Parasite-endemic Areas Research Articles

Allergic bronchopulmonary aspergillosis with marked peripheral blood eosinophilia and pulmonary eosinophilia: A case report

Allergic bronchopulmonary aspergillosis (ABPA) is an immune-related pulmonary disease caused by sensitization of airway by Aspergillus fumigatus. The disease manifests as bronchial asthma and recurring pulmonary shadows, which may be associated with bronchiectasis. The diagnosis of ABPA mainly depends on serological, immunological, and imaging findings. Pathological examination is not necessary but may be required in atypical cases to exclude pulmonary tuberculosis, tumor, and other diseases through lung biopsy. An 18-year-old man presented with recurrent wheezing, cough, and peripheral blood eosinophilia. Chest computed tomography showed pulmonary infiltration. There was a significant increase in eosinophils in bronchoalveolar lavage fluid. There was no history of residing in a parasite-endemic area or any evidence of parasitic infection. Pathologic examination of bronchoalveolar lavage fluid excluded fungal and mycobacterial infections. The patient was receiving medication for comorbid diseases, but there was no temporal correlation between medication use and clinical manifestations, which excluded drug-induced etiology. Histopathological examination of lung biopsy specimen showed no signs of eosinophilic granulomatosis with polyangiitis, IgG4-related diseases, or tumors. The diagnosis of ABPA was considered based on the history of asthma and the significant increase in serum Aspergillus fumigatus-specific immunoglobulin (Ig)E. Eosinophil-related diseases were excluded through pathological biopsy, which showed typical pathological manifestations of ABPA. The possibility of ABPA should be considered in patients with poorly controlled asthma, especially those with eosinophilia, lung infiltration shadows, or bronchiectasis. Screening for serum IgE, Aspergillus fumigatus-specific IgE and IgG, and alveolar lavage can help avoid misdiagnosis.

A New Role for Old Friends: Effects of Helminth Infections on Vaccine Efficacy.

Vaccines are one of the most successful medical inventions to enable the eradication or control of common and fatal diseases. Environmental exposure of hosts, including helminth infections, plays an important role in immune responses to vaccines. Given that helminth infections are among the most common infectious diseases in the world, evaluating vaccine efficiency in helminth-infected populations may provide critical information for selecting optimal vaccination programs. Here, we reviewed the effects of helminth infections on vaccination and its underlying immunological mechanisms, based on findings from human studies and animal models. Moreover, the potential influence of helminth infections on SARS-CoV-2 vaccine was also discussed. Based on these findings, there is an urgent need for anthelmintic treatments to eliminate helminth suppressive impacts on vaccination effectiveness during implementing mass vaccination in parasite endemic areas.

Prevalence and Risk Factors for Intestinal Protozoan Infections in Children with Cancer in Taif, Western Saudi Arabia.

Cancer is a category of diseases that cause an individual's immune system to become suppressed. In a case-control study, the current study aims to detect the frequency of intestinal parasites and related risk factors in children with cancer. Stool samples were collected from 178 children with cancers (cases) and 150 cancer-free children (controls) who sought treatment for diarrheal episodes at nearby hospitals. Samples were processed by direct smear examination, concentration technique, permanent staining by Lugol's iodine, modified Ziehl-Neelsen, modified trichrome, and chromotrope 2R stains. The overall prevalence of intestinal parasites was 7.3% (24/328), with non-statistically significant differences between cases (7.8%; 14/178) and controls (6.6%; 10/150). Children with leukemia had a higher infection rate (9%; 9/100) than children with lymphoma (6.9%; 3/43) or solid tumors (5.7%; 2/35). Blastocystis sp. (3.3%) was the most common intestinal parasite found in cases, followed by Cryptosporidium sp. (2.2%), Giardia lamblia (1.6%), and Microsporidia sp. (0.5%). For all parasites, no statistical difference was found between the two groups. (p > 0.05). Male gender, young age, non-bottled water use, travel to parasite-endemic areas, living in an urban area, and infrequent hand washing were all associated with intestinal parasitosis, with non-statistical significance observed between the two groups. In children with cancer, intestinal parasites were found to be significantly associated with chronic (p = 0.04) and severe (p = 0.03) diarrhea. Children with cancer, particularly those with hematological cancers, should be screened for intestinal parasites on a regular basis and treated for their overall health.

First detection of Echinococcus multilocularis in Croatia.

