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Alterations in the plantar footprint in the child are a cause for concern in parents.Determine the frequency of plantar footprint alterations in school children. Determine if there is a relationship between overweight and obesity with the presence of alterations of the plantar footprint.Observational, transversal and prospective study. 959 schoolchildren aged six to 13 were evaluated. Weight, size, body mass index for age were recorded. The plantar footprint was cataloged on flat foot and cavus foot using the arch index. For statistical analysis and comparison, the SPSS version 24 program was used with the 2 and ANOVA tests.530 children (55.3%) and 429 girls (44.7%). The median age was 8.97 years. 182 children were found (19%) with alteration of the plantar footprint, 42.3% with flat foot and 57.7% with cavus foot. None of them had foot symptoms. 131 children were overweight and 52 obese, without influencing the presence of any alteration of the plantar footprint (p = 0.20). The flat-foot ratio was higher in men (2.5:1) and standing cavus major in women (1.3:1).In our study group we find a higher prevalence of the cavus foot compared to the flat foot. Body weight did not influence plantar footprint alterations.Las alteraciones de la huella plantar en el niño es causa de preocupación en los padres de familia.Determinar la frecuencia de alteraciones de la huella plantar en escolares. Determinar si existe relación entre el sobrepeso y la obesidad con la presencia de alteraciones de la huella plantar.Estudio observacional, transversal y prospectivo. Se evaluaron 959 escolares de seis a 13 años de edad. Se registró peso, talla, índice de masa corporal para la edad. La huella plantar se catalogó en pie plano y pie cavo utilizando el índice del arco. Para el análisis y comparación estadística se utilizó el programa SPSS versión 24 con las pruebas 2 y ANOVA.Se revisaron 530 niños (55.3%) y 429 niñas (44.7%). La media de edad fue de 8.97 años. Se observaron 182 niños (19%) con alteración de la huella plantar, 42.3% con pie plano y 57.7% con pie cavo. Ninguno mostró sintomatología del pie. Ciento treinta y un niños tenían sobrepeso y 52 obesidad, sin influir en la presencia de alguna alteración de la huella plantar (p = 0.20). La relación de pie plano fue mayor en los hombres (2.5:1) y de pie cavo fue mayor en las mujeres (1.3:1).En nuestro grupo de estudio se encontró mayor prevalencia del pie cavo en comparación con el pie plano. El peso corporal no influyó en las alteraciones de la huella plantar.

Until now, three genotypes of Zika virus (ZIKV) have been detected (two African lineages and one Asian lineage). After the declaration of Public Health Emergency of International Concern issued by The Pan American Health Organization and the World Health Organization authors from some Latin American countries have identified the Asian genotype as the lineage responsible for the Zika epidemic in the western hemisphere. However, data from the Caribbean are sparse, and there is no published data regarding the genotypes that produced isolated outbreaks in Cuba. Aiming to realize the molecular characterization of ZIKV in Cuba, we will sequence by next-generation sequencing the full genome of the ZIKV identified in samples from Cuban patients of different provinces in which ZIKV produced outbreaks. All samples required for this study have been collected during the molecular surveillance of Arboviral diseases conducted at the National Reference Laboratory at Pedro Kourí Tropical Medicine Institute. Viral RNA will be purified from urine and serum samples collected from patients with confirmed ZIKV infection by real time PCR. Using evolutionary dynamics studies, we will map the spread of a virus or of particular variants in time and space in order to understand how frequently ZIKV has been introduced into Cuba. Moreover, we will evaluate the amino acid diversity of each ZIKV proteins. Further, we will evaluate the population dynamics of ZIKV in samples from patients with varying clinical outcomes. The results will allow us to characterize the ZIKV genome and its evolution into the Cuban population that would also have impact for vaccine development, diagnosis, and pathogenesis studies.

