Focal screening and treatment for malaria: defining the sentinel population

Abstract Background With increasing spatial heterogeneity of malaria transmission and a shift of the disease burden towards older children and adults, pregnant women attending antenatal care (ANC) have been proposed as a pragmatic sentinel population for malaria surveillance. However, the representativeness of routine ANC malaria test-positivity and its relationship with prevalence in other population subgroups are yet to be investigated. Methods Monthly ANC malaria test-positivity data from all Tanzanian health facilities for January 2014 to May 2016 was compared to prevalence data from the School Malaria Parasitaemia Survey 2015, the Malaria Indicator Survey (MIS) 2015/16, the Malaria Atlas Project 2015, and a Bayesian model fitted to MIS data. Linear regression was used to describe the difference between malaria test-positivity in pregnant women and respective comparison groups as a function of ANC test-positivity and potential covariates. Results The relationship between ANC test-positivity and survey prevalence in children follows spatially and biologically meaningful patterns. However, the uncertainty of the relationship was substantial, particularly in areas with high or perennial transmission. In comparison, modelled data estimated higher prevalence in children at low transmission intensities and lower prevalence at higher transmission intensities. Conclusions Pregnant women attending ANC are a pragmatic sentinel population to assess heterogeneity and trends in malaria prevalence in Tanzania. Yet, since ANC malaria test-positivity cannot be used to directly predict the prevalence in other population subgroups, complementary community-level measurements remain highly relevant.

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SARS-CoV-2 vaccine antibody response and breakthrough infections in patients receiving dialysis

10.1101/2021.10.12.21264860 ◽

2021 ◽

Author(s):

Shuchi Anand ◽

Maria E Montez-Rath ◽

Jialin Han ◽

Pablo Garcia ◽

LinaCel Cadden ◽

...

Keyword(s):

Antibody Response ◽

Mitigation Strategies ◽

Breakthrough Infection ◽

Post Vaccination ◽

Correlates Of Protection ◽

Igg Index ◽

Nested Case Control ◽

High Throughput Assay ◽

Prior Infection ◽

Sentinel Population

Background: Patients receiving dialysis are a sentinel population for groups at high risk for death and disability from COVID-19. Understanding correlates of protection post-vaccination can inform immunization and mitigation strategies. Methods: Monthly since January 2021, we tested plasma from 4791 patients receiving dialysis for antibodies to the receptor-binding domain (RBD) of SARS-CoV-2 using a high-throughput assay. We qualitatively assessed the proportion without a detectable RBD response and among those with a response, semiquantitative median IgG index values. Using a nested case-control design, we matched each breakthrough case to five controls by age, sex, and vaccination-month to determine whether peak and pre-breakthrough RBD IgG index values were associated with risk for infection post-vaccination. Results: Among 2563 vaccinated patients, the proportion without a detectable RBD response increased from 6.6% [95% CI 5.5-8.1] in 14-30 days post-vaccination to 20.2% [95% CI 17.1-23.8], and median index values declined from 92.7 (95% CI 77.8-107.5) to 3.7 (95% CI 3.1-4.3) after 5 months. Persons with SARS-CoV-2 infection prior-to-vaccination had higher peak index values than persons without prior infection, but values equalized by 5 months (p=0.230). Breakthrough infections occurred in 56 patients, with samples collected a median of 21 days pre-breakthrough. Peak and pre-breakthrough RBD values <23 (equivalent to <506 WHO BAU/mL) were associated with higher odds for breakthrough infection (OR: 3.7 [95% CI 2.0-6.8] and 9.8 [95% CI 2.9-32.8], respectively). Conclusions: The antibody response to SARS-CoV-2 vaccination wanes rapidly, and in persons receiving dialysis, the persisting antibody response is associated with risk for breakthrough infection.

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Risk Factors Associated with Dengue Transmission and Spatial Distribution of High Seroprevalence in Schoolchildren from the Urban Area of Medellin, Colombia

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2018/2308095 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Leidy Diana Piedrahita ◽

Ivony Y. Agudelo Salas ◽

Katherine Marin ◽

Andrea I. Trujillo ◽

Jorge E. Osorio ◽

...

