Immune Profile of Honduran Schoolchildren with Intestinal Parasites: The Skewed Response against Geohelminths

Factors influencing stunted growth in children: A study in Bandung regency focusing on a deworming program

The prevalence of neglected tropical diseases, specifically those caused by soil-transmitted helminths (STHs) and other parasites that infest the intestine as part of their life cycle, remains a problem in Indonesia. We assessed the effects of deworming programs and socioeconomic and ecological factors on the incidence rate of infections with STHs and other parasites in an urban area of the Bandung Regency. We recruited 361 children with stunted growth who met the inclusion criteria, and 48 of those children were at high risk of STH infection. The study was conducted between September 2020 and September 2021. We collected possible socioeconomic factors influencing the incidence rate of infections. We found the incidence rate of STH infections among the children with stunted growth to be 3.6%. We confirmed infections with Cyclospora and Cryptosporidium after a Ziehl-Nieelsen stool smear examination in two of the 48 children at risk of infection. We found 43.75% of the children had short stature and weight below the normal limits, while stunting and severe stunting were associated with Ascaris lumbricoides infection (44.70%, p = 0.035). Parents of children with stunted and severely stunted growth were more likely to have a low education level, lack knowledge about deworming program, and to be earning a low income. The mother's occupation had a particularly strong influence on the severity of the stunting (89.58%, p = 0.012). Our results show that deworming programs can affect the growth and development of children and that socioeconomic and ecological factors also play a role.

Immunological and Haematological Relevance of Helminths and Mycobacterium tuberculosis Complex Coinfection among Newly Diagnosed Pulmonary Tuberculosis Patients from Bobo-Dioulasso, Burkina Faso

The effect of helminthiasis on host immunity is a neglected area of research, particularly in tuberculosis (TB) infection. This study aimed to evaluate the effect of helminthiasis on immunological and haematological parameters in newly diagnosed TB patients in Bobo-Dioulasso. After all biological analyses, we formed three subpopulations: group 1 (n = 82), as control, were participants without helminthic or Mycobacterium tuberculosis complex infection (Mtb-/Helm-), group 2 (n = 73) were TB patients without helminthic infection (Mtb+/Helm-), and group 3 (n = 22) were TB patients with helminthic infection (Mtb+/Helm+). The proportion of helminth coinfection was 23.16% (22/95) in TB patients, and Schistosoma mansoni infection was found in 77.3% (17/22) cases of helminthiasis observed in this study. A low CD4 T cell count and a low CD4:CD8 ratio were significantly associated with concomitant infection with helminths and the Mtb complex (Mtb+/Helm+) compared to the other groups (p < 0.05). However, there was no statistically significant difference in the CD8 median among the three participating groups (p > 0.05). Lymphopenia, monocytosis, thrombocytosis, and hypochromic microcytic anaemia were the haematological defects observed in the Mtb+/Helm+ and Mtb+/Helm- patients. Exploring these types of immune-haematological biomarkers would be a valuable aid in diagnosing and a better follow-up and monitoring of the tuberculosis-helminthiasis coinfection.

Low diagnostic performance of thick blood smears of 50 µl in comparison with direct examination of 10 µl blood and the leukoconcentration technique of 5ml blood among loiasis-suspected patients with low microfilaremia in Gabon, Central Africa, using the STARD-BLCM guidelines

BACKGROUND

The aim of this study was to determine performance indicators of thick blood smears of 50 µl (TBS-50), following the Standards for the Reporting of Diagnostic Accuracy Studies-Bayesian Latent Class Model (STARD-BLCM) guidelines. TBS-50 was compared with two common parasitological techniques-direct examination of 10 µl blood and a leukoconcentration of 5 ml-for the diagnosis of microfilaremic loiasis.

METHODS

The study population was recruited among patients of the Department of Parasitology-Mycology-Tropical Medicine over a period of 1 year. Age, sex, symptoms, and eosinophilia variables were recorded from laboratory registers and medical files. Direct examination of 10 µl of blood, TBS-50, and the leukoconcentration technique with 5 ml of blood were performed for each patient. The classical formula and BLCM were used to determine the diagnostic accuracy of the three techniques as well as the prevalence of microfilaremic loiasis. Three models were built within the framework of BLCM-the BLCM model I and alternative models II and III-for sensitivity analysis.

RESULTS

In total, 191 patients consented to be included. The direct blood examination and TBS-50 yielded comparable qualitative and quantitative results. Hence, they are reported together. The prevalence of Loa loa microfilaremia was 9.4% (95% CI 5.7-14.5; n = 18/191) with direct blood examination/TBS-50 and 12.6% [8.2-18.1] (n = 24/191) for leukoconcentration. Comparing TBS-50 with the leukoconcentration method using the classical formula, the sensitivity was 75.0% [53.3-90.2], specificity was 100.0% [97.8-100.0], the positive predictive value was 100.0% [81.5-100.0], and the negative predictive value was 96.5% [92.6-98.7]. The prevalence of microfilaremic loiasis was estimated at 9.7% [6.2-13.7] using BLCM model I. The outputs of BLCM model I showed sensitivity of 78.9% [65.3-90.3], specificity of 100.0% [99.3-100.0], a positive predictive value of 99.1% [87.2-100.0], and a negative predictive value of 93.0% [87.3-97.7] for direct blood examination/TBS-50.