Toxoplasma gondii is an intracellular parasite capable of infecting all nucleated cells in a diverse array of species. Toxoplasma plaque assay have been described using Bacto Agar. Because of its experimental advantages carboxymethyl cellulose overlay, medium viscosity was choosing and the aim of this work was to develop alternative method for formation of T. gondii plaques. Tachyzoites were inoculated onto monolayers of Vero cells and cultured at 37° C under 5 % CO2. The cultures were followed up by microscopy inspection. Small plaques were visible by naphtol blue stain 4 days after infection. Larger plaques could be observed by day 10 of culture. The carboxymethyl cellulose is a cheap reagent and the methodology is easier, faster than assays under agar overlay. This is the first description of the carboxymethyl cellulose overlay use for obtaining the formation of T. gondii plaques and may be useful in consequent obtaining tachyzoites for detailed studies., {"references":["J.G. Montoya and O. Liesenfeld, \"Toxoplasmosis\", 2004, The Lancet\n363, pp. 1965-1976.","Chatterton, R. Evans, D. Ashburn, A.W.L. Joss and D.O. Ho-Yen,\n\"Toxoplasma gondii in vitro culture for experimentation\", 2002, Journal\nof Microbiology Methods 51, pp. 331-335.","X. Li, Y. Hao, D. Chen, Q. Liu, J. Ding and W. Zhang, \"Expression of\nthe tandem enhanced yellow fluorescent marker gene in Toxoplasma\ngondii\", 2009, Parasitology Research 105, pp. 287-291.","D.S. Roos, R.G. Donald, N.S. Morrissette and A.L. Moulton, \"Molecular\ntools for genetic dissection of the protozoan parasite Toxoplasma\ngondii\", 1994, Methods in Cell Biology 45: pp. 27-63.","E.R. Pfefferkorn and L.C. Pfefferkorn, \"Toxoplasma gondii: isolation\nand preliminary characterization of temperature sensitive mutants\",\n1976, Experimental Parasitology 39: pp. 365-376.","P.K. Russell, S. Udomsakdi and S.B. Halstead, \"Antibody response in\ndengue and dengue hemorrhagic fever\", 1967, Japan Journal of\nMedicine Science Biology 20: Supp:103-8.","M. Matrosovich, T. Matrosovich, W. Garten and H.D. Klenk, \"New lowviscosity\noverlay medium for viral plaque assays\", 2006, Virology\nJournal 3: pp. 63. Epub Aug 31, 2006. DOI: 10.1186/1743-422X-3-63.","P. Herzog, C. Drosten and M. Muller, \"Plaque assay for human\ncoronavirus NL63 using human colon carcinoma cells\", 2008, Virology\nJournal 5: pp. 138. Epub Nov 12, 2008. DOI: 10.1186/1743-422X-5-\n138.","S.D. Chaparas and R.W. Schlesinger, \"Plaque assay of Toxoplasma on\nmonolayer of chick embryo fibroblasts\", 1959, Proceedings of the\nSociety for Experimental Biology and Medicine 102: pp. 431-437.\n[10] D.H. Hollander, \"Colonial morphology of Trichomonas vaginalis in\nagar\", 1976, Journal of Parasitology 62: pp. 826-828.\n[11] D.E. Mueller and W.A. Petri, \"Clonal growth in petri dishes of\nEntamoeba histolytica\", 1995, Transaction of the Royal Society of\nTropical Medicine and Hygiene 89: pp. 123.\n[12] E.M. Valido and W.L. Rivera, \"Colony growth of philippine isolates of\nBlastocystis hominis in simplified, soft agar medium\", 2007,\nParasitology Research 101: pp. 213-217.\n[13] M. Hess, T. Kolbe, E. Grabensteiner and H. Prosl, \"Clonal cultures of\nHistomonas meleagridis, Tetratrichomonas gallinarum and a\nBlastocystis sp. established through micromanipulation\", 2006,\nParasitology 133: pp. 547-554.\n[14] S.A. Edgar and C.T. Seibold, \"A new coccidium of chickens, Eimeria\nmivati sp. n. (Protozoa: Eimeriidae) with details of its life history\",\n1964, Journal of Parasitology 500: pp. 193-204.\n[15] J.R. Sreekumar, A.K. Rao, A. D. Mishra, G.C. Ray and G.C. Bansal, \"In\nvitro generation of cloned populations of Toxoplasma gondii\", 2003,\nParasitology Research 90: pp. 489-492."]}

