Predictive markers of transmission in areas with different malaria endemicity in north-eastern Tanzania based on seroprevalence of antibodies against Plasmodium falciparum

Abstract Objective A community-based cross-sectional study was done to assess Plasmodium falciparum exposure in areas with different malaria endemicity in north-eastern Tanzania using serological markers; PfAMA-1 and PfMSP-119. Results Bondo had a higher seroprevalence 36.6% (188) for PfAMA-1 as compared to Hai 13.8% (33), χ2 = 34.66, p < 0.01. Likewise, Bondo had a higher seroprevalence 201(36.6%) for PfMSP-1 as compared to Hai 41 (17.2%), χ2 = 29.62, p < 0.01. Anti-PfAMA-1 titters were higher in malaria positive individuals (n = 47) than in malaria negative individuals (n = 741) (p = 0.07). Anti-PfMSP-1 antibody concentrations were significantly higher in malaria-positive individuals (n = 47) than in malaria-negative individuals (n = 741) (p = 0.003). Antibody response against PfAMA-1 was significantly different between the three age groups; < 5 years, 5 to 15 years and > 15 years in both sites of Bondo and Hai. Likewise, antibody response against PfMSP-119 was significantly different between the three age groups in the two sites (p < 0.001). We also found significant differences in the anti-PfAMA-1and anti-PfMSP-119 antibody concentrations among the three age groups in the two sites (p = 0.004 and 0.005) respectively. Immunological indicators of P. falciparum exposure have proven to be useful in explaining long-term changes in the transmission dynamics, especially in low transmission settings.

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Predictive markers of transmission in areas with different malaria endemicity in north-eastern Tanzania based on seroprevalence of antibodies against Plasmodium falciparum

10.21203/rs.3.rs-586890/v2 ◽

2021 ◽

Author(s):

Robert Diotrephes Kaaya ◽

Debora C Kajeguka ◽

Johnson J Matowo ◽

Arnold J Ndaro ◽

Franklin W Mosha ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Antibody Response ◽

Age Groups ◽

Transmission Dynamics ◽

Serological Markers ◽

Low Transmission ◽

Malaria Endemicity ◽

North Eastern ◽

Long Term Changes

Abstract Objective The objective of this study was to assess Plasmodium falciparum exposure in areas with different malaria endemicity in north-eastern Tanzania using serological markers; PfAMA-1 and PfMSP-119.Results Bondo had a higher seroprevalence 36.6% (188) for PfAMA-1 as compared to Hai 13.8% (33), χ2=34.66, p<0.01. Likewise, Bondo had a higher seroprevalence 201(36.6%) for PfMSP-1 as compared to Hai 41 (17.2%), χ2 =29.62, p<0.01. Anti-PfAMA-1 titters were higher in malaria positive individuals (n = 47) than in malaria negative individuals (n = 741) (p = 0.07). Anti-PfMSP-1 antibody concentrations were significantly higher in malaria-positive individuals (n = 47) than in malaria-negative individuals (n = 741) (p = 0.003).Antibody response against PfAMA-1 was significantly different between the three age groups; <5 years, 5 to 15 years and >15 years in both sites of Bondo and Hai. Likewise, antibody response against PfMSP-119 was significantly different between the three-age groups in the two sites. (p<0.001). We also found significant differences in the anti-PfAMA-1and anti-PfMSP-119 antibody concentrations among the three age groups in the two sites (p=0.004 and 0.005) respectively. Immunological indicators of Plasmodium falciparum exposure have proven to be useful in explaining long-term changes in the transmission dynamics especially in low transmission settings.

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Prevalence and Correlates of Alcohol Consumption among Hill-Tribe Adolescents below the Legal Drinking Age—A Community-based Cross-Sectional Study in Northern Thailand

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17218266 ◽

2020 ◽

Vol 17 (21) ◽

pp. 8266

Author(s):

Narongsak Noosorn ◽

Civilaiz Wanaratwichit ◽

Shamsudeen YAU ◽

Nuansiri Kedsai

Keyword(s):

Alcohol Use ◽

Age Groups ◽

Binary Logistic Regression ◽

Cross Sectional Study ◽

Sectional Study ◽

Community Based ◽

Thai Population ◽

Cross Sectional ◽

Northern Thailand ◽

Prevention Interventions

Alcohol drinking has been prevalent among various hill tribes of northern Thailand due to their distinctively different lifestyles, traditions, cultures and beliefs than the general Thai population; the majority of these traditions involve annual rounds of customary rituals that make alcohol abundantly accessible to all age groups. To study the prevalence and predictors of alcohol use, a community-based analytical cross-sectional study was conducted between October 2017–September 2018 among 480 sampled adolescents aged 12 through 18 years drawn by stratified random sampling. A proprietary questionnaire developed by the researchers was used to collect the data which were analyzed using binary logistic regression. The prevalence of alcohol use in the previous 30 days was 46.7%. Drinking predictors were: having at least a drinking parent, drinking peers, ever been sent to buy alcohol, smoking, cordial relationship with peers, gambling, family violence experience, stress and leisure time company. Therefore, our results suggest that prevention interventions should be designed with a focus on discouraging parents from sending children to buy alcohol and drinking or smoking in their presence; to reduce both social and commercial access to alcohol, age limits should be imposed on alcohol intake at all ceremonious events, while strictly reinforcing the law that prohibits selling alcohol to minors.

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Long-Term Duration of Antibody Response to SARS CoV-2 in One of the Largest Slums of Buenos Aires

10.1101/2021.03.05.21253010 ◽

2021 ◽

Author(s):

Vanina Pagotto ◽

Lorena Luna ◽

Julieta Salto ◽

Magdalena Wagner Manslau ◽

Silvana Figar ◽

...

Keyword(s):

Antibody Response ◽

Buenos Aires ◽

Humoral Response ◽

Cross Sectional Study ◽

Older Individuals ◽

Sectional Study ◽

Cross Sectional ◽

The People ◽

Igg Level

AbstractThe durability of the antibody response following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections has not been fully elucidated. We have performed a cross-sectional study in one of the largest slums of Buenos Aires, Barrio Padre Mugica in June 2020, detecting a seroprevalence of 53.4%. To evaluate the persistence of the humoral response against SARS-CoV-2 in this area, we designed a second study assessing only the people that were IgG positive in the first survey. The IgG levels against the full spike (S) protein in 175 individuals that were seropositive, at least 6 months before, were evaluated in a second survey. The positivity rate was 92.0%, 161 from 175 individuals remained IgG positive. We observed a contraction in the overall IgG levels measured by ELISA. The median IgG dropped 62% from June to December 2020. Most of the individuals tested (87%) reported to be asymptomatic or oligo-symptomatic. No difference was found between men and women, but people aged less than 50 showed a lower IgG level in each period compared to older individuals. Our data indicate sustained humoral immunity for at least 6 months in a specific socio-economical setting in a population that was mainly asymptomatic for COVID-19.

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