[Emergence of dengue hemorrhagic fever in the Americas. Reemergence of dengue]. / La emergencia de la fiebre hemorrágica del dengue en las Américas. Reemergencia del dengue.

Dengue is at present the most important human arbovirosis. It is the main cause of hospitalization and death among children from southeast Asia. Two fifth of the world population live in dengue risk areas. In 1997, over 100 countries reported epidemic and more than 50,000,000 cases and 25,000 deaths were estomated. Nowadays, the Americas is passing through the same situation Asia faced years ago. In 1997, 27 countries reported cases of dengue, and in 14 of them cases of dengue hemorrhagic fever were documented. In all, 387,459 cases of classic dengue and 11,645 of dengue hemorrhagic fever were registered. During the last 2 decades dengue has increased significantly in our region with ups and downs in the annual incidence since 1981. It should be remarked that every 3 or 4 years there is a cyclic decrease and a further increase of the incidence, though it trends to rise. As regards dengue hemorrhagic fever, the situation is not more favorable. The Cuban epidemic that appeared in 1981 was completely untimely in the region. In 1989, 8 years later, the second important dengue hemorrhagic fever epidemic emerged in Venezuela, and from that moment on there has been an increasing tendency of this clinical form of the disease. The factors of the emergence and reemergence are present and rise year after year. The neoliberal policies and the consequent privatization of the health services in most of the countries allow us to watch a gloomy future in relation to the development of dengue and its severe form, the dengue hemorrhagic fever/dengue shock syndrome.

[Immunogenicity of the Heberbiovac-HB vaccine in doses of 10.5 and 2.5 micrograms in 6-9-year-old students]. / Inmunogenicidad de la vacuna Heberbiovac-HB a las dosis de 10,5 y 2,5 micrograms en niños escolares de 6 a 9 años de edad.

The Heberbiovac-HB recombinant hepatitis B vaccine was administered at dosages of 10.5 and 2.5 micrograms in 3 groups of children aged 6-9 with a vaccination schedule at 0, 1 and 6 months of age. The immunogenecity attained between dosages was compared. The seroconversion with protective titres obtained at 2 months varied from 88.9% with 10 micrograms to 79.4% with 2.5 micrograms, whereas at 7 months it was higher than 98% in the 3 groups. The geometrical mean with 10 mg was 136.63 and 2,356.8 UI/L-1; with 5 micrograms, 77.62 and 1,958.9 UI/L-1; and with 2.5 micrograms, 32.15 and 376.3 UI/UL-1, at 2 and 7 months, respectively. A high immunogenic power of the vaccine is observed at dosages of 10 and 5 micrograms with similar results. In spite of the fact that the dosage of 2.5 micrograms is immunogenic, the response is not desirable. These results state the possibility of using a lower dosage (5 micrograms) for a low risk infantile population, which favors the cost-benefit.

[Immunogenicity of the Heberbiovac-HB vaccine in the physically and mentally handicapped]. / Inmunogenicidad de la vacuna Heberbiovac-HB en impedidos físicos y mentales.

The recombinant DNA Heberbiovac-HB vaccine against hepatitis B was applied to 2 groups of children at 2 homes for the physically and mental disabled at doses of 10 and 5 micrograms with the scheme 0, 1 and 6 months to study its immunogenicity, which was evaluated at 2, 7 and 12 months after the first dose was administered. On the 60th day it was obtained 80.9% of seroprotection in children who received 10 micrograms, whereas in the group that was vaccinated with 5 micrograms 65.0% of seroprotection was attained and there were no significant differences between the groups. 100% of seroprotection (> or = 10 UI/L) was obtained in the 2 vaccinated groups when the immune response was measured 1 month after the third dose was applied. A year later, seroprotection was 100% for the 2 groups of children. The geometrical mean of the antibody titres (TMG) reached levels above 10 UI/L, which is the minimum protector, in the 2 study groups 30 days after the second dose. A month after the third dose, the TMG attained values of 527.7 UI/L in the group of 10 micrograms and of 324.7 UI/L in that of 5 micrograms. No remarkable differences were found between the groups (p < 0.05). Finally, 365 days later, the TMG descended to 139.7 UI/L and 57.3 UI/L in the same groups, respectively. It was demonstrated the high immunogenic power of this vaccine, which makes it recommendable for protecting the physical and mentally disabled children from hepatitis B virus.