Papers dealing with the study of the immune response to dengue virus infection and with the role it may play in the pathogenesis of dengue hemorrhaghic fever are increasingly important. The memory human T cell response in individuals with history of dengue infection during the Cuban epidemic was studied in this paper for a further evaluation of the antigenicity of viral proteins. To this end, mononuclear cells of peripheral blood from individuals immune to dengue and from a group of control subjects with viral antigens were incubated. It was obtained a significant proliferative response of lymphocytes from individuals with history of infection against dengue virus type 2 compared with control subjects. It was proved this way the dengue virus-specific memory T CD4+ cell response in the individuals under study.

In the last few years an increasing rise of new infectious diseases or of other diseases considered to be under control has been observed. The so called emerging and reemerging diseases are those new infections that have come up in a population or those existing diseases which incidence and geographic extension are on a rapid increase. Factors such as social and economic situations, medical assistance, food production, changes in human behaviours, environmental changes, health systems deterioration, and adaptation and changes of microorganisms are related with the emergence or reemergence of a number of entities. This paper sets forth an analysis of the emergence and reemergence of viral diseases and of those factors that have had an impact on this situation.

Strains A-15 (isolated in Cuba, 1981), Jamaica (isolated in Jamaica, 1981) and Nueva Guinea "C" (standard) from dengue-2 virus were compared according to the time of appearance of the cytopathic effect (CPE), to the time of appearance of specific fluorescence and to the kynetics of viral multiplication on being innoculated in the cell lines AP-61 (Aedes pseudoscutellaris) and C6/36 HT (Aedes albopictus). The results showed that the CPE of highest intensity and earliest appearance was for A-15, followed by Jamaica and Nueva Guinea "C" (NGC). AP-61 seems to favor the CPE of Jamaica with respect to that of the same strain in C6/36 HT. The fluorescence was earlier for Jamaica and A-15 and more intensive for the latter, whereas NGC manifested late. This behaviour was similar in the 2 cellular systems. The greatest titres during the kinetics of viral multiplication were obtained from A-15 in both lines, although in AP-61 they tend to be equal from the 4th day on. The strain A-15 showed a particular behaviour of these biological properties on comparing them with the other strains under study, which may be related to changes found in its neucleotide sequence.

These types of monoclonal antibodies 8E8, 3F7 and 1E9 to dengue 4 virus H-241 strain. These monoclonal antibodies show various patterns of reactivity to the four dengue serotypes and different antigen preparations of serotype 4 when they were tested in various serological methods. The monoclonal antibody 8E8 exhibited a specificity of serotype (D-2; by hemagglutination inhibition); subcomplex (D-2 and D-4 by immunofluorescence) and complex (by immunoperoxidase technique). It was able to neutralize by 80% homologous virus and it turned out to be the only reactive monoclonal antibody in the complement fixation test. The monoclonal 3F7 did not react to by hemagglutination inhibition, recognized serotypes D-1, D-2, D-3 and D-4 by immunofluorescence and only serotypes D1 and D4 by immunoperoxidase technique but it was unable to neutralize the homologous virus. The 1E9 antibody was reactive to serotypes D1, D-2, D-3 and D-4 only by hemagglutination inhibition and neutralized serotype D-4. All the monoclonal antibodies were able to react to various dengue antigens through an ELISA of double antibody and showed fluorescent activity against 38th pass in Beagle dog kidney culture; however, they could not react to a D-4 recombinant antigen.

