The structure and migration patterns of the population of Uruguay through isonymy.

Surname distribution can be a useful tool for studying the genetic structure of a human population. In South America, the Uruguay population has traditionally been considered to be of European ancestry, despite its trihybrid origin, as proved through genetics. The aim of this study was to investigate the structure of the Uruguayan population, resulting from population movements and surname drift in the country. The distribution of the surnames of 2,501,774 people on the electoral register was studied in the nineteen departments of Uruguay. Multivariate approaches were used to estimate isonymic parameters. Isolation by Distance was measured by correlating isonymic and geographic distances. In the study sample, the most frequent surnames were consistently Spanish, reflecting the fact that the first immigration waves occurred before Uruguayan independence. Only a few surnames of Native origin were recorded. The effective surname number (α) for the entire country was 302, and the average for departments was 235.8 ± 19. Inbreeding estimates were lower in the south-west of the country and in the densely populated Montevideo area. Isonymic distances between departments were significantly correlated with linear geographic distance (p < 0.001) indicating continuously increasing surname distances up to 400 km. Surnames form clusters related to geographic regions affected by different historical processes. The isonymic structure of Uruguay shows a radiation towards the east and north, with short-range migration playing a major role, while the contribution of drift, considering the small variance of α, appears to be minor.

Extended composite index of anthropometric failure in Argentinean preschool and school children.

OBJECTIVE: The Composite Index of Anthropometric Failure (CIAF) can only be applied to children under 5 years of age and does not contemplate obesity. The aim of this study was to propose an Extended CIAF (ECIAF) that combines the characterization of malnutrition due to undernutrition and excess weight, and apply it in six Argentine provinces. DESIGN: ECIAF excludes children not in anthropometric failure (group A) and was calculated from a percentage of children included in malnutrition categories B: wasting only; C: wasting and underweight; D: wasting, stunting and underweight; E: stunting and underweight; F: stunting only; Y: underweight only; G: only weight excess; and H: stunting and weight excess. SETTING: Cross-sectional study conducted in Buenos Aires, Catamarca, Chubut, Jujuy, Mendoza and Misiones (Argentina). PARTICIPANTS: 10 879 children of both sexes aged between 3 and 13·99. RESULTS: ECIAF in preschool children (3 to 4·99 years) was 15·1 %. The highest prevalence was registered in Mendoza (16·7 %) and the lowest in Misiones (12·0 %). In school children (5 to 13·99 years) ECIAF was 28·6 %. Mendoza also recorded the highest rate (30·7 %), while Catamarca and Chubut had the lowest values (27·0 %). In the whole sample, about 25 % of the malnutrition was caused by undernutrition and 75 % by excess weight. CONCLUSIONS: The ECIAF summarizes anthropometric failure by both deficiency and excess weight and it highlights that a quarter of the malnutrition in the Argentine population was caused by undernutrition, although there are differences between Provinces (P < 0·05). ECIAF estimates are higher than those of CIAF or under-nutrition.

The asymmetry of dermatoglyphic finger ridge counts and the geographic altitude of the Jujenean population in northwest Argentina.

Asymmetry is omnipresent in the living world and therefore is a measure of developmental noise and instability. The main stressing agent in high-altitude ecosystems is hypobaric hypoxia. The variation in bilateral dermatoglyphic symmetry in populations from the Province of Jujuy in northwest Argentina is analyzed, and these results are compared to those for other populations with different ethnic and environmental backgrounds. Fingerprints were collected from 310 healthy students (140 males and 170 females) aged 18-20 years from three localities in Jujuy Province-Abra Pampa (3484 m above sea level), Humahuaca (2939 m above sea level), and San Salvador de Jujuy (1260 m above sea level). Asymmetry by sex was assessed based on radial and ulnar ridge counts to determine its pattern of variability (directional asymmetry [DA], fluctuating asymmetry [FA] and antisymmetry), and asymmetry and diversity indices were calculated. A bivariate plot and principal component analysis (PCA) were used to compare these indices with those for other populations. Homogeneity was found between populations and sexes when radial and ulnar ridges were counted. FA values did not show significant differences by locality or side (ulnar and radial), but significant differences were found by finger and sex, with males showing significantly greater FA values. The asymmetry and diversity indices clearly group the Andean populations and separate them from populations of different ethnic and geographic origin. Only the diversity index showed significant differences by locality in males, which suggests a substantially different genetic component in Abra Pampa male samples.

