Abstract in English:ABSTRACT Cuban participation in and contributions to education, medical care and research on diabetes and pregnancy in Latin America dates back to the 1970s when the Latin American Diabetes Association was founded. The Cuban health system and its professionals recognized early the problems presented by diabetes during pregnancy for the health of an expectant mother and her children and assimilated and disseminated important lessons that became influential in the region. These included: importance of adopting a program within primary health care that offers national coverage for diabetic pregnant women, with a special focus on pre-conception monitoring of diabetic women; benefits of defining a specific range for application of a fasting glucose test to identify risk of gestational diabetes through selective screening for the disease; using insulin to treat gestational diabetes; controlling excessive weight at the beginning and during pregnancy; and underscoring the importance of interdisciplinary treatment of diabetes in pregnancy. The goal was to improve care and research in reproductive health for diabetic pregnant women and their children in Cuba.
Abstract in English:ABSTRACT Virologist Dr María Guadalupe Guzmán is recognized as a global leader in dengue research and heads the Pedro Kourí Tropical Medicine Institute’s work as a WHO/PAHO Collaborating Center for the Study of Dengue and Its Vector. The Institute (IPK) was founded in 1937 and is now Cuba’s national reference center for the diagnosis, treatment, control and prevention of communicable diseases. Dr Guzmán is also president of the Cuban Society of Microbiology and Parasitology and directs IPK’s Scientific Council, which is responsible for setting the Institute’s research priorities. A recent h-index analysis found that Dr Guzmán is among the most widely-published and cited Cuban researchers. As part of the National Intersectoral Commission for COVID-19, IPK was integral to the design of Cuba’s COVID-19 Prevention and Control Plan, approved in February 2020, more than a month before the first cases were confirmed in Cuba. This included the three-tiered biosafety training program for frontline health professionals, designed and launched at IPK, which built on the institution’s experience preparing Cuban doctors who served in West Africa with the Henry Reeve Emergency Medical Contingent during the 2014–2016 Ebola outbreak. As of this writing, the Contingent has served in 39 countries fighting COVID-19. Prior to departure, members were trained in biosafety at IPK. Today, IPK conducts COVID-19 testing and research and provides patient care. The institution is supported by an integrated national network of diagnostic laboratories, hospitals and isolation centers. In addition to research related to the clinical evolution and epidemiology of COVID-19, IPK has several studies under way on its diagnosis, pathogenesis, kinetics, immunity and genetics. In July 2020, Dr Guzmán, along with 7 other Cuban specialists, was appointed to the InterAcademy Partnership’s (IAP) COVID-19 Expert Group, a 60-member, multi-disciplinary group comprised of researchers from around the world. The group is designed to promote knowledge sharing and regional and international collaborations concerning the coronavirus using a multisector approach that takes into account the health, social and environmental factors related to the disease. This MEDICC Review interview took place in early July, a few days before the Cuban IAP appointments were announced.
Abstract in English:ABSTRACT INTRODUCTION Double-negative T lymphocytes act as immunomodulators in immune response. This subpopulation is rare in blood but important in the immunopathogenesis of autoimmune diseases, viral infections, cancer and transplant rejection. These disorders have been studied in Cuba using flow cytometry, but normal values of these cells have not yet been established. OBJECTIVE Estimate preliminary reference values for double-negative T lymphocytes according to sex and age in Cuban adults. METHODS A cross-sectional study was carried out in a population of 182 healthy adult residents of Havana: 93 women and 89 men aged 18–80 years with no chronic diseases, toxic habits (smoking, excessive alcohol or caffeine intake) or medications that might alter quantity or functioning of immune-system cells. Peripheral blood was drawn to determine immunophenotype with monoclonal antibodies. The phenotype of double-negative T lymphocytes was quantified as CD45+/CD3+/CD4-/CD8-/CD56- using a Gallios flow cytometer (Beckman-Coulter, France). Medians and ranges (to the 5th and 95th percentiles) were calculated for sex and age, for both percentages and absolute values. To evaluate the effects of sex and age, both variables as well as their interaction were included in a linear model. RESULTS Respective median and range values were total percentage values 3.4 (1.6–7.4) and total absolute values (cells/μL) 57.5 (23.0–157.0). The effect of age on lymphocyte values (percentage and absolute) was significant, with lower numbers in the 51–80 years' age group (p <0.001). Percentage values according to age group were: 18–25 years, 3.8 (2.2–7.4); 26–50 years, 3.7 (1.7–8.7); and 51–80 years 2.6 (1.3–6.6). Absolute values by age group were: 18–25 years, 90 (32.6–163.7); 26–50 years, 65 (28.8–184.0); and 51–80 years 38.5 (17.9–90.1). Desegregating data by sex and age: percentage of women aged 18–25 years 5.2 (2.1–7.8), 26–50 years 4.0 (1.8–7.7), and 51–80 years 2.5 (1.3–5.8); percentage of men aged 18–25 years 3.4 (2.3–7.3), 26–50 years 3.8 (1.5–8.7), and 51–80 years 2.6 (1.2–7.3). Absolute values: women aged 18–25 years 112.0 (40.0–153.1), 26–50 years 67.0 (26.7–138.3), and 51–80 years 40 (18.6–92.0); and men aged 18–25 years 71.5 (32.1–166.7), 26–50 years 61.5 (29.9–188.7), and 51–80 years 36 (13.5–81.7). The low sex*age interaction confirms these differences occur in both men and women. Values decrease with age, with a more abrupt fall starting at 50 years. CONCLUSIONS Estimated reference values were determined for absolute values and relative proportions of double-negative T lymphocytes in healthy Cuban adults according to sex and age. Age was found to have a significant effect.
