bims-mosdis 2022-02-20 papers

bims-mosdis

Biomed News

on Mosquito distribution and disease

Issue of 2022–02–20
fourteen papers selected by
Richard Halfpenny, Staffordshire University

Mosquito population structure, pathogen surveillance and insecticide resistance monitoring in urban regions of Crete, Greece.
Ecology of breeding habitats of mosquito population and screening for virus of Japanese encephalitis and West Nile in the coastal area of Kerala, India.
Aedes albopictus and Cache Valley virus: a new threat for virus transmission in New York State.
Seasonal abundance and infection of Japanese encephalitis vectors from Gorakhpur district, Uttar Pradesh, India.
Mitochondrial Diversity of the Asian Tiger Mosquito Aedes albopictus (Diptera: Culicidae) in Peninsular Malaysia.
Abundances of transfer RNA modifications and transcriptional levels of tRNA-modifying enzymes are sex-associated in mosquitoes.
Seasonality and transmissibility of Plasmodium ovale in Bagamoyo District, Tanzania.
Mayaro virus infection in French Guiana, a cross sectional study 2003-2019.
On multifactorial drivers for malaria rebound in Brazil: a spatio-temporal analysis.
Community sensitization to improve acceptability of indoor residual spraying (IRS) in Mewat district of Haryana, India: A community-based interventional study.
Five-Year Trend of Malaria Prevalence in Mojo Town, Central Ethiopia: Shifting Burden of the Disease and Its Implication for Malaria Elimination: A Retrospective Study.
Pretreatment gametocyte carriage in symptomatic patients with Plasmodium falciparum and Plasmodium vivax infections on the Thai-Myanmar border.
Advancing Malaria Prevention and Control in Africa Through the Peace Corps-US President's Malaria Initiative Partnership.
Identifying forms of interventions towards cross border malaria in the Asia-Pacific region: a scoping review protocol.

PLoS Negl Trop Dis. 2022 Feb 17. 16(2): e0010186

Mosquito population structure, pathogen surveillance and insecticide resistance monitoring in urban regions of Crete, Greece.

Emmanouil A Fotakis, Konstantinos Mavridis, Anastasia Kampouraki, Sofia Balaska, Filianna Tanti, George Vlachos, Sandra Gewehr, Spiros Mourelatos, Antonios Papadakis, Maria Kavalou, Dimitrios Nikolakakis, Maria Moisaki, Nikolaos Kampanis, Manolis Loumpounis, John Vontas.

BACKGROUND: In Greece vector borne diseases (VBD) and foremost West Nile virus (WNV) pose an important threat to public health and the tourist industry, the primary sector of contribution to the national economy. The island of Crete, is one of Greece's major tourist destinations receiving annually over 5 million tourists making regional VBD control both a public health and economic priority.
METHODOLOGY: Under the auspices of the Region of Crete, a systematic integrative surveillance network targeting mosquitoes and associated pathogens was established in Crete for the years 2018-2020. Using conventional and molecular diagnostic tools we investigated the mosquito species composition and population dynamics, pathogen infection occurrences in vector populations and in sentinel chickens, and the insecticide resistance status of the major vector species.
PRINCIPAL FINDINGS: Important disease vectors were recorded across the island including Culex pipiens, Aedes albopictus, and Anopheles superpictus. Over 75% of the sampled specimens were collected in the western prefectures potentially attributed to the local precipitation patterns, with Cx. pipiens being the most dominant species. Although no pathogens (flaviviruses) were detected in the analysed mosquito specimens, chicken blood serum analyses recorded a 1.7% WNV antibody detection rate in the 2018 samples. Notably detection of the first WNV positive chicken preceded human WNV occurrence in the same region by approximately two weeks. The chitin synthase mutation I1043F (associated with high diflubenzuron resistance) was recorded at an 8% allelic frequency in Lasithi prefecture Cx. pipiens mosquitoes (sampled in 2020) for the first time in Greece. Markedly, Cx. pipiens populations in all four prefectures were found harboring the kdr mutations L1014F/C/S (associated with pyrethroid resistance) at a close to fixation rate, with mutation L1014C being the most commonly found allele (≥74% representation). Voltage gated sodium channel analyses in Ae. albopictus revealed the presence of the kdr mutations F1534C and I1532T (associated with putative mild pyrethroid resistance phenotypes) yet absence of V1016G. Allele F1534C was recorded in all prefectures (at an allelic frequency range of 25-46.6%) while I1532T was detected in populations from Chania, Rethymnon and Heraklion (at frequencies below 7.1%). Finally, no kdr were detected in the Anopheles specimens included in the analyses.
CONCLUSIONS/SIGNIFICANCE: The findings of our study are of major concern for VBD control in Crete, highlighting (i) the necessity for establishing seasonal integrated entomological/pathogen surveillance programs, supporting the design of targeted vector control responses and; ii) the need for establishing appropriate insecticide resistance management programs ensuring the efficacy and sustainable use of DFB and pyrethroid based products in vector control.