Development of subcutaneous fat in Spanish and Latin American children and adolescents: Reference values for biceps, triceps, subscapular and suprailiac skinfolds.

Subcutaneous fat skinfolds represent a reliable assessment instrument of adiposity status. This study provides current percentile references for four subcutaneous skinfolds (biceps, triceps, subscapular, suprailiac) applicable to children and adolescents in Spain and in Latin American countries where data are scarce. The design consisted of a cross-sectional multicenter study performed with identical methods in 5 countries (Argentina, Cuba, Mexico, Spain and Venezuela). Total sample comprised 9163 children and youths (boys 4615 - girls 4548) aged 6-18 years, healthy and without apparent pathologies. Percentiles 3, 5, 10, 25, 50, 75, 90, 95 and 97 were calculated by the LMS method. Sexual dimorphism was assessed using the t-test and age differences with ANOVA. Normalized growth percentile references were obtained according to sex and age for each skinfold. The mean values of four skinfolds were significantly greater in girls than boys (p<0.001) and, in both sexes, all skinfolds show statistical differences through age (p<0.001) with different magnitudes. Except triceps in girls, peaks between 11 and 12 years of age are more noticeable in boys than in girls. Although the general model of growth is known, the skinfold measurements show variability among populations and differences of magnitude are presented according to the analyzed population. Therefore, these age and sex-specific reference percentile values for biceps, triceps, subscapular and suprailiac skinfolds, derived from a large sample of Spanish and Latin American children and adolescents, are a useful tool for adiposity diagnosis in this population for which no reference values were available.

Identification of 17 novel mutations in 40 Argentinean unrelated families with mucopolysaccharidosis type II (Hunter syndrome).

Mucopolysaccharidosis type II (MPSII) is an X-linked lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase (IDS). The human IDS gene is located in chromosome Xq28. This is the first report of genotype and phenotype characterization of 49 Hunter patients from 40 families of Argentina. Thirty different alleles have been identified, and 57% were novel. The frequency of de novo mutations was 10%. Overall, the percentage of private mutations in our series was 75%.

Surnames in Chile: a study of the population of Chile through isonymy.

In Chile, the Hispanic dual surname system is used. To describe the isonymic structure of this country, the distribution of 16,277,255 surnames of 8,178,209 persons was studied in the 15 regions, the 54 provinces, and the 346 communes of the nation. The number of different surnames found was 72,667. Effective surname number (Fisher's α) for the entire country was 309.0, the average for regions was 240.8 ± 17.6, for provinces 209.2 ± 8.9, and for communes 178.7 ± 4.7. These values display a variation of inbreeding between administrative levels in the Chilean population, which can be attributed to the 'Prefecture effect' of Nei and Imaizumi. Matrices of isonymic distances between units within administrative levels were tested for correlation with geographic distance. The correlations were highest for provinces (r = 0.630 ± 0.019 for Euclidean distance) and lowest for communes (r = 0.366 ± 0.009 for Lasker's). The geographical distribution of the first three-dimensions of the Euclidean distance matrix suggests that population diffusion may have taken place from the north of the country toward the center and south. The prevalence of European plus European-Amerindian (95.4%) over Amerindian ethnicity (4.6%, CIA World Factbook) is compatible with diffusion of Caucasian groups over a low-density area populated by indigenous groups. The significant excess of maternal over paternal indigenous surnames indicates some asymmetric mating between nonAmerindian and Amerindian Chileans. The available studies of Y-markers and mt-markers are in agreement with this asymmetry. In the present work, we investigate the Chilean population with the aim of detecting its structure through the study of isonymy (Crow and Mange,1965) in the three administrative levels of the nation, namely 15 regions, 54 provinces, and 346 communes.

Sex differences in fingerprint ridge density in the Mataco-Mataguayo population.

