Breast Cancer Screening: Knowledge, Attitudes, and Practices among Female University Students in The Gambia.

Background: Breast cancer is the second most prevalent form of cancer in The Gambia, with an incidence rate of approximately 15% and a mortality rate exceeding 50% in 2020. The all-age prevalence stands at 11.25 per 100,000 population.

Prevalence and factors associated with unplanned pregnancy in The Gambia: findings from 2018 population-based survey.

Background: Unplanned pregnancy is a public health issue that has detrimental implications for the mother and baby alike. However, few studies have been conducted in The Gambia on this subject. As a result, the prevalence of unplanned pregnancy among women of reproductive age in The Gambia was investigated, as well as the factors associated with it.

Childhood vaccination uptake and associated factors among children 12-23 months in rural settings of the Gambia: a community-based cross-sectional study.

Background: Globally, immunization prevents 2-3 million deaths annually from vaccine-preventable diseases such as diphtheria, tetanus, pertussis, influenza, and measles. In developing countries, several immunization programs have made progress, but the coverage remains a standstill in some areas. In order to inform policies and practices, the present study aimed at assessing vaccination uptake and contextual-associated factors among children aged 12-23 months in rural Gambia.

Knowledge, Attitude, and Practice of Provincial Dwellers on Prevention and Control of Schistosomiasis: Evidence from a Community-Based Cross-Sectional Study in the Gambia.

Background: Socioeconomically disadvantaged and neglected communities were found to be the most affected groups for schistosomiasis as a result of inadequate safe water and sanitation facilities. In order to inform policies and practices, the present study examined the influence of sociodemographic factors and attitudes on the knowledge and practice in the prevention and control of schistosomiasis in eighteen endemic rural communities in the Gambia.

Methods: In January 2019, a community-based cross-sectional study was conducted in which 383 household heads in rural communities across Kuntaur and Janjanbureh Local Government Areas (LGAs) in Central River Region were recruited.

Enhancement of cytokine-driven NK cell IFN-γ production after vaccination of HCMV infected Africans.

Human cytomegalovirus (HCMV) infection drives the phenotypic and functional differentiation of NK cells, thereby influencing the responses of these cells after vaccination. NK cell functional differentiation is particularly advanced in African populations with universal exposure to HCMV. To investigate the impact of advanced differentiation on vaccine-induced responses, we studied NK-cell function before and after vaccination with Trivalent Influenza Vaccine (TIV) or diphtheria, tetanus, pertussis, inactivated poliovirus vaccine (DTPiP) in Africans with universal, lifelong HCMV exposure.

Immunological impact of an additional early measles vaccine in Gambian children: responses to a boost at 3 years.

Background: Measles vaccine in early infancy followed by a dose at 9 months of age protects against measles and enhances child survival through non-specific effects. Little is known of immune responses in the short or long term after booster doses.

Methods: Infants were randomized to receive measles vaccine at 9 months of age (group 1) or 4 and 9 months of age (group 2).

Placental malaria is associated with attenuated CD4 T-cell responses to tuberculin PPD 12 months after BCG vaccination.

Background: Placental malaria (PM) is associated with prenatal malaise, but many PM+ infants are born without symptoms. As malaria has powerful immunomodulatory effects, we tested the hypothesis that PM predicts reduced T-cell responses to vaccine challenge.

Methods: We recruited healthy PM+ and PM- infants at birth.

Age-dependent maturation of Toll-like receptor-mediated cytokine responses in Gambian infants.

The global burden of neonatal and infant mortality due to infection is staggering, particularly in resource-poor settings. Early childhood vaccination is one of the major interventions that can reduce this burden, but there are specific limitations to inducing effective immunity in early life, including impaired neonatal leukocyte production of Th1-polarizing cytokines to many stimuli. Characterizing the ontogeny of Toll-like receptor (TLR)-mediated innate immune responses in infants may shed light on susceptibility to infection in this vulnerable age group, and provide insights into TLR agonists as candidate adjuvants for improved neonatal vaccines.

Epstein-Barr virus but not cytomegalovirus is associated with reduced vaccine antibody responses in Gambian infants.

Background: Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are persistent herpesviruses that have various immunomodulatory effects on their hosts. Both viruses are usually acquired in infancy in Sub-Saharan Africa, a region where childhood vaccines are less effective than in high income settings. To establish whether there is an association between these two observations, we tested the hypothesis that infection with one or both viruses modulate antibody responses to the T-cell independent meningococcal polysaccharide vaccine and the T-cell dependent measles vaccines.

