Progress toward interruption of endemic measles transmission in Tunisia

Measles was the second leading cause of infant mortality in Tunisia prior to introduction of measles vaccination in 1979. The number of reported measles cases has decreased from 3007 in 1981 to 47 cases in 2000 due in part to the high coverage rates achieved after 1992. During 1998, a measles catch-up campaign vaccinated 1,846,657 children (95%) aged 6-16 years, and a follow-up campaign for children aged 9 months to 5 years in 2001 reached 547,766 (94%). During 1999-2001, 1717 cases of rash and fever illness were tested for measles; only 3 (0.2%) were positive for measles. From February to July 2002, an outbreak of measles involving 87 cases occurred in Tunisia in a health care setting and 56 (64%) patients were aged 15-30 years. The low number of laboratory-confirmed measles cases during 1999-2001 suggests endemic measles transmission may have been interrupted.

Association of HLA class II genes with susceptibility to Crohn's disease

BACKGROUND

Published studies on the association between HLA class II genes and inflammatory bowel disease are contradictory perhaps because of the limited size and ethnic heterogeneity of the populations studied.

AIM

To compare the frequencies of HLA class II genes in a large number of French patients with Crohn's disease and in an ethnically matched control group.

METHODS

344 patients (196 F, 148 M, mean age 23.6 years) with Crohn's disease were molecularly genotyped for the HLA-DQB1 and DRB1 alleles. The results were compared with those for an ethnically matched control population of 488 white adults.

RESULTS

There were two significant variations of alleles at the DQB1 locus: an increase in DQB1*0501 allele frequency (chi 2 = 10.6, corrected p value (pc) = 0.01, odds ratio (OR) = 1.61) and a decrease in DQB1*0602/0603 allele frequencies (chi 2 = 8.43, pc = 0.037, OR = 0.66). DRB1 analysis showed associations with three allelic variations: an increase in the frequencies of DRB1*01 (chi 2 = 12.86, pc = 0.003, OR = 1.75) and DRB1*07 alleles (chi 2 = 11.18, pc = 0.008, OR = 1.58) and a very significant decrease in that of the DRB1*03 allele (chi 2 = 19.7, pc = 9.10(-5), OR = 0.46).

CONCLUSION

The alleles DRB1*01 and DRB1*07 are associated with susceptibility to Crohn's disease. The strong negative association between the DRB1*03 allele and Crohn's disease suggests that the HLA-DRB1*03 allele mediates 'resistance' to Crohn's disease.