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Timothy M S Barkham

Publications and source records attributed to Timothy M S Barkham.

7 recordsLinked to original sources

Latent tuberculosis infection treatment and T-cell responses to Mycobacterium tuberculosis-specific antigens.

RATIONALE: There is currently no available test for monitoring the effect of treatment of latent tuberculosis infection (LTBI) to indicate cure or predict risk of subsequent progression to disease. OBJECTIVE: We used the T-SPOT.TB assay, which measures T-cell interferon-gamma responses to the Mycobacterium tuberculosis-specific peptides early secretory antigenic target 6-kD protein (ESAT-6) and culture filtrate protein 10 (CFP-10), to determine the effect of LTBI treatment on these responses. METHODS: A total of 226 tuberculosis contacts with positive T-SPOT.TB results underwent repeat testing on LTBI treatment completion. The majority (96%) received 6 months of isoniazid. The pre- and post-treatment T-SPOT.TB results were analyzed according to the combined and separate responses to ESAT-6 and CFP-10 antigens. RESULTS: The T-SPOT.TB reverted to negative in 85 (37.6%) contacts at treatment completion. Treatment had a significant effect on the response to CFP-10 (p < 0.001; reversion rate, 48.6%), but not on the response to ESAT-6 (p = 0.081; reversion rate, 21.6%). The median number of spot-forming cells (SFCs)/2.5 x 10(5) peripheral blood mononuclear cells (PBMCs) pre- and post-treatment was 6 versus 4.5 for ESAT-6 (p = 0.116) and 11 versus 4 for CFP-10 (p < 0.001). There was a significant difference between the change (fall) in the pre- and post-treatment responses to CFP-10 (6 SFCs/2.5 x 10(5) PBMCs) and ESAT-6 (0 SFCs/2.5 x 10(5) PBMCs; p < 0.001). Significantly different age-related T-cell responses to the two antigens were found. CONCLUSION: LTBI treatment had a differential effect on T-cell responses to ESAT-6 and CFP-10 as measured by the T-SPOT.TB. The quantitative response to CFP-10 may be a useful LTBI treatment-monitoring tool.

Adolescent↗

Persistence of W135 Neisseria meningitidis carriage in returning Hajj pilgrims: risk for early and late transmission to household contacts.

After an outbreak of meningococcal disease caused by Neisseria meningitidis W135, associated with the Hajj pilgrimage in 2001, 15% of returning vaccinated pilgrims carried a single W135 clone, and 55% were still carriers 6 months later. Transmission to 8% of their unvaccinated household contacts occurred within the first few weeks, but no late transmission took place. Public health interventions are needed to protect household contacts.

Adolescent↗

Absence of Neisseria meningitidis W-135 electrophoretic Type 37 during the Hajj, 2002.

We document the absence of carriage of Neisseria meningitidis W-135 of the sequence type 11 in returning pilgrims after the Hajj 2002. This finding contrasts with the 15% carriage rate we previously reported in pilgrims returning from the Hajj 2001. The epidemiology of carriage may be changing or may have been controlled by vaccination and a policy of administering antibiotics to pilgrims from countries with a high incidence of meningococcal disease.

Carrier State↗

Meningococcal carriage in Umra pilgrims returning from Saudi Arabia.

BACKGROUND: Moslems from all over the world go to Mecca and Medina in Saudi Arabia for two types of pilgrimage: the major pilgrimage (hajj) and the minor (umra). An international outbreak of meningococcal disease with serogroup W-135 occurred in association with hajj pilgrimage in the years 2000 and 2001, and it has been shown that pharyngeal carriage of a single W-135 strain was high in returning hajj pilgrims. We investigated the meningococcal carriage in umra pilgrims to determine the extent of circulation of this strain, during the minor pilgrimage. METHOD: Tonsillopharyngeal swabs were taken from umra returnees. Serogrouping and pulsed field gel electrophoresis were performed on all meningococcal isolates. Subjects were questioned about the occurrence of symptoms of upper respiratory tract infection and use of antibiotics during the pilgrimage. RESULTS: were compared with those previously reported in hajj pilgrims. Results: We enrolled 160 pilgrims returning from the umra pilgrimage in 2001. The meningococcal carriage rate was 1.3%, which is significantly lower compared with the hajj pilgrimage (17%; p<0.001). None of the umra pilgrims carried serogroup W-135, whereas 90% of the isolates in returning hajj pilgrims were Neisseria meningitidis W-135. CONCLUSIONS: Meningococcal carriage during the umra pilgrimage was significantly lower compared with the hajj pilgrimage in the year 2001. No carriage of N. meningitidis W-135 was documented in umra pilgrims, whereas this was the predominant serogroup in hajj pilgrims. Public health measures to reduce the potential introduction of N. meningitidis W-135 into the countries of origin of returning pilgrims need to be prioritized for the hajj pilgrimage.

Adolescent↗