Intestinal helminthiasis and anaemia in youngsters from Matriz da Luz, district of São Lourenço da Mata, state of Pernambuco, Brazil

Prevalence of iron deficiency anemia in Brazilian women of childbearing age: a systematic review with meta-analysis

BACKGROUND

Iron deficiency anemia (IDA) is among the most common micronutrient deficiencies in women of childbearing age and may affect children's development. Brazil has several national programs to tackle this condition, such as food fortification and supplementation for pregnant women, but IDA prevalence in this population has not been systematically reviewed. We sought to determine the prevalence of IDA in Brazilian women of childbearing age through a systematic review with metanalysis.

METHODOLOGY

A protocol was previously published on the PROSPERO platform under the code CRD42020200960. A panel of the National Council for Scientific and Technological Development (CNPq) approved the protocol of this study under the public call number 26/2019. The main databases searched were MEDLINE, Web of Science, Scopus, Lilacs, and SciELO. In gray literature, the Brazilian Digital Library of Theses and Dissertations and the annals of the Brazilian Congress of Epidemiology and the Brazilian Congress of Public Health were accessed. The search strategy involved terms related to the condition (IDA) and the age group of the population of interest (teenagers and adults). Studies that had assessed the prevalence of IDA in Brazilian women of childbearing age (10-49 years) were included. Three independent reviewers read all titles and abstracts and extracted data from the included studies. Random effects meta-analyses using the Freeman-Tukey arcsine transformation were carried out with prevalence data, and meta-regression was conducted to test for subgroup differences. The quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

From 21,210 unique records screened, 237 full-texts were retrieved, of which 91 were included in the qualitative synthesis, and 83 were included in the meta-analysis. The overall IDA prevalence was 25% (95% CI [23-28], 83 studies). The subgroup of studies that used random sampling showed a prevalence of 22% (95% CI [17-27], 22 studies), whereas in those with non-random sampling, the prevalence was 27% (95% CI [23-30], 61 studies), without significant differences between subgroups in the metaregression (P = 0.13). High prevalence of IDA were found in the subgroups of studies conducted in the North and Northeast regions (30%; 95% CI [24-37]; seven studies, and 30%; 95% CI [26-34]; 27 studies, respectively), in studies conducted with indigenous population (53%; 95% CI [27-78], four studies), and with studies that had their collections after 2015 (28%; 95% CI [23-34], nine studies).

CONCLUSIONS

IDA in women of childbearing age remains a public health problem in Brazil, especially in the North and Northeast region. The national programs should be strengthened and more thoroughly supervised to decrease this condition nationally.

Update on the mapping of prevalence and intensity of infection for soil-transmitted helminth infections in Latin America and the Caribbean: a call for action

It is estimated that in Latin America and the Caribbean (LAC) at least 13.9 million preschool age and 35.4 million school age children are at risk of infections by soil-transmitted helminths (STH): Ascaris lumbricoides, Trichuris trichiura and hookworms (Necator americanus and Ancylostoma duodenale). Although infections caused by this group of parasites are associated with chronic deleterious effects on nutrition and growth, iron and vitamin A status and cognitive development in children, few countries in the LAC Region have implemented nationwide surveys on prevalence and intensity of infection. The aim of this study was to identify gaps on the mapping of prevalence and intensity of STH infections based on data published between 2000 and 2010 in LAC, and to call for including mapping as part of action plans against these infections. A total of 335 published data points for STH prevalence were found for 18 countries (11.9% data points for preschool age children, 56.7% for school age children and 31.3% for children from 1 to 14 years of age). We found that 62.7% of data points showed prevalence levels above 20%. Data on the intensity of infection were found for seven countries. The analysis also highlights that there is still an important lack of data on prevalence and intensity of infection to determine the burden of disease based on epidemiological surveys, particularly among preschool age children. This situation is a challenge for LAC given that adequate planning of interventions such as deworming requires information on prevalence to determine the frequency of needed anthelmintic drug administration and to conduct monitoring and evaluation of progress in drug coverage.

