Molecular Confirmation of Bacillus Calmette Guerin Vaccine Related Adverse Events among Saudi Arabian Children

PLoS One
[Accessed 22 November 2014]
http://www.plosone.org/

Research Article
Molecular Confirmation of Bacillus Calmette Guerin Vaccine Related Adverse Events among Saudi Arabian Children
Sahal Al-Hajoj mail, Ziad Memish, Naila Abuljadayel, Raafat AlHakeem, Fahad AlRabiah, Bright Varghese
Published: November 19, 2014
DOI: 10.1371/journal.pone.0113472
Abstract
Background
Bacillus Calmette Guerin (BCG) is the only available vaccine for tuberculosis (TB). Low grade complications in healthy recipients and disseminated vaccine associated complications among immuno-suppressed individuals were noticed globally after administration. Recently a series of clinically suspected BCG associated suppurative and non-suppurative lymphadenitis cases were reported from different regions of Saudi Arabia. However a molecular confirmative analysis was lacking to prove these claims.
Methodology
During 2009–2010, 42 Mycobacterium bovis BCG suspected clinical isolates from children diagnosed with suppurative lymphadenitis from different provinces of the country were collected and subjected to 24 loci based MIRU-VNTR typing, spoligotyping and first line anti-TB drugs susceptibility testing.
Principal Findings
Of the total 42 cases, 41 (97.6%) were Saudi nationals and particularly male (64.3%). Majority of the cases were aged below 6 months (83.3%) with a median of age 4 months. All the enrolled subjects showed left axillary mass which suppurated in a median of 4 months after vaccination. Among the study subjects, 1 (2.4%) case was reactive to HIV antigen and 2 (4.8%) case had severe combined immunodeficiency. Genotyping results showed that, 41 (97.6%) isolates were identical to the vaccine strain Danish 1331 and one to Tokyo 172-1. Phylogenetic analysis revealed all the Danish 1331 isolates in a single cluster.
Conclusion
Elevated proportion of suppurative lymphadenitis caused by M. bovis BCG reported in the country recently is majorly related to the vaccine strain Danish 1331. However lack of nationwide data on real magnitude of BCG related adverse events warrants population centric, long term future studies.