PMC

*Cases according to each database: CMBD: Scabies related admissions/million inhabitants. RENAVE: Scabies cases detected in outbreaks/million inhabitants. BDCAP: Scabies cases diagnosed in Primary Care/million inhabitants. ODR: Occupational scabies cases/million active population.

Map of studies demonstrating associations between HTLV-1 and scabies. a) French Guiana: case review of crusted scabies, 6/6 (100%) crusted scabies cases seropositive for HTLV-1 []. b) Lima, Peru: prevalence study, 16/23 (69.6%) crusted scabies cases seropositive for HTLV-1; 3/3 (100%) recurrent crusted scabies cases seropositive for HTLV-1 []. c) Peru: national HTLV-1 prevalence study, 2/9 (22.2%) with recurrent scabies and HTLV-1 []. d) Southeastern Brazil: family study, 2/15 (13.3%) with scabies in HTLV-1 positive group; 0/15 (0%) with scabies in HTLV-1 negative group []. e) Rio de Janeiro, Brazil: case-control study, 3/60 (5%) with scabies in HTLV-1 seropositive group (all with HAM/TSP); 0/38 (0%) with scabies in HTLV-1 seronegative group []. f) Bahia, Brazil: child prevalence study (n = 30), 70% with HTLV-1 had scabies; 3.3% with HTLV-1 had crusted scabies []. g) Bahia, Brazil: scabies case review, 47/91 (51.6%) of all scabies cases HTLV-1 seropositive; 21/23 (91.3%) with crusted scabies cases HTLV-1 seropositive; 8/35 (22.9%) with severe scabies HTLV-1 seropositive; 0/33 (0%) with typical scabies HTLV-1 seropositive []. h) Bahia, Brazil: case-control study, 4/179 (2.2%) with scabies in HTLV-1 seropositive group; 0/193 (0%) with scabies in HTLV-1 seronegative group (P = 0.053) []. i) Kumamoto, Japan: case series. 2/2 (100%) cases of HTLV-1 (both with ATL) and crusted scabies []. j) Far North Queensland, Australia: prevalence study, 1/13 (7.7%) HTLV-1 seropositive results when scabies noted on serological tests requests []. k) Alice Springs, Australia: Prevalence study, 5/5 (100%) crusted scabies cases seropositive for HTLV-1; 3/9 (33.3%) mild scabies cases seropositive for HTLV-1 []. l) Alice Springs, Australia: case-control study, 75/502 (14.2%) with scabies in HTLV-1 seropositive group; 80/994 (8.5%) with scabies in HTLV-1 seronegative group (P = 0.001) []. m) Alice Springs, Australia: Inpatient case series. 2/2 (100%) scabies admissions HTLV-1 seropositive []. Figure created with BioRender.com. HTLV-1 – human T-lymphotropic virus type 1, HAM/TSP – HTLV-1-associated myelopathy/tropical spastic paraparesis, ATL – adult T-cell leukaemia/lymphoma.

Among the 110 LTCHs, cases of scabies were reported in 79 LTCHs. The prevalence of scabies in each year was calculated based on the number of hospitals that reported scabies cases (n = 79).

In preparing an ex vivo scabies preparation, mineral oil preserves scabies’ scybala, whereas potassium hydroxide does not. The technique for obtaining a scabies preparation is that of a very superficial shave biopsy (without anaesthesia), with the scalpel blade virtually parallel to the skin.