DOI: https://doi.org/10.1371/journal.pntd.0010186
J Vector Borne Dis. 2021 Jul-Sep;58(3):58(3): 232-239

Ecology of breeding habitats of mosquito population and screening for virus of Japanese encephalitis and West Nile in the coastal area of Kerala, India.

R Balasubramanian, V Arathy Nadh, S Sahina.

   BACKGROUND & OBJECTIVES: Japanese encephalitis (JE) and West Nile virus (WNV) are two mosquito-borne diseases of medical and veterinary importance. Climate impacts in certain ecosystems are better understood; however, coastal brackish water ecosystems and their role in vector borne viral diseases have not been well studied. Hence, the aim of this study is to evaluate the distribution, spatial pattern as well as the screening of these mosquitoes for JE and WN virus in coastal area of Alappuzha district, Kerala, India.
METHODS: Immature mosquitoes were collected using dipper methods along the coastal wetlands areas. Adult mosquitoes were collected in four sampling sites with light trap filled with dry ice, operating overnight. The collected mosquitoes were identified by species, using the taxonomic keys. Mosquitoes were pooled for virus detection. Water samples were collected using standard methods.
RESULTS: The total quantity of rainfall and salinity varied from zero to 365.2 mm and from 1.5 to 28 ppt respectively. A total of 10,695 adult mosquitoes and 38,083 immatures revealed the presence of five genus and 23 species. The most predominant species was Culex tritaeniorhynchus. Immature collections Cx. sitiens was the only one species collected during the summer season and in the monsoon season the pond was replaced by fresh water mosquitoes such as Cx. tritaeniorhynchus and Cx. gelidus. A total of 186 pools were screened for JEV and WNV. However, none of the pools were found as positive for the virus.
INTERPRETATION & CONCLUSION: The major vector of JEV Cx. tritaeniorhynchus and Cx. gelidus have adapted to immature development in coastal brackish water habitats. The public health authorities need to recognize thepotential impact on human health of brackish water-adapted mosquito vectors that weretraditionally considered to be freshwater species, and take appropriate surveillance and control measures.

Keywords:  adaptation; biotic and abiotic factors brackish water; rainfall; salinity

DOI:  https://doi.org/10.4103/0972-9062.318307
Emerg Microbes Infect. 2022 Feb 18. 1-26

Aedes albopictus and Cache Valley virus: a new threat for virus transmission in New York State.

Constentin Dieme, Joseph G Maffei, Maryam Diarra, Cheri A Koetzner, Lili Kuo, Kiet A Ngo, Alan P Dupuis, Steven D Zink, P Bryon Backenson, Laura D Kramer, Alexander T Ciota.

  We report surveillance results of Cache Valley virus (CVV; Peribunyaviridae, Orthobunyavirus) from 2017-2020 in New York State (NYS). Infection rates were calculated using the maximum likelihood estimation (MLE) method by year, region, and mosquito species. The highest infection rates were identified among Anopheles spp. mosquitoes and we detected the virus in Aedes albopictus for the first time in NYS. Based on our previous Anopheles quadrimaculatus vector competence results for nine CVV strains, we selected among them three stains for further characterization. These include two CVV reassortants (PA and 15041084) and one CVV lineage 2 strain (Hu-2011). We analyzed full genomes, compared in vitro growth kinetics and assessed vector competence of Aedes albopictus. Sequence analysis of the two reassortant strains (PA and 15041084) revealed 0.3, 0.4, and 0.3% divergence; and 1, 10, and 6 amino acid differences for the S, M, and L segments, respectively. We additionally found that the PA strain was attenuated in vertebrate (Vero) and mosquito (C6/36) cell culture. Furthemore, Ae. albopictus mosquitoes are competent vectors for CVV Hu-2011 (16.7-62.1% transmission rates) and CVV 15041084 (27.3-48.0% transmission rates), but not for the human reassortant (PA) isolate, which did not disseminate from the mosquito midgut. Together, our results demonstrate significant phenotypic variability among strains and highlight the capacity for Ae. albopictus to act as a vector of CVV.