Keyword(s):

Seroconversion Rate ◽

Target Population ◽

Multivariate Regression Analysis ◽

Socioeconomic Conditions ◽

Effective Prevention ◽

Dengue Transmission ◽

One Year ◽

Vaccination Campaigns ◽

Sentinel Population ◽

Main Factor

Dengue fever is an increasing health problem in tropical and subtropical regions. During 2010 in Medellin, the younger population presented a particularly high dengue incidence rate. This study estimated dengue virus (DENV) transmission in schoolchildren (aged 5–19 years) in Medellin from 2010 to 2012. A longitudinal serological survey (IgG) and spatial analysis were conducted to determine the distribution of DENV seroprevalence. A total of 4,385 schoolchildren participated for at least one year. Dengue seroprevalence significantly increased during the studied period (53.8% to 64.6%; p<0.001). A significantly higher seroconversion rate was observed in 2010-2011 (16.8%) compared to 2011-2012 (7.8%). Multivariate regression analysis showed that the main factor associated with the seroprevalence was the aging. Furthermore, in 2010, patients with high socioeconomic status presented a lower risk. Predominant multitypic and DENV4 monotypic antibody responses were demonstrated. Geostatistical analysis evidenced a temporal clustering distribution of DENV seroprevalence in 2010. Population density and Ae. aegypti House Index were significantly correlated with the observed pattern. This study revealed high DENV transmission in schoolchildren determined as “sentinel population.” High DENV risk was found in districts with combined poorly socioeconomic conditions and densest human and mosquito populations. These findings may allow to target population for effective prevention and vaccination campaigns.

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Revisiting Western Hudson Bay: Using aerial surveys to update polar bear abundance in a sentinel population

Biological Conservation ◽

10.1016/j.biocon.2013.12.040 ◽

2014 ◽

Vol 170 ◽

pp. 38-47 ◽

Cited By ~ 29

Author(s):

Seth Stapleton ◽

Stephen Atkinson ◽

Daryll Hedman ◽

David Garshelis

Keyword(s):

Polar Bear ◽

Hudson Bay ◽

Aerial Surveys ◽

Western Hudson Bay ◽

Sentinel Population

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Disproportionate and increasing burden of HIV infection among men who have sex with men in Slovenia: surveillance data for 1999-2008

Eurosurveillance ◽

10.2807/ese.14.47.19419-en ◽

2009 ◽

Vol 14 (47) ◽

Cited By ~ 6

Author(s):

I Klavs ◽

N Bergant ◽

Z Kastelic ◽

A Lamut ◽

T Kustec

Keyword(s):

Hiv Infection ◽

Mandatory Reporting ◽

Infection Prevalence ◽

Outpatient Services ◽

Hiv Diagnosis ◽

Male Clients ◽

Hiv Test ◽

Positive Prevention ◽

Sex With Men ◽

Sentinel Population

The report presents data on HIV infection among men who have sex with men (MSM) in Slovenia during 1999-2008. HIV surveillance was based on universal mandatory reporting of HIV/AIDS cases, monitoring HIV infection prevalence among sentinel populations of MSM and STI patients and selected behaviour indicators in a sentinel population of MSM. Among 48 newly diagnosed HIV cases reported for 2008, 34 were MSM. Since 1999, the annual reported rate of HIV diagnoses in MSM rose from 7.1 to 46.8 per million men aged 15-64 years (an increase of more than six times). During 1999-2008, the proportion of MSM diagnosed with AIDS within three months of HIV diagnosis declined from 60% to 21%, however, the corresponding rate per million men aged 15-64 increased from 4.3 to 9.6. During 1999-2008, HIV prevalence among male clients of STI outpatient services tested for syphilis (including a substantial proportion of MSM) increased from 0% to 3.4%, and it remained below 5% in a sentinel population of MSM in Ljubljana. In the same sentinel population of MSM, the proportion reporting HIV test last year increased from 29% in 2003 to 38% in 2008 while the proportion reporting condom use at last anal intercourse decreased from 81% in 2004 to 66% in 2008. The burden of HIV among MSM in Slovenia is disproportionately high and increasing fast. Promotion of safer sexual behaviour and HIV testing among MSM as well as positive prevention among MSM with diagnosed HIV infection are urgently needed.