Soil-transmitted helminths (STH) are part of the group of neglected infectious diseases (NID) in Latin America and the Caribbean (LAC), and are associated with several adverse chronic effects on child health. Although control interventions such as periodic administration of anthelmintic drugs, health education, improved access to safe water and sanitation, among others, are acknowledged to be an important means to reduce morbidity and to achieve control, epidemiological information on prevalence status is lacking at the lowest sub-national administrative levels (municipalities, districts or provinces) in many countries thus hindering decision making regarding not only the treatment, but also the monitoring of progress in deworming coverage, the assessment of epidemiological impact on parasite prevalence and load and, therefore, the achievement of the overall public health goals. Epidemiological surveys can be expensive and require time and effort for their implementation, which could explain the low number of studies published with data on prevalence and intensity of infection in the Americas. The use of alternative methodologies, for instance those based on geographical information systems and remote sensing technologies, or of sentinel surveillance in schools may help countries in the task of collecting information and support the implementation of integrated control programs against STH.

Polyparasite helminth infections and their association to anaemia and undernutrition in Northern Rwanda

BACKGROUND

Intestinal schistosomiasis and soil-transmitted helminth (STH) infections constitute major public health problems in many parts of sub-Saharan Africa. In this study we examined the functional significance of such polyparasite infections in anemia and undernutrition in Rwandan individuals.

METHODS

Three polyparasite infection profiles were defined, in addition to a reference profile that consisted of either no infections or low-intensity infection with only one of the focal parasite species. Logistic regression models were applied to data of 1,605 individuals from 6 schools in 2 districts of the Northern Province before chemotherapeutic treatment in order to correctly identify individuals who were at higher odds of being anaemic and/or undernourished.

FINDINGS

Stunted relative to nonstunted, and males compared to females, were found to be at higher odds of being anaemic independently of polyparasite infection profile. The odds of being wasted were 2-fold greater for children with concurrent infection of at least 2 parasites at M+ intensity compared to those children with the reference profile. Males compared to females and anaemic compared to nonanaemic children were significantly more likely to be stunted. None of the three polyparasite infection profiles were found to have significant effects on stunting.

CONCLUSION

The present data suggest that the levels of polyparasitism, and infection intensities in the Rwandan individuals examined here may be lower as compared to other recent similar epidemiological studies in different regions across sub-Saharan Africa. Neither the odds of anaemia nor the odds of stunting were found to be significantly different in the three-polyparasite infection profiles. However, the odds of wasting were higher in those children with at least two parasites at M+ intensity compared to those children with the reference profile. Nevertheless, despite the low morbidity levels indicated in the population under study here, we recommend sustainable efforts for the deworming of affected populations to be continued in order to support the economic development of the country.

Fatores associados à anemia em crianças e adolescentes de escolas públicas de Salvador, Bahia, Brasil

Trata-se de um estudo para avaliar os fatores associados à anemia. Participaram deste estudo 1.013 indivíduos com idade entre 7 e 14 anos, matriculados na rede pública de ensino em Salvador, Bahia, Brasil. Os participantes foram submetidos a exame de sangue para dosagem de hemoglobina, exame antropométrico e obtiveram-se informações sobre consumo alimentar e condições sócio-econômicas, domiciliares e ambientais da família, além do cuidado materno dispensado à criança. Foi detectada uma prevalência de 24,5% de anêmicos entre os participantes, com valor médio dos níveis de hemoglobina de 12,68g/dL, concentração mínima de 7,7g/dL e máxima de 16,8g/dL. A anemia foi significativamente associada à inadequação crescente de consumo de ferro biodisponível (ORadequação entre 50% a 99,9% = 1,57; IC95%: 1,07-2,29;p = 0,020 e ORadequação < 50% = 1,68; IC95%: 1,10-2,56; p = 0,016) e à renda familiar menor do que 1 salário mínimo (OR = 1,42; IC95%: 1,03-1,96; p = 0,035). A prevalência de anemia em crianças e adolescentes é elevada, especialmente em indivíduos mais pobres e com baixo consumo de ferro biodisponível.

