bims-mosdis Biomed News
on Mosquito distribution and disease
Issue of 2022–03–06
fourteen papers selected by
Richard Halfpenny, Staffordshire University
  1. EVITA Dengue: a cluster-randomized controlled trial to EValuate the efficacy of Wolbachia-InfecTed Aedes aegypti mosquitoes in reducing the incidence of Arboviral infection in Brazil.
  2. Mosquito fauna in Extremadura (western Spain): Updated catalog with new records, distribution maps, and medical relevance.
  3. Diversity and distribution of larval habitats of mosquitoes (Diptera: Culicidae) in northern Spain: from urban to natural areas.
  4. Diversity of Mosquitoes (Diptera: Culicidae) in An Atlantic Forest Urban Park, Salvador, Brazil.
  5. Peridomestic conditions affect La Crosse virus entomological risk by modifying the habitat use patterns of its mosquito vectors.
  6. Blood-feeding patterns of Anopheles vectors of human malaria in Malawi: implications for malaria transmission and effectiveness of LLIN interventions.
  7. Insecticide resistance of Dengue vectors in South East Asia: a systematic review.
  8. Diversity of mosquito fauna (Diptera, Culicidae) in higher-altitude regions of Croatia.
  9. Screening for odorant receptor genes expressed in Aedes aegypti involved in host-seeking, blood-feeding and oviposition behaviors.
  10. Situation of insecticide resistance in malaria vectors in the World Health Organization of Eastern Mediterranean region 1990-2020.
  11. First records of five species of mosquitoes (Diptera: Culicidae) in Galicia, including the first evidence of the genus Coquillettidia in northwestern Spain.
  12. Biological traits of wild-caught populations of Aedes aegypti in dengue endemic and non-endemic regions of Kenya.
  13. Malaria in Haiti: A descriptive study on spatial and temporal profile from 2009 to 2018.
  14. Surveillance of Plasmodium vivax transmission using serological models in the border areas of China-Myanmar.
  1. Trials. 2022 Mar 02. 23(1): 185
    EVITA Dengue: a cluster-randomized controlled trial to EValuate the efficacy of Wolbachia-InfecTed Aedes aegypti mosquitoes in reducing the incidence of Arboviral infection in Brazil.
    Matthew H Collins, Gail E Potter, Matt D T Hitchings, Ellie Butler, Michelle Wiles, Jessie K Kennedy, Sofia B Pinto, Adla B M Teixeira, Arnau Casanovas-Massana, Nadine G Rouphael, Gregory A Deye, Cameron P Simmons, Luciano A Moreira, Mauricio L Nogueira, Derek A T Cummings, Albert I Ko, Mauro M Teixeira, Srilatha Edupuganti.
       BACKGROUND: Arboviruses transmitted by Aedes aegypti including dengue, Zika, and chikungunya are a major global health problem, with over 2.5 billion at risk for dengue alone. There are no licensed antivirals for these infections, and safe and effective vaccines are not yet widely available. Thus, prevention of arbovirus transmission by vector modification is a novel approach being pursued by multiple researchers. However, the field needs high-quality evidence derived from randomized, controlled trials upon which to base the implementation and maintenance of vector control programs. Here, we report the EVITA Dengue trial design (DMID 17-0111), which assesses the efficacy in decreasing arbovirus transmission of an innovative approach developed by the World Mosquito Program for vector modification of Aedes mosquitoes by Wolbachia pipientis.
    METHODS: DMID 17-0111 is a cluster-randomized trial in Belo Horizonte, Brazil, with clusters defined by primary school catchment areas. Clusters (n = 58) will be randomized 1:1 to intervention (release of Wolbachia-infected Aedes aegypti mosquitoes) vs. control (no release). Standard vector control activities (i.e., insecticides and education campaigns for reduction of mosquito breeding sites) will continue as per current practice in the municipality. Participants (n = 3480, 60 per cluster) are children aged 6-11 years enrolled in the cluster-defining school and living within the cluster boundaries who will undergo annual serologic surveillance for arboviral infection. The primary objective is to compare sero-incidence of arboviral infection between arms.