The tuberculin skin test (TST) is affected by recent BCG vaccination but not by exposure to non-tuberculosis mycobacteria (NTM) during early life.

The tuberculin skin test (TST) is widely used in TB clinics to aid Mycobacterium tuberculosis (M.tb) diagnosis, but the definition and the significance of a positive test in very young children is still unclear. This study compared the TST in Gambian children at 4(1/2) months of age who either received BCG vaccination at birth (Group 1) or were BCG naïve (Group 2) in order to examine the role of BCG vaccination and/or exposure to environmental mycobacteria in TST reactivity at this age.

Delaying bacillus Calmette-Guérin vaccination from birth to 4 1/2 months of age reduces postvaccination Th1 and IL-17 responses but leads to comparable mycobacterial responses at 9 months of age.

Bacillus Camette-Guérin (BCG) vaccine is the only licensed vaccine against tuberculosis, yet its protective efficacy is highly variable between different geographical regions. We hypothesized that exposure to nontuberculous mycobacteria attenuates BCG immunogenicity by inducing mycobacterial-specific regulatory T cells (Tregs). Gambian neonates were recruited at birth and randomized to receive BCG vaccination either at birth or at 4 1/2 mo.

Placental malaria is associated with reduced early life weight development of affected children independent of low birth weight.

Background: Infection with Plasmodium falciparum during pregnancy contributes substantially to the disease burden in both mothers and offspring. Placental malaria may lead to intrauterine growth restriction or preterm delivery resulting in low birth weight (LBW), which, in general, is associated with increased infant morbidity and mortality. However, little is known about the possible direct impact of the specific disease processes occurring in PM on longer term outcomes such as subsequent retarded growth development independent of LBW.

Maintenance of large subpopulations of differentiated CD8 T-cells two years after cytomegalovirus infection in Gambian infants.

Background: In a previously published study, we found that large differentiated subpopulations of CD8 T-cells emerged rapidly after CMV infection in young infants and persisted throughout the following year. Here we describe a follow-up study conducted on the same infants to establish whether the differentiated subpopulations continued through the second year post-infection.

Methodology / Principal Findings: CMV-specific cells identified using tetramers remained more activated and differentiated than the overall CD8 population.

Effects of antenatal and postnatal environments on CD4 T-cell responses to Mycobacterium bovis BCG in healthy infants in the Gambia.

The Mycobacterium bovis BCG vaccine has a poor record of efficacy in low-income tropical settings. Against this background, we evaluated the immune response of infants to mycobacterial antigens over the 2 years following BCG vaccination at birth by measuring the gamma interferon (IFN-gamma), interleukin-2 (IL-2), and CD154 responses of CD4 T cells. Similar numbers of cells expressed IFN-gamma in infants, 4- to 5-year-old children, and adults, while CD154 was not expressed at comparable levels until the second year of infancy.

CD4(+) T cell responses to cytomegalovirus in early life: a prospective birth cohort study.

We compared cytomegalovirus (CMV)-specific interferon-gamma (IFN-gamma), interleukin 2 (IL-2), and CD154 CD4(+) T cell responses of infants to those from chronically infected adults and from children aged 4-5 years. Magnitudes of the responses were similar, although coexpression of IFN-gamma plus CD154 occurred more than coexpression of IFN-gamma plus IL-2 or IL-2 plus CD154. Responses remained constant during infancy, although the proportion of IFN-gamma-producing cells increased from infancy to adulthood.

Cytomegalovirus infection induces T-cell differentiation without impairing antigen-specific responses in Gambian infants.

Cytomegalovirus (CMV) infection induces profound differentiation of T cells, and is associated with impaired responses to other immune challenges. We therefore considered whether CMV infection and the consequent T-cell differentiation in Gambian infants was associated with impaired specific responses to measles vaccination or polyclonal responses to the superantigen staphylococcal enterotoxin B (SEB). While the concentration of undifferentiated (CD27(+) CD28(+) CCR7(+)) T-cells in peripheral blood was unaffected by CMV, there was a large increase in differentiated (CD28(-) CD57(+)) CD8 T-cells and a smaller increase in differentiated CD4 cells.

Cytomegalovirus infection in Gambian infants leads to profound CD8 T-cell differentiation.

Cytomegalovirus (CMV) infection is endemic in Gambian infants, with 62% infected by 3 months and 85% by 12 months of age. We studied the CD8 T-cell responses of infants to CMV following primary infection. CMV-specific CD8 T cells, identified with tetramers, showed a fully differentiated phenotype (CD28(-) CD62L(-) CD95(+) perforin(+) granzyme A(+) Bcl-2(low)).