Giardia lamblia-infected preschoolers present growth delays independent of the assemblage A, B or E.

BACKGROUND: Intestinal parasite Giardia can affect children's physical development mainly stunting even in asymptomatic cases. The protozoa G. lamblia is divided into assemblages A-H. However, it is still unclear whether clinical manifestations and pathogenesis may vary according to the infecting assemblage. OBJECTIVES: To investigate whether G. lamblia assemblages influence differently the physical development of preschoolers from a community of Rio de Janeiro, Brazil. METHODS: Anthropometric parameters were analysed from children attending a daycare centre and stool samples were obtained for the G. lamblia diagnosis. G. lamblia isolates from positive samples were genotyped. Data were analysed in order to verify whether there is a relationship between G. lamblia infection and the physical development of children according to the assemblage. FINDINGS: Herein we demonstrated that although eutrophic, G. lamblia-infected daycare preschoolers from a low-income community presented growth delay compared to non-infected ones. This effect was observed for the three assemblages (A, B or E) found infecting humans. MAIN CONCLUSION: G. lamblia causes growth delays on children independent of infecting assemblage (A, B or E).

First report of Leishmania RNA virus 1 in Leishmania (Viannia) braziliensis clinical isolates from Rio de Janeiro State - Brazil.

BACKGROUND: Leishmania parasites carry a double-stranded RNA virus (Leishmania RNA virus - LRV) that has been divided in LRV1 and LRV2. OBJECTIVES: Leishmania (Viannia) braziliensis clinical isolates were assessed in order to determine LRV presence. METHODS: Two-round polymerase chain reaction (PCR and nested PCR) was performed to detect LRV1 or LRV2 in L. (V.) braziliensis clinical isolates (n = 12). FINDINGS: LRV1 was detected in three clinical isolates which was phylogenetically related to other sequences reported from other American tegumentary leishmaniasis (ATL) endemic areas of Brazil. Patients infected with L. (V.) braziliensis LRV-negative showed only cutaneous lesions while LRV-positive reported different manifestations. MAIN CONCLUSION: Data presented here show for the first time that LRV1 is circulating in L. (V.) braziliensis clinical isolates from Rio de Janeiro State in Brazil.

Epidemiology of Giardia duodenalis assemblages in Brazil: there is still a long way to go.

Giardia duodenalis infection is distributed worldwide and can achieve prevalence around 60%, especially in developing countries. This protozoan is divided into eight assemblages, in which A and B have high zoonotic potential, whereas C to H are host-specific. This scenario is changing as molecular studies progress, highlighting that knowledge on host-specificity still has a long way to go. Understanding the players involved in transmission routes enables rational designs of control strategies. Considering the high prevalence of giardiasis, this review aims to gather together the data on available studies on the distribution of G. duodenalis assemblages in Brazil until September 2020.

In vitro-induction of metronidazole-resistant Giardia duodenalis is not associated with nucleotide alterations in the genes involved in pro-drug activation.

Giardiasis is an infectious disease caused by Giardia duodenalis. The pro-drug metronidazole (MTZ) is the first-line treatment for giardiasis. Parasite's proteins as pyruvate:ferredoxin oxidoreductase (PFOR), ferredoxin (Fd), nitroreductase-1 (NR-1) and thioredoxin reductase (TrxR) participate in MTZ activation. Here, we showed Giardia trophozoites long-term exposed to MTZ presented higher IC50 than controls, showing the drug influenced the parasite survival. That reduction in MTZ's susceptibility does not seem to be related to mutations in the genes pfor, fd, nr-1 or trxr. It points that different mechanism as alterations in other metabolic pathways can account for Giardia resistance to MTZ therapy.

Identification of Giardia lamblia Assemblage E in Humans Points to a New Anthropozoonotic Cycle.

