SARS-CoV-2 seropositivity and COVID-19 among 5 years-old Amazonian children and their association with poverty and food insecurity

BackgroundThe epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children.Methodology/Principal findingsWe retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Juruá Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2–48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9–8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID-19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4–9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2–2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8–3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and–even more markedly–of having had clinically apparent COVID-19 by the age of 5 years.Conclusions/SignificanceChildhood SARS-CoV-2 infection and COVID-19-associated illness are substantially underdiagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease.     

The association of genetic markers and malaria infection in the Brazilian Western Amazonian region

Almost all individuals (182) belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil) were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D). The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.     

Esterase D in Cebus apella from the Amazonian region*

Research programs involving the study of genetic variation of proteins have been carried out both in humans and catarrhine primates but rarely in New World species. Considering the great possibilities offered by protein variations as genetic markers in systematic and evolutionary studies in this group of organisms, the authors are specially interested in the investigation of genetic polymorphisms of blood proteins in Amazonian primates. In this paper we describe the electro phoretic patterns of erythrocyte esterases obtained from blood samples of 57 Cebus apella specimens. Blood hemolysates from Cebus display four main set of bands in azo-coupled stained gels. These bands are identified as esterases P, A1, A2 and B by their electro phoretic migration, substrate specificity and eserine reaction. The use of the fluoregenic reagent 4-methylumbelliferyl acetate revealed the presence of a fifth set of enzymes not detected by the azo-coupled staining method. This ser of enzymes, probably a polymorphic genetic system, was named ESD as in humans.     

Polymorphism of human HLA-DRB1 leukocyte antigen alleles and its association to juvenile rheumatoid arthritis in a sample of Colombian mestizo children

Oligotypes of the human leukocyte antigen HLA Class II, DRB1 alleles were characterized at the molecular level in a group of Colombian children suffering juvenile rheumatoid arthritis (JRA). The distribution of these alleles was examined in a group of Colombian mestizo children (genetic admixture of Amerindians, Europeans and Africans) suffering from clinically distinct JRA subsets in order to detect HLA allele frequency differences in patients with different JRA subsets. A group of 65 patients with JRA and 65 controls were characterized for the subtypes of the HLA-DRB1 alleles using polymerase chain reaction with sequence-specific oligonucleotide probes (PCR-SSOP). The oligotyping protocol recommended by the 12th International Histocompatibility Workshop held in St. Malo, Paris, in 1996, was used. Subtype HLA-DRB1*1104 was the allele most strongly associated with susceptibility to JRA (Fisher's p = 0.013, odds ratio (OR) = 16.79, etiologic fraction (EF) = 0.93). HLA-DRB1*1602 was also associated with susceptibility to a lesser degree (Fisher's p = 0.016, OR = 8.98, EF = 0.88). HLA-DRB1 alleles participating in JRA protection were HLA-DRB1*1501 (preventive fraction (PF) = 0.466, p = 0.005) and HLA DRB1*1402 (PF = 0.49, p = 0.009). The relationship between some HLA-DRB1 alleles and clinical features was also compared. The presence of rheumatic factor was associated with the alleles HLA-DRB1*0407 (p = 0.05, OR = 11.2, EF = 0.45) and HLA-DRB1*1302 (p = 0.02, OR = 22.8, EF = 0.63). There was also an association between HLA-DRB1*0701 (p = 0.001, OR = 58, EF = 0.73) with expressing ANA +. We found that in the oligoarticular subset, the allele HLA-DRB1*1104 (p = 0.0034, OR = 41.53, EF = 0.97) was the one expressed most commonly. In the poliarticular group, the alleles most frequently expressed were HLA-DRB1*0404 (Fisher's p = 0.012, OR = 8.75, EF = 0.88). In patients with systemic JRA, the HLA-DRB1*1602 allele (p = 0.005, OR = 21.33, EF = 0.95) was most frequent. These results suggested that the MHC genes of mestizo children influence not only the clinical expression of the disease, but also the susceptibility to its development.     

G and P genotypes of rotavirus circulating among children with diarrhea in the Colombian northern coast.

