Serology with ML Flow test in health professionals from three different states of Brazil

Abstract

BACKGROUND In highly endemic countries, transmission and sub-clinical infection of leprosy are likely and the disease manifests itself in individuals without any known close contact with a leprosy patient. Health workers are social contacts belonging to the same network (the Health System) and some of them share the same social environment (nursing assistants) as patients with known patients and / or carriers. OBJECTIVE To identify ML Flow seropositivity among health professionals. METHODS We conducted a cross-sectional study using a serological survey with the ML Flow test in 450 health professionals (doctors, nurses and nursing assistants), in order to detect seropositivity in areas of high and low endemicity in municipalities from three Brazilian states (RJ, MS and RS). RESULTS The results showed general 16% seropositivity, higher in low endemic areas, regardless of whether there was direct care for leprosy patients. Paradoxically, a statistical association was observed between the area studied and seropositivity, as the place with the lowest endemicity (CA) had the highest seropositivity rate (p = 0.033). CONCLUSION The authors suggest these results are associated with a presence of an unspecified link to bovine serum albumin (BSA), carrier of PGL-1 in the ML Flow test, and recommend expanded seroepidemiological research utilizing tests with human and bovine albumin.

Could Mycobacterium leprae Infection Be an Occupational Disease? A Survey in Healthcare Workers From an Endemic Area in the Amazonian Region

“…When we compared the results of seropositivity among HCW who reported previous work with leprosy patients with the results of the group who did not, a significant statistical difference was found for the ML Flow test, suggesting that there is an occupational risk. Our results are different from the findings by Calado et al, 7 who did not observe a difference related to exposure in the workplace. No significant differences were found relating to the length of time employed (>10 years vs ≤10 years) or exposure to leprosy outside the workplace.…”

“…Methodologic differences in our recruitment strategy may have influenced the results. Our study randomly selected HCW and Calado et al 7 used the snowball sampling technique, which may have introduced a bias in the study. Another possible explanation could be the dietary habits, such as the consumption of bovine meat, leading to unspecific bindings in serologic tests due to the presence of anti-BSA antibodies.…”