Giardia lamblia is a pathogen transmitted by water and food that causes infection worldwide. Giardia genotypes are classified into 8 assemblages (A-H). Assemblages A and B are detected in humans, but they are potentially zoonotic because they infect other mammalian hosts. Giardia in samples from 44 children was genotyped. Conserved fragments of the genes encoding ß-giardin and glutamate dehydrogenase were sequenced and their alignment were carried out with sequences deposited in GenBank. As expected for Rio de Janeiro, the majority of samples were related to assemblage A. Surprisingly, assemblage E was detected in 15 samples. Detection of assemblage E in humans suggests a new zoonotic route of Giardia transmission.

Enterobius vermicularis in Brazil: An integrative review.

Enterobius vermicularis, an intestinal helminth, is transmitted through the ingestion of eggs found in food, water, dust, or other fomites, including infected individuals. This review aimed to examine the frequency and distribution of E. vermicularis infections in Brazil between 1991 and 2022. The conducted bibliographic survey revealed that the frequency of E. vermicularis infections in Brazil ranged from 0.1 to 26.1%, depending on factors such as population ethnicity, individual age group, geographic area, time frame, and diagnostic method. However, these findings were based on a limited number of publications, suggesting that the actual prevalence rates of E. vermicularis infection may still be unknown and potentially underestimated.

High Frequency of Cryptosporidium hominis Infecting Infants Points to A Potential Anthroponotic Transmission in Maputo, Mozambique.

Cryptosporidium is one of the most important causes of diarrhea in children less than 2 years of age. In this study, we report the frequency, risk factors and species of Cryptosporidium detected by molecular diagnostic methods in children admitted to two public hospitals in Maputo City, Mozambique. We studied 319 patients under the age of five years who were admitted due to diarrhea between April 2015 and February 2016. Single stool samples were examined for the presence of Cryptosporidium spp. oocysts, microscopically by using a Modified Ziehl-Neelsen (mZN) staining method and by using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) technique using 18S ribosomal RNA gene as a target. Overall, 57.7% (184/319) were males, the median age (Interquartile range, IQR) was 11.0 (7-15) months. Cryptosporidium spp. oocysts were detected in 11.0% (35/319) by microscopy and in 35.4% (68/192) using PCR-RFLP. The most affected age group were children older than two years, [adjusted odds ratio (aOR): 5.861; 95% confidence interval (CI): 1.532-22.417; p-value < 0.05]. Children with illiterate caregivers had higher risk of infection (aOR: 1.688; 95% CI: 1.001-2.845; p-value < 0.05). An anthroponotic species C. hominis was found in 93.0% (27/29) of samples. Our findings demonstrated that cryptosporidiosis in children with diarrhea might be caused by anthroponomic transmission.

Recirculation of Giardia lamblia Assemblage A After Metronidazole Treatment in an Area With Assemblages A, B, and E Sympatric Circulation.

Giardia lamblia is an intestinal protozoan subdivided into eight assemblages, labeled alphabetically from A to H. Assemblages A, B, and E infect humans and can have a sympatric circulation. We investigated the assemblage recirculation in children living within a high prevalence area of Giardia infection. One hundred and ninety-four children were evaluated and 85 tested positive for Giardia by PCR. These infected individuals were recruited, treated with metronidazole and then reexamined for infections at 20 and 40 days after treatment that included PCR and the genotyping was performed by sequencing beta-giardin and glutamate dehydrogenase gene targets. Giardia assemblages A (n = 43), B (n = 21), E (n = 17), and A/E (n = 4) were identified in infected children. Assemblage A was found in all reoccurrences of infection, including four that had been infected by assemblages B and E. Since both persistence and reinfection could account for the results, the level of nucleotide homology was determined before and after treatment. Most suggested that reinfections were by the same strain, but four presented a distinct genotypic profile. The results suggest that the differences in the genotypic profiles were due to reinfections, which appear to occur with frequency in high Giardia burden areas and soon after the end of therapy. It is not yet possible to define whether the recurrent cases were related to parasite resistance. However, the evidence of rapid reinfections and ready availability of treatment raises the potential for creating resistant strains. This highlights the need to address how Giardia burden is maintained within high prevalence areas.