Concentrações de hemoglobina e ferritina sérica em escolares da rede pública municipal de Teresina, Piauí, Nordeste do Brasil

OBJETIVOS: avaliar o estado nutricional de ferro em escolares de instituições públicas de ensino de Teresina, Piauí, Brasil. MÉTODOS: corte transversal, envolvendo amostra aleatória, selecionada em duas etapas, de 747 escolares (7-11 anos), de ambos os sexos, no período de agosto / setembro de 2000. A anemia foi rastreada em 747 escolares e para o diagnóstico adotou-se a concentração de hemoglobina (Hb) <11,5g/dL. As reservas corporais de ferro foram estimadas em 207 escolares, mediante análise das concentrações de ferritina sérica (FerS), considerando-se baixas reservas valores <15 µg/L. RESULTADOS: a prevalência de concentrações inadequadas de Hb (< 11,5g/dL) foi de 14,3% (IC95% 12,2-17,4) e de reservas inadequadas de ferro (FerS< 15,0µg/L) de 20,3% (IC95% 15,2-26,6). A prevalência de anemia foi semelhante entre os sexos (p=0,60) e as faixas etárias (p=0,85). Comportamento distributivo similar foi observado no que diz respeito às reservas inadequadas de ferro, frentes às variáveis sexo (p=0,19) e idade (p=0,24). As concentrações de FerS não mostraram correlação (r=0,1; p=0,168) com as de Hb. A prevalência de anemia ferropênica (Hb< 11,5 g/dL e FerS< 15,0 µg/L) foi de 26,3% (IC95% 17,3-37,5). CONCLUSÕES: em Teresina, a deficiência de ferro e a anemia em escolares devem ser consideradas como um problema de saúde pública que requer efetivo programa de prevenção e controle. No entanto, a anemia parece não ser explicada apenas pela deficiência de ferro; outros fatores etiológicos devem, portanto, ser considerados, a exemplo da deficiência de outros micronutrientes, infecções/infestações parasitárias, distúrbios hereditários e exposição a poluentes ambientais.

The synergistic effect of concomitant schistosomiasis, hookworm, and trichuris infections on children's anemia burden

OBJECTIVE

To estimate the degree of synergism between helminth species in their combined effects on anemia.

METHODS

Quantitative egg counts using the Kato-Katz method were determined for Ascaris lumbricoides, hookworm, Trichuris trichiura, and Schistosoma japonicum in 507 school-age children from helminth-endemic villages in The Philippines. Infection intensity was defined in three categories: uninfected, low, or moderate/high (M+). Anemia was defined as hemoglobin <11 g/dL. Logistic regression models were used to estimate odds ratios (OR), 95% confidence intervals (CI), and synergy index for pairs of concurrent infections.

RESULTS

M+ co-infection of hookworm and S. japonicum (OR = 13.2, 95% CI: 3.82-45.5) and of hookworm and T. trichiura (OR = 5.34, 95% CI: 1.76-16.2) were associated with higher odds of anemia relative to children without respective M+ co-infections. For co-infections of hookworm and S. japonicum and of T. trichiura and hookworm, the estimated indices of synergy were 2.9 (95% CI: 1.1-4.6) and 1.4 (95% CI: 0.9-2.0), respectively.

CONCLUSION

Co-infections of hookworm and either S. japonicum or T. trichiura were associated with higher levels of anemia than would be expected if the effects of these species had only independent effects on anemia. This suggests that integrated anti-helminthic treatment programs with simultaneous deworming for S. japonicum and some geohelminths could yield a greater than additive benefit for reducing anemia in helminth-endemic regions.