Some biological properties of Dengue-2 strains such as A-15 (isolated in Cuba in 1981); Jamaica (isolated in Jamaica in 1981) and New Guinea "C" (NG"C") standard strain differing in their nucleotide sequences were studied. The results showed that the cytopathic effect in C6/36 HT cell line occurred earlier in A-15 strain and that fluorescence was first detected in Jamaica and A-15 strains. This seems to indicate that rapid detection of strains does not have any relation to neither their history of passage nor the original isolation system. A-15 and NG"C" strains exhibited an heterogeneous pattern formed by big and small plaques but average size of plaques in NG"C" was lower whereas Jamaica showed only small plaques. The most neurovirulent strain in mice was NG"G" followed by A-15 whereas Jamaica was not neurovirulent at all. These results indicate that A-15 has a different biological behaviour which is probably due to intrinsic differences. It should be taken into account that 7 amino acid changes were found in the envelope protein which may have affected the expression of some biological properties.

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.

The cellular immune response to dengue type 2 virus envelope protein was studied. To this end, the lympho-proliferative capacity of T-lymphocytes obtained from splenocytes of animals immunized with the protein when they were stimulated by such protein and dengue 2 virus. It was realized that splenocytes proliferated significantly in response to both types of viral antigens and that the values of stimulation indexes were higher in response to the whole virus than to the protein alone. Based on the above-mentioned, it was concludes that purified dengue 2 virus envelope protein was capable of generating specific and memory responses of antigen T-cell to dengue 2 type virus.

A dengue epidemic that Cuba reported in 1997 registered more than 500,000 cases of dengue fever produced by viral serotype 1. In 1981, there was an epidemic of dengue hemorrhagic fever produced by serotype 2 of the virus. This time 344,203 clinical cases were reported, 10,312 of which were severe cases of hemorrhagic fever that led to 158 fatalities (101 of them among children). The reintroduction of dengue, and specifically of dengue viral serotype 2 (Jamaica genotype), was quickly detected in January 1997 through an active surveillance system with laboratory confirmation of cases in the municipality of Santiago de Cuba, in the province of the same name. The main epidemiological features of this outbreak are reported in this paper. A total of 3,012 cases were reported and serologically confirmed. These included 205 cases classified as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), 12 of which were case fatalities (all among adults). Secondary infection with dengue virus was one of the most important risk factors for DHF/DSS. Ninety-eight percent of the DHF/DSS cases and 92% of the fatal cases had contracted a secondary infection. It was the first time dengue hemorrhagic fever was documented as a secondary infection 16 to 20 years after initial infection. Belonging to the white racial group was another important risk factor for DHF/DSS, as had been observed during the 1981 epidemic. During the most recent epidemic it was demonstrated that the so called "fever alert" is not useful for early detection of an epidemic. Measures taken by the country's public health officials prevented spread of the epidemic to other municipalities plagued by Aedes aegypti.

The plaque reduction neutralization assay was standardized to differentiate an infection caused by dengue from another infection produced by yellow fever. Serum samples from Cuban donors were used to this end. Information on previous vaccination against yellow fever was available. Samples from Costa Rican patients with a clinical picture of dengue and with no antecedents of vaccination against yellow fever were also utilized. The optimal plaque staining day was the fifth day and the smallest serum dilution capable of differentiating an infection resulting from dengue from another infection caused by yellow fever was of 1/5. According to the high specificity of the standardized technique, risk factor studies of dengue hemorrhagic fever could be made among individuals vaccinated against yellow fever, which is a present and important topic.

The genomic characterization of the strain of light cytopathic effect by nucleotide sequence is presented. It was possible to sequence 90% of the strain of light cytopathic effect. A close relationship with Coxsackie A9 was observed. The greatest mutations occurred in the region of the genome that codifies for the structural proteins. Therefore, it may be considered as a variant of Coxsackie A9 never reported before.

A series of experiments was made at the Virology Department of the "Pedro Kourí" Institute of Tropical Medicine aimed at obtaining new evidences on the possible antigenic relations existing between the viruses isolated from patients with epidemic neuropathy and the structures of the human nervous system. According to the results it may be finally inferred that the persistence and/or autoimmunity may be considered as mechanisms through which the studied viruses participate in the etiopathogenesis of the epidemic neuropathy in Cuba. For future experiments it is very important to identify the possible viral epitopes involved in the molecular mimicry that are responsible for the probable autoimmune mechanisms or for the viral persistence.

