Revista Cubana de Medicina Tropical最新文献

Introduction: in the last few years, the Incidence rate of fascioliosis caused by Fasciola hepatica has increased worldwide. Cuba is one of the countries that have reported sporadic cases and also some outbreaks of fasciolosis.

Objective: to describe clinical and therapeutic features of this trematodiasis of digestive transmission found in 87 patients, who had been admitted to "Pedro Kourí" Institute of Tropical Medicine from January 1996 to December 2005.

Methods: patients were divided into 2 groups according to the prescribed drug, that is, triclabendazole and dihydroemetine. The clinical variables were collected at the time of diagnosis and 90 days after treatment; the means and the standard deviation were estimated.

Results: males was slightly predominant (54) in our series of patients admitted to the institute service. Consumption of watercress (Nasturtium officinale) was found in almost half of the patients. Abdominal pain, fever and malaise were the most frequent symptoms. Both drugs were useful to treat F. hepatica.

Conclusions: this study showed the usefulness of lab tests for diagnosis and follow-up of patients after treatment. The anti-parasitic drugs dihydroemetine and triclabendazole proved to be effective at the prescribed doses in this research with minor adverse effects.

Introduction: dengue is an infectious disease caused by ARN genome virus and has 4 recognized serotypes (DEN-1, DEN-2, DEN-3 and DEN-4) that are transmitted by Aedes aegypti as the main vector. The clinical manifestations of dengue in pregnancy are similar to those of the general population, except that the ecosystem is made up by the mother and the fetus where the virus with its genetic characteristics is introduced and finds special conditions for development and evolution.

Objective: to study the progression of the dengue symptoms in women who got sick during their pregnancy for one year of follow-up.

Methods: an observational descriptive research was conducted to find out the existence of sequelae in women who were infected with dengue 3 during their pregnancy. A cohort of 28 pregnant women, who had been admitted to "Juan Bruno Zayas Alfonso" General Hospital at the time of the dengue outbreak from April to November 2006, was studied. The diagnosis was serologically confirmed.

Results: after one-year of follow-up, it was observed that amnesia (25 %) and menstrual disorders (14.3%) affected these women. Amnesia was significant when the infection occurred in the third trimester of pregnancy, p=0.0377.

Conclusions: dengue 3 infection may cause amnesia in pregnant women who suffered this disease, particularly in their third trimester of pregnancy.

Histoplasmosis, an infection caused by the fungus Histoplasma capsulatum, has been reported all over the world and is considered endemic in the American continent, including Cuba. This fungus grows on the soils contaminated with bird and bat excreta, where it produces a great number of microconidia that could cause the infection when they are inhaled. The clinical spectrum varies from asymptomatic infections to serious disseminated diseases involving one or many organ systems and affects mainly AIDS patients, patients with hematological neoplasias, transplant recipients or other immunosuppressed patients. The main risk groups include those individuals whose working activities make them be exposed to aerosols contaminated with H. capsulatum. Lab diagnosis is based on the microscopic observation, isolation and identification of the fungus in fluid or tissue samples of patients, and on specific antigen and antibodies detection. The molecular methods based on polymerase chain reaction have not been sufficiently defined, and they could be an important advance in the early diagnosis of this mycosis. Itraconazole is recommended for treatment of moderate, localized and chronic infection whereas amphotericin B is the drug of choice for disseminated and serious manifestations, particularly in its lipidic formulations. At present, histoplasmosis is considered one of the most important systemic mycoses in the Americas, and it is widely spread over all regions of Cuba.

Introduction: during the Cuban epidemic that occurred in Santiago de Cuba in 1997, there was observed increasing severity in the course of time, in terms of proportion of serious dengue haemorrhagic cases and deaths that could be due to the emergence of escape mutants to neutralization with greater virulent potential.

Objective: to study some biological attributes of a group of strains isolated at different points of time during the Santiago de Cuba epidemic in 1997.

Methods: nine DENV-2 strains were studied. The cytopathogenic effect, the viral growth in C6/36 HT and VERO cell lines, the virus plaque sizes, the sensitivity to temperatures, the neurovirulence in newborn mice and the influence of the pH in the union of the virus to the cell as well as in the multiplication medium were all evaluated.

Results: the strains isolated at the end of the epidemic differed from those of the beginning showing increased neurovirulence in newborn mice and higher viral titers and greater cytopathogenic effect in HT C6/36 cells. On the other hand, the virus and the cell union was favored by acid pH when testing strains from the beginning of the epidemic, whereas this union was favored by the basic PH in the strains isolated at the end of the epidemic

Conclusions: the present study managed to show that in addition to the previously observed genotypical changes, there were phenotypical differences among the strains isolated at different points of time in the epidemic; all these aspects may be associated with differences in the viral fitness and/or in the virulent potential of these strains.