[Investigation of Babesia in farm workers and blood donors in the province of Ciego de Avila]. / Pesquisaje de Babesia en trabajadores agropecuarios y donantes en la provincia de Ciego de Avila.

A descriptive study of cases was conducted in which 781 sera were investigated using the indirect immunofluorescent technique with antigens of Babesia bovis and Babesia bigemina at the National Center for Agricultural Health. Of them, 371 came from agricultural workers and 410 from donors in the province of Ciego de Avila. It was started from dilutions of 1/64. An epidemiological survey was done to each seropositive so as to know the risk factors. The test of difference of proportions was used to compare the percentages of positives. The geometrical means were calculated in both group and they were compared with the U test of Mann Whitney. Among the agricultural workers it was detected 7% with antibodies against 3.9% of the donors (p < 0.05). It was found a greater circulation of Babesia bovis than of Babesia bigemina.

[Adverse reactions and immune response to Heberbiovac-HB vaccine administered to infants simultaneously with DPT and VA-MENGOC-BC]. / Reacciones adversas y respuesta inmune de la vacuna Heberbiovac-HB aplicada a lactantes, simultáneamente con la DPT y la VA-MENGOC-BC.

The Cuban recombinant yeast-derived hepatitis B vaccine (Heberbiovac-HB) was administered to 2 groups of infants aged 3 months. A dosage of 10 micrograms was used through a scheme of 0, 1 and 6 and 0, 1, 2 and 12, coinciding with the DPT and anti-meningococcal vaccines, according to the immunization schedule. Reactogenicity and immunogenicity were studied in both groups. The reactions observed were mild and similar to other studies, where fever , erythema and induration were the most common signs. These 2 groups had high percentages of children with titres of antibodies anti HBs above 100 UI/L-1. It is demonstrated the acceptable reactogenicity of the vaccine and the non-immunological interference of other vaccines.

Prescription of antibiotics for mild acute respiratory infections in children.

Acute respiratory infections (ARI), the leading class of ailments causing people to seek health care, rarely require antibiotics. Nevertheless, many physicians prescribe them needlessly. Hence, reducing the unnecessary use of antibiotics is one aim of any ARI control program. To help determine whether this aim might be achieved through a combination of refresher training for family physicians and public education campaigns, two 1991 interventions were carried out in four health areas (designated A, B, C, and D) in the city of Havana, Cuba. In each area, 10 clinics staffed by family physicians were selected through simple random sampling. In two areas (A and B), a refresher training program on ARI for health personnel was instituted at each clinic, while in areas A and C a community education program was set up. No intervention was carried out in area D. Simultaneously, from January through December 1991 trained individuals visited and administered a standard questionnaire every 15 days to 1,600 families (40 per clinic) systematically selected by random sampling. The aim of this procedure was to record the number of ARI episodes occurring among children under 5 years old, the treatment chosen in these cases, and whether antibiotics were employed. The results showed that when the two interventions were initiated, antibiotics were prescribed for 26%, 20%, 11%, and 19% of the mild ARI cases occurring in areas A, B, C, and D respectively (P > 0.05). In the period immediately following the interventions, antibiotic prescription rates declined by 26% and 63% in areas A and B, while increasing by 2% and 48% in areas C and D. Overall, prescription of antibiotics in the intervention areas A and B combined decreased by 54% (95% CI: 31-69%). These data suggest that a refresher training program for health personnel can rapidly reduce the unnecessary prescribing of antibiotics for ARI cases, but that public education alone does not appear effective.

