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Virology

Below the belt blows

HTLV-1 spreads like the AIDS virus and causes erectile dysfunction

Salvador, the capital of the state of Bahia, unfortunately has the highest incidence of patients with the HTLV-1 virus in Brazil. In each group of 1,000 inhabitants, 20 are contaminated with the human T-cell lymphotropic virus, a silent malady, which in 5% of cases causes a serious type of leukemia or a myelopathy, a neurological illness that brings on problems of locomotion and loss of muscular control. The incidence of the malady in Salvador is five times greater than that observed in São Paulo and seven times higher that of Rio de Janeiro. In Brazil, it is estimated that 2 million people have been contaminated. Such numbers have the agreement of the country’s blood banks, which since 1993, by obligation, have carried out tests against HTLV-1 in all of the donated blood. The expressive size of the malady has transformed the capital of Bahia into its very own research environment into HTLV-1, a retrovirus that has distant relations with HIV, the virus that causes AIDS.

A study published in the March edition of the International Journal of Impotence Research noted that the sexual activity behavior between the victims of the illness is more common than that which had been calculated and that erectile dysfunction, associated with other urinary symptoms, is an important marker for the start of the illness. Signed by the urologist Neviton Castro, from the Immunology Service of the Professor Edgard Santos University Hospital, linked to the Federal University of Bahia (UFBA), the research accompanies a group of 79 patients attended to at the Multidisciplinary Ambulatory of HTLV-1 of the institution, where since 2000 more than 800 patients had already passed through. The rate of those who had not managed to achieve satisfactory erections in more than half of their attempts to have sexual intercourse reached 36.7% and 45.5% responded that they had had little or on sexual satisfaction, taking into account the time gap of thirty days before the research. The majority of the victims were between 35 and 50 years of age.

In 95% of the individuals infected, the HTLV-1 does not present a symptom, although those with the virus continue to spread the illness. In the remaining 5%, after a period of latency, which can last up to 20 years, two distinct maladies can appear. One is the leukemia of the T cells, which, once installed, implies a survival of 24 months at the maximum. Thanks to an enzyme, the reverse transcriptase, the genome of the HTLV-1 integrates itself into the host cell. In some cases this integration makes the infected cell suffer a process of turning it malignant. The T-lymphocite, responsible to a large degree for immunity mediated by way of the cell, is the target of the virus.

Erectile dysfunction and difficulty in controlling urination, are associated to one of the symptoms of the disease, the myelopathy called tropical spastic paraparesis. Transported into an inflammatory process that leads to the destruction of the myelin sheath, the insulator of the nerve cells. Other observed symptoms are the progressive loss of movement of the lower limbs, inflammation of the ocular sphere until a serious form of scabies, acariasis. “We’ve had rare cases in which young patients stopped being able to walk and went on to have erection problems and control in the act of urinating”, says Castro. “One is dealing with an incapacitating illness, for which there’re few treatment options”, he says. A cure does not exist. The therapies to impede the proliferation of the virus and to reduce the speed of degeneration, bring together corticosteroids, vitamin C and interferon. As well, there is no vaccine against this retrovirus, which suffers constant mutations. Remedies of the Viagra family are efficient for minimizing a good number of the cases of erectile dysfunction, but the strategy does not work for the more serious patients.

Slaves
Both the HTLV-1 and the HIV are transmitted via sexual intercourse, blood contamination, the sharing of needles or breastfeeding. The coincidences end right there. The HIV infects the T-lymphocites and destroys them, bringing about an extremely severe immune-depression. On the other hand, the HTLV-1 causes an anomalous multiplication of the lymphocites, associated with the emergence of inflammatory processes. It also brings about a depression of the immunological system, although in a much more milder form than that of the HIV. A doctorate thesis to be defended by Rita Mascarenhas, from the Bahia School of Medicine and Public Health and from the Advanced Laboratory of Public Health of the Oswaldo Cruz Foundation (Fiocruz), in Salvador, has provided evidence of a drop in the immunological response even in the victims of HTLV-1 who had not suffered an anomalous proliferation of the T-lymphocites. Rita belongs to a research group led by the pathologist Bernardo Galvão, responsible for an outstanding piece of work highlighted in the analysis of HTLV in Salvador. During 2002, they also set up an ambulatory service that accompanies around 400 patients, the HTLV center, and have dedicated themselves to research in the field of immunology and to the study of the virus’ origin.

“More and more the HTLV-1 is seen as a syndrome with indications of being immunosuppressant and having different clinical inflammatory manifestations”, says  Fernanda Grassi, a medical doctor and researcher at Fiocruz in Salvador. The research carried out by the Fiocruz and UFBA  groups complement each other. The immunosuppressant action of HTLV-1 had already been evidenced in research by the medical doctor Edgar Carvalho, from  UFBA, showing that the victims are more susceptible to maladies such as tuberculosis and schistossomosis and suffer an aggravation of the situation brought about the intestinal parasitosis strongyloidiasis.

A study carried out by Luiz Carlos Alcântara, a researcher with the Advanced Laboratory of Public Health and a professor at the Bahia School of Medicine and Public Health, found answers for the exaggerated prevalence of HTLV-1 in Salvador. The phenomenon, which mixes up genetics and history, will be the result of multiple introductions of strains of the virus coming from the south of Africa. Bantu slaves brought from Angola and Madagascar between the 17th and 19th centuries had brought with them the subtypes most disseminated in Salvador. In the same manner, the virus is especially prevalent in the south east of the United States where there had been a grouping of blacks. Nevertheless, one is not dealing with a disease linked to Africans. Infection through the HTLV-1 is endemic in the islands of southern Japan, with 40% of the population contaminated, and in the Caribbean where the contagion reaches 10%.

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