Introduction: polymorphic variants of FcgammaRIIa receptor have been associated to susceptibility to develop several infectious diseases. The relationship between the polymorphism of this receptor and the susceptibility to dengue hemorrhagic fever was recently reported.

Objectives: to explore whether the association of the homocygotic variants of the receptor to susceptibility to or protection from a disease could be also related with the IgG antibody titters and the exposure to a number of infections.

Methods: a retrospective analytical study was performed on individuals who had been infected with the dengue virus 4 during the 2006 epidemic in the City of Havana and were tracked down in 2008. A total number of 97 individuals were recruited of whom 68 had suffered dengue fever and 29 had had dengue hemorrhagic fever. A 10-mL blood sample was taken from each of them and then placed in EDTA anticoagulant for DNA isolation and 5 mL placed in dry tubes to obtain serum. The genetic polymorphism of FcgammaRIIa receptor, the total anti-dengue IgG antibody titers and the antecedent of dengue infection were determined.

Results: it was interesting to note that there was very significant direct relation (p< 0.0001) between high anti-dengue IgG antibodies titers and the number of infections suffered by these people. This behaviour was present in those individuals with the HH homocygotic variant.

Conclusion: it seems that those individuals with polymorphism in FCgammaRIIa-H/H receptor would tend to non-elimination of IgG antibodies through this receptor, which is associated to the number of infections suffered by the individual.

Introduction: in April 2009, a new virus was identified in Mexico and North America as the cause of a respiratory disease. The virus quickly spread over other countries. On June 11, 2009 the World Health Organization (WHO) reported cases in 74 countries and territories located in 2 of its regions. The high sustained transmission of this virus worldwide led to establish the phase 6 or the pandemic phase, indicating that the situation had to do with spreading rather than increased severity.

Objectives: to report on already known or new events after the administration of vaccine A(H1N1) called Pandemrix, to identify the most frequent events occurred in pregnant women and to research into the associated severe events.

Methods: a prospective descriptive study was designed to characterize the adverse effects of Pandemrix reported across the country from April 1st to June 30th, 2010. A total of 1,123,526 people were vaccinated in which 100% of pregnant women were included.

Results: active surveillance nationwide reported 5 763 signs and symptoms detected in 3 401 people (615 reports from pregnant women). The overall rate of reports was 302.7 x 100 000 doses administered. Adverse events such as fever, headache, pain, swelling and redness at the injection site, malaise, arthralgia, allergic reactions, nausea and vomiting were reported as common symptoms. These 10 symptoms and signs accounted for 79.1% of all the reported events. A total number of 80 317 pregnant women were vaccinated of whom 615 reported adverse effects, accounting for 0.8 % of the vaccinated pregnant women. Fever was the most notified symptom in children (193) followed by local reactions at the injection site (23), vomiting (20), arthralgia (17), headache (11), malaise (10) and high fever-related seizures (6). Eight events were analyzed as severe.

Conclusions: the administration of the vaccine was related to 3 events, unrelated to other 3 events and 2 were classified as inconclusive (3 miscarriages). No deaths were reported. The capacity of the Cuban Health System for the administration of this vaccine with active surveillance in a short period of time was proved. Data from monitoring of events that were supposedly attributable to vaccination or immunization did not notify any unusual event. Therefore, no safety problem is associated to the Pandemrix vaccine.

Introduction: human leptospirosis requires rapid and early microbiological diagnosis since it is a common lethal disease worldwide.

Objectives: to increase the quality of microbiological diagnosis of this infection, to expand the knowledge on the circulation of groups of leptospiras in Cuba and to show the benefits of an agglutination assay using Cuban latex particles and of commercial immunochromatogenic systems LEPTO Dipstick, Lepto Tek Lateral Flow, Lepto Tek Dri Dot and SD Leptospira IgM-IgG.

Methods: this descriptive research used sera from positive and negative control cases to evaluate and measure the diagnostic value of rapid serological diagnosis systems with respect to the microagglutination method of reference (MAT). All the techniques used in this report are described in the Manual of Operations and Procedures of the Leptospira Lab in "Pedro Kourí" Institute of Tropical Medicine.

Results: all the studied diagnosis systems exhibited acceptable values of sensitivity, specificity and agreement when compared to the international microagglutination method of reference with live microorganisms. The great selectivity (antigen reactivity) and the diagnostic reliability of the diagnostic systems were confirmed; particularly the mixed Cuban-made latex, the LEPTO Dipstick and the SD Leptospira IgM-IgG.