First report of treatment failure in a patient with cutaneous leishmaniasis infected by Leishmania (Viannia) naiffi carrying Leishmania RNA virus: a fortuitous combination?

We report the case of a 32-year-old man from Rio de Janeiro, who was infected in the Amazon region of Brazil by Leishmania (Viannia) naiffi. Generally, patients with L. naiffi cutaneous leishmaniasis exhibit a good therapeutic response to either pentavalent antimonials or pentamidine. However, after pentamidine treatment, this patient's infection evolved to therapeutic failure. To understand this clinical outcome, we investigated the presence of the Leishmania RNA virus (LRV) in parasites isolated from the cutaneous lesion; herein, we discuss the possible association between a poor response to pentamidine therapy and the presence of the LRV.

Giardiasis Alters Intestinal Fatty Acid Binding Protein (I-FABP) and Plasma Cytokines Levels in Children in Brazil.

Giardiasis is an intestinal infection caused by ingestion of water or food contaminated with cysts of Giardia lamblia. Susceptibility is higher in children and overall prevalence can reach up to 90% in low-income areas, although outbreaks are also reported in developed countries. Both parasite and immune-mediated epithelial damage has been observed in vitro and in animal models. However, whether enterocytes are directly damaged during infection is not entirely known. Our goal was to identify whether plasma levels of intestinal fatty acid binding protein (I-FABP), a marker of enterocyte damage, are related to the immune response in giardiasis. Blood plasma was collected from 31 children (19 Giardia-positive) from a public day care in Rio de Janeiro, Brazil. The levels of I-FABP were increased in Giardia-infected children compared to children without detectable infection. There was no difference in I-FABP levels in giardiasis caused by different genetic assemblages of Giardia. Levels of IL-8 were decreased, while there was a trend to elevated IL-17 in the Giardia-positive children. A positive correlation was observed between I-FABP and IL-17 levels as well as TNF, suggesting that epithelial damage can be related to cytokine production during giardiasis. These results help elucidate the relationship between the disruption of the intestinal mucosal barrier and immune responses to G. lamblia in children.

Enterobius vermicularis in Brazil: An integrative review

ABSTRACT Enterobius vermicularis, an intestinal helminth, is transmitted through the ingestion of eggs found in food, water, dust, or other fomites, including infected individuals. This review aimed to examine the frequency and distribution of E. vermicularis infections in Brazil between 1991 and 2022. The conducted bibliographic survey revealed that the frequency of E. vermicularis infections in Brazil ranged from 0.1 to 26.1%, depending on factors such as population ethnicity, individual age group, geographic area, time frame, and diagnostic method. However, these findings were based on a limited number of publications, suggesting that the actual prevalence rates of E. vermicularis infection may still be unknown and potentially underestimated.

The presence of Giardia lamblia assemblage A in dogs suggests an anthropozoonotic cycle of the parasite in Rio de Janeiro, Brazil.

BACKGROUND: Giardia lamblia is a zoonotic protozoan that is classified into 8 genotypes and is distributed worldwide. Assemblages A and B were found to infect dogs and humans, whereas assemblages C and D are dog host-specific. Our objective was to investigate the G. lamblia genotypes circulating in a canine population in Rio de Janeiro, RJ. RESULTS: Sixty stool samples positive for G. lamblia from street dogs were characterized. Fragments of the conserved genes encoding beta-giardin (ß-gia) and glutamate dehydrogenase (gdh) were used as targets. The sequences from beta-giardin and glutamate dehydrogenase genes obtained from all 60 dog samples were 100% similar to G. lamblia genotype A. CONCLUSION: The detection of genotype A suggests that G. lamblia transmission in Rio de Janeiro has a predominantly anthropozoonotic cycle.

