Pathways of TB Transmission in Children-A Systematic Review of Molecular Epidemiological Studies

TY - JOUR

T1 - Pathways of TB Transmission in Children-A Systematic Review of Molecular Epidemiological Studies

AU - Diel, Roland

AU - Nienhaus, Albert

PY - 2023/1/18

Y1 - 2023/1/18

N2 - The widespread paradigm that younger children usually do not transmit M. tuberculosis complex (Mtbc) to their contacts has not yet been proven by genotypically confirmed transmissions. Therefore, we undertook a systematic review of molecular-epidemiological studies to investigate documented source and secondary TB (tuberculosis) cases among children. We searched the literature published before August 2022 using PubMed, Cochrane, and Google Scholar databases. PRISMA statement was used for systematic review. Of 312 records retrieved, 39 studies including children aged below 15 years offered epidemiological links between cluster members. In the 39 studies from 16 countries, 225 children were reported as cluster members of whom the overwhelming majority were infected by adults. Only 3 children-of those were 2 children aged below 10-were reported to be the definite source cases of 11 other children and 1 adult with genotypically matched Mtbc isolates. To date, molecular-epidemiological studies involving children with verified transmission links are scarce. As far as the heterogeneity of the studies we identified allows, we could conclude that the results confirm the paradigm that children aged below 10 hardly ever transmit Mtbc to others. The true extent of TB transmission through children may, however, be underestimated by those selected studies.

AB - The widespread paradigm that younger children usually do not transmit M. tuberculosis complex (Mtbc) to their contacts has not yet been proven by genotypically confirmed transmissions. Therefore, we undertook a systematic review of molecular-epidemiological studies to investigate documented source and secondary TB (tuberculosis) cases among children. We searched the literature published before August 2022 using PubMed, Cochrane, and Google Scholar databases. PRISMA statement was used for systematic review. Of 312 records retrieved, 39 studies including children aged below 15 years offered epidemiological links between cluster members. In the 39 studies from 16 countries, 225 children were reported as cluster members of whom the overwhelming majority were infected by adults. Only 3 children-of those were 2 children aged below 10-were reported to be the definite source cases of 11 other children and 1 adult with genotypically matched Mtbc isolates. To date, molecular-epidemiological studies involving children with verified transmission links are scarce. As far as the heterogeneity of the studies we identified allows, we could conclude that the results confirm the paradigm that children aged below 10 hardly ever transmit Mtbc to others. The true extent of TB transmission through children may, however, be underestimated by those selected studies.

KW - Adult

KW - Humans

KW - Child

KW - Mycobacterium tuberculosis/genetics

KW - Tuberculosis/epidemiology

KW - Molecular Epidemiology

KW - Epidemiologic Studies

KW - Only Child

U2 - 10.3390/ijerph20031737

DO - 10.3390/ijerph20031737

M3 - SCORING: Review article

C2 - 36767111

VL - 20

JO - INT J ENV RES PUB HE

JF - INT J ENV RES PUB HE

SN - 1660-4601

IS - 3

M1 - 1737

ER -