Revista Cubana de Medicina Tropical最新文献

Introduction: On April 2009, the Mexican health authorities reported increased hospitalization indexes caused by pneumonia with high mortality rates to the Pan-American Health Organization (PAHO). The National Epidemiological Surveillance System of Mexico noticed that this increase mainly occurred in the 20-40 year old population. A new type of swine influenza A (H1N1) virus was identified by laboratory studies as the etiological agent of the first pandemic of the 21st century. On April 26 2009, the National Anti-pandemic Plan was activated by the Cuban Ministry of Public Health, and on May 7th, the lab-confirmed index case appeared. An integrated surveillance system with laboratory confirmation was set up.

Objectives: To detect pandemic influenza virus during the pandemic wave.

Methods: The epidemiological weeks 37 to 41 witnessed a rise of the number of sick people seen by the medical services. In this period, the samples taken from patients clinically diagnosed with severe acute respiratory infection were selected for this analysis; they were divided into three groups, that is, 370 children and adults in critical condition, 55 pregnant women in severe condition and 30 fatal cases. The diagnosis of the pandemic virus was performed by Real Time Polymerase Chain Reaction Test (PCR). Other respiratory viruses were tested by conventional PCR.

Results: The pandemic influenza virus was detected in 65 children and adults, 20 pregnant women and 9 fatal cases. The seasonal influenza A (H3N2) virus was identified in 81 cases of severe acute respiratory infection covering all age groups, 10 pregnant women and 5 deceased on the basis of real time polymerase chain reaction test. Other respiratory viruses were also monitored by the end-point polymerase chain reaction.

Conclusions: The comprehensive analysis of these results contributes to the national and regional surveillance of respiratory viruses for the improvement of the prevention and control programs of the acute respiratory infections.

Introduction: Given the importance of dengue in America, it is indispensable to know the cause of death of the infected people and to evaluate the few necropsy studies available.

Objective: To describe and to analyze the relevant clinical and pathological findings in fatal dengue cases of dengue in a Venezuelan endemic area.

Methods: Eight fatal cases, according to clinical and epidemiological dengue criteria and/or confirmed by complete serological tests were studied after complete clinical necropsy. The tissues were processed by standard histopathological techniques.

Results: All these cases showed severe lung disease (diffuse alveolar damage, non cardiogenic pulmonary edema, thromboembolism, bronchopneumonia, pneumonitis, intralveolar hemorrhage). Six presented with pleural or abdominal effusion. Focal hepatic necrosis was found in two cases. The cause of death was related to respiratory failure in six (6) cases secondary to lung disease; two with hypovolemic shock, and one developed liver failure.

Conclusion: the studied dengue cases showed fatal severe pulmonary compromise leading to death, unlike those reported in other studies of autopsies in The Americas. They also developed multiple organ failure, which in most cases led to death not directly associated to hypovolemic shock. These findings in autopsies will allow designing therapeutic strategies to avoid mortality.

Introduction: In Cuba, as well as in other countries, Pediculus capitis infestation has increased since the 70's; this is the reason why a program aimed at controlling and preventing this infestation was designed. This program includes quality control studies of the active synthetic pyrethroid Permethrin and its activity at 1% on lice and 5% on scabies. Due to its low toxicity and positive risk/benefit ratio, Permethrin is a pediculicide of choice to decrease Pediculus capitis infestation.

Objective: To validate an analytical method using high performance liquid chromatography and its application in the quantification of 12 samples from 2 batches of Cuban-made 1% permethrin pediculicidal preparation.

Methods: Linearity, precision and accuracy parameters were determined. Seven calibration standards and working solutions with concentrations ranging from 100 to 15000 microg/mL were prepared. These validation parameters were verified through the correlation coefficient, the variation coefficient and the percentage relative error.

Results: The specificity of this method was proved in the chromatograms that showed retention times of 8,8 to 9,2 min for the isomer trans and 10,7 to 11,2 min for the isomer cis. The correlation coefficient for both isomers was higher than 0,99; the variation coefficient was under 3% and the percentage relative error was--3 and 1% for the inter-day and intraday studies, respectively. The mean permethrin concentration in 1% solution batches was estimated at 6 780,14 microg/mL.

Conclusions: The validated method was linear, precise and exact within the range of the studied concentrations. The estimated concentration of permethrin was below the expected rate according to the composition of 1% permethrin solution (9 100-10 900 microg/mL). This method may be useful for the quantification of 1% permethrin solutions in the quality studies of the product sold to the population.

Introduction: The acute diarrheal diseases are one of the main causes of morbidity and mortality in children aged under 5 years and in the general population; this demands a great deal of care in the healthcare services. The situation worsens due to the overuse of antimicrobials and the development of bacterial resistance, being the latter an emerging health problem in different areas of the world. Among the causative microorganisms of acute diarrheal diseases are those of Aeromonas genus, recognized as second risk emerging pathogens.

Objectives: To determine the most frequently isolated Aeromonas species in fecal samples from acute diarrheal patients and their antimicrobial susceptibility.

Methods: The Bauer-Kirby's method allowed identifying the susceptibility to several antimicrobials of 100 isolated samples coming from the provincial hygiene and epidemiology centers during 2007 and 2008.

Results: Identification of the species was accomplished in 67% of isolates, being A. caviae (33%) y A. hydrophila (29%) the predominant species. It was demonstrated that 100% of isolates got resistant to at least one of the studied antimicrobials. Drug resistance to cefalotine, sulfonamides and nalidixic acid showed the highest percentages.