    DISCUSSION: DMID 17-0111 aims to determine the efficacy of Wolbachia-infected mosquito releases in reducing human infections by arboviruses transmitted by Aedes aegypti and will complement the mounting evidence for this method from large-scale field releases and ongoing trials. The trial also represents a critical step towards robustness and rigor for how vector control methods are assessed, including the simultaneous measurement and correlation of entomologic and epidemiologic outcomes. Data from this trial will inform further the development of novel vector control methods.
    TRIAL REGISTRATION: ClinicalTrials.gov NCT04514107 . Registered on 17 August 2020 Primary sponsor: National Institute of Health, National Institute of Allergy and Infectious Diseases.
    Keywords:  Arbovirus; Chikungunya; Clinical trial; Cluster-randomized controlled trial; Dengue; Prevention; Vector control; Vector-borne disease; Wolbachia; Zika
    DOI:  https://doi.org/10.1186/s13063-022-05997-4
  2. J Vector Ecol. 2021 Jun;46(1): 70-82
    Mosquito fauna in Extremadura (western Spain): Updated catalog with new records, distribution maps, and medical relevance.
    Daniel Bravo-Barriga, Antonio P Gouveia de Almeida, Sarah Delacour-Estrella, Rosa Estrada Peña, Javier Lucientes, José M Sánchez-Murillo, Eva Frontera.
      An important element of vector control and surveillance of mosquito-borne diseases is updated information on vector species distribution. The aim of this study was to collect available information about mosquito species reported in Extremadura between 1920 and 2020 and create a catalog that would combine both published data and our recent field identifications. An exhaustive list is hereby presented, including species status and detailed distribution maps at a municipal level as well as their importance for public health. A total of 33 species, classified into five genera: Anopheles (five species), Aedes (14), Culex (nine), Culiseta (four), and Orthopodomyia (one) has been recorded, including 31 autochthonous, one invasive, Aedes (Stegomyia) albopictus, and one disappeared since 1953, Aedes (Stegomyia) aegypti. For the first time in Extremadura, we report the presence of important vectors such as Aedes (Aedimorphus) vexans vexans and Culex (Culex) perexiguus, and the new record of six species in the province of Badajoz, namely: Aedes (Dahliana) echinus, Aedes (Fredwardsius) vittatus, Aedes (Ochlerotatus) berlandi, Aedes (Ochlerotatus) pulcritarsis, Culex (Culex) mimeticus, and Culiseta (Culiseta) subochrea. Nineteen of these species are potential vectors of medical and veterinary relevance.
    Keywords:  Checklist; Extremadura; diversity; mosquitoes
    DOI:  https://doi.org/10.52707/1081-1710-46.1.70
  3. J Vector Ecol. 2021 Dec;46(2): 173-185
    Diversity and distribution of larval habitats of mosquitoes (Diptera: Culicidae) in northern Spain: from urban to natural areas.
    Mikel A González, Aitor Cevidanes, Fátima Goiri, Jesús F Barandika, Ana L García-Pérez.
      Studies of the biodiversity of mosquito larval habitats are important for vector-borne disease control programs and help to improve vector distribution maps. This study was designed to investigate the geographical distribution of mosquito species and their larval habitats in urban, rural, and natural areas in northern Spain. Pre-imaginal stages were collected over two sampling periods (spring and summer) in 2019. In the laboratory, immature specimens were reared to the adult stage for species identification by morphological taxonomy and/or molecular methods. In total, 2,182 specimens belonging to 13 different native mosquito species of five genera were collected from 135 sampling points of which 59.2% harbored larvae. Culex pipiens s.l. was the most abundant species (45.1%), followed by Culex torrentium (12.3%), Anopheles maculipennis s.l. (10.2%), Culex hortensis (9.5%), and nine other species with lower frequencies that accounted for less than 25%. By molecular identification, An. maculipennis s.s. was identified as the only species within the An. maculipennis species complex and Cx. pipiens pipiens as the predominant subspecies of the Cx. pipiens species complex. Margins in large sunlit water bodies were the most suitable sites for An. maculipennis s.l., whereas Cx. pipiens s.l. was present in both natural and artificial habitats. The larval site index, species richness, and relative abundance of the mosquitoes were determined based on the characteristics of the sites where they were collected. The public health importance and ecology of some identified mosquitoes is also discussed.
