination program in China. The Atlas has important reference value for summing up historical experience in the national malaria elimination program of China, and malaria control and elimination in other endemic countries in the world.

Keywords:  China; atlas; control; elimination; malaria; transmission

DOI:  https://doi.org/10.1007/s11684-021-0917-7
Rev Bras Epidemiol. 2022 ;pii: S1415-790X2022000100436. [Epub ahead of print]25 e220039

Temporal and spatial analysis of municipal dengue cases in Paraná and social and environmental indicators, 2012 to 2021: ecological study.

Gustavo Cezar Wagner Leandro, Laiz Mangini Cicchelero, Marcia Procopiuk, Fernanda de Oliveira Biaggio Correa, Pamela Cristina Fragata Dos Santos, Adriana Rezende Lopes, Oscar Kenji Nihei.

OBJECTIVE: Analyze the temporal trend and spatial distribution of the incidence rate of dengue cases in Paraná and its regions between 2012 to 2021 and investigate associated sociodemographic and environmental variables.
METHODS: Ecological study with temporal and spatial analysis of the dengue incidence rate reported in the Disease and Notification Information System (SINAN) in the period 2012 to 2021 and investigation of sociodemographic and environmental variables. To identify differences between municipal incidence rates the Mann-Whitney and Kruskal-Wallis test followed by Dunn's test for multiple comparisons were used. Prais-Winsten regression was used for temporal trend analysis and for spatial analysis the univariate and bivariate Local Moran analysis were applied.
RESULTS: 548,683 cases of dengue were confirmed in the period, the highest state incidence rate was observed in 2020, with 15 health regions presenting more than 500 cases/100,000 inhabitants. Higher incidences were observed among women, age group of 20-59 years and white color/race. Despite annual variations, a stationary trend was observed for incidence rates according to sex, age group, color/race and macro-region. More than half of the municipalities in Paraná formed spatial clusters (Moran's I=0.679), where 73 (18.3%) municipalities with high incidence rate formed clusters. High-High clusters of dengue incidence rate with urbanization and High-Low clusters of incidence rate with vegetation cover were observed.
CONCLUSION: Sociodemographic and environmental determinants were related to the high incidence rates of dengue and heterogeneous spatial distribution in the state of Paraná, indicating the need to strengthen health surveillance actions.

DOI: https://doi.org/10.1590/1980-549720220039
Mem Inst Oswaldo Cruz. 2022 ;pii: S0074-02762022000101134. [Epub ahead of print]117 e220127

Fast surveillance response reveals the introduction of a new yellow fever virus sub-lineage in 2021, in Minas Gerais, Brazil.

Miguel Souza Andrade, Fabrício Souza Campos, Cirilo Henrique de Oliveira, Ramon Silva Oliveira, Aline Alves Scarpellini Campos, Marco Antônio Barreto de Almeida, Vagner de Souza Fonseca, Danilo Simonini-Teixeira, Anaiá da Paixão Sevá, Andrea Oliveira Dias Temponi, Fernando Maria Magalhães, Danielle Costa Capistrano Chaves, Maira Alves Pereira, Ludmila Oliveira Lamounier, Givaldo Gomes de Menezes, Sandy Micaele Aquino-Teixeira, Maria Eduarda Gonçalves-Dos-Santos, Sofía Bernal-Valle, Nicolas Felipe Drumm Müller, Jader da Cruz Cardoso, Edmilson Dos Santos, Maria Angélica Mares-Guia, George Rêgo Albuquerque, Alessandro Pecego Martins Romano, Ana Cláudia Franco, Bergmann Morais Ribeiro, Paulo Michel Roehe, Filipe Vieira Santos de Abreu.

BACKGROUND: In Brazil, the yellow fever virus (YFV) is maintained in a sylvatic cycle involving wild mosquitoes and non-human primates (NHPs). The virus is endemic to the Amazon region; however, waves of epidemic expansion reaching other Brazilian states sporadically occur, eventually causing spillovers to humans.
OBJECTIVES: To report a surveillance effort that led to the first confirmation of YFV in NHPs in the state of Minas Gerais (MG), Southeast region, in 2021.
METHODS: A surveillance network was created, encompassing the technology of smartphone applications and coordinated actions of several research institutions and health services to monitor and investigate NHP epizootics.
FINDINGS: When alerts were spread through the network, samples from NHPs were collected and YFV infection confirmed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and genome sequencing at an interval of only 10 days. Near-complete genomes were generated using the Nanopore MinION sequencer. Phylogenetic analysis indicated that viral genomes were related to the South American genotype I, clustering with a genome detected in the Amazon region (state of Pará) in 2017, named YFVPA/MG sub-lineage. Fast YFV confirmation potentialised vaccination campaigns.
MAIN CONCLUSIONS: A new YFV introduction was detected in MG 6 years after the beginning of the major outbreak reported in the state (2015-2018). The YFV strain was not related to the sub-lineages previously reported in MG. No human cases have been reported, suggesting the importance of coordinated surveillance of NHPs using available technologies and supporting laboratories to ensure a quick response and implementation of contingency measures to avoid YFV spillover to humans.