CONCLUSIONS

TBS-50 demonstrates low sensitivity relative to two other techniques. In one in five cases, the result will be falsely declared negative using these methods. However, this method can be deployed with limited funds.

Effects of helminths on the human immune response and the microbiome

Helminths have evolved sophisticated immune regulating mechanisms to prevent rejection by their mammalian host. Our understanding of how the human immune system responds to these parasites remains poor compared to mouse models of infection and this limits our ability to develop vaccines as well as harness their unique properties as therapeutic strategies against inflammatory disorders. Here, we review how recent studies on human challenge infections, self-infected individuals, travelers, and endemic populations have improved our understanding of human type 2 immunity and its effects on the microbiome. The heterogeneity of responses between individuals and the limited access to tissue samples beyond the peripheral blood are challenges that limit human studies on helminths, but also provide opportunities to transform our understanding of human immunology. Organoids and single-cell sequencing are exciting new tools for immunological analysis that may aid this pursuit. Learning about the genetic and immunological basis of resistance, tolerance, and pathogenesis to helminth infections may thus uncover mechanisms that can be utilized for therapeutic purposes.

Effects of Soil-Transmitted Helminths and Intestinal Protozoan Infections on Haemoglobin Levels among School-Aged Children in Belo and Bui, North West Cameroon: A Cross-Sectional Study

Introduction. Soil-transmitted helminths (STH) remain a public health problem worldwide especially in low-income countries. Soil-transmitted helminths are known to affect both growth and haemoglobin levels. In this study, we determine the prevalence of intestinal parasites and explored its association with anaemia in school-aged children (SAC). Methodology. A cross-sectional study was carried out amongst pupils selected from 18 primary schools in four communities of the North West Region. Stool samples were examined using direct wet mount and formol-ether concentration techniques, while finger prick was performed for the measurement of haemoglobin with a haemoglobinometer. Results. The results showed significant variation of STHs, intestinal protozoan prevalence, and anaemia between age, sex, and communities. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworms was 15.1%, 0.8%, and 2%, respectively, with an overall STH prevalence of 18.3% across the four communities. Soil-transmitted helminths were more prevalent in Mbessa (30.2%) in comparison to Nkor (26.7%), Djottin (17.5%), and Kumbo (9.6%) communities. The prevalence of Entamoeba histolytica/dispar was 25.4% and Giardia duodenalis (6.9%), with an overall intestinal protozoa prevalence of 31% across the four communities. The prevalence of anaemia in the study population was 23.1%. Conclusion. Soil-transmitted helminths, intestinal protozoan infections, and anaemia are prevalent in the study area. Anaemia was observed to be associated with STH, intestinal protozoa, and the communities under study. This study recommends continuous deworming and health education on personal sanitation and environmental sanitation.

Correlation of Total IgE Level and Intensity of Infection among Soil Transmitted Helminthiasis Farmers in Klungkung Regency, Bali, Indonesia

The phenomena of increasing total IgE level in Soil Transmitted Helminthiasis and its protective role in resistance of infection remains unclear. The purpose of this study was to determine the correlation between total IgE and the intensity of Soil transmitted helminthiasis among farmers in these area. Total 162 farmer, age ranged 25-80 years participated in this cross sectional analytic study. Kato-Katz method was used to diagnose Soil Transmitted Helminthiasis and to determined infection intensity based on egg per gram (EPG). Total IgE levels were measured by enzyme linked flourescent assay (ELFA). The results of this study showed that 13,56% farmer positive  for Soil Transmitted Helminthiasis, with single infection of Ascaris lumbricoides were 1,85%, 9,26% for Trichuris trichiura, 0,61% for Hookworm and mixed infection that were 1,23% for A.lumbricoides+T.trichiura 0,61%  for A.lumbricoides+Hookworm. The intensity of infection were in mild category. Total IgE level in Soil transmitted Helminthiasis group was significantly different compared with noninfected group (p<0.05, t-test). There was significant correlation between EPG and total IgE level (r=0.667, p=0.001, Spearman test). As a conclusion total IgE level was significantly correlated with EPG, this fact can be used to develop management of Soil Transmitted Helminthiasis theraphy.

High Endemicity of Soil-Transmitted Helminths in a Population Frequently Exposed to Albendazole but No Evidence of Antiparasitic Resistance

INTRODUCTION

Soil-transmitted helminths (STHs) are gastrointestinal parasites widely distributed in tropical and subtropical areas. Mass drug administration (MDA) of benzimidazoles (BZ) is the most recommended for STH control. These drugs have demonstrated limited efficacy against Trichuris trichiura and the long-term use of single-dose BZ has raised concerns of the possible emergence of genetic resistance. The objective of this investigation was to determine whether genetic mutations associated with BZ resistance were present in STH species circulating in an endemic region of Honduras.