Age-related changes in hookworm infection, anaemia and iron deficiency in an area of high Necator americanus hookworm transmission in south-eastern Brazil

Surprisingly few detailed age-stratified data exist on the epidemiology of hookworm and iron status, especially in Latin America. We present data from a cross-sectional survey examining 1332 individuals aged 0-86 years from a community in south-east Brazil for hookworm, anaemia and iron deficiency. Sixty-eight percent of individuals were infected with the human hookworm Necator americanus. The force of infection (lambda=0.354) was similar to estimates from other areas of high hookworm transmission. Individuals from poorer households had significantly higher prevalence and intensity of infection than individuals from better-off households. The prevalence of anaemia, iron deficiency and iron-deficiency anaemia was 11.8%, 12.7% and 4.3%, respectively. Anaemia was most prevalent among young children and the elderly. Univariate analysis showed that haemoglobin and serum ferritin were both significantly negatively associated with hookworm intensity among both school-aged children and adults. Multivariate analysis showed that, after controlling for socio-economic status, iron indicators were significantly associated with heavy hookworm infection. Our results indicate that, even in areas where there is a low overall prevalence of anaemia, hookworm can still have an important impact on host iron status, especially in school-aged children and the elderly.

Prevalência e fatores associados à ocorrência de anemia entre menores de seis anos de idade em Pelotas, RS

OBJETIVOS: Determinar a prevalência e investigar fatores associados à ocorrência de anemia entre menores de seis anos de idade atendidos pela Pastoral da Criança em Pelotas, RS. MÉTODOS: Na fase de rastreamento de uma intervenção nutricional, as crianças foram avaliadas através de estudo transversal. No domicílio, após consentimento informado, a mãe foi entrevistada, sendo coletadas informações sobre características demográficas e socioeconômicas da família, saúde da criança, características ao nascer, amamentação e freqüência semanal de consumo de alimentos. As crianças foram pesadas e medidas. Foi coletada uma amostra de sangue capilar da polpa digital em microcuveta e a leitura da concentração de hemoglobina foi feita em fotômetro portátil (Hemocue). Considerou-se como tendo anemia quando a concentração de hemoglobina era inferior a 11 g/dl. Por se tratar de desfecho freqüente, a associação com as variáveis independentes foi analisada por regressão de Poisson. A análise obedeceu a modelo hierárquico previamente definido. RESULTADOS: Foram identificadas 362 crianças menores de seis anos, sendo a hemoglobina dosada em 304 (84,0%) delas. A prevalência de anemia foi de 53,0% (IC95% 47,2% - 58,7%). Os fatores de risco foram a menor idade da criança, cor não branca, presença de família numerosa e classe social E (em comparação à D). A disponibilidade de água encanada dentro de casa e o maior peso ao nascer mostraram-se fatores protetores. CONCLUSÕES: os achados deste estudo mostram uma alta prevalência de anemia entre as crianças alvo da ação da Pastoral da Criança, bem como a presença de diversos fatores de risco e poucos fatores de proteção, o que mostra a necessidade de intervenções preventivas.

[Imported hookworm infection in African immigrants in Spain: study of 285 patients]

BACKGROUND AND OBJECTIVE

Hookworm infection is a worldwide intestinal parasitic disease affecting more than one billion people. It represents an important public health problem in rural areas of developing countries. In our environment, it is generally considered an imported disease due to the immigration process.

PATIENTS AND METHOD

Retrospective observational study of African immigrants diagnosed with hookworm infection at the Immigration and Tropical Medicine Unit of the Hospital of Mataró over the period 1984-1999.

RESULTS

We identified 285 patients, mainly young males, from Gambia or Senegal, with a precarious job who had arrived in Spain 3 years earlier or less. Abdominal pain was the commonest reason for consultation (28.8%) cases. Non digestive symptoms were 35.6% and 4.6% remained assymptomatic. 60% had a concomitant infectious disease. Laboratory tests showed iron-deficiency anemia in 28.4% and eosinophilia in 52.3%. 70% of patients did not come to visit after treatment.

CONCLUSIONS

Microbiologic stool examination is recommended as part of the health assessment of immigrants from countries where hookworm infection is highly prevalent, even in the absence of abdominal symptoms or abnormalities of the red and white blood series.