This study describes the benefits of using reverse transcriptase polymerase chain reaction (RT-PCR) for the rapid detection and typing of dengue virus in clinical samples. Twenty-seven serum specimens from patients with dengue fever and dengue hemorrhagic fever in Colombia, Nicaragua, and Panama were directly subjected to RT-PCR for the detection of dengue virus. The resulting double-stranded DNA product was typed by a second round of PCR amplification (nested PCR) with type-specific primers, viral culture/indirect immunofluorescence (IIF), and enzyme-linked electroimmunoassay for IgM anti-dengue antibodies. The amplified virus genome was detected and typed within 8 hours. Nested RT-PCR, using viral culture and IIF as the gold standard, showed 100% sensitivity; 78% specificity; 69% positive predictive value, and 100% negative predictive value. It is noteworthy that two of the specimens whose results were positive with nested RT-PCR and negative with viral culture showed specific IgM antibodies. The results of the RT-PCR were in close agreement with those obtained through viral culture. This suggests PCR can greatly facilitate the rapid and early diagnosis of dengue infection.

Up to 1993, Panama was the only country in Central America where the autochthonous transmission of dengue virus had been detected without experimenting an explosive epidemic despite being reinfected with the Aedes aegypti mosquito since 1985. The characteristics of this first outbreak reported on November 19, 1993, are described in this paper. It is shown that even when there is a Program for the Surveillance and Control of Dengue, which considers low levels of Aedes aegypti infection and a system for the early detection of the virus, the epidemics appear if the community does not take an active part as it happened in 1994, 1995, and 1996. The 14 cases reported were located in an area under the responsibility of the Health Center in San Isidro, Belisario Porras, Special District of San Miguelito, in Panama City (13 cases in 4 blocks of the sector of Santa Librada and 1 case in San Isidro Valley). 3 patients were under 15 and 8 over 36, the other 3 were between 15 and 24.9 were females. The dengue type 2 virus was isolated in 3 patients. The presence of IgM and IgG antibodies to dengue was demonstrated in 11 patients, whereas in 8 over 20 it was observed a secondary type answer. According to the clinical picture, the epidemic was classified as dengue fever. The seroepidemiological survey carried out in the sector of Santa Librada and its surroundings 5 months after the appearance of the symptoms in the first case showed a prevalence of antibodies to dengue of 5.7% (46/802), mainly among individuals over 44. These results confirmed that the outbreak was geographically limited.

For the classification of dengue cases the WHO/PAHO includes the hemagglutination inhibition test as one of the serological techniques used to this end and it is also accepted the possibility of using the ELISA with a titer equivalent to that established by the IH. In this paper, it is explained the usefulness of the inhibition ELISA for the classification of a probable case, a confirmed case, and type of dengue infection (primary or secondary).

The immunohistochemical techniques may be very useful for the detection of antigens of the dengue virus in infected tissues. The results obtained with the use of 2 IHC methods: one direct and another indirect amplified with a biotin universal antibody and a streptavidin peroxidase system (LSAB) (the peroxidase enzyme is used in both) are shown in this paper. These methods were applied on paraffin-embedded tissues from mice that were inoculated with the dengue virus intracerebrally. Our objective is to have a technique at the laboratory allowing to identify these antigens in the tissues in order to apply them on the diagnosis and on the studies connected with the obtention of immunogens.

It is reported the isolation of 2 dengue strains, 3 in samples from Nicaraguan patients suffering from dengue with hemorrhagic manifestations, which showed the reintroduction of this serotype in the region after being 17 years out of circulation. It is also reported the genetic characterization of the isolated strain, which, according to its classification, belongs to the group of dengue 2 strains isolated in Southeast Asi and which have been associated to hemorrhagic dengue. These results suggest the origin of this strain.