    Keywords:  Anopheles maculipennis; Culex pipiens; biodiversity; larval habitats; mosquitoes; northern Spain
    DOI:  https://doi.org/10.52707/1081-1710-46.2.173
  4. J Med Entomol. 2022 Mar 04. pii: tjac007. [Epub ahead of print]
    Diversity of Mosquitoes (Diptera: Culicidae) in An Atlantic Forest Urban Park, Salvador, Brazil.
    Raquel Lima de Souza, Gabriel Dos Santos Ferreira, Lairton Souza Borja, Romero de Jesus Nazaré, Vánio Andre Mugabe, Hernan Darío Argibay, Moyra Machado Portilho, Leile Camila Jacob-Nascimento, Mitermayer Galvão Reis, Uriel D Kitron, Guilherme Sousa Ribeiro.
      We identified mosquito species (Diptera: Culicidae) in an Atlantic Forest fragment located in a large urban park in Salvador, Brazil, one year after a citywide epizootic of yellow fever virus (YFV). Between May 2 and August 2, 2018, adult mosquitoes were collected using the human attraction method, followed by trapping with hand-nets, and CO2-baited light traps placed at ground level and in the canopy. We collected a total of 11,914 mosquitoes, which belonged to three tribes, five genera, and at least seven species. The most abundant taxa captured by CO2-baited light traps were Culex quinquefasciatus (Say, Diptera: Culicidae) Limatus spp. (Diptera: Culicidae), and Wyeomyia spp. (Diptera: Culicidae), while by human attraction, Cx. quinquefasciatus, Wyeomyia spp., and Aedes albopictus (Skuse, Diptera: Culicidae) were captured most often. The diversity of mosquitoes by species was greater in the park area with restinga vegetation compared to the area with dense rainforest. Although vectors commonly associated with sylvatic YFV transmission were not captured, we collected several species capable of transmission of other arboviruses. Given the high likelihood of encounters between mosquitoes and human visitors in environments, such as the one studied, periodic entomological surveys to determine the risk of arbovirus transmission in these settings are warranted.
    Keywords:  Brazil; arbovirus; entomological survey; mosquito
    DOI:  https://doi.org/10.1093/jme/tjac007
  5. J Vector Ecol. 2021 Jun;46(1): 34-47
    Peridomestic conditions affect La Crosse virus entomological risk by modifying the habitat use patterns of its mosquito vectors.
    Tuamami T Tamini, Brian D Byrd, J Alan Goggins, Charles B Sither, Laura White, Gideon Wasserberg.
      Anthropogenic land-use change may affect the transmission risk for endemic vector-borne diseases such as La Crosse encephalitis. In this study, we applied a comparative ecological approach to evaluate differences in vector species abundance, gonotrophic status, and environmental variables among six residential habitats (historical case houses) and six paired adjacent forest patches in a La Crosse virus endemic area of North Carolina. A total of 93,158 container Aedes spp. eggs were obtained by ovistrips and 1,040 resting mosquito adults were collected by large-bore aspiration from 10 June through 8 October, 2010. At sites characterized by high densities of artificial containers, the totals of eggs and adult mosquitoes were higher in the peridomestic plots. At sites characterized by lower densities of artificial containers, the totals of eggs and adult mosquitoes were higher in the forested plots. Although Aedes triseriatus, the primary La Crosse virus vector, was more commonly found in forested habitat overall, in sites characterized by high density of artificial containers, it was found in higher abundance in the peridomestic habitat. Similarly, the proportion of gonotrophically active (parous and gravid) mosquitoes was higher in the peridomestic habitat for sites with highartificial container density. Our study suggests that La Crosse virus transmission risk may be higher at peridomestic habitats with higher densities of artificial containers and thus reinforces the importance of public health measures to improve source reduction efforts.
    Keywords:  Aedes albopictus; Aedes japonicus; Aedes triseriatus; La Crosse virus; disease ecology; emerging infectious diseases
    DOI:  https://doi.org/10.52707/1081-1710-46.1.34
  6. Malar J. 2022 Mar 03. 21(1): 67
    Blood-feeding patterns of Anopheles vectors of human malaria in Malawi: implications for malaria transmission and effectiveness of LLIN interventions.