Ridge density (RD), the number of digital ridges per unit area, varies according to sex, age, and population origin. The main objective of this study was to determine the extent of sexual dimorphism in RD and to set the age at which it appears, in an Amerindian sample from the Mataco-Mataguayo population. The sample studied for this research consisted of 99 males and 110 females, between 6 and 25 years old, which amounts to a total of 2090 fingerprints. Ridge count was carried out on distal radial and distal ulnar and on proximal regions of each finger to explore the RD patterns in order to identify similarities and differences among samples, areas, age groups, and sexes. RD decreased with age and, at all ages, RD was higher on the distal (radial and ulnar) areas, followed by the proximal sides. Females were found to have higher RD than males when older than 12 years, but not when younger. In the radial area, the Mataco-Mataguayo population, in both sexes, presented the RD similar to Spanish samples, but higher than all other populations analysed to date using this method. Variations in RD in the Amerindian population based on sex, age, and topology were confirmed in this work, and it is postulated that these variations are due to developmental differences among individuals and populations. A comparison between the Mataco-Mataguayo and Spanish populations is presented.

The LMS method and weight and height centiles in Jujuy (Argentina) children.

Human growth and its resulting patterns display a great inter- and intra-population heterogeneity that reflects the quality of life, health and nutritional condition of populations. The aim of this work was to expand the knowledge about the growth of Jujenean children by statistical procedures that graphically express the relation of anthropometric variables to age and allow their comparison with specific references. Anthropometric data came from 9092 children (0-5 years) from various localities of Jujuy province (northwest Argentina) located at 1200 m above sea level (ma.s.l.). The centiles of weight for age (W/A) and height for age (H/A) were obtained by the LMS method using maximum penalized likelihood. A statistical and graphic comparison was made with the corresponding Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) centile references. In general, estimated centiles were lower than those in both references. Discrepancies for H/A in comparison with the CDC reference ranged between 1.09+/-0.59% and 1.66+/-0.34%, and for W/A between 1.82+/-1.56% and 3.36+/-1.4%. In comparison with the WHO reference, discrepancies ranged from 1.38+/-0.65% to 1.87+/-0.41% for H/A, and from 1.12+/-1.28% to 2.74+/-1.49% for W/A. Centile discrepancies were attributed to the characteristics of early childhood feeding and the interaction of a set of biological and mesological factors that the Jujenean population is exposed to. Growth and nutritional conditions of this population should be evaluated with the WHO reference, for it reflects the recent growth pattern of biologically and culturally healthy children raised in favourable conditions, a pattern that also reflects that of Jujenean children.

Isonymic structure of the Argentine Northwest.

Surname distribution may be used as a substitute for quantitative information on the genetic structure of human populations due to panmictic deviations. This study analysed the isonymic structure of the Argentine Northwest (ANW) populations. Surname distribution of 2,576,548 voters (year 2001) in the 117 departments of the region was analysed. Fisher's alpha and coefficient of random relationship by isonymy were estimated. A dendrogram of the 117 departments was constructed from the matrix of Euclidean distances. In general, alpha values found were lower than country averages, while kinship values were higher. Ten clusters were identified showing a spatial distribution closely related to geographic characteristics, means of communication, and location of economic activities of the region. The resulting pattern could be basically characterized by grouping the departments into two large clusters: (a) Those located in the centre of the region, which include the provincial capitals, presented greater diversity of surnames and a lower degree of kinship. (b) Those located in the regional periphery showed greater isolation and kinship. Isonymic parameters estimated agree with the demographic characteristics of populations, historical antecedents of population settlement and ANW geographic features.

Allele and genotype frequencies of metabolic genes in Native Americans from Argentina and Paraguay.

Interethnic differences in the allele frequencies of CYP2D6, NAT2, GSTM1 and GSTT1 deletions have been documented for Caucasians, Asians, and Africans population. On the other hand, data on Amerindians are scanty and limited to a few populations from southern areas of South America. In this report we analyze the frequencies of 11 allele variants of CYP2D6 and 4 allele variants of NAT2 genes, and the frequency of GSTM1 and GSTT1 homozygous deleted genotypes in a sample of 90 donors representing 8 Native American populations from Argentina and Paraguay, identified as Amerindians on the basis of their geographic location, genealogical data, mitochondrial- and Y-chromosome DNA markers. For CYP2D6, 88.6% of the total allele frequency corresponded to *1, *2, *4 and *10 variants. Average frequencies for NAT2 *4, *5, *6 and *7 alleles were 51.2%, 25%, 6.1%, and 20.1%, respectively. GSTM1 deletion ranged from 20% to 66%, while GSTT1 deletion was present in four populations in less than 50%. We assume that CYP2D6 *2, *4, *10, *14; NAT2 *5, *7 alleles and GSTM1 and GSTT1 *0/*0 genotypes are founder variants brought to America by the first Asian settlers.