Serological studies were carried out using the haemagglutination inhibition and neutralization tests so as to know the circulation dynamics of some arboviruses with the use of Western and Eastern equine encephalitis antigens and St Louis encephalitis antigens in human serum from sound and symptomatic individuals, as well as from sentinel birds, between 1987 and 1991, and during 1994. 1.7% of the asymptomatic subjects tested presented neutralizing antibodies to to Eastern equine and 4.8% to St Louis encephalitis. 16 patients with seroconversion by haemagglutination inhibition to St Louis virus were detected. Surveillance of sentinel birds showed that during 1988, 1989, and 1994. St. Louis circulated in the municipalities of Morón, Bolivia and Chambas; whereas in the latter the Eastern equine encephalitis circulated in 1988 and 1989. Antibodies to Western equine encephalitis were detected in sound individuals by haemagglutination inhibition due seemingly to heterologous antibodies, since there were no neutralizing antibodies against this virus.

It is reported the nucleotide and amino acidic sequence of a great variability region in the dengue 2 virus genome, starting from the RNA of the original virus with no passage in the isolation systems. It is compared with the first strain of dengue 2 isolated during the 1981 epidemic with 4 passages in lactating mouse. Results show that the nucleotide sequence of serum and of strain A15 are the same.

4 primer sets, were used to allow the amplification of a nucleotide sequence with unique size for each of the dengue virus serotypes by polymerase chain reaction (PRC). The method consisted in the extraction of ribonucleic acid from supernatant of infected cell cultures, reverse transcription-polymerase chain reaction (RT-PCR). This was completed in approximately 7 hours in a simple tube. The size of the amplified sequence was evidenced by electrophoresis in Agarose gel stained with ethidium. The method showed a sensitivity of at least 2.5 plate forming units (pfu) per tube of reaction. It es useful for the detection and simultaneous identification of the 4 serotypes, starting from supernatants of infected strains cultures from different countries of the Caribbean, Central America, and South America.

The ELISA was standardized to detect monoclonal antibodies of dengue virus proteins E and NS1. One indirect ELISA was applied, using C6-36 cells inoculated with the A-15 strain, isolated during the dengue 2 epidemic in 1981 as an antigen source. These cells were fixed in ELISA plates at a 200,000 cell/well concentration. A cell control in similar conditions was used. Specific monoclonal antibodies to both proteins were used to standardize the system. Studies at different incubation periods, to determine the highest expression moment of these proteins in the cell membrane, were carried out. The results show a full response at 72 hours postinoculation for both proteins; a 14.7 ng/mL sensitivity was obtained for the detection of NS1, and of 1.43 ng/mL for E protein. This system allows the monoclonal antibodies primary screening to dengue 2 virus E and NS1 proteins.

From the end of 1991 to June, 1993, an epidemic neuropathy affecting 50,963 persons occurred in Cuba. Two clinical forms of the disease were observed: the optic form (with or without peripheral manifestations, 52% of the cases) and the peripheral form (48%). The epidemiological studies revealed nutritional disorders, mainly a vitamin B complex deficiency due to economic difficulties faced by the country in the "special period". Smoking habit and alcohol consumption were identified as risk factors, particularly for the most severe forms of the disease. In the virological studies of the cerebrospinal fluid (CSF) a Coxsackie 9 virus was isolated in Vero cells in 4% of the cases, as well as another agent with mild cytopathogenic effect in 80% of the samples. Sixty seven percent of the CSF samples inoculated to lactating mice caused the disease or the death of the animals. The viral persistence was confirmed in the cerebrospinal fluid during al least 21 days in a group of patients, and for a year in another group.

Determinations of neutralizing antibodies to the strain 47/93 IPK (CA9) and to the strain 590 were performed in serum samples from patients presenting with epidemic neuropathy and from a group of seemingly healthy subjects. Determinations were also done in the reference strains CA9 and CB1-6 by the microneutralization technique. Patients and their contacts showed significantly higher percentages of neutralizing antibodies to the strain 47/93 than the control group and residents of municipalities with a low rate of the disease. This difference was also confirmed regarding the geometric mean titres with the use of the reference strains CA9 and CB2-4. An increased circulation of the strain 47/93 within the infantile population from 1981 to 1993 was evidenced. Patients exhibited significantly lower percentages and geometric mean titres of neutralizing antibodies to the strain 590 than the control group, despite the fact that in 25/28 certain agents having a mild cytopathogenic effect had been isolated. The possibility of two mechanism of neutralization is stated and an hypothesis on the mechanism by which these viruses may be involved in the pathophysiology of the disease is formulated.