Abstract in English:ABSTRACT INTRODUCTION Cirrhosis of the liver is a chronic disease that is widespread and irreversible. It represents the final stage of numerous diseases that affect the liver. By the end of 2017, it was the 11th most common cause of death, with a loss of 41.4 million years of disability-adjusted life years, which represent 2.1% of the total years of life lost in the global mortality burden. In Cuba, cirrhosis and other chronic liver diseases have been among the top 10 causes of death for several decades, their rates consistently increasing, from 576 deaths in 1970 (6.7 per 100,000 population) to 1738 in 2017 (15.5 per 100,000 population), with a risk of death that is 4.6 times higher in men. OBJECTIVE Characterize deaths from cirrhosis of the liver in Cuba from 1987 to 2017. METHODS An ecological time-series study was conducted for 1987 to 2017 using information obtained from the mortality database of the Medical Records and Health Statistics Bureau of Cuba’s Ministry of Public Health. The study universe consisted of all deceased persons in the country whose underlying cause of death was cirrhosis of the liver. Both general mortality rates and specific mortality were calculated by age group, sex and etiological classification using adjusted and crude rates. Rates were age-adjusted using the direct method, and the population from the 2002 Census of Population and Housing was considered as the standard population. Percentages and means were also calculated according to selected variables and the relative risk of death due to the disease according to sex, age group and etiological classification. The trend and forecast for mortality rates were estimated for this disease. RESULTS The crude mortality rate from cirrhosis of the liver was 9.0 per 100,000 population for the period. Those aged ≥75 years had the highest risk of death (48.3 per 100,000 population). The crude and adjusted mortality rates were almost double for men (12.4 vs. 5.6 and 11.7 vs. 5.6 per 100,000 population, respectively), as was the total relative risk of death, which was 2.2 times higher. Nonalcoholic cirrhosis accounted for 71.6% of deaths. By the end of 2017, risk of death from cirrhosis had climbed to 14.8 per 100,000 population (adjusted rate: 10.6 per 100,000 population), a signal that mortality had progressively increased over the 31 years analyzed. In addition, forecasts predict that death rates will continue their gradual increase, reaching 19.2 per 100,000 population in 2025. CONCLUSIONS Deaths from cirrhosis of the liver constitute a substantial health burden in Cuba. The upward trend and forecast, in addition to increased risk of mortality in men and older adults, are similar to those reported internationally. The finding that most of these deaths result from nonalcoholic cirrhosis should be further studied, as formulation of effective public health strategies depends largely on attaining a better understanding of the etiology, progression and social determinants of the disease.