    Rex B Mbewe, John B Keven, Themba Mzilahowa, Don Mathanga, Mark Wilson, Lauren Cohee, Miriam K Laufer, Edward D Walker.
       BACKGROUND: Access to human hosts by Anopheles mosquitoes is a key determinant of vectorial capacity for malaria, but it can be limited by use of long-lasting insecticidal nets (LLINs). In Malawi, pyrethroid-treated LLINs with and without the synergist piperonyl butoxide (PBO) were distributed to control malaria. This study investigated the blood-feeding patterns of malaria vectors and whether LLINs containing pyrethroid and PBO led to a reduction of human blood feeding than those containing only pyrethroids.
    METHODS: Mosquitoes were sampled inside houses from May 2019 through April 2020 by aspiration, pyrethrum spray catch, and light trap methods in two sites. One site (Namanolo, Balaka district) had LLINs containing only pyrethroids whereas the other (Ntaja, Machinga district) had LLINs with both pyrethroids and PBO. Anopheles species, their blood-meal host, and infection with Plasmodium falciparum were determined using PCR methods.
    RESULTS: A total of 6585 female Anopheles were sampled in 203 houses. Of these, 633 (9.6%) were blood-fed mosquitoes comprising of 279 (44.1%) Anopheles arabiensis, 103 (16.3%) Anopheles gambiae 212 (33.5), Anopheles funestus, 2 (0.3%), Anopheles parensis and 37 (5.8%) were unidentified Anopheles spp. Blood meal hosts were successfully identified for 85.5% (n = 541) of the blood-fed mosquitoes, of which 436 (81.0%) were human blood meals, 28 (5.2%) were goats, 11 (2.0%) were dogs, 60 (11.1%) were mixed goat-human blood meals, 5 (0.9%) were dog-human, and 1 was a mixed dog-goat. Human blood index (fraction of blood meals that were humans) was significantly higher in Namanolo (0.96) than Ntaja (0.89). Even though human blood index was high, goats were over-selected than humans after accounting for relative abundance of both hosts. The number of infectious Anopheles bites per person-year was 44 in Namanolo and 22 in Ntaja.
    CONCLUSION: Although LLINs with PBO PBO may have reduced human blood feeding, access to humans was extremely high despite high LLIN ownership and usage rates in both sites. This finding could explain persistently high rates of malaria infections in Malawi. However, this study had one village for each net type, thus the observed differences may have been a result of other factors present in each village.
    Keywords:  Anopheles; Blood; Host; Malaria; Mosquitoes; Nets
    DOI:  https://doi.org/10.1186/s12936-022-04089-7
  7. Afr Health Sci. 2021 Sep;21(3): 1124-1140
    Insecticide resistance of Dengue vectors in South East Asia: a systematic review.
    Mohd Rohaizat Hassan, Noor Atika Azit, Suhaiza Mohd Fadzil, Siti Rasidah Abd Ghani, Norfazilah Ahmad, Azmawati Mohammed Nawi.
       Background: The insecticides used widely has led to resistance in the vector and impose a challenge to vector control operation.
    Objectives: This review aims to analyse the distribution of insecticide resistance of dengue vectors in South East Asia and to describe the mechanism of insecticide resistance.
    Methods: Literature search for articles published on 2015 to 2019 from PubMed, Scopus and ProQuest was performed. Total of 37 studies included in the final review from the initial 420 studies.
    Results: Pyrethroid resistance was concentrated on the west coast of Peninsular Malaysia and Northern Thailand and scattered at Java Island, Indonesia while organophosphate resistance was seen across the Java Island (Indonesia), West Sumatera and North Peninsular Malaysia. Organochlorine resistance was seen in Sabah, Malaysia and scattered distribution in Nusa Tenggara, Indonesia. V1016G, S989P, F1269C gene mutation in Aedes Aegypti were associated with Pyrethroid resistance in Singapore and Indonesia. In Malaysia, over-expressed with monooxygenase P450 genes (CYP9J27, CYP6CB1, CYP9J26 and CYP9M4) Glutathione S-transferases, carboxylesterases commonly associated with pyrethroids resistance in Aedes Aegypti and CYP612 overexpressed in Aedes Albopictus. The genetic mutation in A302S in Aedes Albopictus was associated with organochlorine resistance in Malaysia.
