Risk of transfusion-transmitted human T-cell lymphotropic virus-type I in Latin America.

In a recent publication, G. Schmunis et al presented data from Latin America on blood quality and on important approaches to preventing human immmunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS), and other infectious diseases that may be transmitted by blood transfusion. Mass screening between 1987 and 1988 in Peru of blood from more than 90,000 donors highlighted potential problems in the donor population, and it also uncovered inappropriate practices related to the use of blood transfusions. Since then, adequate screening of the blood supply for HIV was implemented and new transfusion-related AIDS cases have been prevented during the past 8 years.     

Human T lymphotropic virus type-I and adult T-cell leukemia in Japan

HTLV-I is the first retrovirus to be associated directly with human malignancy. In ATL-endemic areas, the rate of HTLV-I carriers is high. Both HTLV-I and ATL have been shown to be endemic in some regions of the world, especially in southwest Japan, the Caribbean islands, South Americas, and parts of Central Africa. Antibodies against HTLV-I have been found in over one million individuals, and more than 700 cases of ATL have been diagnosed each year in Japan alone. The cumulative incidence of ATL among HTLV-I carriers in Japan is estimated at 2.5% (3-5% in males, 1-2% in females). In endemic areas, HTLV-I Ab were found in the sera of 6 to 37 percent of healthy adults over 40 years of age. This clustering is thought to be due to the limited transmission of virus between socially isolated populations. The diagnostic criteria for HTLV-I associated ATL have been defined as follows. 1) Histologically and/or cytologically proven lymphoid malignancy with T cell antigens. 2) Abnormal T-lymphocytes present in the peripheral blood, except in the lymphoma type. 3) Serum specimens for all patients with ATL have HTLV-I Ab. 4) Demonstration of clonality of HTLV-I proviral DNA is a definite diagnosis of ATL. ATL shows diverse clinical features but can be divided into four subtypes: acute, chronic, smoldering, and lymphoma type. The pattern of HTLV-I transmission is through one of three different modes. Infected mothers can transmit the virus to newborns mainly via breast milk. The virus also can be transmitted from male to female by sexual intercourse, and through blood transfusion. Chemotherapy is not effective; the acute and lymphoma types have a poor prognosis. ATL is generally treated with curative intent using combination chemotherapy, although long-term success has been very limited. Unfortunately that advance did not translate into an improvement in the overall survival; the median remain 10 months. In contrast, smoldering ATL, or some cases of chronic ATL, may have a more protracted natural course, which may be compromised by aggressive chemotherapy. Alternative strategies for both acute and chronic forms are clearly needed. After infection of HTLV-I, there is a long latent period before onset of ATL. Analyses by PCR showed that clearly proliferation occurred in intermediate state or even carriers with high virus load. Such clonal proliferation might be preleukemic stage, which suggested that carriers with high virus load should be risk group to have ATL.     

Human T-cell lymphotropic virus type I associated adult T-cell leukaemia/lymphoma in Taiwan Chinese

Twenty-five Chinese patients with human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukaemia/lymphoma (ATLL) were identified in Taiwan. No patients had been outside Taiwan and none were descendants of Japanese heritage. Their ages ranged from 28 to 71 years. There were 17 men and eight women. Main clinical and laboratory features at presentation were lymphadenopathy (16), skin lesions (11), hepatosplenomegaly (11), pulmonary lesions (11), hypercalcaemia (10) and bone marrow infiltration (14). Peripheral blood was characterized by leucocytosis with presence of pleomorphic abnormal lymphocytes but rare anaemia or thrombocytopenia. The clinical subtypes were acute in 15, chronic in three, smouldering in one, and lymphoma type in six. The immunophenotypes of the ATLL cells were characterized by the expression of CD2+, CD4+, CD7-, CD8- and CD25+. The overall prognosis was poor with a median survival of 5 months. The acute form had a significantly shorter survival (2 months) than lymphoma type (13 months). Susceptibility to various infections was common. Pulmonary complications accounted for 73% of the causes of death. The clinicopathologic features of ATLL in Taiwan are indistinguishable from those in HTLV-I endemic areas. The present series adds to the knowledge of the worldwide pattern of the disease.     