Abstract in English:ABSTRACT BACKGROUND The novel coronavirus SARS-CoV-2 is responsible for the current global pandemic. There is a concerted effort within the global scientific community to identify (and thereby potentially mitigate) the possible modes of transmission through which the virus spreads throughout populations. OBJECTIVE Summarize the ways in which SARS-CoV-2 is transmitted and provide scientific support for the prevention and control of COVID-19. EVIDENCE AQUISITION We conducted an extensive literature search using electronic databases for scientific articles addressing SARS-CoV-2 transmission published from December 28, 2019 through July 31, 2020. We retrieved 805 articles, but only 302 were included and discussed in this review. The report captured relevant studies investigating three main areas: 1) viral survival, 2) transmission period and transmissibility, and 3) routes of viral spread. DEVELOPMENT Currently available evidence indicates that SARS-CoV-2 seems to have variable stability in different environments and is very sensitive to oxidants, such as chlorine. Temperature and humidity are important factors influencing viral survival and transmission. SARS-CoV-2 may be transmitted from person to person through several different routes. The basic mechanisms of SARS-CoV-2 transmission person-to-person contact through respiratory droplets, or via indirect contact. Aerosolized transmission is likely the dominant route for the spread of SARS-CoV-2, particularly in healthcare facilities. Although SARS-CoV-2 has been detected in non-respiratory specimens, including stool, blood and breast milk, their role in transmission remains uncertain. A complicating factor in disease control is viral transmission by asymptomatic individuals and through what would otherwise be understood as innocuous human activities. CONCLUSIONS This article provides a review of the published research regarding human-to-human transmission of SARS-CoV-2 and insights into developing effective control strategies to stop viral propagation.
Abstract in English:ABSTRACT INTRODUCTION Age-related cognitive disorders, including Alzheimer disease, are among the main causes of disability and dependence in older adults worldwide. High blood homocysteine levels (hyperhomocysteinemia) are a risk factor for diseases whose metabolism involves different B vitamins. Antioxidant vitamins provide a protective effect by mitigating oxidative stress generated by these diseases. Epidemiological studies have presented varying results on the relationships between blood levels of these vitamins and such cognitive disorders. OBJECTIVE Evaluate the association of vitamin and homocysteine levels with mild cognitive impairment and Alzheimer disease in a group of Cuban older adults. METHODS A cross-sectional study was conducted in Havana, Cuba, of 424 persons aged ≥65 years: 43 with Alzheimer disease, 131 with mild cognitive impairment, and 250 with no signs of cognitive impairment. Dementia was diagnosed using criteria of the International 10/66 Dementia Research Group and Diagnostic and Statistical Manual of Mental Disorders (DSM IV), and mild cognitive impairment was diagnosed using Petersen’s criteria. Blood levels of vitamins (thiamine, B-2, folate, B-12, C and A) and homocysteine were measured by standard procedures. Analysis of variance for continuous variables and percentage comparison tests for dichotomous variables were used to compare groups. RESULTS Persons with Alzheimer disease presented significantly lower levels of vitamins B-2, C and A than healthy participants (p <0.05). Homocysteine levels were significantly higher in those with Alzheimer disease and mild cognitive impairment than in participants with no cognitive impairment (p <0.05). Statistically, levels of thiamine, folic acid, and vitamin B-12 were not significantly different across groups. Compared with those without cognitive impairment, prevalence rates (PR) in the Alzheimer group were significantly higher for hyperhomocysteinemia (PR = 3.26; 1.84–5.80) and deficiency of all B vitamins: thiamine (PR = 1.89; 1.04–3.43), B-2 (PR = 2.85; 1.54–5.26), folate (PR = 3.02; 1.53–5.95), B-12 (PR = 2.21; 1.17–4.19), vitamin C (PR = 3.88; 2.12–7.10) and A (PR = 5.47; 3.26–9.17). In mild cognitive impairment, prevalence rates were significantly higher for hyperhomocysteinemia (PR = 1.42; 1.08–1.87), vitamin B-2 deficiency (PR = 1.70; 1.24–2.32) and vitamin A deficiency (PR =1.88; 1.05–3.38). CONCLUSIONS Hyperhomocysteinemia and various vitamin deficiencies are related to Alzheimer disease and mild cognitive impairment. Longitudinal studies are needed to further elucidate the relationship between different nutritional biomarkers and dementia. A better understanding of this relationship could provide a basis for therapeutic and preventive strategies.