A study on the prevalence of rotavirus G and P genotypes was carried out based on 253 stool specimens obtained from children living in the Colombia northern coast region who were less than 3-years-old and who suffered from acute diarrhea. A previous study had detected the presence of rotavirus A in 90 (36.5%) of the 246 samples tested by enzyme immunoassay (EIA), and these strains were investigated in the present study. Of these, 50 strains yielded an RNA electropherotype, most of which (80.0%) had long profiles and 20.0% of which had short profiles. Genotyping of 84 positive samples indicated that 67.9% of the strains could be typed. G1 (57.9%), was the most predominant VP7 genotype, followed by G3 (21.1%), G9 (15.8%) and G2 (5.3%). Among the VP4 genotypes, P[4] (49.1%) was the most prevalent, followed by P[6] 36.4% and P[8] (14.5%). Neither G4 nor G8 nor P[9] types were detected. The most common G-P combinations were G3 P[4] (8.8%) and G9 P[6] (7.0%), followed by G1 P[4] and G1 P[8] (5.3% each). All G1 P[8] strains showed long RNA profiles, whereas G3 P[4] and G9 P[6] displayed both long and short patterns. Mixed infections involved 21.0% of strains. There was a marked diversity among strains collected, and novel strains, including G9, as well as other atypical combinations of G and P genotypes, such as G9 P[6] and G3 P[4], were found.     

Delirium prevalence in a Colombian hospital,association with geriatric syndromes and complications during hospitalization

BackgroundThe aim of this paper is to describe the prevalence of Delirium and the factors associated with its presentation and complications identified in a geriatric unit in Colombia.Material and methodsThis is a retrospective observational study that included all patients admitted consecutively for two years in a geriatric unit of a hospital in Bogotá, Colombia. We assessed delirium prevalence with the Confusion Assessment Method (CAM). The independent variables were age, sex, functional impairment (Barthel < 90), malnutrition (MNA < 12), pressure ulcers at admission, state of the social support network, number of comorbidities, polypharmacy (5 or more drugs), complications such as ICU requirement, hospital stay, in-hospital functional impairment and mortality were also evaluated. As an exclusion criterion: not having CAM registered in the medical record, all the patients had this information.ResultsWe studied 1599 subjects with a mean age of 86 years (IQR 9). Delirium prevalence was 51.03%. Delirium was associated with a higher rate of: pressure ulcers on admission [OR 3.76 (CI 2.60–5.43 p < 0.001)], functional impairment [OR 2.38 (CI 1.79–3.16 p < 0.001)], malnutrition [OR 2.06 (CI 1.56–2.73 p < 0.001)], and infection [OR 1.46 (CI 1.17–1.82 p < 0.001)]. Moreover delirium has a higher association with mortality [OR 2.80 (1.03–7.54 p = 0.042)], in-hospital functional decline [OR 1.82 (1.41–2.36 p < 0.001)], and longer hospital stay [OR 1.04 (1.04–1.09 p = 0.006)]; independently of age, sex, pressure ulcers on admission, functional impairment, malnutrition, dementia, infection and limited social network.ConclusionOur study suggests that infectious diseases and geriatric syndromes such as, functional dependence, pressure ulcers, malnutrition or major cognitive impairment are independently associated with the presence of delirium on admission. Additionally, the presence of delirium is independently associated during hospitalization with complications, longer hospital stay, functional impairment and mortality.     

The association of intestinal parasitosis and H. pylori infection in children and adults from a Mexican community with high prevalence of parasitosis

Background. ABSTExperimental evidences have suggested that a Th1 response is unable to eliminate H. pylori colonization; whereas a Th2 response, like the one induced by vaccination, reduces H. pylori infection in animal models. Some parasitic infections induce a polarized Th2 response, which theoretically would favor a reduced H. pylori prevalence. The aim of this work was to study the possible association between parasitic infections and H. pylori prevalence. Materials and Methods. The study population included 120 children and 188 adults from a low socioeconomic level village. H. pylori prevalence was determined in serum by ELISA; parasitic infections were identified in feces by microscopic examination; and total serum IgE levels, as an indirect indicator of some parasitic infections, were determined by ELISA. Results. In children, H. pylori prevalence was no different between those with and without intestinal parasitic infection. By contrast, adults with intestinal parasitic infection had a significantly lower H. pylori prevalence than adults without parasites (62.6% compared with 80.4%; p = 0.006, OR 2.45). Also in adults, but not in children, total IgE levels were significantly higher in those without H. pylori infection than in those with H. pylori infection (p < 0.001). Conclusions. Intestinal parasitic infections and serum IgE levels showed an age‐dependent association with H. pylori prevalence. In adults, but not in children, intestinal parasitic infections and increased IgE levels where associated with a reduced H. pylori prevalence.     

