Sequence of the env gene of some KwaZulu-Natal, South African strains of HTLV type I

Infective dermatitis associated with HTLV-1 mimics common eczemas in children and may be a prelude to severe systemic diseases

Infective dermatitis associated with human T-cell lymphotropic virus type 1 (HTLV-1) (IDH) is a chronic dermatitis that has been observed in a variable proportion of HTLV-1-infected children. IDH may serve as an early clinical marker for HTLV-1 infection and an indicator of increased risk for developing other HTLV-1-associated conditions. Factors that lead only some infected children to develop IDH are poorly understood. The variable clinical presentation of IDH, in particular its chronicity, the morphology and distribution of the lesions, and its clinical resemblance to other cutaneous inflammatory conditions, make it necessary to distinguish it from other common dermatoses.

Human T cell lymphotropic virus type 1- associated infective dermatitis in KwaZulu Natal, South Africa

Background

The Human T cell lymphotropic virus type 1 (HTLV-1)-associated infective dermatitis (IDH), is a chronic relapsing dermatitis which usually presents in children older than 2 years. A total of 300 cases have been reported worldwide (Latin America, the Caribbean and only 5 from Senegal). Neither IDH, nor its complications have been reported from the rest of Africa. We aimed to examine the clinical and aetiological characteristics of IDH in a cohort of South African children.

Methods

Attendees at the dermatology clinic at King Edward VIII Hospital, Durban underwent clinical examination. After obtaining consent those suspected of IDH had specimens taken for blood counts, immunoglobulins, serum protein electrophoresis, viral studies (including genotyping), skin swabs and stool examinations.

Results

Nineteen of 60 suspected cases recruited over 3 years met the diagnostic criteria for IDH. The male-to-female ratio was 1:2; mean age 8 years (range 0.7 to 15). Dermatitis mostly affected the scalp (78.9%) and axilla (73.7%); fewer children had nasal crusting (47.4%). Mean Ig A, IgG and IgM were raised, at 3.52 g/l, 22.6 g/l and 1.38 g/l, respectively. The median CD4 cell count was 1958 cells/mm³. Viral genotyping of all tested samples were positive for the Cosmopolitan, Subtype A (HTLV-1a).

Conclusions

IDH is a distinct entity which also affects South Africans. Our patients were older at presentation and the majority did not present with nasal crusting as has been described in other countries.

Tracing the origin of Brazilian HTLV-1 as determined by analysis of host and viral genes

We compared the genetic diversity of the Brazilian human T-cell lymphotropic virus type 1 isolates with those found in KwaZulu-Natal (KZN), South Africa, and with the genetic background of the hosts. The seroprevalence rate in KZN was 1.7%. All sequences belonged to the A subgroup. The presence of South African sequences in two different clusters from Brazil, and the finding of the beta-globin haplotype in infected hosts are consistent with the transmission of this virus from southern Africa to Brazil.