Molecular Epidemiology of HIV-1 and HTLV-1/2 Among Female Sex Workers in Four Cities in the State of Para, Northern Brazil

Human T Cell Lymphotropic Virus Type 1 Global Prevalence Associated with the Human Development Index: Systematic Review with Meta-Analysis

In 2012, the number of people infected with human T cell lymphotropic virus type 1 (HTLV-1) was estimated to be 10 million worldwide. Prevalence varies according to geographic location, ethnic factors, sex, age, populations exposed to risk factors, income, and education, reaching countries with the worst socioeconomic scenarios. There is a need to determine the current global prevalence of HTLV-1 and examine its association with countries' human development index (HDI) to provide data for global health policy. Systematic review with meta-analysis is according to PRISMA 2020 recommendations. It was registered at PROSPERO, CRD42021223146. Prevalence or cross-sectional studies of HTLV-1 infection with at least 100 participants, screening, and confirmatory serologic testing were included. Studies with incomplete or unavailable results or with duplicate information were excluded. Data were selected by two independent investigators and analyzed using R software, a metapackage that generated the forest plots [95% confidence interval (CI)]. Heterogeneity was assessed using the I² statistic, and funnel plot asymmetry was assessed using Egger's test. Countries were compared using an HDI cutoff ≥0.8. Methodological quality was assessed using Joanna Briggs Institute (JBI) criteria. The overall prevalence of HTLV-1 infection was 0.91% (95% CI: 0.80-1.02, p < .0001) and was higher in low HDI countries [1.18% (95% CI: 1.03-1.34)] than in high HDI countries [0.41% (95% CI: 0.27-0.57)]. Prevalence varied according to the populations studied: it was higher in the general population [1.65% (95% CI: 1.08-2.34)] compared to pregnant women [0.34% (95% CI: 0.17-0.57)] and blood donors [0.04% (95% CI: 0.01-0.08)]. Consistently, prevalence for each population group was higher in low HDI countries than in high HDI countries. The worldwide prevalence of HTLV-1 infection is highly heterogeneous, with a global prevalence of 0.91%. In high HDI countries, the observed prevalence is approximately three times lower than in low HDI countries. In the general population, the observed prevalence is about 5 times higher than in pregnant women and 41 times higher than in blood donors.

HIV Infection and Oral Manifestations: An Update

Human immunodeficiency virus (HIV) causes a complete depletion of the immune system; it has been a major health issue around the world since the 1980s, and due to the reduction of CD4+ T lymphocytes levels, it can trigger various opportunistic infections. Oral lesions are usually accurate indicators of immunosuppression because these oral manifestations may occur as a result of the compromised immune system caused by HIV infection; therefore, oral lesions might be initial and common clinical features in people living with HIV. So, it is necessary to evaluate and understand the mechanism, prevalence, and risk factors of oral lesions to avoid the increase morbidity among those with oral diseases.

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

Human T-lymphotropic viruses 1 and 2 (HTLV-1 and HTLV-2) infection has been described in several Amazonian populations; however, there is still a lack of data on the prevalence of the virus in riparian populations living in rural areas of the state of Pará. The present study aimed to evaluate the prevalence of HTLV-1/2 infection in four riverine communities and one rural area in the state of Pará and to describe the possible risk factors for infection. A total of 907 individuals responded to an epidemiological survey and gave blood samples collected for anti-HTLV-1/2 antibodies by immunoenzymatic assay (EIA). The serum-reactive samples were subjected to confirmation by an in-line assay (Inno-Lia) and by proviral DNA screening using real-time PCR (qPCR). The total prevalence was 0.8% (7/907) for HTLV-1/2 (CI: 0.2−1.3%), with 0.66% HTLV-1 and 0.11% HTLV-2. The prevalence by sex was 0.7% in women (4/565) and 0.9% in men (3/342). Among seropositive patients, 83.3% (5/7) reported being sexually active, and 57.1% (4/7) reported not having the habit of using condoms during their sexual relations. Intrafamily infection was also observed. The results reinforce the need for public policies to prevent and block the spread of HTLV, especially in riparian communities that are subject to difficulties in accessing the Unified Health System (Sistema Único de Saúde/SUS) because infected individuals need clinical monitoring for surveillance and early diagnosis of symptoms associated with HTLV-1.