Echinococcus multilocularis has been spreading through Europe but has not yet been reported in Croatia. We report the results of a surveillance programme to detect E. multilocularis in red foxes (Vulpes vulpes) in different parts of Croatia. PCR-based screening of faecal samples from 238 red foxes in 2015 and 150 in 2016 indicate prevalences of 7.5% in 2015 and 6.6% in 2016 (overall 7.2%, CI 4.9 to 10.3). Positive samples were confirmed by sequencing parts of the nad1 gene and the gene encoding mitochondrial 12S rRNA. Geographic locations of all examined and positive cases were mapped to provide data on the distribution of E. multilocularis. Our results provide the first detection of E. multilocularis in Croatia and extend the southern boundary of this parasite's endemic area.

English

Infections of the urinary tract are important part of infectious diseases that mainly involve bacteria. In parasite endemic areas, bacterial and parasitic co-infections may occur, however in Saint-Louis region which is a Schistosoma-endemic area, little is known about this association. Here this study aim to investigate the spectrum of bacterial and parasitic urinary infections as well as co-infections with both species. Concordantly to the current algorithm at the biomedical laboratory at Saint Louis Hospital, bacterial and parasitic investigation has been performed using the conventional method of bacteriological and parasitological examination of urine. Data were collected from register records from 2000 to 2010, recorded and analysed using Epi Info 7. 17107 urines samples were recorded and among which, 2352 (14%) were positive bacterial cultures including mainly Escherichia coli (54%) and Klebsiella spp (19%). Seven hundred and forty-three parasites have been identified including Trichomonas vaginalis (64%), Schistosoma haematobium (34%) and Schistosoma mansoni (2%). Both parasites and bacteria were found in 55 samples with T. vaginalis/E. coli (79%) as main combination, followed by T. vaginalis /Klebsiella spp. (11%). Regarding S. haematobium, it was found to be associated with E. coli in 7 samples and Klebsiella spp. in 4 samples. In the region of Saint-Louis, the urinary tract infections are dominated by bacterial infections including mainly E. coli and Klebsiella spp and may, for lesser extent, be caused by Schistosoma haematobium and Trichomonas vaginalis. Thus, the evaluation of the impact bacterial and parasitic co-infection in the urinary tract should have a particular interest especially in Schistosoma endemic area and need further study to better understand the potential interactions. Key words: Urines, bacteria, parasites, co-infection, Saint-Louis, Senegal.

Helminths in the hygiene hypothesis: sooner or later?

There is increasing recognition that exposures to infectious agents evoke fundamental effects on the development and behaviour of the immune system. Moreover, where infections (especially parasitic infections) have declined, immune responses appear to be increasingly prone to hyperactivity. For example, epidemiological studies of parasite-endemic areas indicate that prenatal or early-life experience of infections can imprint an individual's immunological reactivity. However, the ability of helminths to dampen pathology in established inflammatory diseases implies that they can have therapeutic effects even if the immune system has developed in a low-infection setting. With recent investigations of how parasites are able to modulate host immune pathology at the level of individual parasite molecules and host cell populations, we are now able to dissect the nature of the host–parasite interaction at both the initiation and recall phases of the immune response. Thus the question remains – is the influence of parasites on immunity one that acts primarily in early life, and at initiation of the immune response, or in adulthood and when recall responses occur? In short, parasite immunosuppression – sooner or later?

Molecular identification of Theileria parasites of northwestern Chinese Cervidae.

BackgroundTheileria and Babesia protozoan parasites are transmitted mainly by tick vectors. These parasites cause heavy economic losses to the live-stock industry, as well as affecting the health of wild animals in parasite-endemic areas. Identification of infectious agents in wild animals is not only crucial for species preservation, but also provides valuable information on parasite epidemiology. Here, we conducted a molecular surveillance study in Northwestern China to assess the prevalence of blood pathogens in cervids.MethodsPCR analysis and microscopic evaluation of blood smears to detect Theileria- and Babesia-related diseases in Cervidae were conducted, in which 22 blood samples from red deer (n = 22) in Qilian Mountain and 20 from sika deer (n = 20) in Long Mountain were collected and tested for the presence of Theileria and Babesia. The 18S rRNA gene was amplified, and selected polymerase chain reaction (PCR)-positive samples were sequenced for species identification.ResultsPCR revealed that 9.1% of the Qilian Mountain samples and 20% of the Long Mountain samples were positive for Theileria uilenbergi; 90.09% of the Qilian Mountain samples (n = 22) were positive for T. capreoli, but all of the Long Mountain samples (n = 20) were negative for T. capreoli; no other Theileria or Babesia species were found. PCR showed that T. uilenbergi and T. capreoli were present in red deer in Qilian Mountain, while only T. uilenbergi was found in sika Deer in Long Mountain. The 18S rRNA gene sequences were aligned against the corresponding GenBank sequences of known isolates of Theileria and Babesia and subjected to phylogenetic analysis. The phylogenetic tree showed that the newly isolated Theileria spp. could be classified as belonging to two clades: one group belonged to the same clade as T. uilenbergi, the other to a clade containing T. capreoli.ConclusionsOur results provide important data to increase understanding of the epidemiology of Cervidae theileriosis, and will assist with the implementation of measures to control theileriosis transmission to Cervidae and small ruminants in central China.

