Stephen L Quaye - Academia.edu (original) (raw)

Papers by Stephen L Quaye

The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPT... more The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women (ISTp) is an alternative approach.

A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVacT... more A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVacTM) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere.

Background. Study of meningococcal carriage is essential to understanding the epidemiology of Nei... more Background. Study of meningococcal carriage is essential to understanding the epidemiology of Neisseria meningitidis infection.
Methods. Twenty cross-sectional carriage surveys were conducted in 7 countries in the African meningitis belt; 5 surveys were conducted after introduction of a new serogroup A meningococcal conjugate vaccine (MenAfriVac). Pharyngeal swab specimens were collected, and Neisseria species were identi␣ed by microbiological and molecular techniques.
Results. A total of 1687 of 48 490 participants (3.4%; 95% con␣dence interval [CI], 3.2%–3.6%) carried menin- gococci. Carriage was more frequent in individuals aged 5–14 years, relative to those aged 15–29 years (adjusted odds ratio [OR], 1.41; 95% CI, 1.25–1.60); in males, relative to females (adjusted OR, 1.17; 95% CI, 1.10–1.24); in indi- viduals in rural areas, relative to those in urban areas (adjusted OR, 1.44; 95% CI, 1.28–1.63); and in the dry season, relative to the rainy season (adjusted OR, 1.54; 95% CI, 1.37–1.75). Forty-eight percent of isolates had genes encoding disease-associated polysaccharide capsules; genogroup W predominated, and genogroup A was rare. Strain diversity was lower in countries in the center of the meningitis belt than in Senegal or Ethiopia. The prevalence of genogroup A fell from 0.7% to 0.02% in Chad following mass vaccination with MenAfriVac.
Conclusions. The prevalence of meningococcal carriage in the African meningitis belt is lower than in indus- trialized countries and is very diverse and dynamic, even in the absence of vaccination.

Background: Vaginitis is a wide spread inflammatory condition of the female genital tract. It aff... more Background: Vaginitis is a wide spread inflammatory condition of the female genital tract. It affects a wide range of women all over the world. The condition is caused by several types of microorganism including yeast, especially Candida species. Objective: The aim of this study was to assess the incidence of vaginal candidiasis in a Girl's Senior High School in Bolgatanga, Ghana. Methodology: High Vaginal Swabs were randomly taken from consenting female students for the study. The students also completed a structured questionnaire assessing demographic characteristics, symptoms, and risk factors of candidiasis. A total of 94 students between the ages of 17 and 23 were randomly recruited for the study. Standard microbiological techniques such as Gram's stain, wet mount and culture were used to analyse the swabs. Results: Candida species was isolated from 24 of the 94 students representing 25.5%. The highest incidence rates of 50.0% were recorded in the 21 years old participants followed by 45.5% in the 20 years group. Among the symptoms, vaginal itching and burning sensation recorded the highest percentages among the positive for Candida participants; 30.0% and 29.2% respectively. The most common associated risk factors contributing to vaginal candidiasis in this study was antibiotic use which recorded 50.0% while initiation of sexual activity recorded 32.1%.

The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPT... more The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women (ISTp) is an alternative approach.

A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVacT... more A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVacTM) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere.

Background. Study of meningococcal carriage is essential to understanding the epidemiology of Nei... more Background. Study of meningococcal carriage is essential to understanding the epidemiology of Neisseria meningitidis infection.
Methods. Twenty cross-sectional carriage surveys were conducted in 7 countries in the African meningitis belt; 5 surveys were conducted after introduction of a new serogroup A meningococcal conjugate vaccine (MenAfriVac). Pharyngeal swab specimens were collected, and Neisseria species were identi␣ed by microbiological and molecular techniques.
Results. A total of 1687 of 48 490 participants (3.4%; 95% con␣dence interval [CI], 3.2%–3.6%) carried menin- gococci. Carriage was more frequent in individuals aged 5–14 years, relative to those aged 15–29 years (adjusted odds ratio [OR], 1.41; 95% CI, 1.25–1.60); in males, relative to females (adjusted OR, 1.17; 95% CI, 1.10–1.24); in indi- viduals in rural areas, relative to those in urban areas (adjusted OR, 1.44; 95% CI, 1.28–1.63); and in the dry season, relative to the rainy season (adjusted OR, 1.54; 95% CI, 1.37–1.75). Forty-eight percent of isolates had genes encoding disease-associated polysaccharide capsules; genogroup W predominated, and genogroup A was rare. Strain diversity was lower in countries in the center of the meningitis belt than in Senegal or Ethiopia. The prevalence of genogroup A fell from 0.7% to 0.02% in Chad following mass vaccination with MenAfriVac.
Conclusions. The prevalence of meningococcal carriage in the African meningitis belt is lower than in indus- trialized countries and is very diverse and dynamic, even in the absence of vaccination.

Background: Vaginitis is a wide spread inflammatory condition of the female genital tract. It aff... more Background: Vaginitis is a wide spread inflammatory condition of the female genital tract. It affects a wide range of women all over the world. The condition is caused by several types of microorganism including yeast, especially Candida species. Objective: The aim of this study was to assess the incidence of vaginal candidiasis in a Girl's Senior High School in Bolgatanga, Ghana. Methodology: High Vaginal Swabs were randomly taken from consenting female students for the study. The students also completed a structured questionnaire assessing demographic characteristics, symptoms, and risk factors of candidiasis. A total of 94 students between the ages of 17 and 23 were randomly recruited for the study. Standard microbiological techniques such as Gram's stain, wet mount and culture were used to analyse the swabs. Results: Candida species was isolated from 24 of the 94 students representing 25.5%. The highest incidence rates of 50.0% were recorded in the 21 years old participants followed by 45.5% in the 20 years group. Among the symptoms, vaginal itching and burning sensation recorded the highest percentages among the positive for Candida participants; 30.0% and 29.2% respectively. The most common associated risk factors contributing to vaginal candidiasis in this study was antibiotic use which recorded 50.0% while initiation of sexual activity recorded 32.1%.