title: Molecular confirmation of Bacillus Calmette Guerin vaccine related adverse events among Saudi Arabian children.
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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: Sahal
authors.initials: S
authors.lastname: Al-Hajoj
authors.affiliation: Preventive Medicine Directorate, Ministry of Health, Riyadh, Saudi Arabia.
authors.forename: Ziad
authors.initials: Z
authors.lastname: Memish
authors.affiliation: Preventive Medicine Directorate, Ministry of Health, Riyadh, Saudi Arabia.
authors.forename: Naila
authors.initials: N
authors.lastname: Abuljadayel
authors.affiliation: Preventive Medicine Directorate, Ministry of Health, Riyadh, Saudi Arabia.
authors.forename: Raafat
authors.initials: R
authors.lastname: AlHakeem
authors.affiliation: Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: Fahad
authors.initials: F
authors.lastname: AlRabiah
authors.affiliation: Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: Bright
authors.initials: B
authors.lastname: Varghese
mesh_terms: D001500:BCG Vaccine / Q000009:adverse effects* / Q000276:immunology; D016000:Cluster Analysis; D005260:Female; D056426:Genetic Loci; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008199:Lymphadenitis / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009163:Mycobacterium bovis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D012529:Saudi Arabia / Q000453:epidemiology; D016511:Severe Combined Immunodeficiency / Q000453:epidemiology / Q000209:etiology; D014376:Tuberculosis / Q000517:prevention & control; D014611:Vaccination / Q000009:adverse effects
chemical_list: D001500:BCG Vaccine