Human T-cell lymphotropic virus I and adult T-cell leukemia: report of a cluster in North Carolina

PURPOSE: Human adult T-cell leukemia-lymphoma is a malignant, proliferative disease of CD4+ lymphocytes associated with infection with human T-cell lymphotropic virus type I (HTLV-I). Following the presentation of a patient who was infected with the virus, we undertook a study of his family members and sexual contacts to see if a cluster of infected persons could be identified. CASE REPORT: A black heterosexual North Carolina native with a history of drug abuse presented with jaundice, and pancytopenia subsequently developed. He then became hypercalcemic and leukemic, with high numbers of circulating, morphologically abnormal CD4+ lymphocytes. RESULTS: As determined by radioimmunoassay and immunoblot analyses, the serum of the index case contained antibodies against core proteins (p19 and p24) of HTLV-I. When cultured in vitro with interleukin-2, the lymphocytes expressed HTLV-I specific core proteins. The virus recovered from these T cells was transmitted to cord blood T cells, which became immortalized for continuous growth in vitro, expressed HTLV-I p19 protein, and displayed characteristic C-type particles by electron microscopy. Studies of family members and sexual contacts, all of whom were black, heterosexual central North Carolina natives, revealed five of 28 whose serum had anti-HTLV-I antibodies as determined by radioimmunoassay and immunoblot. Neither the patient nor the seropositive family/contacts had antibodies against human immunodeficiency virus proteins. Four of the six people with HTLV-I infection had no history of intravenous drug abuse. Three of the five seropositive family/contacts had circulating, morphologically abnormal lymphocytes suggestive of "preleukemic" or "smoldering" human adult T-cell leukemia-lymphoma.     

Leptospirosis in Latin America

Leptospirosis is a common disease in Latin America. Transmission to humans occurs by contact with water or soil contaminated with the urine of rodents, dogs, or livestock. Pathogenesis is still poorly understood, and bacterial toxin or virulence factors are probably responsible for many features of the disease. The anicteric form is the most frequent presentation, and its clinical picture resembles influenza or other acute febrile diseases. Icterohemorrhagic leptospirosis, or Weil's syndrome, represents the severe form of the disease. Its clinical picture is similar to bacterial sepsis and multiple organ involvement occurs, mainly in kidneys and lungs, and causes great morbidity and mortality. Death is often related to multiple organ failure and pulmonary hemorrhages. Diagnosis is based on serology or blood, cerebrospinal fluid and urine cultures in specific media. Treatment involves a combination of antibiotics and supportive measures.     

AIDS in Latin America

The epidemic in Latin America has placed an unexpected additional burden on the health care systems and national economies, already weak and affected by severe problems. Specific regional diseases in addition to common opportunistic infections, and particularly the high incidence of TB, produce a different picture compared with the United States and Europe. Access to ARV therapy is far from being universal in Latin America; nevertheless, some countries are providing HAART to all eligible patients, showing that it is not impossible to improve quality of care for people living with HIV infection in the region. Before assuming as definitive and irreversible that at least one or two generations will be sacrificed on the altar of inequity of our uneven world, we as acting scientists should join the struggle of millions of human beings claiming their right to be treated with the best drugs that science can offer today.     

Demonstration of antibodies to human T-cell lymphotropic virus-I tax in patients with the cutaneous T-cell lymphoma, mycosis fungoides, who are seronegative for antibodies to the structural proteins of the virus