Spatial distribution of Cordyceps spp. (Ascomycotina: Clavicipitaceae) and its impact on the ants in forests of Amazonian Colombian foothill

Entomopathogenic fungi of the genus Cordyceps were sampled in the foothills of the Colombian Amazon region (450-600 msnm altitude. January and May, 1998, i.e. dry and wet seasons, respectively). Healthy and Cordyceps-parasitized ants from a nearly pristine, a naturally disturbed and a human-disturbed forests were collected on 100 quadrants (1 m2) per forest. Litter, shrubs and trunks were explored as substrates, and samples were gathered in vertical strata from 50 cm to 2 m high. Azteca was the predominant ant genus in near pristine forest whereas Camponotus, Pheidole and Crematogaster were dominant in disturbed forests. In the naturally disturbed forest we found 759 individuals of Cordyceps unilateralis and 69 of C. lloydii var. binata parasitizing Camponotus spp. (Formicidae: Formicinae), whereas C. kniphofioides var. ponerinarum and C. australis were found only in six cases infecting the ants Paraponera clavata and Pachycondila crassinoda (Formicidae: Ponerinae). In the human disturbed forest it were found 34 individuals of C. unilateralis on Camponotus. In the near pristine forest we did not find parasitized ants. The Camponotus spp. ants parasitized by C. unilateralis and C. lloydii var. binata were found predominantly in the substratum foliage up to 1 m. It was concluded that the incidence of Cordyceps-ant interactions is not influenced by the conservation status of the forest. Instead, relative humidity and presence/absence of host ants appear to be key factors. Also, the microspatial distribution of the interactions seems to follow a definite pattern. This work observations support the hypothesis on coevolution of dispersion mechanisms in Cordyceps and ant pheromonal codes.     

Random spatial distribution of Schistosoma mansoni and hookworm infections among school children within a single village

Schistosomes and soil-transmitted helminths currently infect a third of the world's human population. An important feature of these parasitic infections is their focal distribution, which has significant implications for control. Only a few studies have been carried out at the microepidemiological scale, comparing infection levels among individuals or households within a single village. In this study, data are presented from a cross-sectional survey, examining all children attending a primary school in rural C?te d'Ivoire over several consecutive days for Schistosoma mansoni, soil-transmitted helminths, and intestinal protozoa. All houses in the main village were mapped, and school children were linked to these households for small-area spatial analyses. Comparison between the 260 school children who live within the main village and the 89 children who reside in nearby settlements revealed significant differences in the overall prevalence and intensity of infections with S. mansoni and hookworm, confirming the focal nature of these 2 parasites. On the other hand, S. mansoni and hookworm infections exhibited random spatial patterns within the main village. The validity of these results is discussed in the context of this epidemiological setting, drawing attention to the issue of scale. Our findings have direct implications for intervention because they call for a uniform, community-wide approach to control schistosomiasis and soil-transmitted helminthiasis. Implementation can be relatively straightforward, and the proposed control approach might be cost-effective and prove sustainable.     

Sulfate-reducing bacteria in floating macrophyte rhizospheres from an Amazonian floodplain lake in Bolivia and their association with Hg methylation

Five subgroups of sulfate-reducing bacteria (SRB) were detected by PCR in three macrophyte rhizospheres (Polygonum densiflorum, Hymenachne donacifolia, and Ludwigia helminthorriza) and three subgroups in Eichhornia crassipes from La Granja, a floodplain lake from the upper Madeira basin. The SRB community varied according to the macrophyte species but with different degrees of association with their roots. The rhizosphere of the C4 plant Polygonum densiflorum had higher frequencies of SRB subgroups as well as higher mercury methylation potentials (27.5 to 36.1%) and carbon (16.06 +/- 5.40%), nitrogen (2.03 +/- 0.64%), Hg (94.50 +/- 6.86 ng Hg g(-1)), and methylmercury (8.25 +/- 1.45 ng Hg g(-1)) contents than the rhizosphere of the C3 plant Eichhornia crassipes. Mercury methylation in Polygonum densiflorum and Eichhornia crassipes was reduced when SRB metabolism was inhibited by sodium molybdate.     