    Conclusions: Rotation of insecticide, integration with synergist and routine assessment of resistance profile are recommended strategies in insecticide resistance management.
    Keywords:  Aedes; Insecticide resistance; mortality; pyrethroid; vector management
    DOI:  https://doi.org/10.4314/ahs.v21i3.21
  8. J Vector Ecol. 2021 Jun;46(1): 65-75
    Diversity of mosquito fauna (Diptera, Culicidae) in higher-altitude regions of Croatia.
    Nataša Bušić, Mladen Kučinić, Enrih Merdić, Branka Bruvo-Mađarić.
      Global climate change and the accompanying rise in temperature could affect the biology and ecology of a number of vectors, including mosquitoes. High altitude areas that were previously unsuitable for the spread of mosquito vector populations could become suitable. The aim of this research was to study the distribution of mosquito species in higher altitude regions of Croatia. Samples were collected in three areas: Slavonian Mountains, Gorski Kotar, and Middle Velebit. Specimens were morphologically determined and confirmed by DNA barcoding and other genetic markers and showed the presence of 16 species belonging to six genera. The most abundant species were the Culex pipiens complex with 50% of the collected specimens. Both pipiens (Linnaeus, 1758) and molestus (Forskal, 1775) biotypes and their hybrids were identified within the complex, followed by Culex torrentium (Martini, 1925) (20.2%), Culiseta longiareolata (Macquart, 1838) (8.5%), and the invasive species Aedes japonicus (Theobald, 1901) (7.8% of the total number of collected specimens). The remaining 12 species made up 14.7% of the collected specimens. Intraspecific COI p-distances were within the standard barcoding threshold for OTUs, while interspecific genetic distances were much higher, confirming the existence of barcoding gaps. Mosquito fauna of Croatian mountains showed a moderate variety and made 30.8% of the total number of recorded mosquito species in Croatia thus far.
    Keywords:  COI; ITS2; Mosquito diversity; microsatellite loci; species complex
    DOI:  https://doi.org/10.52707/1081-1710-46.1.65
  9. Parasit Vectors. 2022 Mar 04. 15(1): 71
    Screening for odorant receptor genes expressed in Aedes aegypti involved in host-seeking, blood-feeding and oviposition behaviors.
    Meng Ni, Teng Zhao, Hui-Xin Lv, Man-Jin Li, Dan Xing, Tong-Yan Zhao, Chun-Xiao Li.
       BACKGROUND: Aedes aegypti is one of the most important vectors of zoonotic diseases worldwide, and its survival and reproductive processes depend heavily on its olfactory system. In this study, the expression levels of all odorant receptor (OR) genes of Ae. aegypti were explored during different physiological periods to identify olfactory genes that may be associated with mosquito blood-feeding and the search for oviposition sites.
    METHODS: Four experimental groups, consisting of Ae. aegypti males, pre-blood-feeding females, post-blood-feeding females and post-oviposition females, were established. A total of 114 pairs of primers targeting all messenger RNA encoded by OR genes were designed based on the whole genome of Ae. aegypti. The expression of OR genes was evaluated by real-time fluorescence quantitative PCR for relative quantification and the comparison of differences between groups.
    RESULTS: A total of 53 differentially expressed OR genes were identified between males and females in Ae. aegypti antennae. Also, eight, eight and 13 differentially expressed OR genes were identified in pre- versus post-blood-feeding females, in pre- versus post-oviposition females and in post-blood-feeding versus post-oviposition females, respectively. In addition, 16 OR genes were significantly differentially expressed in multiple physiological periods of the mosquitoes.
    CONCLUSIONS: A large number of ORs with significant intergroup differences and high expression levels were screened in this study. Some of these genes are reported for the first time, providing possible targets for the development of mosquito control pathways based on the olfactory system.
    Keywords:  Aedes aegypti; Blood-feeding; Odor receptor; Olfaction; Oviposition
    DOI:  https://doi.org/10.1186/s13071-022-05196-9
  10. Toxicol Res (Camb). 2022 Feb;11(1): 1-21
    Situation of insecticide resistance in malaria vectors in the World Health Organization of Eastern Mediterranean region 1990-2020.