Cross-reactive IgE antibody responses to tropomyosins from Ascaris lumbricoides and cockroach

Evidence indicates that infection with Ascaris lumbricoides may promote development of allergy and asthma. To study the role of tropomyosin, a pan-allergen in invertebrates, in IgE responses to A lumbricoides. Recombinant A lumbricoides and Periplaneta americana tropomyosins were expressed in Pichia pastoris. Levels of IgE to tropomyosins from A lumbricoides and P americana were determined by chimeric ELISA in sera from 119 children living in a parasite-endemic area and 112 patients with cockroach allergy from the allergy clinics. Presence of tropomyosin in A lumbricoides larvae at L3 stage was evaluated by immunofluorescence using mAb 1A6, directed against mite tropomyosin. Molecular modeling of P americana and A lumbricoides tropomyosins was performed by using the MODELLER program. A lumbricoides tropomyosin showed 69% to 98% sequence identity to tropomyosins from other invertebrates. The predicted structure of A lumbricoides tropomyosin was similar to that of P americana tropomyosin and showed the characteristic coiled-coil structure. Strong correlation was found for IgE antibodies to tropomyosins from A lumbricoides and P americana in sera from children living in a parasite-endemic area and from patients with cockroach allergy. Larvae of A lumbricoides reacted strongly with mAb 1A6. Tropomyosin induces IgE responses in A lumbricoides-infected children and in patients allergic to cockroach.

Eosinophilia in a Patient From South America

Asymptomatic eosinophilia is a common finding in returning travelers and immigrants from parasite-endemic areas. We present a 49-year-old man from Guyana who immigrated to the United States 4 years prior to examination. He had persistent asymptomatic eosinophilia, and multiple stool examinations were negative for ova and parasites. Although the list of parasitic diseases associated with eosinophilia is extensive, the differential diagnosis of asymptomatic eosinophilia with negative stool evaluations is rather limited. We discuss herein elements of the clinical history and examination essential for evaluating eosinophilia in patients at risk of parasitic diseases and present a simple algorithm to guide diagnostic testing. Despite the importance of repeated stool examinations for the presence of ova and parasites, in practice this test is not sensitive. Serologic testing for chronic parasitic infections is often necessary. Most cases without a definitive diagnosis can be conservatively managed with serial monitoring or empirically treated with antihelminthic therapy, but patients with an absolute eosinophil count of more than 3000/microL or more than 1500/microL for more than 6 months are at risk of end organ damage and should be referred for specialized parasitic and/or hematology consultation.

Coexistence of Trypanosoma cruzi Genotypes in Wild and Periodomestic Mammals in Chile

Epidemiologic evidence suggests a preferential association of Trypanosoma cruzi genotypes TCI and TCII with marsupials and placental mammals, respectively. We identify T. cruzi genotypes from 117 infected mammals. Minicircle DNA amplified by polymerase chain reaction and hybridization with a panel of four specific probes showed frequencies for the T. cruzi genotypes TCI, TCIIb, TCIId, and TCIIe of 38%, 41%, 26%, and 9%, respectively, in wild mammals. In peridomestic mammals, frequencies for the same clones were 29%, 33%, 43%, and 14%, respectively. As a whole, mixed infections are found in more than 31% of the cases, which indicates the coexistence of multiclonal strains circulating in nature, and the absence of specific associations between T. cruzi genotypes and reservoir hosts, including marsupials. The direct characterization of parasite genotypes emphasizes the importance of obtaining unbiased epidemiologic information from parasite-endemic areas. Results are discussed in the context of competition or facilitation of T. cruzi genotypes within hosts.