Although most patients with the cutaneous T-cell lymphoma, mycosis fungoides (MF), are seronegative for human T-cell lymphotropic virus-I or -II (HTLV-I/II) when tested by assays that measure only antibodies to the viral structural proteins, the majority of such patients harbor HTLV-I-related pol and tax proviral sequences that encode proteins not included in routinely used serologic tests. Tax mRNA has also been detected in their peripheral blood mononuclear cells (PBMC). Therefore, it seemed possible that these patients have antibodies to the tax protein. To investigate this, enzyme-linked immunosorbent assays (ELI- SAs) and Western blot assays were set up, using as antigens the full- length HTLV-I tax cloned from the prototypic HTLV-I-infected cell line, C91PL, and from PBMC of a MF patient, as well as a synthetic peptide made to the carboxy-terminal 20 amino acids of tax-I. Of 60 MF patients whose PBMC were shown to be positive for tax proviral DNA and mRNA, 50 (83%) were shown to have tax antibodies. The antigen derived from the MF patient was most useful in detecting such antibodies. These results demonstrate the need for including other HTLV-related antigens in addition to gag and env in serologic tests used to identify HTLV- infected individuals. The findings underscore the fact that individuals considered seronegative on the basis of currently used tests can be infected with HTLV.     

Human T-cell lymphotropic virus type III associated disorders. The spectrum in the heterosexual population

Eleven heterosexual patients (nine women, two men) without classic risk factors for development of acquired immunodeficiency syndrome (AIDS) were seen between March 1983, and April 1985, and diagnosed as having AIDS (four), persistent, generalized lymphadenopathy (PGL) (four), or asymptomatic human T-cell lymphotropic virus type III (HTLV-III) carrier state (three). The clinical presentations and course of those with AIDS or PGL were similar to those reported in homosexual men with AIDS or PGL, with reversed T4/T8 ratio, and the presence of antibody to HTLV-III. Asymptomatic carriers had normal T4/T8 ratios, had an absence of HTLV-III antibodies, but had HTLV-III virus cultured from blood. We conclude that the heterosexual population, with or without history of sexual exposure to individuals at risk for AIDS, may develop a wide range of clinical manifestations secondary to HTLV-III, varying from AIDS to the asymptomatic carrier state.     

Evaluation of the cervicovaginal environment in asymptomatic Human T-cell lymphotropic virus type 1 infected women

Introduction

Human T-cell lymphotropic virus type 1 (HTLV-1) is sexually transmitted and causes persistent infection. This virus induces activation of the immune system and production of inflammatory cytokines. This study aimed to assess the cytokine profile and cytopathological findings in the cervicovaginal fluid of asymptomatic HTLV-1-infected women.

Hepatitis E in Latin America

Hepatitis E virus produces an emerging health problem, knowledge about epidemiology of hepatitis E virus infections in the USA and Latin America is still limited. The wide-ranging clinical manifestations lead to an extensive underestimation of the global seroprevalence. Clinical and diagnostic accuracy are critical to improve patient management.     

Prenatal care in Latin America

Available data on the coverage of prenatal care in Latin America were reviewed. In recent years, only Bolivia had a coverage of prenatal care of less than 50 per cent. More than 90 per cent of pregnant women received prenatal care in Chile, Cuba, the Dominican Republic, and Puerto Rico. Prenatal care increased between the 1970 and 1980 in the Dominican Republic, Ecuador, Guatemala, Honduras, Mexico, and Peru. The coverage of prenatal care decreased in Bolivia and Colombia. The mean number of visits increased in Cuba and Puerto Rico. The increase of prenatal care in Guatemala and Honduras is due to increased care by traditional birth attendants, compared to the role of health care institutions. We compared the more recent data on tetanus immunization of pregnant women to the more recent data on prenatal care. The rates of tetanus immunization are always lower than the rates of prenatal care attendance, except in Costa Rica. The rates of tetanus immunization was less than half as compared to the rates of prenatal care in Bolivia, Guatemala, and Peru. To improve the content of prenatal care should be an objective complementary to the increase of the number of attending women.     

Gastroenterology training in Latin America

Latin America is characterized by ethnic, geographical, cultural, and economic diversity; therefore, training in gastroenterology in the region must be considered in this context. The continent’s medical education is characterized by a lack of standards and the volume of research continues to be relatively small. There is a multiplicity of events in general gastroenterology and in sub-disciplines, both at regional and local levels, which ensure that many colleagues have access to information. Medical educat...