Spread of Human T-Lymphotropic Virus 1 and 2 Among Relatives of People Who Use Illicit Drugs in Northern Brazil

The human T-lymphotropic virus 1 (HTLV-1) and 2 (HTLV-2) can be transmitted between humans by mechanisms associated with horizontal and vertical routes. Recently, high prevalence rates and levels of genetic diversity for HTLV-1 and HTLV-2 were detected among people who use illicit drugs (PWUDs) in the Brazilian state of Pará. None of the PWUDs with HTLV-1 or HTLV-2 were aware of their carrier condition of the retrovirus, and they ability to spread it to their family group, sexual partners, and other contacts. Thus, this study evaluated the presence of HTLV-1 and HTLV-2 in families of PWUDs in the state of Pará, in Northern Brazil. This descriptive study used convenience sampling and accessed 37 PWUDs and their respective families (n = 97) in 18 municipalities in the state of Pará, northern Brazil. All participants provided personal data and were tested for the presence of HTLV-1 and HTLV-2 using enzyme-linked immunosorbent assay and western blotting. HTLV positive samples were selected for Nested-PCR, and viral genotyping by nucleotide sequencing and phylogenetic analysis. HTLV-1 or HTLV-2 infections were detected in 15 families of PWUDs: 27 family members of PWUDs were infected with HTLV-1 (27.8%) and another 20 of them with HTLV-2 (20.6%). Subtypes 1a [subgroup A (54.5%)], 2b (20.5%), and 2c (25.0%) were detected. High horizontal (76.9%) and vertical (61.4%) transmission rates of HTLV were ascertained. Factors that facilitate the acquisition and transmission of HTLV-1 and HTLV-2 were reported by the participants, such as long-term relationships, unprotected sex, breastfeeding, and lack of knowledge about the condition of being a carrier of the retrovirus. Evidence indicates intrafamilial transmission of HTLV from PWUDs to members of their respective families. Key interventions should urgently be employed for the control and prevention of HTLV-1 and HTLV-2 to reduce the spread of this retrovirus in PWUDs and the general population in Northern Brazil and elsewhere.

HTLV-1 Is Also a Sexually Transmitted Infection

HTLV-1 is a retrovirus which causes diverse diseases in 10% of its infected population, significantly worsening their quality of life and mortality rate. Even though it is globally distributed and is endemic in many countries (including Peru), it is still highly neglected. It spreads through vertical, sexual and parenteral transmission. As no effective treatment against this virus exist, prevention is required to contain it. The World Health Organization published a technical report on the matter in 2021, with the collaboration of international HTLV-1 experts. However, neither the impact of sexual transmission (cause of the majority of adult cases and infection in non-endemic areas) nor its prevention were considered. Evidence is presented, which shows the magnitude of sexual transmission, its risk factors and preventive measures; hoping it will encourage health workers to help eradicate this infection.

Work-Related Human T-lymphotropic Virus 1 and 2 (HTLV-1/2) Infection: A Systematic Review

Human T-lymphotropic virus 1 and 2 (HTLV-1/2) belong to the delta group of retroviruses which may cause a life-long infection in humans, HTLV-1 leading to adult T-cell leukemia/lymphoma and other diseases. Different transmission modes have been described, such as breastfeeding, and, as for other blood-borne pathogens, unsafe sexual activity, intravenous drug usage, and blood transfusion and transplantation. The present systematic review was conducted to identify all peer-reviewed studies concerning the work-related infection by HTLV-1/2. A literature search was conducted from January to May 2021, according to the PRISMA methodology, selecting 29 studies: seven related to health care workers (HCWs), five to non-HCWs, and 17 to sex workers (SWs). The findings showed no clear evidence as to the possibility of HTLV-1/2 occupational transmission in HCWs, according to the limited number and quality of the papers. Moreover, non-HCWs showed a higher prevalence in jobs consistent with a lower socioeconomic status or that could represent a familial cluster, and an increased risk of zoonotic transmission from STLV-1-infected non-human primates has been observed in African hunters. Finally, a general increase of HTLV-1 infection was observed in SWs, whereas only one paper described an increased prevalence for HTLV-2, supporting the urgent need for prevention and control measures, including screening, diagnosis, and treatment of HTLV-1/2, to be offered routinely as part of a comprehensive approach to decrease the impact of sexually transmitted diseases in SWs.

The Epidemiological Impact of STIs among General and Vulnerable Populations of the Amazon Region of Brazil: 30 years of Surveillance

Sexually transmitted infections (STIs) represent a worldwide public health problem and, although many of them are curable, they continue to be neglected, especially in areas with a low human development index, such as in the northern region of Brazil. This review describes the results of 30 years of studies at the Virus Laboratory at the Federal University of Pará, including the prevalence and molecular epidemiology of HIV-1, HTLV-1/2, HPV, HBV, Treponema pallidum and Chlamydia trachomatis among urban and non-urban populations, and also in vulnerable groups in the Brazilian Amazon. Control strategies and challenges in preventing STIs are discussed considering this immense geographic region, where essential health services are unable to reach the entire population, especially the most vulnerable, such as female sex workers, people who use illicit drugs, remnants of quilombolos and indigenous communities.