[The immunogenicity of the Heberbiovac-HB vaccine in children]. / Inmunogenicidad de la vacuna Heberbiovac-HB en niños.

The Cuban recombinant vaccine against hepatitis B virus was applied with doses of 10 ìg to children under 15 in a scheme from 0, 1 to 6 months. The immunogenicity was evaluated at 2, 7, and 12 months and showed 100% of seroconversion with protective titres. 65.9, 100, and 83.5% of the vaccinated attained titres higher that 100 UI/L at 60, 210, and 360 days. The geometrical mean was of 213.6, 8208.2, and 568.0 UI/L, respectively. All the groups obtained 100% of seroconversion; however, there were significant differences (p < 0.05) in favor of the preschool and school children compared with those over 10 as regards the response level (titres higher than 100 UI/L) and the geometrical mean of antibody titres in the 3 samples. It was demonstrated the high immunogenic power of the vaccine at these ages, which makes it recommendable for their protection against the hepatitis B virus (HBV).

[The reactogenicity of Heberbiovac-HB vaccine at different doses]. / Reactogenicidad de la vacuna Heberbiovac-HB a diferentes dosis.

Reactogenicity was measured after applying the Heberbiovac-HB recombinant vaccine against hepatitis B virus to three groups of children aged 6-9 years. The vaccine was derived from yeast cells, administered at doses of 10, 5, and 2.5 g, with a schedule of 0, 1 and 6 months. The overall observed symptomatology was low (12.2%) in the three groups with 10.7%, 13.5%, and 12.3% for 10, 5, and 2.5 g, respectively. The predominant symptoms and signs were febricula (7.0%), local pain (3.1%), and erythema (1.2%). No significant differences were found when making a comparison between groups and sexes. An acceptable reactogenicity of the immunogen was confirmed, thus its use is recommended for the protection against hepatitis B virus.

[Effectiveness of VA-MENGOC-BC in children from 0 to 5 years of age in Cuba. First year of observation]. / Efectividad de VA-MENGOC-BC de 0 a 5 años en Cuba. Primer año de observación.

The effectiveness or post-license efficacy of the BC antimeningococcal vaccine (VA-MENGOC-BC) was assessed 1 year after the end of the immunization campaign in children aged 0 to 5 years. Occurrence of the disease before and after intervention is described and effectiveness is estimated following the recommendations described by Orenstein et al. We used 2 case definitions to compare results in groups formed following different criteria, according to the employed diagnostic tests. Two formulas are used to assess efficacy: one, estimating the rates among vaccinated and non-vaccinated; and the other one, estimating the ratio of cases per vaccinated population. The increase of the relative annual decrease of the incidence occurring since 1985--a decrease of 10% or less--which in 1990 reached 34.6% should be stressed; the ratio of new cases prevented by the intervention was higher than 75%. Effectiveness or post-license efficacy was close to 90%, independently from the case definition variant or formula employed.

[The National Toxoplasma Survey. I. Prevalence by sex and age. Cuba, 1987]. / Encuesta Nacional de Toxoplasma. I. Prevalencia por sexos y edades. Cuba, 1987.

A national seroepidemiological survey was carried out to assess the prevalence of anti-Toxoplasma gondii antibodies. 8863 samples taken in filter paper through the ELISA test were analyzed and 29.70% positivity was obtained. No significant differences were found regarding sex. Seropositivity increased with age, up to the 20-29 age group, with a stable behavior in over-29-year age groups. The highest percentage of annual change was registered in the 5-9 age group (1.62%). This parameter reached 0.93% in the women's 25-29 age group.

[Primary-care morbidity and true morbidity due to acute respiratory infections]. / Morbilidad asistida y morbilidad real por infecciones respiratorias agudas.