Surnames in Argentina: a population study through isonymy.

In order to study the isonymic structure of Argentina, the surname distributions of 22.6 million electors registered for the year 2001 were analyzed in the 24 districts (distritos) and 541 municipalities (municipios) of the country. The number of different surnames found was 414,441. Matrices of isonymic distances between districts were constructed and tested for correlation with the geographic distance between the capital towns of the districts. We found that, for the whole of Argentina, Euclidean distance was correlated with the log of geographic distance (r=0.480+/- 0.067). A dendrogram of the 24 regions was built from the matrix of Euclidean distances, using the UPGMA method. The clusters identified by the dendrogram are coincident with conterminous geographical regions of the country. Random inbreeding calculated from isonymy, F(ST), was highest in La Rioja, Corrientes, and Santiago del Estero. It was lowest in the area of Buenos Aires and in the north-central region of Santa Fé. Average Fisher's alpha for municipalities was 358; for districts, it was 422; and for Argentina as a unit, it was 602. The geographical distribution of alpha in 541 municipalities, high in the east and lower in the west of the country, is compatible with the settlement in the 20th century of subsequent waves of immigrants moving from the North Atlantic coast toward the foot of the Andes and toward the south. The present structure of Argentina indicates that migration dominates over drift.

Genetic structure and admixture in urban populations of the Argentine North-West.

BACKGROUND: From the ethnic point of view, the Argentine North-West (ANW) constitutes one of the most noticeable areas in the country due to the cultural peculiarities that integrate it to the Andean world and the ethno-historical and demographic characteristics of how it became populated. AIM: The study analysed the genetic structure and diversity of the ANW urban populations, and the contribution of parental populations to its genetic pool. SUBJECTS AND METHODS: Previously reported data on allele frequencies of HLA-A and HLA-B loci of 1293 individuals from Jujuy, Salta, Tucumán, Santiago del Estero, Catamarca and La Rioja were used. Our estimates include: (a) genetic intra-population diversity; (b) genetic distances between populations; (c) linkage disequilibrium (LD); (d) admixture rates and genetic distances with respect to three parental populations (European, American Indian and African). RESULTS: Low intra-population genetic differentiation and low genetic distances between populations were found. Differential LD distribution varied according to province, with 60% variance due to intra-population differences. The Spanish contribution (50%) predominated in ANW, followed by the American Indian (40%) and African (10%) contributions, and a marked inter-population heterogeneity of genetic admixture rates was observed. The shortest genetic distance was found in the American Indian parental population, and the longest in the African parental population. CONCLUSION: Five hundred years after the Spanish conquest, urban populations at ANW that have probably been subject to the same evolutionary forces present low genetic diversity and a similar genetic structure. Genetic distances and admixture percentages observed agree with census and ethno-historical data on settlement in the region.

Birth seasonality in Jujeño (north-west Argentina) altitude populations.

Seasonality of births has been related to multiple factors, including environmental, biological and sociocultural ones, in populations of diverse geographic and cultural origin. However, the relationship between this variable of bioanthropologic interest and geographic altitude has not been adequately explored. The aim of this study was to analyse the monthly distribution pattern of birth rates in Jujeño (north-west Argentina) populations located at different geographic altitude levels. Data were provided by the Statistical Reports on Liveborns (n = 110,404) in the province of Jujuy, 1985-1992. Records were grouped by birthplace into the four geographic regions of the province: Ramal (350 m.a.s.l.), Valle (1200 m.a.s.l.), Quebrada (2500 m.a.s.l.) and Puna (3500 m.a.s.l.). Henry's coefficients of seasonality were estimated. A chi-square test for goodness of fit (chi2) was used to identify statistically significant seasonal variations. Edwards' test was used to detect simple harmonic cycles in birth distribution. Statistically significant seasonal patterns were found in the four geographic regions and they respond to a cyclic model of simple harmonic variation. The greatest Henry coefficients were observed in spring and summer in the higher regions (Puna and Quebrada). whereas they were seen in autumn and winter in the lowlands (Valle and Ramal). It is suggested that these patterns reflect the influence of environmental and socioeconomic altitude-related factors and inter-regional cultural diversity, rather than the influence of geographical altitude per se.

