scholarly journals PvMSP8 as a Novel Plasmodium vivax Malaria Sero-Marker for the Peruvian Amazon

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 282
Author(s):  
Elizabeth Villasis ◽  
Katherine Garro ◽  
Angel Rosas-Aguirre ◽  
Pamela Rodriguez ◽  
Jason Rosado ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Area Under The Curve ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Population Based ◽  
Peruvian Amazon ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Malaria Exposure ◽  
Plasmodium Vivax Malaria

The measurement of recent malaria exposure can support malaria control efforts. This study evaluated serological responses to an in-house Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) expressed in a Baculovirus system as sero-marker of recent exposure to P. vivax (Pv) in the Peruvian Amazon. In a first evaluation, IgGs against PvMSP8 and PvMSP10 proteins were measured by Luminex in a cohort of 422 Amazonian individuals with known history of Pv exposure (monthly data of infection status by qPCR and/or microscopy over five months). Both serological responses were able to discriminate between exposed and non-exposed individuals in a good manner, with slightly higher performance of anti-PvMSP10 IgGs (area under the curve AUC = 0.78 [95% CI = 0.72–0.83]) than anti-PvMSP8 IgGs (AUC = 0.72 [95% CI = 0.67–0.78]) (p = 0.01). In a second evaluation, the analysis by ELISA of 1251 plasma samples, collected during a population-based cross-sectional survey, confirmed the good performance of anti-PvMSP8 IgGs for discriminating between individuals with Pv infection at the time of survey and/or with antecedent of Pv in the past month (AUC = 0.79 [95% CI = 0.74–0.83]). Anti-PvMSP8 IgG antibodies can be considered as a good biomarker of recent Pv exposure in low-moderate transmission settings of the Peruvian Amazon.

scholarly journals Application of 23 novel serological markers for identifying recent exposure to Plasmodium vivax parasites in an endemic population of western Thailand

2021 ◽  
Author(s):  
Sadudee Chotirat ◽  
Narimane Nekkab ◽  
Chalermpon Kumpitak ◽  
Jenni Hietanen ◽  
Michael T White ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Spatial Clustering ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Serological Markers ◽  
Igg Antibody ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Recent Exposure ◽  
Increased Risk

AbstractThailand is aiming for malaria elimination by the year 2030. However, the high proportion of asymptomatic infections and the presence of the hidden hypnozoite stage of Plasmodium vivax are impeding these efforts. We hypothesized that a validated surveillance tool utilizing serological markers of recent exposure to P. vivax infection could help to identify areas of ongoing transmission. The objective of this exploratory study was to assess the ability of P. vivax serological exposure markers to detect residual transmission ‘hot-spots’ in Western Thailand. Total IgG levels were measured against a panel of 23 candidate P. vivax serological exposure markers using a multiplexed bead-based assay. A total of 4255 plasma samples from a cross-sectional survey conducted in 2012 of endemic areas in the Kanchanaburi and Ratchaburi provinces were assayed. We compared IgG levels with multiple epidemiological factors that are associated with an increased risk of P. vivax infection in Thailand, including age, gender and spatial location, as well as Plasmodium infection status itself. IgG levels to all proteins were significantly higher in the presence of a P. vivax infection (n=144) (t test, p<0.0001). Overall seropositivity rates varied from 2.5% (PVX_097625, merozoite surface protein 8) to 16.8% (PVX_082670, merozoite surface protein 7), with 43% of individuals seropositive to at least 1 protein. Higher IgG levels were associated with older age (>18 years, p<0.05) and males (17/23 proteins, p<0.05), supporting the paradigm that men have a higher risk of infection than females in this setting. We used a Random Forests algorithm to predict which individuals had exposure to P. vivax parasites in the last 9-months, based on their IgG antibody levels to a panel of 8 previously validated P. vivax proteins. Spatial clustering was observed at the village and regional level, with a moderate correlation between PCR prevalence and sero-prevalence as predicted by the algorithm. Our data provides proof-of-concept for application of such surrogate markers as evidence of recent exposure in low transmission areas. These data can be used to better identify geographical areas with asymptomatic infection burdens that can be targeted in elimination campaigns.

scholarly journals Application of 23 Novel Serological Markers for Identifying Recent Exposure to Plasmodium vivax Parasites in an Endemic Population of Western Thailand

2021 ◽  
Vol 12 ◽  
Author(s):  
Sadudee Chotirat ◽  
Narimane Nekkab ◽  
Chalermpon Kumpitak ◽  
Jenni Hietanen ◽  
Michael T. White ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Spatial Clustering ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Serological Markers ◽  
Igg Antibody ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Recent Exposure ◽  
Increased Risk

