Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05117528 |
| Other study ID # |
LEO 24005 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
July 27, 2021 |
| Est. completion date |
September 30, 2022 |
Study information
| Verified date |
November 2022 |
| Source |
London School of Hygiene and Tropical Medicine |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Group A Streptococcus (GAS) is a bacteria which causes severe infections and leads to deadly
diseases such as rheumatic heart disease which kills over 300,000 people a year globally,
particularly in low-income countries. It is not know how GAS is spread between people, how
often people carry GAS in their throat or on their skin without having symptoms, or what
factors increase the chance of this occurring. It is important to understand these factors in
order to know how to reduce GAS-related disease.
This study will follow 444 people in The Gambia, over 12 months, taking samples from the
throats and skin of people living in the same households, and asking questions about
themselves and their behaviour, at regular intervals. By taking samples over time, the
investigators hope to understand how common it is to carry GAS without having symptoms, how
GAS is spread between people, and whether carrying GAS leads to more GAS infections in people
or their household members.
The study will use state-of-the-art techniques to look at the DNA of GAS bacteria that we
find, and combine this with a mathematical model to investigate how different strains spread
to people within and between households in the community.
Description:
Type of study and design
The study is a prospective, longitudinal (open) cohort study within households in Sukuta, The
Gambia. Households will be recruited, and all available household members asked to
participate. Households will be followed for 12 months, with up to monthly visits (at least
3-monthly visits), and more frequently for some subgroups of participants.
A total of 45 households will be recruited, including every available household member as
individual participants (resulting in a cohort of approximately 450 participant with the
average household size in Sukuta being around 10).
Households will be enrolled for 12 months, with enrolment aiming to commence before the rainy
season, to ensure that the enrolment period will span one full rainy season, with dry periods
either side. Every household will undergo an enrolment visit (MV0), then up to monthly visits
(MV1, MV2, MV3 etc., up to MV12) or less frequently if practical constraints arise.
At each visit an oropharyngeal swab, normal skin swab, oral fluid sample and dried blood spot
sample will be taken from all individuals, data collected on socio-demographics, social
mixing behaviour and clinical examination findings. Examination findings recorded will
include evidence of pharyngitis, pyoderma, and scabies. In addition, a blood sample for serum
will be taken at the beginning and end of the study for detailed functional immune responses.
Swabs will also be taken from any pyoderma lesions, from common touch points in the household
such as door handles, and settle plates used inside households.
Swabs will be transported the same day to the laboratory and plated for microbiological
culture. The culture will identify the presence of GAS from the swabs, and if present,
antibiotic resistance will be determined and isolates stored for later use. Additionally, if
Groups C and G Streptococcus are identified the isolates will be stored, and from normal skin
and pyoderma wound swabs, any Staphylococcus aureus isolates will stored.
Swabs from participants will be cultured for the presence of GAS and isolates will undergo
whole genome sequencing in order to assess phylogenetic relatedness of strains identified.
These data, combined with temporal incidence of strain acquisition, clinical data and
household situation will be used to build a mathematical model of GAS transmission to
identify key routes of transmission within and between households.
Sub-studies:
Intensified incident GAS surveillance cohort
A subgroup of 12 households, most with at least one asymptomatic GAS carrying individual at
baseline, and some with no carriers, will form a cohort to undergo intensified swabbing. This
cohort will be used to assess incidence of GAS carriage and disease with greater resolution
than the main cohort. All household members present will undergo more frequent swabbing, with
a view to being visited every week for 6 months. At these visits, more detailed social-mixing
behaviour data will be collected.
Estimating duration of GAS carriage
A further subgroup will also be identified to allow for greater resolution in the estimation
of the duration of GAS carriage. Following enrolment, any participant who becomes GAS carrier
positive (i.e. was negative at baseline or the previous visit, and then becomes positive
asymptomatically) will have weekly swabs taken from the same site that was positive, until 2
GAS negative swabs have been taken in a row.
Estimating GAS infection incidence
To assess incidence of clinical GAS disease in the cohort throughout the study, all
participants reporting symptoms suggestive of possible clinical GAS infection such as
pharyngitis or pyoderma (but also including invasive infections), will be visited for an
unscheduled visit where a clinical and health-seeking history will be recorded, a swab,
saliva and DBS taken, and treatment (or further management) will be delivered according to
WHO guidelines or best local practice. Furthermore, at each scheduled visit, any individual
identified with symptoms of clinical GAS infection will undergo the same process of
history-taking, swabbing, treatment and follow up.