Genetic structure of Native Andean populations from Argentina inhabiting different altitudes.

On the basis of erythrocyte and serum protein polymorphisms, we investigated the level of genetic differentiation among 3 Argentinian native populations sharing ethnic and morphological characteristics but inhabiting different altitudes in the Andes. Of the 15 loci studied, 8 are monomorphic. Phenotype distribution of the polymorphic systems are in agreement with Hardy-Weinberg equilibrium, except for malic enzyme (MOD), where a silent allele was found. The 2 highland populations exhibit a close genetic similarity, probably as a result of intense gene flow. The lowland population shows reduced genetic diversity, which suggests the influence of stochastic phenomena such as the founder effect.

GM, KM immunoglobulin allotypes and other serum genetic markers (HP, GC, PI, and TF) among South American populations living at different altitudes (Jujuy Province, Argentina): admixture estimates.

A total of 154 individuals belonging to three populations located at different altitude levels in northwest Argentina (San Salvador de Jujuy, 1,200 m; Tilcara, 2,500 m; Abra Pampa, 3,500 m) were studied for the GM, KM, HP, GC, PI and TF genetic systems. Individuals were selected on the basis of ethnocultural affiliation. Gene frequency values were found to be comparable to those reported for other South American populations. The populations studied showed a close genetic identity and an absence of interpopulation heterogeneity. Distribution of the GM phenotypes and haplotypes corresponds to historical data on human settlements in Jujuy Province. The presence of some alleles and the anthropological significance of the allele distribution are discussed, as are the effects of the admixture with Africans and Spaniards. The genetic pattern appears to be the result of a varying admixture due to the genetic isolation in populations located at various altitude levels.

[Chagas diseases seroepidemiology in schoolchildren of Jujuy]. / Seroepidemiología de la enfermedad de Chagas en escolares de Jujuy.

Chagas disease constitutes the main zoonosis in the province of Jujuy, Argentina, where it is one of the most important issues in public health. The purpose of this paper is to analyze the results of a serologic evaluation carried out for a seven-year period among schoolchildren in the Jujenean capital city. The population under study consisted of all seventh grade students of all schools in San Salvador de Jujuy. They were classified into three socioeconomic levels: High, Medium and Low levels. Indirect hemagglutination and immunofluorescence tests were performed. Percentages of seroprevalence were determined by sex, age group, and socioeconomic level. To analyze and check results, the following tests were applied: ANOVA, Tukey's and chi-square test. General prevalence was 1.95% with inter-annual statistically non-significant variations. Statistically significant variations were found among: 1) sex, where the feminine sex exhibited higher seroprevalence; 2) age groups, in which 12-year-olds showed higher seroprevalence; 3) socioeconomic levels, where seroprevalence increased as socioeconomic level decreased. Chagasic seroprevalence in children populations is an indicator that allows assessing both transmission risks in the community and the efficiency of preventive measures to control the vector. Data resulting from this study would indicate: 1) an adequate control both of non-vectorial transmission as well as of the vector, since no temporal variation was recorded in seroprevalence in the age-group analyzed; 2) higher seroprevalence in children belonging to a lower socioeconomic level, probably due to migrations of already-infected mothers coming from neighboring endemic, less epidemiologically controlled areas.

Seroepidemiología de la enfermedad de Chagas en escolares de Jujuy. / [Chagas diseases seroepidemiology in schoolchildren of Jujuy]

Chagas disease constitutes the main zoonosis in the province of Jujuy, Argentina, where it is one of the most important issues in public health. The purpose of this paper is to analyze the results of a serologic evaluation carried out for a seven-year period among schoolchildren in the Jujenean capital city. The population under study consisted of all seventh grade students of all schools in San Salvador de Jujuy. They were classified into three socioeconomic levels: High, Medium and Low levels. Indirect hemagglutination and immunofluorescence tests were performed. Percentages of seroprevalence were determined by sex, age group, and socioeconomic level. To analyze and check results, the following tests were applied: ANOVA, Tukeys and chi-square test. General prevalence was 1.95