Thailand is aiming for malaria elimination by the year 2030. However, the high proportion of asymptomatic infections and the presence of the hidden hypnozoite stage of Plasmodium vivax are impeding these efforts. We hypothesized that a validated surveillance tool utilizing serological markers of recent exposure to P. vivax infection could help to identify areas of ongoing transmission. The objective of this exploratory study was to assess the ability of P. vivax serological exposure markers to detect residual transmission “hot-spots” in Western Thailand. Total IgG levels were measured against a panel of 23 candidate P. vivax serological exposure markers using a multiplexed bead-based assay. A total of 4,255 plasma samples from a cross-sectional survey conducted in 2012 of endemic areas in the Kanchanaburi and Ratchaburi provinces were assayed. We compared IgG levels with multiple epidemiological factors that are associated with an increased risk of P. vivax infection in Thailand, including age, gender, and spatial location, as well as Plasmodium infection status itself. IgG levels to all proteins were significantly higher in the presence of a P. vivax infection (n = 144) (T-test, p &lt; 0.0001). Overall seropositivity rates varied from 2.5% (PVX_097625, merozoite surface protein 8) to 16.8% (PVX_082670, merozoite surface protein 7), with 43% of individuals seropositive to at least 1 protein. Higher IgG levels were associated with older age (&gt;18 years, p &lt; 0.05) and males (17/23 proteins, p &lt; 0.05), supporting the paradigm that men have a higher risk of infection than females in this setting. We used a Random Forests algorithm to predict which individuals had exposure to P. vivax parasites in the last 9-months, based on their IgG antibody levels to a panel of eight previously validated P. vivax proteins. Spatial clustering was observed at the village and regional level, with a moderate correlation between PCR prevalence and sero-prevalence as predicted by the algorithm. Our data provides proof-of-concept for application of such surrogate markers as evidence of recent exposure in low transmission areas. These data can be used to better identify geographical areas with asymptomatic infection burdens that can be targeted in elimination campaigns.

scholarly journals Factors Associated with Immunoglobulin G Subclass Polarization in Naturally Acquired Antibodies to Plasmodium falciparum Merozoite Surface Proteins: a Cross-Sectional Survey in Brazilian Amazonia

2006 ◽  
Vol 13 (7) ◽  
pp. 810-813 ◽  
Author(s):  
Kézia K. G. Scopel ◽  
Cor J. F. Fontes ◽  
Marcelo U. Ferreira ◽  
Érika M. Braga
Keyword(s):  
Plasmodium Falciparum ◽  
Immunoglobulin G ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Surface Proteins ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Falciparum Merozoite ◽  
Immunoglobulin G Subclass ◽  
Current Exposure

ABSTRACT We investigated immunoglobulin G (IgG) subclass antibody responses to Plasmodium falciparum merozoite surface protein 1 (MSP-1) and MSP-2 in 112 malaria-exposed subjects in Brazil. IgG3 polarization was primarily epitope driven, being little affected by cumulative or current exposure to malaria and not affected by a subject's age and Fcγ receptor IIA genotype.

scholarly journals Immunoglobulin G responses to variant forms of Plasmodium vivax merozoite surface protein 9 upon natural infection in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sunisa Songsaigath ◽  
Takashi Makiuchi ◽  
Chaturong Putaporntip ◽  
Urassaya Pattanawong ◽  
Napaporn Kuamsab ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Natural Infection ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Serum Samples ◽  
Ligand Complex ◽  
Erythrocyte Invasion ◽  
Malaria Exposure ◽  
Significant Difference ◽  
Malaria Episodes

AbstractMerozoite surface protein 9 (MSP9) constitutes a ligand complex involved in erythrocyte invasion by malarial merozoites and is a promising vaccine target. Plasmodium vivax MSP9 (PvMSP9) is immunogenic upon natural malaria exposure. To address whether sequence diversity in PvMSP9 among field isolates could affect natural antibody responses, the recombinant proteins representing two variants each for the N- and the C-terminal domains of PvMSP-9 were used as antigens to assess antibody reactivity among 246 P. vivax-infected patients’ sera from Tak and Ubon Ratchathani Provinces in Thailand. Results revealed that the seropositivity rates of IgG antibodies to the N-terminal antigens were higher than those to the C-terminal antigens (87.80% vs. 67.48%). Most seropositive sera were reactive to both variants, suggesting the presence of common epitopes. Variant-specific antibodies to the N- and the C-terminal antigens were detected in 15.85% and 16.70% of serum samples, respectively. These seropositivity rates were not significant difference between provinces. The seropositivity rates, levels and avidity of anti-PvMSP9 antibodies exhibited positive trends towards increasing malaria episodes. The IgG isotype responses to the N- and the C-terminal antigens were mainly IgG1 and IgG3. The profile of IgG responses may have implications for development of PvMSP9-based vaccine.

