{'fraction_non_alphanumeric': 0.03170289855072464, 'fraction_numerical': 0.009510869565217392, 'mean_word_length': 5.293447293447294, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Human T-lymphotrophic virus-a neglected cause of chronic pain?

Human T-lymphotrophic virus-type 1 (HTLV-1) is a retrovirus first identified in humans in 1980. Infection can lead to a variety of neurological, oncological, and inflammatory sequelae, and there is an increasing awareness of the high prevalence of pain experienced by people infected with HTLV-1. Little is known about themechanisms involved in pain generation in HTLV-1 and there is a paucity of evidence about effective analgesic interventions. Although more prevalent in specific parts of the world, a mobile global community means that HTLV-1 infection may be an underrecognised cause of chronic pain in regions unfamiliar with its presentation. This review aims to provide a clinical outline for recognition and diagnosis of HTLV-1, as well as the current understanding of pain presentations and pathophysiology associated with the infection. HTLV-1 is a blood-borne infection, transmitted in a similar way to HIV and hepatitis C: through sexual contact; breastfeeding and childbirth; blood transfusion and organ transplantation; and through the reuse of needles and syringes. Most of those infected with HTLV-1 remain asymptomatic carriers, but a significant proportion (;10%) develops oncological, inflammatory, or neurological complications, the most common being HTLV-1–associated myelopathy/tropical spastic paresis (HAM/ TSP) (Fig. 1). HTLV-1 is a persistent infection in humans for which there is no cure, and no antiretroviral (ARV) therapy has been shown to reduce viral burden, or prevent the development of symptomatic disease. Serological screening for HTLV-1 infection is performed using enzyme-linked immunoassays to detect antibodies to nuclear proteins and envelope glycoproteins. All repeat reactive samples undergo further investigation, usually by Western Blot/ immunoblot to both confirm infection and distinguish between HTLV-1 and HTLV-2. Molecular tests are used when serology is indeterminate. Quantification of HTLV proviral DNA is then used to determine risk of HTLV-associated disease and to monitor infection, by quantifying the percentage of peripheral blood mononuclear cells infected (for review see Ref. 1).