with inter-annual statistically non-significant variations. Statistically significant variations were found among: 1) sex, where the feminine sex exhibited higher seroprevalence; 2) age groups, in which 12-year-olds showed higher seroprevalence; 3) socioeconomic levels, where seroprevalence increased as socioeconomic level decreased. Chagasic seroprevalence in children populations is an indicator that allows assessing both transmission risks in the community and the efficiency of preventive measures to control the vector. Data resulting from this study would indicate: 1) an adequate control both of non-vectorial transmission as well as of the vector, since no temporal variation was recorded in seroprevalence in the age-group analyzed; 2) higher seroprevalence in children belonging to a lower socioeconomic level, probably due to migrations of already-infected mothers coming from neighboring endemic, less epidemiologically controlled areas.

Characteristic distribution of HTLV type I and HTLV type II carriers among native ethnic groups in South America.

To confirm the geographic and ethnic segregation of HTLV-I and HTLV-II carriers in native populations in South America, we have conducted a seroepidemiological study of native populations in South America, including HTLV-I carriers distributed among seven ethnic groups in the Andes highlands of Colombia, Peru, Bolivia, Argentina, and Chile, and two ethnic groups on Chiloe Island and Easter Island; and HTLV-II carriers distributed among seven ethnic groups of the lowlands along the Atlantic coast of Colombia, Orinoco, Amazon, and Patagonia, and one ethnic group on Chiloe Island. The incidence rate of HTLV-I and HTLV-II carriers varied among the ethnic groups, ranging from 0.8 to 6.8% for HTLV-I seropositivity and from 1.4 to 57.9% for HTLV-II seropositivity. A new HTLV-I focus was found among the Peruvian Aymara (1.6%), the Bolivian Aymara (5.3%) and Quechua (4.5%), the Argentine Puna (2.3%), and the Chilean Atacama (4.1%), while on HTLV-II focus was found among the Brazilian Kayapo (57.9%), the Paraguayan Chaco (16.4%), and the Chilean Alacalf (34.8%) and Yahgan (9.1%). The distribution of HTLV-I/II foci showed a geographic clustering of HTLV-I foci in the Andes highlands and of HTLV-II foci in the lowlands of South America. It was thus suggested that South American natives might be divided into two major ethnic groups by HTLV-I and HTLV-II carrier state.

A seroepidemiological survey of HTLV-I/II carriers in the Puna Jujeña.

Human T-cell leukemia virus type I (HTLV-I) carriers are clustered in limited groups in the world. One of these groups is the Andean native population of South America. As part of an international collaborative study devoted to explore the clustering of HTVL-I carriers in different countries, the aim of this paper was to evaluate the seroprevalence of HTLV-I/II virus in the native population of Puna Argentina in Jujuy. Blood samples of individuals of three populations of Puna Jujeña (Susques, Rinconada, Cochinoca) were screened with particle agglutination (PA), immunofluorescence (IF) and western immunoblotting analysis (WB) tests. Two out 86 (2.32%) individuals examined in the Puna Jujeña showed positive results for HTLV-I antibodies. It is concluded that the Province of Jujuy, in particular its less miscegenated highest altitude areas, constitute the northern and southern Andean natural geographical clustering of HTLV-I. This distribution is probably linked both to a history of prehistoric human dispersal in the Andes and to high mother- to-child transmission of the virus under close conditions of each group.

A seroepidemiological survey of HTLV-I/II carriers in the Puna Jujeña.

Human T-cell leukemia virus type I (HTLV-I) carriers are clustered in limited groups in the world. One of these groups is the Andean native population of South America. As part of an international collaborative study devoted to explore the clustering of HTVL-I carriers in different countries, the aim of this paper was to evaluate the seroprevalence of HTLV-I/II virus in the native population of Puna Argentina in Jujuy. Blood samples of individuals of three populations of Puna Jujeña (Susques, Rinconada, Cochinoca) were screened with particle agglutination (PA), immunofluorescence (IF) and western immunoblotting analysis (WB) tests. Two out 86 (2.32

) individuals examined in the Puna Jujeña showed positive results for HTLV-I antibodies. It is concluded that the Province of Jujuy, in particular its less miscegenated highest altitude areas, constitute the northern and southern Andean natural geographical clustering of HTLV-I. This distribution is probably linked both to a history of prehistoric human dispersal in the Andes and to high mother- to-child transmission of the virus under close conditions of each group.