Conclusions: Tetracycline and chloramphenicol are recommended as the drugs of choice for treating intestinal infections caused by these microorganisms in Cuba.

Introduction: Sialic acid of the erythrocytes has hemorreologic and hemodynamic importance, so its reduction causes erythrocyte aggregation and low blood flow.

Objective: To study the effect of A. lumbricoides on the anionic charge of erythrocytes and of desialated erythrocytes, taking the time of contact of the erythrocytes with parasite extracts into account.

Methods: Twenty parasite extracts and Group O erythrocyte suspensions in saline medium (GR) and in bromelin enzymatic medium (GR(b)) were used. The erythrocytes were treated by incubating the globular sediment with the same volume of parasite extracts, at 37 degrees C for 15, 30, 45, 60, 90 and 120 min. There was a control for each treatment interval (erythrocytes without contact with parasite extracts). The polybrene's method was simultaneously applied to the controls, the GR ad the GR(b). Each obtained aggregation was given a scoring. C(exp)CAS[EA) was calculated as the quotient between the treated erythrocytes scoring and the control.

Results: the statistical analysis allowed arriving to the conclusion that the time of GR and GR(B) treatment had a highly significant effect on the value of C(exp) CAS[EA]; the median of C(exp) CAS[EA]; was significantly higher for GR than for GR(B); the sialic acid uptake in GR was higher from 90 minutes on, whereas this parameter was lower in G(B) at 15 min; no significant differences were observed for the rest of the treatment times. The results showed that the sialic acid uptake by the parasite depended on the time of treatment and that the parasite extract caused more alteration in the superficial charge of GR(B).

Conclusions: The reduction of sialic acid could be related to thrombosis and anemia in ascariosis. The experience gained allows us to consider that the effect of the parasite may be more significant in diabetic and hypertensive individuals.

Introduction: live attenuated oral Vibrio cholerae Ol El Tor, Ogawa strain 638 has demonstrated to be well tolerated and immunogenic when administrated orally in studies carried out in healthy volunteers.

Objectives: to evaluate the protection against cholera infection in a challenge clinical trial, for the technological and pharmaceutical scale-up of this vaccinal candidate as active ingredient at industrial level.

Methods: a total of 21 healthy volunteers were involved in this trial; the vaccine candidate was administered to 12 of them and the remaining nine were given the placebo. Twenty eight days later, all of them received an infective dose of a V. cholerae virulent strain.

Results: diarrheas were observed in 7 out of 9 placebos whereas not a single vaccinated volunteer showed diarrheas. More frequent and intense loose stools were found in the placebo volunteers with O-blood group. All volunteers in he placebo group excreted V. cholerae, but only three (25%) out of the 12 vaccinated volunteers did so.

Conclusion: in this challenge clinical trial model, the 638 strain proved to protect people against the diarrhea caused by a virulent V. cholerae strain.

Introduction: the population's knowledge is important to develop participatory processes that support the reduction of Aedes aegypti.

Objectives: to identify sociodemographic factors, knowledge, perceptions and practice in the population of three people's councils in Lisa municipality about Aedes aegypti control and dengue prevention; to determine the association of these sociodemographic factors with the adequate level of knowledge about dengue, and relate the implementation of suitable practice to risk knowledge and perceptions.

Methods: cross-sectional study was conducted in which surveys and an observational guide were applied to a randomized sample of individuals living in the selected areas. Percentages from the people's councils were compared whereas two logistic regression models to set relations among the studied variables were adjusted for.

Results: the most cited breeding site for Aedes aegypti was garbage (67.3%), the most referred preventive measure was container covering (90.2%); perception of risk of getting sick was low or non-existent (55%); regarding the visited houses, the most used practices were cleaning of backyards and water tank protection. In the multi-variate analysis, the young people showed better knowledge than people aged over 59 years whereas those people having better knowledge of breeding sites and preventive measures were the ones who followed adequate practice.

Conclusions: it was demonstrated that adequate knowledge on dengue and its vector are related to better implementation of suitable preventive measures in the house; however, specific aspects on breeding sites should be taken into consideration within the educational programs carried out in each locality.

A case of chromoblastomycosis caused by Cladophialophora carrionii is reported. The diabetic and hypertensive patient presented serpiginous and verrucous lesions, with centrifugal evolution. The patient, with a history of disease for 59 years, had not been diagnosed or treated before. Dematiaceous septate hyphal and elliptical conidia were seen on microscopic observations. The isolated fungus was identified on the basis of micro-macromorphologic characteristics.

Introduction: in dengue outbreaks or epidemics, the chemical pesticides play a fundamental role to control disease-borne adult mosquitoes and to support the Vector Control program in Cuba.

Objectives: to find out the effectiveness and the efficiency of insecticidal formulations in use for the control of Aedes aegypti mosquito in three strains from the City of Havana.

Methods: bioassays followed the methodology recommended by the World Health Organization. Efficacy and efficiency were compared in the studied insecticides between the cold spraying and the thermal spraying. A standardization test was applied to verify the nature of each variable; one three-factor ANOVA to see any differences among the mortality means and the Kruskal-Wallis test to find out difference among the mortality values for each type of treatment with respect to the preparation of one liter of mixture (efficiency), for a significance level of p < 0,05.

Results: when comparing the mortality figures reached with both types of treatment, it was evinced that there was a highly significant difference between them, the most favourable results corresponded to thermal spraying, which proved the efficacy of this treatment and its efficiency (effectiveness/cost).

Conclusions: there exists a highly significant difference between the formulations, which favors Galgothrin 25 EC.