The present work presents the study of morbidity due to acute respiratory infections (ARI) in areas of the town of Lisa in Ciudad Habana, and Isla Juventud (Cuba), to characterize different aspects of morbidity measured by health care attendance and to measure true morbidity. About 90% of consultations for ARI were first-time consultations, while their ratio to further consultations was 5.3. True morbidity rates (TMR), obtained trough active research, ranged from 110.4 to 163.4 cases per 1000 inhabitants, considerably higher than morbidity rates measured by primary care consultations (MRPCC) in the same time period. The true morbidity index (TMI), as measured by the ratio of the two previous rates, ranged from 5 to 15. A high proportion (47.6%) of cases reported no medical care attendance. These results provide approximate estimates of true morbidity in the study area, and allow the establishment of a new control program, also improving epidemiologic surveillance within primary care activities.

[Methodology for the epidemiologic study on acute respiratory infections]. / Metodología para un estudio epidemiológico sobre infecciones respiratorias agudas.

The foundations and methodology for an epidemiological study on acute respiratory diseases are described. The study took place in 4 urban health areas in Havana City and 4 rural doctor's offices in Matanzas. A discussion is carried out regarding the intervention design for the staff of the health primary assistance team headed by the family doctor.

[Field trial of the Cuban recombinant vaccine against hepatitis B (Heberbiovac HB). Study in newborn infants born to AgsHB+ mothers]. / Ensayo de campo de la vacuna recombinante cubana contra la hepatitis B (Heberbiovac HB). Estudio en recién nacidos hijos de madres AgsHB+.

A study was conducted on 106 newborns, whose AgsHB positive mothers received active protection against hepatitis B (83 with the Cuban-produced Heberbiovac HB vaccine and 23 with the Engerix-B vaccine manufactured by S. Kline as control group, following the scheme 0, 1 and 2 months with the first dose administered in the first 12 hours after birth. Samples were taken to study virus B markers at birth (umbilical cord) after 30, 60, 90 and 180 days. Laboratory determinations were carried out by the ELISA technique with diagnostic kits from the firm Organon Tecknica. Ten or more IU/L of anti-HBs present in serum was considered as the lowest protective level. Children were classified according to the AgeHB present in mothers, AgsHB in the umbilical cord and the concentration of Ags HB in maternal serum. 100% of the children who received the control vaccine showed serological evidence of seroconversion to anti HBs with protective titres, and the values of the geometric mean of the titres of antibodies were statistically significant (p < 0.01) in all the extractions, favoring the Cuban vaccine. The efficacy of the two preparations used in this research work was 100%. This study makes it possible to report on a recombinant vaccine against hepatitis B (Heberbiovac HB) which represents the first vaccine of this type produced in Latin America, the efficacy of which was proved in the field trial.

[Morbidity from acute respiratory infections in a small community in La Habana City]. / Estudio de la morbilidad por infecciones respiratorias agudas en una pequeña comunidad de Ciudad de La Habana.

A survey was made on morbidity due to acute respiratory infections in a circumscription of the Cristobal Labra Polyclinic, from January 17 to March 2, 1987, in order to contribute some clarifications about such an important health-disease problem. The sample was made up of 75 families representing 297 inhabitants. Questioning included all family members that in the 14 days previous to the visit referred to have or to have had symptoms of acute respiratory infections. The so-called real morbidity index was reached.

[Identification of microorganisms of the Vibrio genus using the method of sample combination]. / Identificacion de microorganismos del genero Vibrio por el metodo de combinacion de muestras.

In order to apply a more rapid, economic and effective method for the isolation of microorganisms of the genus Vibrio. 400 samples of feces from passengers hospitalized at the "Pedro Kouri" Tropical Medicine Institute, Searching Ward, were processed by the combination method. In this study the feces were grouped in combinations of ten; in this way 40 coprocultures were performed. The isolation was carried on enriching the samples in alkaline peptone at pH 8.6 and subcultures in thiosulfate citrate bile salts sucrose agar were performed.