METHODS

A parasitological survey was performed as part of this study, the Kato-Katz technique was used to determine STH prevalence in children of La Hicaca, Honduras. A subgroup of children received anthelminthic treatment in order to recover adult parasite specimens that were analyzed through molecular biology techniques. Genetic regions containing codons 200, 198, and 167 of the -tubulin gene of Ascaris lumbricoides and Trichuris trichiura were amplified and sequenced.

RESULTS

Stool samples were collected from 106 children. The overall STH prevalence was 75.47%, whereby T. trichiura was the most prevalent helminth (56.6%), followed by A. lumbricoides (17%), and hookworms (1.9%). Eighty-five sequences were generated for adjacent regions to codons 167, 198, and 200 of the -tubulin gene of T. trichiura and A. lumbricoides specimens. The three codons of interest were found to be monomorphic in all the specimens.

CONCLUSION

Although the inability to find single-nucleotide polymorphisms (SNPs) in the small sample analyzed for the present report does not exclude the possibility of their occurrence, these results suggest that, at present, Honduras's challenges in STH control may not be related to drug resistance but to environmental conditions and/or host factors permitting reinfections.

Helminth parasites and immune regulation

Helminth parasites are complex metazoans that belong to different taxonomic families but that collectively share the capacity to downregulate the host immune response directed toward themselves (parasite-specific immunoregulation). During long-standing chronic infection, these helminths appear able to suppress immune responses to bystander pathogens/antigens and atopic, autoimmune, and metabolic disorders. Helminth-induced immunoregulation occurs through the induction of regulatory T cells or Th2-type cells (or both). However, secreted or excreted parasite metabolites, proteins, or extracellular vesicles (or a combination of these) may also directly induce signaling pathways in host cells. Therefore, the focus of this review will be to highlight recent advances in understanding the immune responses to helminth infection, emphasizing the strategies/molecules and some of the mechanisms used by helminth parasites to modulate the immune response of their hosts.

SOIL-TRANSMITTED HELMINTH INFECTION AND EOSINOPHIL LEVELS AMONG WASTE COLLECTORS IN BANDA ACEH

ABSTRACT.                 Soil-Transmitted Helminth (STH) has infected more than one billion people worldwide. Waste collectors are at risk for STH infection because their work mostly in contact with soil and waste. Eosinophilia is a sign of human immune response to STH infection in addition to increased IgE and cytokine production. This cross sectional study aims to examine the association between STH infection and eosinophil levels among waste collectors in Banda Aceh. The study sample were 60 waste collectors working for the Sanitation department of Banda Aceh. Examination of stool samples using Kato-Katz technique revealed the prevalence of STH infection among waste collectors was 23.3% (14/60), consisting of T.trichiura infection (21.7%) and mixed infection (1.6%). There were no single infections of A. lumbricoides nor the hookworm infection was found. Blood tests to count eosinophil showed the prevalence of eosinophilia at 21.7%. There was no significant correlation between the intensity of STH infection and eosinophil levels (p value = 1.00). This study does not recommend the use of eosinophilia to indicate STH infection.Keywords: Eosinophilia, Kato Katz, STH infection, Waste Collectors, Banda AcehABSTRAK.                Soil-Transmitted Helminth (STH) menginfeksi lebih dari satu milyar orang di seluruh dunia. Petugas sampah merupakan salah satu kelompok yang berisiko terifeksi STH karena pekerjaannya berhubungan dengan tanah dan sampah. Eosinofilia merupakan salah satu tanda timbulnya respon imun manusia terhadap infeksi STH selain peningkatan IgE dan produksi sitokin. Penelitian ini merupakan penelitian cross sectional untuk mengetahui hubungan infeksi STH dengan kadar eosinofil pada petugas pengangkut sampah. Penelitian di lakukan di Banda Aceh dengan subjek penelitian adalah  petugas pengangkut sampah Dinas Kebersihan dan Keindahan Kota Banda Aceh sebanyak 60 sampel. Pemeriksaan sampel feses dengan tehnik Kato-Katz menunjukkan pevalensi infeksi STH pada petugas pengangkut sampah sebesar 23,3 % (14/60) terdiri dari infeksi T.trichiura 21,7 % dan infeksi campuran 1,6 %. Tidak ditemukan infeksi tunggal A.lumbricoides dan infeksi hookworm. Pemeriksaan darah untuk menghitung eosinofil menunjukkan prevalensi eosinofilia adalah 21,7%. Tidak terdapat hubungan yang signifikan antara intensitas infeksi STH dengan kadar eosinofil darah  (p value= 1.00 ). Penelitian ini tidak menganjurkan eosinofilia sebagai marker adanya infeksi STH.Kata kunci : eosinofilia, Kato-Katz,  infeksi STH, Kato-Katz, petugas sampah, Banda Aceh