    Hassan Vatandoost, Ahmad Ali Hanafi-Bojd, Fatemeh Nikpoor, Ahmad Raeisi, Mohammad Reza Abai, Morteza Zaim.
      Malaria is the most important mosquito-borne disease, which is transmitted by Anopheles species. According to the recent report of World Health Organization, there were an estimated 229 million malaria cases in 2019 in 87 malaria endemic countries. There are several vector control method specially using pesticides. The aim of this study was to collect all the data about insecticide resistant of malaria vectors in the Eastern Mediterranean region countries. In this study, all the published papers related to insecticide resistance of malaria vectors in the region were collected and resistant status of vectors in the countries was mapped. Resistance to different insecticide classes such as pyrethroids, organophosphate, organochlorine and carbamates were evaluated using World Health Organization guidelines. Results showed a wide variety of susceptibility/resistance status to these chemicals according to the location, historical context of pesticide used, genetic background of vectors, age and abdominal conditions of adults may play a role in the susceptibility status of these species to different insecticides. The results of this study is providing a guideline for countries to manage their vector control activities against insecticide resistance of malaria vectors and provide novel approaches such as male sterility, using Wolbachia, using new insecticide with new mode of action.
    Keywords:  Eastern Mediterranean region; insecticide resistance; malaria vectors
    DOI:  https://doi.org/10.1093/toxres/tfab126
  11. J Vector Ecol. 2021 Jun;46(1): 96-102
    First records of five species of mosquitoes (Diptera: Culicidae) in Galicia, including the first evidence of the genus Coquillettidia in northwestern Spain.
    Yasmina Martínez-Barciela, Alejandro Polina González, David Gutiérrez Rial, Josefina Garrido González.
      We present the first records of Coquillettidia (Coquillettidia) buxtoni (Edwards, 1923) (n=15), Culex (Neoculex) impudicus Ficalbi, 1890 (n=12), Culex (Neoculex) territans Walker, 1856 (n=52), Culiseta (Culicella) fumipennis (Stephens, 1825) (n=535), and Culiseta (Culicella) morsitans (Theobald, 1901) (n=54) in the Autonomous Community of Galicia (NW Spain), including the first evidence of the genus Coquillettidia Dyar, 1904 in the northwest of Spain. The field research was carried out in different water ecosystems (ponds, streams, rivers, lakes, and lagoons) belonging to 39 zones throughout the entire Galician territory. The samples were collected intermittently and seasonally through different projects of water quality monitoring between 1998 and 2018. A total of 1,614 mosquito larvae have been analyzed, and 668 of them were identified as species not previously recorded in Galicia. Between 1999 and 2003, the first catches of these species were obtained and since then, more specimens have been detected in different wetlands of Galicia, mainly in spring and summer.
    Keywords:  Coquillettidia buxtoni; Culex impudicus; Culex territans; Culiseta fumipennis; Culiseta morsitans; Keyword Index: Mosquitoes
    DOI:  https://doi.org/10.52707/1081-1710-46.1.96
  12. J Vector Ecol. 2021 Jun;46(1): 19-23
    Biological traits of wild-caught populations of Aedes aegypti in dengue endemic and non-endemic regions of Kenya.
    Caroline Wanjiku, David P Tchouassi, Catherine L Sole, Christian W W Pirk, Baldwyn Torto.
      Variation in vector traits can modulate local scale differences in pathogen transmission. Here, we compared seasonal variation in the wing length (proxy for body size) and energy reserves of adult wild-caught Aedes aegypti populations from a dengue endemic (Kilifi) and non-endemic (Isiolo) area of Kenya. Vector sampling in the dengue endemic site was conducted during the dry and wet seasons. In the non-endemic area, it was limited to the dry season which characterizes this ecology where sporadic or no rainfall is commonplace during the year. We found variation by site in the body size of both sexes, with an overall smaller size of Ae. aegypti populations collected from Isiolo than those from Kilifi. Our results show that although total carbohydrates and lipids levels were highest in both sexes during the dry season, they were two-fold higher in males than females. However, we found weak correlations between body size and energy reserves for both sexes, with body size being more sensitive in identifying differences at a population level. These results provide insights into the determinants of the vectoring potential of Ae. aegypti populations in dengue endemic and non-endemic ecologies in Kenya.