scholarly journals The Fine Specificity, but Not the Invasion Inhibitory Activity, of 19-Kilodalton Merozoite Surface Protein 1-Specific Antibodies Is Associated with Resistance to Malarial Parasitemia in a Cross-Sectional Survey in The Gambia

2004 ◽  
Vol 72 (10) ◽  
pp. 6185-6189 ◽  
Author(s):  
Patrick H. Corran ◽  
Rebecca A. O'Donnell ◽  
Jim Todd ◽  
Chairat Uthaipibull ◽  
Anthony A. Holder ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Ethnic Origin ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Fine Specificity ◽  
Merozoite Surface Protein 1 ◽  
Erythrocyte Invasion ◽  
Antibody Levels

ABSTRACT In a cross-sectional survey of 187 Gambian children and adults, we have analyzed prevalence, fine specificity, and 19-kilodalton merozoite surface protein 1 (MSP-119)-specific erythrocyte invasion inhibitory activity of antibodies to MSP-119 but find no significant association between any of these parameters and prevalence or density of malarial parasitemia, except that, after correcting for total anti-MSP-119 antibody levels, individuals with anti-MSP-119 antibodies that compete with an invasion inhibitory monoclonal antibody (12.10) were significantly less likely to have malaria infections with densities of ≥1,000 parasites/μl than were individuals without such antibodies. This association persisted after correction for age and ethnic origin.

scholarly journals Therapeutic Responses of Plasmodium vivax Malaria to Chloroquine and Primaquine Treatment in Northeastern Myanmar

2014 ◽  
Vol 59 (2) ◽  
pp. 1230-1235 ◽  
Author(s):  
Lili Yuan ◽  
Ying Wang ◽  
Daniel M. Parker ◽  
Bhavna Gupta ◽  
Zhaoqing Yang ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Cumulative Incidence ◽  
Therapeutic Efficacy ◽  
Cumulative Risk ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Radical Cure ◽  
Content Type ◽  
Plasmodium Vivax Malaria

ABSTRACTChloroquine-primaquine (CQ-PQ) continues to be the frontline therapy for radical cure ofPlasmodium vivaxmalaria. Emergence of CQ-resistant (CQR)P. vivaxparasites requires a shift to artemisinin combination therapies (ACTs), which imposes a significant financial, logistical, and safety burden. Monitoring the therapeutic efficacy of CQ is thus important. Here, we evaluated the therapeutic efficacy of CQ-PQ forP. vivaxmalaria in northeast Myanmar. We recruited 587 patients withP. vivaxmonoinfection attending local malaria clinics during 2012 to 2013. These patients received three daily doses of CQ at a total dose of 24 mg of base/kg of body weight and an 8-day PQ treatment (0.375 mg/kg/day) commencing at the same time as the first CQ dose. Of the 401 patients who finished the 28-day follow-up, the cumulative incidence of recurrent parasitemia was 5.20% (95% confidence interval [CI], 3.04% to 7.36%). Among 361 (61%) patients finishing a 42-day follow-up, the cumulative incidence of recurrent blood-stage infection reached 7.98% (95% CI, 5.20% to 10.76%). The cumulative risk of gametocyte carriage at days 28 and 42 was 2.21% (95% CI, 0.78% to 3.64%) and 3.93% (95% CI, 1.94% to 5.92%), respectively. Interestingly, for all 15 patients with recurrent gametocytemia, this was associated with concurrent asexual stages. Genotyping of recurrent parasites at the merozoite surface protein 3α gene locus from 12 patients with recurrent parasitemia within 28 days revealed that 10 of these were the same genotype as at day 0, suggesting recrudescence or relapse. Similar studies in 70 patients in the same area in 2007 showed no recurrent parasitemias within 28 days. The sensitivity to chloroquine ofP. vivaxin northeastern Myanmar may be deteriorating.

scholarly journals The Economic Cost of Diet and Its Association with Adherence to the Mediterranean Diet in a Cohort of Spanish Primary Schoolchildren