Abstract in English:ABSTRACT On August 13, 2020, Cuba’s national regulatory agency, the Center for Quality Control of Medicines, Equipment and Medical Devices (CECMED), authorized clinical trials for SOBERANA 01—Cuba’s first vaccine candidate and the first from Latin America and the Caribbean. On August 24, parallel Phase I/II double blind, randomized, controlled clinical trials were launched at clinical sites in Havana to evaluate the vaccine’s safety and immunogenicity. Analysis of results and development of different formulations are currently under way and Phase III clinical trials are planned for early 2021. At the time of writing, a second vaccine candidate, SOBERANA 02, was in late-stage development and preparing to begin separate trials this fall. Cuba’s biotech industry, comprised of more than 30 research institutes and manufacturing companies in the state-owned conglomerate BioCubaFarma, has developed and distributed vaccines according to international standards of good clinical and manufacturing practices and protocols for decades. BioCubaFarma supplies over 800 products to Cuba’s national health system—349 of those are on Cuba’s Basic Drug List, the medicines approved for use in the country’s health system. Additionally, BioCubaFarma has 2438 patents registered outside Cuba and its products, including vaccines, medicines and medical equipment, are in 100 simultaneous trials at 200 clinical sites and are registered and sold in more than 50 countries. These factors proved advantageous for making a fast, confident pivot towards COVID-19 vaccine development. Specifically, these antecedents meant all necessary technical capacities and regulatory certifications were already in place. Founded in 1989, CECMED was certified as a WHO Level 4 Regulatory Authority of Reference for vaccine control (the highest certification level conferred) in 2017; also in 1989, a team at Cuba’s Finlay Vaccine Institute led by Dr Concepción Campa, developed VA-MENGOC-BC, the world’s first safe, effective vaccine against serogroup B meningococcus; and in 2000, Cuba’s recombinant hepatitis B vaccine received WHO-PAHO pre-qualification. To date, millions of people in Cuba and elsewhere have been immunized against a variety of diseases with vaccines from the island. Shortly after COVID-19 was declared a pandemic by WHO, this expertise was marshaled to develop a Cuban vaccine against the disease. Researchers from the Finlay Vaccine Institute (IFV), the Molecular Immunology Center (CIM) and the University of Havana’s Chemical and Biomolecular Synthesis Laboratory, with support from other BioCubaFarma enterprises, are leading the project aimed at delivering a safe, effective vaccine in 2021. The SOBERANA team, which is working on two vaccine candidates, SOBERANA 01 and SOBERANA 02 and several formulations thereof, is led by Dr Vicente Vérez-Bencomo, IFV Director, Dr Yury Valdés Balbín, IFV Deputy Director; and Dr Dagmar García Rivera, IFV’s Director of Research, a post she has held since 2014. A vaccine expert with a PhD in pharmaceutical sciences, Dr García Rivera is recognized for her multiple contributions to Cuban science, including development of a pneumococcal conjugate vaccine that is concluding Phase III clinical trials in preparation for introduction into the country’s national health system. She was awarded Cuba’s Annual Health Prize, the national prize of the Cuban Academy of Sciences on three occasions, and in 2019, received the Carlos J Finlay Order of Merit. Dr Garcia Rivera has represented Cuba in meetings of WHO, UNICEF and other multilateral organizations. In late September, with safety and immunogenicity trials for SOBERANA 01 continuing apace, Dr Garcia Rivera paused her feverish work schedule for this exclusive interview with MEDICC Review.
Abstract in English:ABSTRACT The COVID-19 pandemic exhibits different characteristics in each country, related to the extent of SARS-CoV-2 local transmission, as well as the speed and effectiveness of epidemic response implemented by authorities. This study presents a descriptive epidemiological analysis of the daily and cumulative incidence of confirmed cases and deaths in Cuba from COVID-19 in the first 110 days after first-case confirmation on March 11, 2020. During this period, 2340 cases (20.7 x 100,000 population) were confirmed, of which 86 patients died (case fatality 3.67%; 52 men and 34 women). Mean age of the deceased was 73.6 years (with a minimum of 35 years and a maximum of 101), with the average age of men lower than that of women. More than 70% of all deceased had associated noncommunicable diseases. The incidence curve ascended for five weeks and then descended steadily. The average number of confirmed cases and deaths for the last week included (June 23–28, 2020) were 25 and 1 respectively; the curve always moved within the most favorable forecast zone of available mathematical models and the effective reproductive number fell below 1 after the fifth week following the onset of the epidemic. We present the prevention and control measures implemented during this period—some unique to Cuba—and assess their effectiveness using two analytical tools: comparison of observed deaths and confirmed cases with those predicted by mathematical models; and estimation of the effective reproductive rate of SARS-CoV-2. Some distinctive features of this strategy include nationwide door-to-door active screening for individuals with fever and/or symptoms of respiratory distress, isolation of cases and quarantine of contacts of confirmed cases and of persons suspected of having the virus. During this period, Cuba’s response to the epidemic was successful in flattening the curve and limiting transmission, resulting in fewer cases and a lower number of subsequent deaths.