The Relevance of a Diagnostic and Counseling Service for People Living With HTLV-1/2 in a Metropolis of the Brazilian Amazon

Abstract

IntroductionTo identify the prevalence of infection in the urban area of the capital city of Belém, Brazil, the Laboratory of Virology of the Federal University of Pará implemented, as a public service, serological screening for human T-lymphotropic viruses 1 and 2 (HTLV-1/2) infection and, if necessary, counseling service and referral to specialized medical care. The project is funded by the National Council of Science and Technology, the Ministry of Health of Brazil and the Pan American Health Organization.MethodsFrom January 2020 to June 2021, 1,572 individuals of both sexes were approached to answer a questionnaire and were tested using an enzyme immunoassay (Murex HTLV-I+II, DiaSorin, Dartford, UK). Seropositive samples were confirmed as HTLV-1 and HTLV-2 infection by line immunoassay (INNO-LIA® HTLV I/II Score, Fujirebio, Japan) and/or by real-time polymerase chain reaction. G and Fisher's exact tests were applied to identify the association between epidemiological characteristics and HTLV-1/2 infection.ResultsOf the 1,572 screened individuals, 63.74% were females between the ages of 30 and 59 years (49.04%). Infection was confirmed in six individuals (0.38%), among whom three (0.19%) were infected with HTLV-1 and three with HTLV-2 (0.19%). Blood transfusion before 1993 was the main risk factor associated with the route of exposure to the virus (p = 0.0442). The infected individuals were referred to a counseling session with a nursing professional, and two patients who manifested signs and symptoms suggestive of myelopathy associated with HTLV were referred to a neurologist.ConclusionThe implementation of the screening service revealed the occurrence of moderate endemicity of HTLV-1/2 in Belém, reinforcing the importance of continuing the service as a means of establishing an early diagnosis and providing counseling as a measure to prevent and control viral transmission in the general population.

Human T-cell lymphotropic virus screening in France: Missed opportunities? A retrospective multicenter study of serological testing in hospital laboratories

“…Along with targeted screening of pregnant women, blood donors, and people who attended clinics for sexually transmitted infection, once-in-life testing has been suggested for HTLV-1, as recommended for HIV and hepatitis B and C [ 27 ]. Concerns have been raised about the need to provide information about transmission-preventive measures for people living with HTLV-1/2 [ 28 ]. Studies are also required on HTLV-1 transmission and HIV pre-exposure prophylaxis.…”

Prevalence and Risk Factors for HTLV-1/2 Infection inRiverside and Rural Populations of the State of Pará

“…A low prevalence of HTLV-1 and HTLV-2 among the quilombola population has been described, ranging from 0.11 to 2.6% and 0.34 to 1.06%, respectively [ 32 , 33 ]. In the urban region of Belém, the rates are usually higher, ranging from 0.19 to 2% [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], as well as in a group of people living with HIV [ 35 ], blood donors [ 17 ], and sex workers [ 36 ], while in pregnant women, this prevalence is considerably lower [ 16 ]. In the Pará region, a high prevalence of HTLV-2 is usually described among indigenous populations because they are closed communities [ 37 , 38 , 39 ].…”

“…It is estimated that Brazil has the highest number of absolute cases of HTLV infection, with approximately 800,000 to 2.5 million people infected [ 9 , 10 ], and epidemiological studies have already demonstrated the presence of this virus in several areas such as São Paulo [ 11 ], Santa Catarina [ 12 ], Salvador [ 13 ], and Pará [ 14 ], as well as other states. Maranhão, Bahia and Pará have high prevalence rates of the virus, as indicated in studies performed in blood donors, in pregnant women or in the general population [ 15 , 16 ].…”

“…Although HTLV-1/2 infection has been described in some populations of the Brazilian Amazon region, especially in indigenous and urban communities [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ], there is still a lack of data that accurately characterize the prevalence of infection in riparian communities and rural areas in the Pará region, which have limited access to public health services [ 21 , 22 ]. Therefore, knowing the prevalence of HTLV-1/2 in riparian and rural populations is of paramount importance for a more accurate description of the geographical distribution of the infection and the risk factors for spreading the virus to design control measures and public health policies for prevention and control, since to date there is no effective treatment to combat the virus and the main associated diseases or a protective vaccine [ 23 ].…”