Laboratory Diagnosis, Treatment, Prevention and Control - Human T-Lymphotropic Viruses Infections

Laboratory Diagnosis

Biopsy is useful for definitive diagnosis and classification of HTLV. The presence of convoluted nuclei, also known as cloverleaf orflower lymphocytes in the peripheral blood is typical of ATL. Provirus can also be demonstrated in these malignant cells. Western blot, immunofluorescence antibody test, and HTLV-ELISA are serological tests used in diagnosis of HTLV-1 infection. HTLV-ELISA is a frequently used test to demonstrate antibodies in the serum for diagnosis of HTLV-1 infection. The test is widely used to study seroprevalence of HTLV-1 infection in the commu-nity in the highly endemic regions of Japan, the Unites states of America, and Africa. High false positivity is a noted problem with ELISA, particularly in areas of low prevalence. Hence, all HTLV-ELISA-positive cases need to be confirmed with Western blot, immunofluorescence antibody test, or polymerase chain reaction (PCR).

Treatment 

No specific treatment is available for the management of HTLV-1 infection. But a limited success has been obtained in chemotherapy of some patients with combination of AZT and interferon-alpha. However, no known regimen increases the survival time of the patients beyond 2 years. Relapse is common.

Prevention and Control

Preventive measures include health education, which should focus on:

a)        avoidance of breast feeding by known infective mothers,

b)       use of safe sexual practices by couples, and

c)        screening of blood donors for HTLV antibodies.

Properties of various retroviruses are summarized in Table 67-4.