The current worldwide situation of dengue infection, and particularly in the American continent, is analyzed taking into account the increasing risk for infection during pregnancy which exists in endemic areas; the consequences of an eventual vertical transmission of the virus are practically unknown yet. We studied 59 women who gave birth to their children between 5 and 9 months after the "peak phase" of the type 2 dengue virus epidemic which broke out in Cuba in 1981. Sera of the mothers and newborns were studied through various serologic techniques in order to detect antibodies; in some cases we tried to isolate the virus, without success, from serum samples taken from the newborns; among these, we found 4 cases with positive IgM. These newborns showed neither apparent fetal damage at birth nor further alterations in a follow-up carried out when they reached 5 years of age. The need of carrying out further studies contributing to establish an adequate management of pregnant women infected by dengue virus is discussed.

We present the results attained in the identification of Eastern equine encephalomyelitis virus isolations in Vero and XL-2 cell systems, using a double-antibody ELISA technique and the indirect immunofluorescence method. The results attained through these two techniques coincided by 100% with identification through neutralization. With the former, the virus was detected within 6-8 hours after inoculation. Better results were attained with XL-2 cells.

The aim of this work was to offer a description of the clinical manifestations developed by patients under 1 year who had dengue virus infection and dengue hemorrhagic fever during the epidemic which broke out in 1981, and to determine if the passive transfer of maternal dengue antibodies to the fetuses influenced the occurrence of a severe development of the disease, through a retrospective study. In 20 cases, type 2 dengue virus infection was confirmed. Eight patients showed the clinical manifestations of dengue hemorrhagic fever of dengue shock syndrome (DHF/DSS), and the other 12 had the typical dengue virus infection. The former were of the white racial phenotype, aged under 6 months. There was a predominance of type 1 dengue antibodies in the mothers of children with DHF/DSS. Fever, rash, vomiting and diarrheas (not frequent) appeared in the two clinical manifestations of the infection; blood leukocytes were predominantly lymphocytic; and erythrocyte sedimentation was always normal. Patients with DHF/DSS presented with some bleeding (87.5%); cyanosis and ascites (37.5%); and shock (25%), as well as hepatomegaly. All these infants with DHF/DSS had thrombocytopenia and most of them showed hemoconcentration. No deaths occurred.

An indirect ultramicro ELISA system (UME) for the determination of antibodies to measles virus by the cuban technology of Ultramicro Analytical Systems (SUMA) was developed. A number of 448 serum samples from the National System of Seroepidemiological Surveillance of Measles were simultaneously processed by the Ultramicro ELISA system and by the haemagglutination inhibition technique. Results were compared in both assays. Afterwards; 120 serum pairs obtained from the same source were studies and processed in a similar way. Results evidenced the usefulness of such immunoenzymatic system for the serological diagnosis and the positive validation of replacing conventional techniques by this novel technology.

The purification of different serotypes of dengue virus from a monoclonal antibody which recognizes an epitope present in the four serotypes bond to a Sepharose 4B matrix activated with cyanogen bromide, is reported. Results evidence that the method employed makes quicker the process of purification with a high degree of purity.

In order to warn the health authorities in our region about the economic damages that a hemorrhagic dengue epidemic may cause, it was decided to study and publish the estimated cost of the Cuban epidemic in 1981, during which 344,203 diseased were reported, 10312 severe cases and 158 deceased. Economic costs include hospitalization expenses, assistance in emergency units, social security, expenses in out-patient treatment, goods not produced and expenses in the anti-vector campaign. Probably, this epidemic which could be controlled in about 4 months, has been the one causing most economic damages to date.