Keywords:  Aedes albopictus; Cache Valley virus; New York State; mosquitoes; surveillance; vector competence; vector-borne infections; viruses

DOI:  https://doi.org/10.1080/22221751.2022.2044733
J Vector Borne Dis. 2021 Jul-Sep;58(3):58(3): 265-272

Seasonal abundance and infection of Japanese encephalitis vectors from Gorakhpur district, Uttar Pradesh, India.

Philip Samuel Paulraj, Velayutham Thenmozhi, Sunil Kumar Mishra, Jaganathasamy Nagaraj, Rajaiah Paramasivan.

   BACKGROUND & OBJECTIVES: Japanese encephalitis (JE) is a major public health problem in many states of India. Uttar Pradesh state contributes 75% of the total cases reported. A longitudinal study was undertaken to find out the seasonal abundance, infection in the JE vectors in Gorakhpur region of Uttar Pradesh, and intervention strategies like indoor residual spraying and long-lasting insecticidal nets were adopted.
METHODS: The vector abundance was monitored from July 2013 to August 2016 at fortnightly intervals and identified using standard mosquito identification keys and screened for viral infection. Intervention measures like indoor residual spraying with lambda-cyhalothrin 10% WP at 25 mg/m2 in 58 gramasabha in Bhathat Block and long-lasting insecticidal nets were distributed @ 2 LLIN for each household with 5-6 members in 5 villages of Korabar block.
RESULTS: A total of 5,36,609 mosquitoes constituting 34 species and 10 genera were collected during this study period. Among the JE vector, peak abundance of Culex tritaeniorhynchus was recorded just before the JE season from July to October in all the blocks. There was a marked reduction in the density of Cx. tritaeniorhynchus from July compared to baseline year 2014 in Bhathat Block where indoor residual spraying (IRS) was performed in June 2015. The vector density declined in 5 villages of Khorabar Block where long-lasting impregnated bed nets (LLINs) were distributed during July 2016.
INTERPRETATION & CONCLUSION: The present study provided knowledge about the seasonal JE vector density and JE virus infection in mosquitoes during the monsoon season in Gorakhpur region of Uttar Pradesh. IRS and the personal protection measure like LLINs were distributed to interrupt the JE transmission in this area which gave encouraging results.

Keywords:  Cx. tritaeniorhynchus; Gorakhpur; Japanese encephalitis; mosquito

DOI:  https://doi.org/10.4103/0972-9062.321740
J Med Entomol. 2022 Feb 18. pii: tjac014. [Epub ahead of print]

Mitochondrial Diversity of the Asian Tiger Mosquito Aedes albopictus (Diptera: Culicidae) in Peninsular Malaysia.

Suzana Misbah, Van Lun Low, Nurul Farhana Mohd Rahim, Rizzuaeammie Jaba, Norasmah Basari, Zubaidah Ya'cob, Sazaly Abu Bakar.

  Aedes albopictus is one of the main mosquito vectors responsible for transmitting arboviruses to humans and animals. The ability of this mosquito to support virus transmission has been linked to vector competence, which is partly attributed to the genetic disparities in Ae. albopictus population. At present, little is known about the biologically important traits of Ae. albopictus in Malaysia. Thus, the study aims to determine the genetic variation of Ae. albopictus based on the mitochondria-encoded sequences of cytochrome oxidase subunit I (COI). A statistical parsimony network of 253 taxa aligned as 321 characters of the COI gene revealed 42 haplotypes (H1-H42), of which H1 was the most widespread haplotype in Peninsular Malaysia. Three highly divergent haplotypes (H21, H30, and H31) were detected from the northern population. Overall, haplotype and nucleotide diversities were 0.576 and 0.003, respectively, with low genetic differentiation (FST = 0.039) and high gene flow (Nm = 12.21) across all populations.

Keywords:   Aedes ; cytochrome oxidase I; genetics; mitochondrial DNA; population

DOI:  https://doi.org/10.1093/jme/tjac014
Insect Biochem Mol Biol. 2022 Feb 15. pii: S0965-1748(22)00023-6. [Epub ahead of print] 103741

Abundances of transfer RNA modifications and transcriptional levels of tRNA-modifying enzymes are sex-associated in mosquitoes.