A COMPARISON OF METHODS FOR DETECTING THE EGGS OF ASCARIS, TRICHURIS, AND HOOKWORM IN INFANT STOOL, AND THE EPIDEMIOLOGY OF INFECTION IN ZANZIBARI INFANTS

This study compared five methods for detecting the eggs of the human parasitic geohelminths Ascaris, Trichuris, and hookworm in infant stool, and describes the epidemiology of infection in infants from a parasite-endemic area. A total of 424 infants 5-11 months old were enrolled from three villages on Pemba Island, Zanzibar. Methods used included the Kato-Katz technique, formol ethyl acetate sedimentation, modified formol ethyl acetate sedimentation, modified Wisconsin floatation, and simple gravity sedimentation. Of methods used alone, Wisconsin floatation and simple gravity sedimentation each provided the highest sensitivity for detecting eggs of these three geohelminths (89.6%). Of methods used in combination, the Kato-Katz technique/simple gravity sedimentation and Wisconsin floatation/simple gravity sedimentation each provided the highest sensitivity (99.0%). Prevalence of geohelminth infection was 26.5%. Between five and nine months of age the mean prevalence was 9.4%, while at 10 and 11 months of age the mean prevalence was 43.4%. Village prevalence varied from 3.6% to 43.8%. Infant geohelminth infection can occur at a high prevalence, and what method is best depends on research specifics.

Investigating IgE cross-reactive antibody responses in invertebrates: Use of recombinant tropomyosin from cockroach and Ascaris lumbricoides

Invertebrates: Use of Recombinant Tropomyosin From Cockroach and Ascaris lumbricoides A. B. R. Santos1, V. S. F. Sales2, V. P. L. Ferriani3, M. D. Chapman4, L. K. Arruda1; 1Internal Medicine, School of Medicine of Ribeirao Preto University of Sao Paulo, Ribeirao Preto, BRAZIL, 2Pharmacology, Federal University of Rio Grande do Norte, Natal, BRAZIL, 3Pediatrics, School of Medicine of Ribeirao Preto University of Sao Paulo, Ribeirao Preto, BRAZIL, 4Indoor Biotechnologies Inc, Charlottesville, VA. RATIONALE: We have previously shown that infection with A. lumbricoides is an important risk factor for wheezing in children living in Brazil. We aimed to use recombinant tropomyosins to investigate IgE antibody responses to Ascaris and cockroach. METHODS: cDNA coding for A. lumbricoides tropomyosin was subcloned into pPIC-9 vector and expression of the recombinant protein was carried out in the Pichia pastoris system. Recombinant tropomyosins from A. lumbricoides and cockroach were used in chimeric ELISA to quantitate specific IgE antibodies in panels of sera from 137 children living in a parasite-endemic area, and 188 patients with asthma and/or rhinitis allergic to cockroach from our clinic. RESULTS: In children from a parasite-endemic area, IgE to tropomyosin was found in 99/137 (72.2 %) of sera; of those, 57 (41.6%) had IgE to both Ascaris and cockroach tropomyosin. Geometric mean (GM) levels of IgE to Ascaris and cockroach tropomyosin were 7.5 IU/mL and 8.1 IU/mL, respectively. There was a significant correlation of levels of IgE to A. lumbricoides and cockroach tropomyosin (r = 0.7, p < 0.0001). Among cockroach allergic patients, presence of IgE to tropomyosin was found in 79/188 (42%), and of those, 48/188 (25.5%) presented IgE to both Ascaris and cockroach tropomyosin, with GM levels of 2.56 UI/mL and 5.4 UI/mL , respectively. There was also a significant correlation of levels of IgE antibodies to both tropomyosins (r = 0.58, p < 0.0001). CONCLUSION: Tropomyosins from invertebrates are important IgEbinding proteins. Recombinant tropomyosins could be used to investigate IgE antibody responses to Ascaris and cockroach. Funding: FAPESP, CNPq

Alleles and haplotypes of tumor necrosis factor (TNF) alpha and beta genes in three ethnic populations of Sulawesi Indonesia.