Conclusions: the procedures used in this research work exceeded the traditional methods including the microagglutination method of reference in terms of easiness, rapidity, technical simplicity and level of performance, and all were useful for the screening of antibodies to leptospiras.

Introduction: the study of the host-parasite interactions is a new challenge to understanding some aspects of the parasitic metabolism and the mechanisms of invasion, immunological evasion and damage. Ascaris lumbricoides may cause anemia and thrombosis. It was previously shown that Ascaris lumbricoides modified the superficial charge of erythrocytes, which means that the parasite can capture sialic acid from the red blood cell.

Objective: to study the effect of adult parasite extracts on the erythrocyte charge using the Alcian Blue method and to compare its sensitivity with the Polybrene method:

Methods: fifty five adult parasite extracts and Group O erythrocyte suspensions were used. The erythrocytes were treated by incubating the sediment with an equal volume of parasite extracts for one hour at 37 degrees C. The control group (erythrocytes without any contact with the parasite extracts) was incubated with pH 7.4 phosphate buffer solution. Alcian Blue method was applied and the percentage erythrocyte anionic charge was determined in the control group and in the treated red cells. The experimental coefficient of erythrocyte anionic charge was defined as the quotient between the initial and the final percentage erythrocyte anionic charge.

Results: it was shown that 27 out of 55 parasite extracts (49.1 %) modified the charge of the red blood cells, being their experimental coefficient of the erythrocyte anionic charge 0.75 +/- 0.1144 whereas the same coefficient amounted to 0,94 +/- 0.0445 for those which did not show any charge variation. The statistical analysis concluded that the Polybrene and Alcian Blue Methods had comparable sensitivities (p>0.20).

Conclusions: A. lumbricoides is able to capture sialic acid from the erythrocyte, which would not only explain the thrombosis attributed to the parasite, but also suggest that the nematode could use this acid either in its metabolic routes or for its strategies of immunological evasion.

Introduction: the earthquake occurred in Haiti in January 2010 led to the worsening of the hygienic, sanitary and environmental conditions and increased the number of breeding sites for disease-borne vectors in the country.

Objectives: to report the first results of the entomological surveillance set by the Cuban advisory group in Haiti after the earthquake.

Methods: the work was carried out in 7 sites located in West department, one of the ten departments of the country; larval sampling was conducted in reservoirs and natural breeding sites based on the methodologies for both. The sampling was weekly in the May-October period in 2010.

Results: twelve mosquito species were reported in the West department as well as the presence of Triatoma rubrofasciata. The fundamental breeding sites of the three most important mosquito species were identified including Aedes aegypti with water tanks followed by worn car rubbers and small artificial deposits, Anopheles albimanus in rice fields, animal footprints and coastal swampy plains, and Culex quinquefasciatus, one lymphatic phylarosis-borne vector still existing in Haiti, in drains and waste water ditches.

Conclusions: these results are the first ones from this surveillance program after the earthquake and represent valuable information for the decision-making at the time of designing a control program to face the occurrence of any epidemics in which these insect vectors might be involved in this department.

Introduction: Bixa orellana L. is one species used in traditional herb medicine in several continents. Among the medicinal properties attributed to this plant, the antimalarial action has been included.

Objective: to evaluate in vitro and in vivo antimalarial activity of extract from B. orellana grown in Cuba.

Methods: the antimalarial activity of the hydroalcoholic extract fro Bija seeds was evaluated in vitro against Plasmodium falciparum Ghana strain and in vivo using a model of murine malaria, that is, Balb/c mice infected with Plasmodium berghei ANKA strain. Citotoxicity was determined against MRC-5 human fibroblasts. Additionally, phytochemical composition of the studied extract was preliminarily informed.

Results: the extract exhibited IC50 (medium inhibitory concentration) of 11.6 microg/mL, CC50 (medium citotoxic concentration) of 60.2 microg/mL and SI (selectivity index) of 5.1. Subcutaneous administration of the extract at a 500 mg/kg dose caused parasitemia reduction of 50.3 +/- 5.8 % on infected animals compared with that of the controls. Phytochemical screening was consistent with detection of triterpenoids and/or steroids, alkaloids, lactonic compounds, phenols, tanins and flavonoids.

Conclusions: the hydroalcoholic extract from B. orellona seeds grown in Cuba showed in vitro and in vivo moderate antimalarial activity. Bioassay-guided fractioning will allow identifying the molecules responsible for the exhibited extract activity and re-evaluating the potentialities of this extract.