Melissa Kelley, Melissa Uhran, Cassandra Herbert, George Yoshida, Emmarie Watts, Patrick A Limbach, Joshua B Benoit.

  As carriers of multiple human diseases, understanding the mechanisms behind mosquito reproduction may have implications for remediation strategies. Transfer RNA (tRNA) acts as the adapter molecule of amino acids and are key components in protein synthesis. A critical factor in the function of tRNAs is chemical modifications which contribute to codon-anticodon interactions. Here, we provide an assessment of tRNA modifications between sexes for three mosquito species and examine the correlation of transcript levels underlying key proteins involved in tRNA modification. Thirty-three tRNA modifications were detected among mosquito species and most of these modifications are higher in females compared to males for three mosquito species. Analysis of previous male and female RNA-seq datasets indicated a similar increase in transcript levels of tRNA modifying enzymes in females among six mosquito species, supporting our observed female enrichment of tRNA modifications. Tissues-specific expressional studies revealed higher transcript levels for tRNA modifying enzymes in the ovaries for Aedes aegypti, but not male reproductive tissues. These studies suggest that tRNA modifications may be critical to reproduction in mosquitoes, representing a potential novel target for control through suppression of fecundity.

Keywords:  Chemical modifications; Mosquitoes; Post-transcriptional modifications; Reproduction; Sex-associated; tRNA

DOI:  https://doi.org/10.1016/j.ibmb.2022.103741
Parasit Vectors. 2022 Feb 14. 15(1): 56

Seasonality and transmissibility of Plasmodium ovale in Bagamoyo District, Tanzania.

Brian B Tarimo, Vincent O Nyasembe, Billy Ngasala, Christopher Basham, Isaack J Rutagi, Meredith Muller, Srijana B Chhetri, Rebecca Rubinstein, Jonathan J Juliano, Mwajabu Loya, Rhoel R Dinglasan, Jessica T Lin, Derrick K Mathias.

   BACKGROUND: Plasmodium ovale is a neglected malarial parasite that can form latent hypnozoites in the human liver. Over the last decade, molecular surveillance studies of non-falciparum malaria in Africa have highlighted that P. ovale is circulating below the radar, including areas where Plasmodium falciparum is in decline. To eliminate malaria where P. ovale is endemic, a better understanding of its epidemiology, asymptomatic carriage, and transmission biology is needed.
METHODS: We performed a pilot study on P. ovale transmission as part of an ongoing study of human-to-mosquito transmission of P. falciparum from asymptomatic carriers. To characterize the malaria asymptomatic reservoir, cross-sectional qPCR surveys were conducted in Bagamoyo, Tanzania, over three transmission seasons. Positive individuals were enrolled in transmission studies of P. falciparum using direct skin feeding assays (DFAs) with Anopheles gambiae s.s. (IFAKARA strain) mosquitoes. For a subset of participants who screened positive for P. ovale on the day of DFA, we incubated blood-fed mosquitoes for 14 days to assess sporozoite development.
RESULTS: Molecular surveillance of asymptomatic individuals revealed a P. ovale prevalence of 11% (300/2718), compared to 29% (780/2718) for P. falciparum. Prevalence for P. ovale was highest at the beginning of the long rainy season (15.5%, 128/826) in contrast to P. falciparum, which peaked later in both the long and short rainy seasons. Considering that these early-season P. ovale infections were low-density mono-infections (127/128), we speculate many were due to hypnozoite-induced relapse. Six of eight P. ovale-infected asymptomatic individuals who underwent DFAs successfully transmitted P. ovale parasites to A. gambiae.
CONCLUSIONS: Plasmodium ovale is circulating at 4-15% prevalence among asymptomatic individuals in coastal Tanzania, largely invisible to field diagnostics. A different seasonal peak from co-endemic P. falciparum, the capacity to relapse, and efficient transmission to Anopheles vectors likely contribute to its persistence amid control efforts focused on P. falciparum.

Keywords:  Anopheles gambiae; Asymptomatic; Direct feeding assay (DFA); Malaria; Plasmodium falciparum; Plasmodium ovale; Tanzania

DOI:  https://doi.org/10.1186/s13071-022-05181-2
Infect Genet Evol. 2022 Feb 10. pii: S1567-1348(22)00040-5. [Epub ahead of print] 105243

Mayaro virus infection in French Guiana, a cross sectional study 2003-2019.