    Keywords:  Aedes aegypti; Energy reserves; body size; dengue; ecological adaptation
    DOI:  https://doi.org/10.52707/1081-1710-46.1.19
  13. Rev Soc Bras Med Trop. 2022 ;pii: S0037-86822022000100302. [Epub ahead of print]55 e0355
    Malaria in Haiti: A descriptive study on spatial and temporal profile from 2009 to 2018.
    Jean Ricardo Jules, Jeronimo Alencar, Martha Cecília Suárez-Mutis, Ernst Jn Baptiste, Hermano de Albuquerque, Maria Goreti Rosa-Freitas, Christian Raccurt, Ricardo Lourenço de Oliveira, Teresa Fernandes Silva-do-Nascimento.
       BACKGROUND: Haiti is one of the Caribbean countries where malaria persists. More than 99% of malaria cases are caused by Plasmodium falciparum, the main vector being the mosquito Anopheles albimanus. In this paper, we describe the epidemiological profile of malaria in Haiti between 2009 and 2018.
    METHODS: We analyzed information on cases reported by the Ministry of Health of Haiti and the World Health Organization (WHO).
    RESULTS: Between 2009 and 2018, 232,479 malaria cases were reported by the Ministry of Public Health and Population (MSPP); an increase in the incidence of malaria in the country in 2010, followed by a decrease in 2011, was primarily observed. Due to recent efforts to reduce malaria by 2020, its incidence declined from 60,130 cases in 2010 to 8,978 cases in 2018. Controversially, in terms of the number of reported cases, the MSPP and WHO report conflicting data. However, the results from both datasets present the same trend in Haiti from 2009 to 2018. The results also illustrate the endemicity of the disease throughout Haiti, both in rural and urban areas, especially along the coast.
    CONCLUSIONS: This study emphasizes the need to promote official data collection and analyses, as well as the application of epidemiological surveillance of malaria at the municipal level, for a better understanding of the real impact of malaria on the Haitian population and to create more appropriate interventions.
    DOI:  https://doi.org/10.1590/0037-8682-0355-2021
  14. Malar J. 2022 Mar 03. 21(1): 69
    Surveillance of Plasmodium vivax transmission using serological models in the border areas of China-Myanmar.
    Meixue Yao, Lishun Xiao, Xiaodong Sun, Zurui Lin, Xiao Hao, Qiong-Qiong Bai, De-Hui Yin.
       BACKGROUND: To understand the Plasmodium vivax malaria transmission intensity and to assess the effectiveness of prevention and control measures taken along the China-Myanmar border, a catalytic model was used to calculate the seroconversion rate, an important indicator of malaria transmission intensity with high sensitivity, which is particularly useful in areas of low transmission.
    METHODS: Five counties in Yunnan Province bordering Myanmar were selected as survey sites, and subjects were obtained in each county by stratified random sampling in 2013-2014. Fingerstick blood was collected from each subject and tested for antibodies to P. vivax Merozoite Surface Protein 1-19 (PvMSP1-19) using indirect ELISA. A catalytic conversion model was used to assess the transmission intensity of P. vivax malaria based on the maximum likelihood of generating a community seroconversion rate.
    RESULTS: A total of 3064 valid blood samples were collected. Antibody levels were positively correlated with age. The seroconversion rate (SCR) values for each village were Luoping (0.0054), Jingqiao (0.0061), Longpen (0.0087), Eluo (0.0079), Banwang (0.0042) and Banbie (0.0046), respectively.
    CONCLUSION: Overall, the intensity of P. vivax malaria transmission in the border areas of Yunnan Province is low and not entirely consistent across counties. Consecutive serological surveys are needed to provide a sensitive evaluation of transmission dynamics and can help to confirm areas where infection is no longer present.
    Keywords:  China–Myanmar border; Plasmodium vivax; Rate; Seroconversion; Serology; Surveillance; Transmission intensity
    DOI:  https://doi.org/10.1186/s12936-022-04096-8
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