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Cataract surgical patients as a candidate sentinel population for SARS‐CoV ‐2 surveillance

Clinical and Experimental Ophthalmology ◽

10.1111/ceo.13844 ◽

2020 ◽

Vol 48 (9) ◽

pp. 1316-1318 ◽

Cited By ~ 1

Author(s):

Joshua Foreman ◽

Myra McGuinness ◽

David A. Mackey ◽

Peter Wijngaarden

Keyword(s):

Surgical Patients ◽

Sentinel Population

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Are tuberculosis patients a ‘sentinel’ population for HIV epidemic in Africa?

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1016/0035-9203(90)90291-l ◽

1990 ◽

Vol 84 (2) ◽

pp. 292 ◽

Cited By ~ 1

Author(s):

J. Hellinger ◽

R. Marlink ◽

L. Kaptue ◽

L. Zekeng ◽

M. Essex

Keyword(s):

Tuberculosis Patients ◽

Hiv Epidemic ◽

Sentinel Population

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Sentinel Surveillance of HIV-1 Infection in Tamilnadu, India

International Journal of STD & AIDS ◽

10.1177/095646249400500613 ◽

1994 ◽

Vol 5 (6) ◽

pp. 445-446 ◽

Cited By ~ 5

Author(s):

Suniti Solomon ◽

S Anuradha ◽

M Ganapathy ◽

Jagadeeswaril

Keyword(s):

Hiv Infection ◽

Blood Donors ◽

Preventive Intervention ◽

Sentinel Surveillance ◽

Steady Increase ◽

Hiv Seropositivity ◽

Control Programmes ◽

And Control ◽

Hiv 1 ◽

Sentinel Population

The objective was to determine the time trends in the prevalence of HIV infection and to evaluate appropriate preventive intervention in different population groups. Sentinel surveillance of HIV-1 infection by anonymous unlinked technique was carried out in Tamilnadu from December 1989 to March 1993. The sentinel population monitored were attendees of STD clinics, blood donors and antenatal mothers. The results of HIV seropositivity were compared for each 6-month period. During the study period there was 10-fold rise of HIV seropositivity among STD patients (1% to 10%), 2-fold rise among antenatal attendees (0.37% to 0.76%), and 3-fold rise in blood donors (0.24% to 0.72%). There was a steady increase in the incidence of HIV infection among those with high risk bheaviour (STD attendees) as well as in the general population. This information is of value in planning and evaluation of preventive and control programmes in India.

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A transmissible γδ intraepithelial lymphocyte hyperproliferative phenotype is associated with the intestinal microbiota and confers protection against acute infection.

10.1101/2021.07.22.453366 ◽

2021 ◽

Author(s):

Luo Jia ◽

Guojun Wu ◽

Sara Alonso ◽

Cuiping Zhao ◽

Alexander Lemenze ◽

...

Keyword(s):

T Cell Receptor ◽

Acute Infection ◽

Immune Surveillance ◽

Cell Receptor ◽

Intraepithelial Lymphocytes ◽

Γδ T Cell ◽

Specific Group ◽

First Line ◽

Necessary And Sufficient ◽

Sentinel Population

Intraepithelial lymphocytes expressing the γδ T cell receptor (γδ IELs) serve as a first line of defense against luminal microbes. Although the presence of an intact microbiota is dispensable for γδ IEL development, several microbial factors contribute to the maintenance of this sentinel population. However, whether specific commensals influence population of the γδ IEL compartment under homeostatic conditions has yet to be determined. We identified a novel γδ IEL hyperproliferative phenotype that arises early in life and is characterized by expansion of multiple Vγ subsets. Horizontal transfer of this hyperproliferative phenotype to mice harboring a phenotypically normal γδ IEL compartment was prevented following antibiotic treatment, thus demonstrating that the microbiota is both necessary and sufficient for the observed increase in γδ IELs. Further, we identified a group of unique gut bacteria represented by 5 amplicon sequence variants (ASV) which are strongly associated with γδ IEL expansion. Using intravital microscopy, we find that hyperproliferative γδ IELs also exhibit increased migratory behavior leading to enhanced protection against bacterial infection. These findings reveal that transfer of a specific group of commensals can regulate γδ IEL homeostasis and immune surveillance, which may provide a novel means to reinforce the epithelial barrier.

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