Rémi Mutricy, Séverine Matheus, Émilie Mosnier, Enguerrane Martinez-Lorenzi, Franck De Laval, Mathieu Nacher, Florence Niemetzky, Pauline Naudion, Félix Djossou, Dominique Rousset, Loïc Epelboin.

Mayaro Virus is an emerging arbovirus which can be responsible of important outbreaks in tropical regions. A retrospective study was performed in French Guiana, an ultraperipheral region of Europe in Amazonia. We identified 17 human cases between 2003 and 2019. The clinical and biological picture was close to Chikungunya with fever and arthralgia. One patient had acute meningo-encephalitis, and 4 had persistent arthralgia. Physicians should be aware of this virus, as imported cases in Europe have already occurred. AUTHOR SUMMARY: Latin America has experienced several epidemics of arboviruses in recent years, some known for a long time, such as the dengue virus, and others of more recent introduction such as the chikungunya or Zika viruses. There are other arboviruses for the moment more discreet which are rife with low noise in several countries of the continent, such as the Mayaro virus. This alphavirus, with a presentation similar to that of the chikungunya virus, is currently confined to transmission by forest mosquitoes, but its potential to be transmitted by coastal mosquitoes such as Aedes aegypti, make it a potential candidate for a continent-wide epidemic. It therefore seems necessary to know this virus as well as possible in order to anticipate the occurrence of a possible new epidemic. We present here a both demographic and clinical study of this endemic arbovirus disease in French Guiana.

DOI: https://doi.org/10.1016/j.meegid.2022.105243
Malar J. 2022 Feb 17. 21(1): 52

On multifactorial drivers for malaria rebound in Brazil: a spatio-temporal analysis.

Mario J C Ayala, Leonardo S Bastos, Daniel A M Villela.

   BACKGROUND: Malaria incidence in Brazil reversed its decreasing trend when cases from recent years, as recent as 2015, exhibited an increase in the Brazilian Amazon basin, the area with the highest transmission of Plasmodium vivax and Plasmodium falciparum. In fact, an increase of more than 20% in the years 2016 and 2017 revealed possible vulnerabilities in the national malaria-control programme.
METHODS: Factors potentially associated with this reversal, including migration, economic activities, and deforestation, were studied. Past incidences of malaria cases due to P. vivax and P. falciparum were analysed with a spatio-temporal Bayesian model using more than 5 million individual records of malaria cases from January of 2003 to December of 2018 in the Brazilian Amazon to establish the municipalities with unexpected increases in cases.
RESULTS: Plasmodium vivax incidence surpassed the past trends in Amazonas (AM), Amapá (AP), Acre (AC), Pará (PA), Roraima (RR), and Rondônia (RO), implying a rebound of these states between 2015 and 2018. On the other hand, P. falciparum also surpassed the past trends in AM, AC, AP, and RR with less severity than P. vivax incidence. Outdoor activities, agricultural activities, accumulated deforestation, and travelling might explain the rebound in malaria cases in RR, AM, PA, and RO, mainly in P. vivax cases. These variables, however, did not explain the rebound of either P. vivax and P. falciparum cases in AC and AP states or P. falciparum cases in RR and RO states.
CONCLUSION: The Amazon basin has experienced an unexpected increase in malaria cases, mainly in P. vivax cases, in some regions of the states of Amazonas, Acre, Pará, Amapá, Roraima, and Rondônia from 2015 to 2018 and agricultural activities, outdoor activities, travelling activities, and accumulated deforestation appear linked to this rebound of cases in particular regions with different impact. This shows the multifactorial effects and the heterogeneity of the Amazon basin, boosting the necessity of focusing the malaria control programme on particular social, economic, and environmental conditions.

Keywords:  Malaria rebound; Plasmodium falciparum; Plasmodium vivax; Spatio-temporal Bayesian model

DOI:  https://doi.org/10.1186/s12936-021-04037-x
J Vector Borne Dis. 2021 Jul-Sep;58(3):58(3): 206-212

Community sensitization to improve acceptability of indoor residual spraying (IRS) in Mewat district of Haryana, India: A community-based interventional study.

Pawan Kumar Goel, Arun Kumar, Manju Rahi, P L Joshi, V P Maheshwari.