Altruism and reciprocity among friends and kin in a Tibetan village

To explain the high level of altruism among unrelated friends, some people propose that friends may apply the feeling and emotions that underlie kin-selected nepotism to each other. Alternatively, altruism among friends may be sustained by an evolved psychology that is sensitive to the dynamic of contingent reciprocity. A recent study (Stewart-Williams, S., 2007. Altruism among kin vs. nonkin: effects of cost of help and reciprocal exchange. Evolution and Human Behavior, 28, 193–198) with North American students showed that the amount of help given and received was less likely to be balanced among friends (as among relatives) than among acquaintances, suggesting that exchange among friends and relatives may rely on similar psychological mechanisms. To assess whether the similar pattern in exchange reflects the similar psychology in exchange, I tested how different types of relationship regulated the amount of help given and received, and people’s emotional reaction to non-reciprocation. I asked 45 participants from a Tibetan village in China to imagine how unhappy they would feel if the target person (sibling, cousin, friend or acquaintance) failed to reciprocate their help in various contexts. I found that overall, friends and relatives were more tolerant to non-reciprocation than acquaintances were. For emotional help, friends were more likely to feel unhappy about non-reciprocation than relatives were, but were similar to relatives in responses to other types of help (aid during crisis, labor, and financial help). The study suggests that people may evaluate the importance of reciprocity differently in various situations, and exhibit different levels of sensitivity to the dynamic of reciprocity. Thus it calls for careful distinctions between friends and kin in the everyday lives of individuals.     

Effort-reward imbalance and its association with health among permanent and fixed-term workers

Background  

In the past decade, the changing labor market seems to have rejected the traditional standards employment and has begun to support a variety of non-standard forms of work in their place. The purpose of our study was to compare the degree of job stress, sources of job stress, and association of high job stress with health among permanent and fixed-term workers.     

Apolipoprotein E polymorphism and its association with serum lipid levels in Brazilian children

The influence of apolipoprotein E (APOE) genotypes on plasma lipid levels was determined in 414 Brazilian healthy children of mixed ethnicity, age 5 to 15 years (mean 8.9+/-2.9). The APOE*3 allele was the most frequent (77%), followed by APOE*4 (17%) and APOE*2 (6%). The pattern of lipid differences among genotypes was similar in both boys and girls. We did not detect an increase in cholesterol levels with the presence of the APOE*4 allele. Because a growing body of evidence suggests that the effect of *4 depends on its interaction with diet, the frequency of *4 might be more variable in children than in adults as well as among populations. Children carrying a *2 allele had lower total cholesterol (TC) and LDL-cholesterol levels (138.47+/-24.32 and 77.72+/-19.42, respectively) compared with *3/*3 children (158.33+/-25.28 and 97.05+/-21.82, respectively). Mean TC/HDLC ratio was also lower in children with the APOE*2 allele (3.27+/-0.66 versus 3.64+/-0.76). In this highly admixed population sample, the *2 anti-atherogenic lipid pattern is already detected in children.     

Apoptotic process in the monkey small intestinal epithelium: I. association with glutathione level and its efflux

The apoptotic process in the normal gastrointestinal mucosa is of interest due to its possible role in physiological cell renewal. The aim of this study was to identify the apoptotic process in the monkey small intestine and the association of glutathione level and its efflux in this process. Monkey small intestinal epithelial cells were separated in to different fractions consisting of villus, middle and crypt cells. Apoptosis was identified by DNA ladder pattern and Hoechst staining. The level of glutathione, its efflux and the enzymes involved in its metabolism were quantitated in these fractions. Apoptotic cells were identified predominantly in the villus tip cell fractions by both DNA ladder pattern and Hoechst dye staining. Glutathione level was 7 fold higher in the crypt cells as compared to villus tip cells the middle cells showing a gradual decrease. A similar pattern was seen in mitochondrial content of glutathione. As the cells mature from crypt to villus, there is increased efflux of GSH, which may be responsible for the decreased level of GSH in apoptotic villus cells. In the monkey small intestine, apoptotic cells are seen in the villus tip fractions and the glutathione level and its efflux may play a role in this process.