DOI: https://doi.org/10.1590/0074-02760220127
Infez Med. 2022 ;30(4): 602-609

Mapping Dengue in children in a Colombian Caribbean Region: clinical and epidemiological analysis of more than 3500 cases.

Sandra Milena Ricardo-Rivera, Leidy Marcela Aldana-Carrasco, Ivan David Lozada-Martinez, Maria Paz Bolaño-Romero, Nicole Acevedo-Lopez, Walter Antonio Sajona-Leguia, Daniela Lucía Bula-García, Feraz Fady Zaghab-Zgieb, Juan Carlos Peralta Farak, Juliana López Ordóñez.

  Dengue continues to be a global public health problem due to its impact in terms of morbidity and mortality and economic burden on health systems, with severe effects mainly on children. Among the objectives of sustainable development is the control of infectious diseases; therefore, it is necessary to evaluate the impact of existing programs on the prevention and management of infectious diseases. The aim of this study was to analyze the epidemiological, clinical, and geospatial behavior of dengue in children in a region of the Colombian Caribbean. A retrospective cross-sectional study was carried out. The data provided by the Municipal Health Secretariat were taken and the cases of dengue and severe dengue in children aged 0 to 17 years reported in Sincelejo, Colombia, were extracted. The sociodemographic and clinical characteristics presented were analyzed and descriptive statistics were performed with tables and graphs of frequency and accumulated percentages. To locate the areas with the highest incidence of cases during the year, a geospatial location of the cases was carried out with the QGIS v.3.8 program. In 2019, there were 3611 cases of dengue fever in children aged 0 to 17 years. There were 1394 (38.6%) cases with warning signs, and 41 (1.1%) cases of severe dengue fever. Cases of severe dengue fever occurred more frequently in women. The incidence rate found was 3927 and 45.1 cases per 100,000 population, for dengue and severe dengue in children, respectively. The age ranges with the highest number of cases were children aged 4 to 9 years with 1778 cases. The clinical presentation was varied, with the most frequent symptoms, in all groups, being fever in 100% of cases, myalgias ≥71%, and arthralgias ≥64%. Only 9% (n=315) of the cases, corresponded to cases in the rural area. A very high incidence of cases of dengue and dengue with alarm signs in children was evidenced in the Colombian Caribbean region, mainly in the urban area, despite the existence of public health programs and strategies to control the burden of diseases transmitted by arbovirus vectors.

Keywords:  Arboviruses; epidemiology; flavivirus; vector-borne disease

DOI:  https://doi.org/10.53854/liim-3004-16
Trans R Soc Trop Med Hyg. 2022 Dec 06. pii: trac112. [Epub ahead of print]

Spatiotemporal analysis of malaria incidence in Côte d'Ivoire from 2015 to 2019.

Konan R M Azongnibo, Negnorogo Guindo-Coulibaly, Emmanuel Bonnet, Maimouna N W Kokro-Djahouri, Konan F Assouho, Mathieu G Niamke, Florence Fournet, Paul K Anoh, Serge-Brice Assi, Akré M Adja.

   BACKGROUND: The collection of malaria cases over time allows the identification of areas with the highest incidence. Our objective was to characterize the spatial distribution of malaria in Côte d'Ivoire from 2015 to 2019 at the health district level.
METHODS: Data on the number of reported malaria cases confirmed by rapid diagnostic test (RDT) in the general population, the number of patients attending medical consultations and the total population by health district and year were collected from the National Malaria Control Program in Côte d'Ivoire. Crude and adjusted incidence rates were estimated for each health district and year. Adjusted incidence rates were used to perform global (Moran's index) and local indicators of spatial autocorrelation (LISA) analyses.
RESULTS: Between 2015 and 2019, mean crude incidence rates increased from 155.5‰ to 229.8‰. We observed significant heterogeneity in malaria incidence rates across the study period and within a given year. The overall Moran index showed spatial autocorrelation for every year analysed except 2017. The LISA analysis showed that the health districts with high incidence rates were concentrated in the western zone of Côte d'Ivoire.
CONCLUSIONS: The use of spatial analyses to identify the areas with the highest malaria incidence rates is a relevant approach to optimize control measures in targeted areas.

Keywords:  Côte d'Ivoire; malaria; spatiotemporal analysis

DOI:  https://doi.org/10.1093/trstmh/trac112
Int J MCH AIDS. 2022 ;11(2): e526

Malaria Elimination: What Can Africa Learn from China?

