Volume 13, Number 7—July 2007
Zinc Cream and Reliability of Tuberculosis Skin Testing
|Characteristic*||Mean (SEM)† or % (n = 50)||Association with size of control TB skin-test reaction (mm)
|Body mass index (kg/m2)||24 (0.52) 10% underweight (<20)||0.2||0.3|
|Anthropometric protein status (corrected arm muscle area; cm2)||36 (1.4)||0.2||0.09|
|Anthropometric fat status (arm fat area; cm2)||14 (1.1)||0.0008||1|
|Plasma zinc (mg/L; n = 49)||0.66 (0.17) 31% deficient (<0.6)||0.3||0.04||0.3||0.03|
|Minor incidental health symptoms||38%||0.06||0.7|
|TB risk factors|
|Age, y||32 (1.3)||0.2||0.2||0.3||0.02|
|Past close contact with a TB patient or past proven diagnosis of TB||42%||0.1||0.4|
|Presence of Baccilus Calmette-Guérin vaccine scar(s)||86%||0.2||0.3|
|Overcrowding (persons/room)||1.3 (0.08)||–0.2||0.9||0.2||0.09|
|Poor household ventilation (subjective assessment)||24%||–0.002||1|
|Food spending/person/d ($US)||0.75 (0.05)||0.1||0.5|
|Dirt floor throughout the home||38%||–0.06||0.7|
|Home built from temporary materials||72%||0.1||0.5|
|No in-house sanitation||84%||0.05||0.7|
|No piped water to home||84%||–0.07||0.6|
*Variables that may influence TB skin-test reaction size are shown together with their associations with the size of the control TB skin-test reactions associated with only zinc cream application.
†SEM, standard error of the mean.
‡Food frequencies: in the previous week, alcohol had been consumed a median of 1 time (median 1 U), dairy produce 3 times, fruit/vegetables 5 times, meat/fish 6 times, and rice/bread/cereals daily.
§Persons with infrequent meat/fish consumption had lower protein stores on muscle anthropometry (p = 0.02), and this tended to be associated with smaller skin-test reactions, as previously reported (1,2).