Polymorphic variation in two cytokine genes, tumor necrosis factor (TNF) -alpha and -beta, was examined in three ethnic groups, the Bugis, the Makassans, and the Torajans, who inhabit Sulawesi, a large island in the Indonesian archipelago, and formerly a Dutch colony. TNF-alpha and -beta are key molecules in immune responses to infection, and both have been implicated in the pathogenesis and clinical manifestations of parasitic diseases. Several polymorphic variants with the potential to affect cytokine levels in autoimmune diseases and parasitic and bacterial infection have been reported. Two loci in the promoter region of TNF-alpha and two sites in the first intron of TNF-beta were scored in a maximum of 150 Bugis, 168 Makassans, and 58 Torajans. Genotypes at the two TNF-alpha loci are not in Hardy-Weinberg equilibrium because of a deficit of heterozygotes (p < 0.05). However, genotypes at the TNF-beta loci exhibit Hardy-Weinberg equilibrium. A comparison of allelic and genotypic frequencies at all TNF loci across the ethnic groups reveals that the differences are significant for TNFalpha(308) (p < 0.01) and for TNFbeta(NcoI) (p < 0.05). Overall, the distribution of the alleles differs from that seen in the few Asian populations for which data are available (p < 0.05). Construction of 4-locus haplotypes showed that, in addition to the five previously reported, four novel haplotypes were present in Sulawesi. These novel haplotypes were in low frequency, and two were seen only in Bugis (haplotypes F and J) and one (haplotype K) only in Makassans. The other, haplotype D, was present in Makassans and Torajans. Preliminary sampling of other ethnic groups suggests that three of these haplotypes (D, F, and J) may be restricted to Asian or Asian-derived populations. The frequency of the common TNF haplotypes differed between Dutch and Sulawesi populations, and these data also indicated that haplotype E, which has a relatively high frequency in the Dutch (25%), may be a useful marker of Dutch/European admixture in Indonesian populations, in which it is either rare (1%) or absent. The results suggest that unique allelic combinations with potential to influence cytokine secretion are present in Sulawesi, possibly as a consequence of parasite-driven selection, and argue for more extensive investigation of haplotype distribution in parasite-endemic areas.

IgA and IgM anti-Naegleria fowleriantibodies in human serum and saliva

Antibodies from IgA and IgM classes that recognize Naegleria fowleri (Nf) proteins were detected by the ELISA assay in serum and saliva from three groups of people: (i) subjects with upper respiratory tract infections (URTI) living in the parasite-endemic area, (ii) healthy persons from the same area, and (iii) healthy persons from a parasite-nonendemic area. In serum and in saliva the titers of IgA antibodies to Naegleria fowleri in the group of patients with URTI was significantly higher than that of the healthy group in the parasite-endemic area; also the titers of IgM antibodies in serum were significantly higher in patients. On the contrary, in saliva the antibodies were higher in healthy people from the parasite-endemic area. In all cases the subjects from the parasite-nonendemic area had lower antibody titers in serum and saliva.Key words: Naegleria fowleri, IgA, IgM antibodies, serum, saliva.

IgA and IgM anti-&lt;i&gt;Naegleria fowleri &lt;/i&gt;antibodies in human serum and saliva

Antibodies from IgA and IgM classes that recognize Naegleria fowleri (Nf) proteins were detected by the ELISA assay in serum and saliva from three groups of people: (i) subjects with upper respiratory tract infections (URTI) living in the parasite-endemic area, (ii) healthy persons from the same area, and (iii) healthy persons from a parasite-nonendemic area. In serum and in saliva the titers of IgA antibodies to Naegleria fowleri in the group of patients with URTI was significantly higher than that of the healthy group in the parasite-endemic area; also the titers of IgM antibodies in serum were significantly higher in patients. On the contrary, in saliva the antibodies were higher in healthy people from the parasite-endemic area. In all cases the subjects from the parasite-nonendemic area had lower antibody titers in serum and saliva.

Immunoblot analysis of IgA antibodies to Naegleria fowleri in human saliva and serum.

The objective of this study was to evaluate the secretory IgA (SIgA) antibody response to Naegleria fowleri (Nf) in individuals living in a parasite endemic area. Saliva and serum samples were obtained from both healthy subjects and patients suffering from a respiratory illness (chronic bronchitis or rhinitis) and were analyzed by immunoblot assay. SIgA from the patients' samples recognized more intensely a greater number of Nf proteins than did SIgA from the healthy control group. The proteins more frequently recognized were those with a molecular weight of 171, 107, 102, 62, 50, 46, and 10 kDa. Some IgA antibodies recognized proteins from Nf and Entamoeba histolytica (Eh) of similar molecular weight. These results suggest that some of those antibodies could have been elicited by a previous intestinal infection with Eh. Through the common mucosal immune system the IgA B-cells activated by Eh antigens can be disseminated to all the mucosae, including the nasal mucosa. SIgA antibodies recognizing Nf proteins, induced either by specific immunization or by cross-reaction, could participate in the resistance to the infection, probably by inhibiting the adherence of Nf trophozoites to the nasal mucosa.

The Prevalence of Parasitism in Preschool Americans in the Philippines`

One hundred and two American children living at Clark Air Base in the Philippines had stools tested for parasites. Seven (6.9%) were positive, isolating Ascaris (3), Giardia (3), and Tricuris (2), but no correlation was found in sex, race, or place of residence. Fourteen children whose parents felt they had symptoms of parasites tested negative. When stationed overseas in a parasite-endemic area, parents worry about their children acquiring parasites, but we were able to confirm a low prevalence in American dependents. Our data does not support mass screening for, or mass treatment of, parasites in this population group.