A high prevalence of human T-lymphotropic virus (HTLV 1/2) infection among Afro-descendants, Esmeraldas province, Ecuador - need for the implementation of surveys and control programs

Human T-Cell Lymphotropic Virus (HTLV 1/2) in Ecuador: Time for Action

The human T-cell lymphotropic viruses of type 1 and 2 (HTLV 1/2) are retroviruses with estimations of 10 million people infected worldwide. HTLV 1/2 viruses are endemic in South America where Indigenous and Afro American populations are considered of high risk. Although several case reports of HTLV 1/2 associated pathologies and some prevalence studies have been reported in Ecuador, the country lacks a national surveillance and control program, and no screening of blood or organ donors is currently done. We discuss the problems associated to HTLV 1/2 in Ecuador and propose a strategy to improve a surveillance and control program.

Sustained COVID-19 community transmission and potential super spreading events at neglected afro-ecuadorian communities assessed by massive RT-qPCR and serological testing of community dwelling population

Background

Neglected ethnic minorities from underserved rural populations in Latin America are highly vulnerable to coronavirus disease 2019 (COVID-19) due to poor health infrastructure and limited access to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis. Esmeraldas is a mainly rural province of the Coastal Region of Ecuador characterized by a high presence of Afro-Ecuadorian population living under poverty conditions.

Objective

We herein present a retrospective analysis of the surveillance SARS-CoV-2 testing in community-dwelling population from Esmeraldas carried out by our university laboratory in collaboration with regional health authorities during the first week of October 2020, in a region where no public SARS-CoV-2 detection laboratory was available at that time.

Results

A total number of 1,259 people were tested for SARS-CoV-2 by Reverse Transcription quantitative Polimerasa Chain Reaction (RT-qPCR), resulting in an overall infection rate of 7.7% (97/1259, 95% CI: [6.32–9.35%]) for SARS-CoV-2, up to 12.1% in some communities. Interestingly, community-dwelling super spreaders with viral loads over 10⁸ copies/ml represented 6.2% of the SARS-CoV-2-infected population. Furthermore, anti-SARS-CoV-2 IgG serological tests were applied to the same study group, yielding an overall seroprevalence of 11.68% (95% CI: [9.98–13.62%]) but as high as 24.47% at some communities.

Conclusion

These results support active COVID-19 community transmission in Esmeraldas province during the first semester of the COVID-19 pandemic as it has been shown for other rural communities in the Ecuadorian Coastal Region.

Real-World Data on Adult T-Cell Leukemia/Lymphoma in Latin America: A Study From the Grupo de Estudio Latinoamericano de Linfoproliferativos

PURPOSE

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive disease caused by the human T-cell leukemia virus type 1. Real-world data of ATLL in Latin America are lacking.

PATIENTS AND METHODS

We analyzed patients with ATLL (acute, lymphomatous, chronic, and smoldering) encountered in 11 Latin American countries between 1995 and 2019. Treatment response was assessed according to the 2009 consensus report. Survival curves were estimated using the Kaplan-Meier method and log-rank test.

RESULTS

We identified 253 patients; 226 (lymphomatous: n = 122, acute: n = 73, chronic: n = 26, and smoldering: n = 5) had sufficient data for analysis (median age 57 years). Most patients with ATLL were from Peru (63%), Chile (17%), Argentina (8%), and Colombia (7%). Hypercalcemia was positively associated with acute type (57% v lymphomatous 27%, P = .014). The median survival times (months) were 4.3, 7.9, 21.1, and not reached for acute, lymphomatous, chronic, and smoldering forms, with 4-year survival rates of 8%, 22%, 40%, and 80%, respectively. First-line zidovudine (AZT)-interferon alfa (IFN) resulted in an overall response rate of 63% (complete response [CR] 24%) for acute. First-line chemotherapy yielded an overall response rate of 41% (CR 29%) for lymphomatous. CR rate was 42% for etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone versus 12% for cyclophosphamide, vincristine, doxorubicin, and prednisone-like regimen (P < .001). Progression-free survival at 1 year for acute type patients treated with AZT-IFN was 67%, whereas 2-year progression-free survival in lymphomatous type patients who achieved CR after chemotherapy was 77%.

CONCLUSION

This study confirms Latin American ATLL presents at a younger age and has a high incidence of lymphomatous type, low incidence of indolent subtypes, and worse survival rates as compared with Japanese patients. In aggressive ATLL, chemotherapy remains the preferred choice for lymphomatous favoring etoposide-based regimen (etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone), whereas AZT-IFN remains a good first-line option for acute subtype.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.