2021 ◽  
Vol 18 (3) ◽  
pp. 1282
Author(s):  
Rosario Pastor ◽  
Noemi Pinilla ◽  
Josep A. Tur
Keyword(s):  
Mediterranean Diet ◽  
Fast Food ◽  
Area Under The Curve ◽  
Economic Cost ◽  
Food Prices ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Old Spanish ◽  
Total Economic Cost ◽  
Data Frequency

Background: Adoption of a certain dietary pattern is determined by different factors such as taste, cost, convenience, and nutritional value of food. Objective: To assess the association between the daily cost of a diet and its overall quality in a cohort of 6–12-year-old Spanish schoolchildren. Methods: A cross-sectional survey was conducted on a cohort (n = 130; 47% female) of 6–12-year-old children schooled in primary education in the central region of Spain. Three-day 24 h records were administered, and the nutritional quality of the diet was also determined by means of Mediterranean Adequacy Index (MAI). A questionnaire on sociodemographic data, frequency of eating in fast-food restaurants, and supplement intake were also recorded. The person responsible for the child’s diet and the schooler himself completed the questionnaires, and homemade measures were used to estimate the size of the portions. Food prices were obtained from the Household Consumption Database of the Spanish Ministry of Agriculture, Fisheries and Food. The economic cost of the diet was calculated by multiplying the amount in grams of the food consumed by each child by the corresponding price in grams and adding up the total amount for each participant. The total economic cost of the diet was calculated in €/day and in €/1000 kcal/day. Results: The area under the curve (AUC) for €/day and €/1000 kcal/day represent 62.6% and 65.6%, respectively. According to AUC values, adherence to Mediterranean diet (MD) is a moderate predictor of the monetary cost of the diet. A direct relationship between the cost of the diet and the adherence to MD was observed [OR (€/1000 kcal/day) = 3.012; CI (95%): 1.291; 7.026; p = 0.011]. Conclusions: In a cohort of Spanish schoolchildren with low adherence to the MD, a higher cost of the diet standardized to 1000 kcal was associated with above-average MAI values.

scholarly journals Population-based cross-sectional prevalence survey of diabetes and diabetic retinopathy in Sohag—Egypt, 2019

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e047757
Author(s):  
Heba AlSawahli ◽  
Caleb D Mpyet ◽  
Gamal Ezzelarab ◽  
Ibrahim Hassanin ◽  
Mohammad Shalaby ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Rapid Assessment ◽  
Good Control ◽  
Population Based ◽  
Secondary Outcome ◽  
Public Health Approach ◽  
Eye Care ◽  
Cross Sectional Survey ◽  
Prevalence Survey ◽  
Cross Sectional

ObjectivesTo determine the prevalence of diabetes mellitus (DM), prevalence of diabetic retinopathy (DR) and sight-threatening conditions among persons with DM aged 50 years and older in Sohag governorate in Upper Egypt.DesignPopulation-based, cross-sectional survey using the standardised Rapid Assessment of Avoidable Blindness with the addition of the Diabetic Retinopathy module methodology.SettingsSohag governorate in Egypt where 68 clusters were selected using probability proportional to population size. Households were selected using the compact segment technique.Participants4078 people aged 50 years and older in 68 clusters were enrolled, of which 4033 participants had their random blood sugar checked and 843 examined for features of DR.Primary and secondary outcomesThe prevalence of DM and DR; secondary outcome was the coverage with diabetic eye care.ResultsThe prevalence of DM was 20.9% (95% CI 19.3% to 22.5%). The prevalence in females (23.8%; 95% CI 21.4% to 26.3%) was significantly higher than in males (18.9%; 95% CI 17.1% to 20.7%) (p=0.0001). Only 38.8% of persons diagnosed with diabetes had good control of DM. The prevalence of DR in the sample was 17.9% (95% CI 14.7% to 21.1%). The prevalence in females was higher (18.9%; 95% CI 14.0% to 23.8%) than in males (17.1%; 95% CI 13.0% to 21.2%). Up to 85.3% of study participants have never had eye examination. Sight-threatening DR (R4 and/or M2) was detected in 5.2% (95% CI 3.4% to 7.0%) with only 2.3% having had laser treatment.ConclusionThe prevalence of uncontrolled DM in Sohag governorate in Egypt is higher than the national prevalence. There is a high prevalence of sight-threatening retinopathy and/or maculopathy with few people having access to diabetic eye care. A public health approach is needed for health promotion, early detection and management of DR.

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