[Anemia in public school first graders in the city of Maceió, Alagoas, Brazil]

A cross-sectional study was conducted in a representative sample of 426 randomly selected first graders (ages 6 to 10 years) from public schools in Maceió, State of Alagoas, Brazil. The aim was to determine the prevalence of anemia, as well as its association with growth retardation. Data were collected from May to July 2000, and determination of hemoglobin (HGB) employed an STKS Coulter counter. Two cut-off points were used to classify anemia, both established by the World Health Organization: HGB < 11.5g/dl and HGB < 12.0g/dl. The indicators height/age (H/A), weight/age (W/A), and weight/height (W/H) below -2.0 standard deviations from the NCHS reference were diagnosed as growth retardation. Prevalence of anemia was 9.9% when HGB < 11.5g/dl was used, and 25.4% when the cut-off point was HGB < 12.0g/dl. Growth retardation was detected in 6.2% of children according to H/A, 4.0% for W/A, and 3.0% for W/H. There was no statistically significant association between the variables in the study. These findings confirm results of previous surveys where prevalence of anemia was much higher than that of growth retardation. The severe consequences of anemia in this age group justify the implementation of broad public policies to overcome this nutritional deficiency.

[Risk factors for multiple intestinal parasites in an indigenous community of the State of Pernambuco, Brazil]

An investigation into the ethno-epidemiological profile of the Pankararu indigenous group in the State of Pernambuco, Brazil, identified multiple intestinal parasites in nearly all members of the community. To detect possible environmental risk factors, we used the data base from a previous survey to test relations between daily living conditions (housing, sanitation, water supply and treatment, and garbage disposal) and the number of different parasite species found in the same household. The sample consisted of 84 families from the original sample of 112. Selection was based on the number of stool tests performed in the family. The mean number of parasite species was 5.0 per family, for a mean family size of 6.1 members. This number was greater for wattle-and-daub houses (mean 6.0 parasite species vs. 4.9 for brick houses; p < 0.03) and when water used in the household was not treated (mean 5.1 parasite species, vs. 4.5 for treated water; p < 0.05). Other household characteristics and hygienic habits did not significantly influence this number. We concluded that multiple intestinal parasitism in the Pernambuco Pankararu community is frequent, to the point of being the rule, and that it relates essentially to water source and treatment.

Prevalence and distribution of soil-transmitted helminth (STH) infections in urban and indigenous schoolchildren in Ortigueira, State of Paranà, Brasil: implications for control

Soil-transmitted helminth (STH) infections represent a major public health problem in poor and developing countries. During the period September-October 1998 we conducted an epidemiological survey of STH infections in schoolchildren of an urban area (group A) and an indigenous reserve (group B), in the Municipality of Ortigueira, State of Paranà, Brazil, to assess potential benefits of mass treatment. Stool samples were examined for helminth eggs by quantitative (Kato-Katz) technique to determine the prevalence and intensity of intestinal parasitic infection. Moreover, we examined the relationship between prevalence and intensity of STH infections and housing/hygienic factors (by means of a 7-item questionnaire). 236 schoolchildren aged 5-15 years were enrolled, 136 in group A and 100 in group B. The prevalence of STH infections was significantly higher in group B (93%) than in group A (22%) (P < 0.001). Detected parasites were: A. lumbricoides (16.1% prevalence in group A, 88% in group B, P < 0.001), hookworms (5.8% in group A, 52% in group B, P < 0.001) and T. trichiura (5.1% in group A, 2% in group B, P = 0.2). Heavy infections were detected in 2.9% and 23% of the children in group A and B, respectively (P < 0.001). Housing/hygienic indicators were significantly poorer in group B. A statistically significant correlation was observed between total prevalence of STH infections and prevalence of high-intensity infections with most housing/hygienic variables. On the basis of these results, mass treatment and educational interventions were suggested for the indigenous community, whereas target treatment and educational interventions were suggested for the urban community. Even in a geographically homogeneous area different epidemiological realities can be found, which in turn can influence infection levels and control programmes.