Claude Ngwayu Nkfusai, Olivia Ngou, Caroline Ekoko Subi, Sofia Mohlin, Fidele Bemadoum, Sylvanus Teboh, Frankline Sevidzem Wirsiy, Luchuo Engelbert Bain.

  For decades now, malaria has been an important public health concern in Africa, which bears the greatest burden for the disease, affecting children and adults alike. Although a few countries (Australia, Brunei, Singapore, and Algeria, among others) have previously eliminated malaria, the World Health Organization (WHO), on June 30, 2021, declared China malaria-free. This commentary seeks to explore what China did differently to eliminate malaria and what Africa can learn from China's experience. First, Africa can use innovative tools and strategies used by China to attain success. Second, Africa can create a multi-sector collaboration among Heads of States in high burden malaria-affected countries by involving all stakeholders such as ministries of health, finance, research, education, development, public security, the army, police, commerce, industry, and information technology, customs, media and tourism to jointly fight malaria in all African countries. Furthermore, African countries could adapt the genetics-based approaches used by China in the elimination of mosquito breeding grounds. Finally, Africa can also adapt a better surveillance system of reporting on malaria daily as China did in their experience.

Keywords:  Africa; China; Elimination; Health; Learn; Malaria; sub-Saharan Africa

DOI:  https://doi.org/10.21106/ijma.526
Sci Transl Med. 2022 Dec 07. 14(674): eabj3776

A randomized controlled trial showing safety and efficacy of a whole sporozoite vaccine against endemic malaria.

Sodiomon B Sirima, Alphonse Ouédraogo, Alfred B Tiono, Jean M Kaboré, Edith C Bougouma, Maurice S Ouattara, Désiré Kargougou, Amidou Diarra, Noelie Henry, Issa N Ouédraogo, Peter F Billingsley, Anita Manoj, Yonas Abebe, Natasha Kc, Adam Ruben, Thomas L Richie, Eric R James, Sudhaunshu Joshi, Biraj Shrestha, Kathy Strauss, Kirsten E Lyke, Christopher V Plowe, Gail E Potter, Catherine Cox, Walter Jones, B Kim Lee Sim, Stephen L Hoffman, Matthew B Laurens.

A highly effective malaria vaccine remains elusive despite decades of research. Plasmodium falciparum sporozoite vaccine (PfSPZ Vaccine), a metabolically active, nonreplicating, whole parasite vaccine demonstrated safety and vaccine efficacy (VE) against endemic P. falciparum for 6 months in Malian adults receiving a five-dose regimen. Safety, immunogenicity, and VE of a three-dose regimen were assessed in adults in Balonghin, Burkina Faso in a two-component study: an open-label dose escalation trial with 32 participants followed by a double-blind, randomized, placebo-controlled trial (RCT) with 80 participants randomized to receive three doses of 2.7 × 106 PfSPZ (N = 39) or normal saline (N = 41) just before malaria season. To clear parasitemia, artesunate monotherapy was administered before first and last vaccinations. Thick blood smear microscopy was performed on samples collected during illness and every 4 weeks for 72 weeks after last vaccinations, including two 6-month malaria transmission seasons. Safety outcomes were assessed in all 80 participants who received at least one dose and VE for 79 participants who received three vaccinations. Myalgia was the only symptom that differed between groups. VE (1 - risk ratio; primary VE endpoint) was 38% at 6 months (P = 0.017) and 15% at 18 months (0.078). VE (1 - hazard ratio) was 48% and 46% at 6 and 18 months (P = 0.061 and 0.018). Two weeks after the last dose, antibodies to P. falciparum circumsporozoite protein and PfSPZ were higher in protected versus unprotected vaccinees. A three-dose regimen of PfSPZ Vaccine demonstrated safety and efficacy against malaria infection in malaria-experienced adults.

DOI: https://doi.org/10.1126/scitranslmed.abj3776
China CDC Wkly. 2022 Nov 04. 4(44): 990-994

Malaria Elimination in China and Sustainability Concerns in the Post-elimination Stage.

Xinyu Feng, Li Zhang, Hong Tu, Zhigui Xia.

  The World Health Organization (WHO) certified China as officially malaria-free on June 30, 2021. Looking back at the public health history in China, malaria elimination has been a product of complex social engineering. Here, we summarized our experience and lessons, and found that malaria control and elimination in China is mainly attributed to governmental leadership, consistent efforts, technological innovations, and adaptive approaches. We also raised that vigilance should focus on imported cases through strengthening surveillance and response systems in order to prevent any re-establishment of transmission after elimination. China should continue to maintain its laboratory, clinical and field epidemiology capabilities. Continuous policy and financial support, multi-sectoral cooperation, and innovative strategies and approaches will remain essential. By integrating these, a malaria-free status can become sustainable.

Keywords:  elimination; malaria; sustainability

DOI:  https://doi.org/10.46234/ccdcw2022.201