In the second half of the year 1985, during the rainy season, an epidemic of Dengue Fever was recognized in Nicaragua. A total of 17,483 cases were reported by the health services. The highest morbidity and attack rates were reported between August and November of the same year. Regions II (Leon and Chinandega), III (Managua) and IV (Masaya, Granada, Carazo y Rivas) reported 89% of the cases; these regions are precisely the more densely populated in the country, located in the Pacific Coast. Leon and Chinandega were the more affected cities reporting 41% of the cases of the epidemic. Sixty seven percent of the cases were adults, 57% were female. The national attack rate was 55.4/10,000 inhab. An intensive campaign for the control of the vector was launched immediately after the epidemic was recognized and by the month of October 1985 morbidity decreased and an endemic situation was established. Seven fatal cases were reported in adults. They were considered as DHF/DSS cases by a multidisciplinary group of pathologists and clinicians, considering the criteria of WHO and the experience obtained during the cuban DHF/DSS epidemic, in 1981. The outbreak was considered as a Classical Dengue Fever epidemic with 7 fatalities. Dengue-1 and -2 were isolated from acute sera and Dengue-1 from one of the dead.

A total of 256 infants younger than three years, hospitalized by acute diarrhea, was studied from December 1983 to May 1984. Presence of rotavirus in their feces was demonstrated in 27.7%; in 4.3% of them, rotaviruses were associated with other agents. Vomiting followed by respiratory symptoms and fever were the main clinical symptoms observed in such patients, and in most of them diarrhea was profuse and liquid. Influence on infection by rotavirus of maternal feeding, hygienic-sanitary conditions, presence of domestic animals, and so forth, could not be demonstrated.

During the dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS) epidemic in Cuba in 1981, we identified some individual risk factors for the development of the severe clinical picture or for the fatal outcome of the disease. The percentage of secondary infection in 3 groups of patients with DHF/DSS was between 95 and 98.3 and it is concluded that secondary infection is an important, but not the only, condition for the development of DHF/DSS. An analysis of these 3 groups of patients and a fourth group of fatal cases showed that chronic diseases such as bronchial asthma, diabetes mellitus and sickle cell anaemia were additional risk factors contributing significantly to the development of DHF/DSS. The study also revealed that race was an individual risk factor, since DHF/DSS was more prevalent in white than in black persons.

A retrospective seroepidemiologic survey is made in the municipalities of Cienfuegos and Palmira to determine the presence of neutralizing antibodies to Den-1 and -2 virus in the population. It was found that 21.4% of the population studied had antibodies to Den-1, 12.3% to Den-2, and that 5.5% had been infected by the two serotypes (secondary infection). It became apparent that in the Palmira municipality the percentage of infection due to Den-1 was higher and it was found that in 1980-1981 there was a late dengue (Den-1) outbreak. Therefore, this municipality was probably the only in the country with 2 epidemic outbreaks due to two dengue serotypes (1 and 2) in a 6 month interval. The potential relationship between this fact and the high lethality of hemorrhagic dengue fever in this municipality is established. The influence of environmental, social, and sanitary factors on the risk of infection is suggested. It was found that Whites and Blacks are equally infected and that infection is not a random phenomenon, instead it is favored by the presence of vectors in and around the housing.

A serologic study is made in two population groups in the Isle of Youth. A total 268 blood samples in blotting paper are subjected to the hemagglutination inhibition technique, using the Eastern equine encephalomyelitis, Western equine encephalomyelitis, Saint Louis encephalitis, and dengue 2 viruses; 16% positivity to flavivirus was found. A second serum sample was taken in people positive by the hemagglutination inhibition technique in order to carry out the techniques of complement fixation and plate reduction neutralization. Nine cases showed complement-fixating antibodies, which is indicative of recent infection and in 29 cases neutralizing antibodies to SLE virus were found.

A bibliographic review of the dengue virus involving the 1952-1978 period and including viral characteristics (serotypes, physical and biological properties, susceptibility within different biological systems, antigenic characteristics, chemical constitution and viral multiplication) and the clinical picture of the disease is made.