Giardia lamblia-infected preschoolers present growth delays independent of the assemblage A, B or E

BACKGROUND Intestinal parasite Giardia can affect children's physical development mainly stunting even in asymptomatic cases. The protozoa G. lamblia is divided into assemblages A-H. However, it is still unclear whether clinical manifestations and pathogenesis may vary according to the infecting assemblage. OBJECTIVES To investigate whether G. lamblia assemblages influence differently the physical development of preschoolers from a community of Rio de Janeiro, Brazil. METHODS Anthropometric parameters were analysed from children attending a daycare centre and stool samples were obtained for the G. lamblia diagnosis. G. lamblia isolates from positive samples were genotyped. Data were analysed in order to verify whether there is a relationship between G. lamblia infection and the physical development of children according to the assemblage. FINDINGS Herein we demonstrated that although eutrophic, G. lamblia-infected daycare preschoolers from a low-income community presented growth delay compared to non-infected ones. This effect was observed for the three assemblages (A, B or E) found infecting humans. MAIN CONCLUSION G. lamblia causes growth delays on children independent of infecting assemblage (A, B or E).

First report of Leishmania RNA virus 1 in Leishmania (Viannia) braziliensis clinical isolates from Rio de Janeiro State - Brazil

BACKGROUND Leishmania parasites carry a double-stranded RNA virus (Leishmania RNA virus - LRV) that has been divided in LRV1 and LRV2. OBJECTIVES Leishmania (Viannia) braziliensis clinical isolates were assessed in order to determine LRV presence. METHODS Two-round polymerase chain reaction (PCR and nested PCR) was performed to detect LRV1 or LRV2 in L. (V.) braziliensis clinical isolates (n = 12). FINDINGS LRV1 was detected in three clinical isolates which was phylogenetically related to other sequences reported from other American tegumentary leishmaniasis (ATL) endemic areas of Brazil. Patients infected with L. (V.) braziliensis LRV-negative showed only cutaneous lesions while LRV-positive reported different manifestations. MAIN CONCLUSION Data presented here show for the first time that LRV1 is circulating in L. (V.) braziliensis clinical isolates from Rio de Janeiro State in Brazil.

First report of treatment failure in a patient with cutaneous leishmaniasis infected by Leishmania (Viannia) naiffi carrying Leishmania RNA virus: a fortuitous combination?

Abstract We report the case of a 32-year-old man from Rio de Janeiro, who was infected in the Amazon region of Brazil by Leishmania (Viannia) naiffi. Generally, patients with L. naiffi cutaneous leishmaniasis exhibit a good therapeutic response to either pentavalent antimonials or pentamidine. However, after pentamidine treatment, this patient's infection evolved to therapeutic failure. To understand this clinical outcome, we investigated the presence of the Leishmania RNA virus (LRV) in parasites isolated from the cutaneous lesion; herein, we discuss the possible association between a poor response to pentamidine therapy and the presence of the LRV.

Giardiasis as zoonosis: between proof of principle and paradigm in the Northwestern region of São Paulo State, Brazil.

OBJECTIVE: In order to evaluate the potential zoonotic transmission of Giardia duodenalis, isolates from humans and dogs in the Northwestern region of the São Paulo State, Brazil were characterized based on the ß-giardin gene. METHODS: The samples were analyzed by sequencing of the Nested-PCR products. RESULTS: The A1 and A2 subgenotypes were detected in human and dogs. Cysts of assemblage B, C and D have not been found in any isolates studied. CONCLUSIONS: These results are consistent with the view that giardiasis in the largest endemic region of the Brazil should not be seen as a single entity.

Giardiasis as zoonosis: between proof of principle and paradigm in the Northwestern region of São Paulo State, Brazil

OBJECTIVE: In order to evaluate the potential zoonotic transmission of Giardia duodenalis, isolates from humans and dogs in the Northwestern region of the São Paulo State, Brazil were characterized based on the β-giardin gene. METHODS: The samples were analyzed by sequencing of the Nested-PCR products. RESULTS: The A1 and A2 subgenotypes were detected in human and dogs. Cysts of assemblage B, C and D have not been found in any isolates studied. CONCLUSIONS: These results are consistent with the view that giardiasis in the largest endemic region of the Brazil should not be seen as a single entity.