   BACKGROUND & OBJECTIVES: Indoor Residual Spraying (IRS) is an important part of malaria prevention and control strategies for villages with annual parasitic incidence (API) of more than 5, or other criteria by National Program of the country. At the time of conception of the study, i.e., in 2012, district Mewat in Haryana state, India was malaria endemic including 35 malaria high risk villages with API more than 5. The current study aimed to improve acceptability of IRS among the residents of Mewat district.
METHODS: This was a community based interventional study. Out of the 14 sub-centers, there were 12 sub-centers catering the population of 79 villages, out of which 35 villages had API of more than five, and hence, fulfilled the criteria for regular IRS. Considering sub-center as the unit of randomization, out of all the 12 sub-centers which cater population of villages with API > 5, equal number of the sub-centers matched according to the population size of those villages were assigned to the intervention and non-intervention (control) groups by randomization using lottery technique. The intervention comprised community sensitization through community meetings, wall paintings and distribution of pamphlets. Baseline and post intervention acceptability of IRS was measured and compared.
RESULTS: There was 21.7% (95% CI 16.12 to 27.15) increase in intention to accept IRS as per guidelines, and 15.2% (95% CI 9.50 to 20.80) increase in the actual acceptance of IRS in intervention group of villages in Mewat district.
INTERPRETATION & CONCLUSION: The intervention can bring about significant increase in the acceptability of IRS which is an important component of malaria control under national programme in district Mewat, Haryana, India.

Keywords:  Acceptability; Behavior; Community sensitization; Indoor Residual Spraying; malaria

DOI:  https://doi.org/10.4103/0972-9062.318319
Infect Drug Resist. 2022 ;15 455-464

Five-Year Trend of Malaria Prevalence in Mojo Town, Central Ethiopia: Shifting Burden of the Disease and Its Implication for Malaria Elimination: A Retrospective Study.

Andargie Abate, Mesfin Assefa, Lemu Golassa.

   Introduction: Malaria continues to strike hardest against the health and economic development in Ethiopia. The peak of malaria incidence follows the main rainfall season in each year; however, its transmission tends to be highly heterogeneous within or between years and from area to area. Thus, this study was aimed to determine the trend prevalence of malaria in Mojo town, central Ethiopia.
Methods: A retrospective study was conducted in Mojo town, East Shoa zone, Ethiopia from February to March 2021. Malaria cases and related data documented between 2016 and 2020 were carefully reviewed from laboratory registration logbooks. The collected data were analyzed using descriptive statistics.
Results: A total of 19,106 blood films were examined from malaria-suspected patients. The overall microscopically confirmed prevalence of malaria was 4.2% (793/19,106). Plasmodium vivax was the predominant species accounting for 76.2% (604/793) of positive samples. Malaria cases declined from 259 in 2016 to 77 in 2020. The proportion of malaria was higher among males (64.8%, 514/793) than females (35.2%, 279/793) (P < 0.0001). Higher malaria cases were observed from the age group 15-24 years followed by the age group of 25-34 (P < 0.0001). The number of malaria cases was at a high level from September to November and lowest from December to February.
Conclusion: Despite a declining trend of malaria prevalence, it remains a public health burden in the area. P. vivax, the predominant species, should get attention during prevention and control strategies for the successful progress of the malaria elimination program.

Keywords:  Ethiopia; Mojo; malaria; retrospective; trend

DOI:  https://doi.org/10.2147/IDR.S348203
J Vector Borne Dis. 2021 Jul-Sep;58(3):58(3): 257-264

Pretreatment gametocyte carriage in symptomatic patients with Plasmodium falciparum and Plasmodium vivax infections on the Thai-Myanmar border.

Pongsakorn Martviset, Sirima Kitvatanachai, Mayuri Tarasuk, Phunuch Muhamad, Kesara Na-Bangchang.

  Background&objectives: Changes in parasite biology, particularly the gametocytogenesis process, could be one of the important contributing factors for worldwide malaria resurgence. The present study investigated the prevalence rates of pretreatment gametocyte carriage and density in Plasmodium falciparum and P. vivax infections in the low malaria-endemic area on the Thai-Myanmar border.
METHODS: One hundred and twenty-six blood samples were collected from patients with signs and symptoms of malaria who attended malaria clinics. Malaria positive cases detected by microscopic examination were confirmed by species-specific nested-PCR in 97 (29 and 68 samples for P. falciparum and P. vivax, respectively).
RESULTS: The proportion of P. vivax and P. falciparum-infected samples was 70.1: 29.9%. The density in P. falciparum positive samples [median (95%CI): 10,340 (5280-19,200) μ/l] was significantly higher than P. vivax positive samples [4508 (3240-6120) μ/l]. Sixteen out of twenty-nine (55.2%) and 36 out of 68 (52.9%) P. falciparum- and P. vivax-infected samples, respectively, were gametocyte-positive. Gametocyte density in the P. falciparum-infected[124 (69-253) /μl] was significantly higher than that of the P. vivax-infected [54 (45-70)/μl] samples. A significant correlation between gametocyte density and pretreatment parasitemia was only detected in P. falciparum-infected, but not P. vivax-infected samples.
INTERPRETATION & CONCLUSION: The observed high prevalence rates of pretreatment gametocyte carriage of both malaria species, which serves as a large malaria reservoir, particularly in P. falciparum infection, could have a significant impact on malaria control in the endemic populations.

Keywords:  Plasmodium falciparum; Plasmodium vivax; Thai-Myanmar border; gametocyte; symptomatic

DOI:  https://doi.org/10.4103/0972-9062.316274
Glob Adv Health Med. 2020 ;9 2164956120976107

Advancing Malaria Prevention and Control in Africa Through the Peace Corps-US President's Malaria Initiative Partnership.

Susan J Henderson, Allison Belemvire, Roman Nelson, Anne Linn, Leah F Moriarty, Emma Brofsky, Mamadou Diaw, David Gittelman.

   Background: Peace Corps is a US government volunteer service agency which provides trained Volunteers to assist host countries in addressing critical development challenges at the community level. The US President's Malaria Initiative provides technical expertise and financial resources to reduce malaria morbidity and mortality in focus countries in sub-Saharan Africa.
Objective: We aim to describe the nature of the collaboration between Peace Corps and President's Malaria Initiative (PMI) and highlight examples of the partnership in select countries.
Methods: We conducted an analysis of retrospective data obtained from Peace Corps and PMI for the years 2014-2019.
Results: Volunteers were able to learn about and work on malaria prevention and control with PMI in three key ways: a malaria-specific training program for staff and Volunteers; malaria-focused small grants; and extension of Volunteer assignments for a third year to support malaria projects. Successful Peace Corps projects supported by PMI, at the community level, were highlighted, with a focus on Rwanda, Benin, Zambia, Madagascar, and Senegal. In Fiscal Year 2019, 1408 Volunteers contributed to malaria prevention activities in 18 Peace Corps programs across Africa, of which 15 were PMI focus countries. While the majority of documented work by Volunteers has involved social and behavior change, there were many other ways to partner with PMI staff.
Conclusion: Each of the proven interventions that PMI supports for malaria prevention and control may have a role for Volunteer involvement. Combined with the technical expertise and the relationships that PMI staff have with national-level counterparts in PMI focus countries, the continued collaboration between Peace Corps and PMI can accelerate the fight against malaria.

Keywords:  Peace Corps; President’s Malaria Initiative; global health; malaria

DOI:  https://doi.org/10.1177/2164956120976107
BMJ Open. 2022 Feb 15. 12(2): e056265

Identifying forms of interventions towards cross border malaria in the Asia-Pacific region: a scoping review protocol.

Utsamani Cintyamena, E Elsa Herdiana Murhandarwati, Iqbal Elyazar, Ari Probandari, Riris Andono Ahmad.

   INTRODUCTION: An ambitious epidemiology strategy has been set by the WHO, targeting malaria elimination for at least 35 countries in 2030. Challenges in preventing malaria cross borders require greater attention to achieve the elimination target. This scoping review aims to identify successful forms of interventions to control malaria transmission across national borders in the Asia-Pacific region.
METHODS AND ANALYSIS: This scoping review will search four electronic databases (PubMed, ScienceDirect, EBSCOhost and ProQuest) limiting the time of publication to the last 10 years. Two independent reviewers will screen all titles and abstracts during the second stage. Study characteristics will be recorded; qualitative data will be extracted and evaluated, while quantitative data will be extracted and summarised. Overall, we will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines.
ETHICS AND DISSEMINATION: This scoping review has received ethical approval from the Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada. The results will be disseminated through peer-reviewed publications, conference presentations and policy briefs.

Keywords:  health policy; public health; tropical medicine

DOI:  https://doi.org/10.1136/bmjopen-2021-056265