Ricardo de Godoi Mattos Ferreira

Further Evidence of an Association between the Presence of Leishmania RNA Virus 1 and the Mucosal Manifestations in Tegumentary Leishmaniasis Patients

Tegumentary Leishmaniasis (TL) is endemic in Latin America, and Brazil contributes approximately 20 thousand cases per year. The pathogenesis of TL, however, is still not fully understood. Clinical manifestations vary from cutaneous leishmaniasis (CL) to more severe outcomes, such as disseminated leishmaniasis (DL), mucosal leishmaniasis (ML) and diffuse cutaneous leishmaniasis (DCL). Many factors have been associated with the severity of the disease and the development of lesions. Recent studies have reported that the presence of Leishmania RNA virus 1 infecting Leishmania (Leishmania RNA virus 1, LRV1) is an important factor associated with the severity of ML in experimental animal models. In the present study, 156 patients who attended Rondonias Hospital of Tropical Medicine with both leishmaniasis clinical diagnoses (109 CL; 38 ML; 5 CL+ML; 3 DL and 1 DCL) and molecular diagnoses were investigated. The clinical diagnosis were confirmed by PCR by targeting hsp70 and kDNA DNA sequences and the species causing the infection were determined by HSP70 PCR-RFPL. The presence of LVR1 was tested by RT-PCR. Five Leishmania species were detected: 121 (77.6%) samples were positive for Leishmania (Viannia) braziliensis, 18 (11.5%) were positive for Leishmania (V.) guyanensis, 3 (1.8%) for Leishmania (V.) lainsoni, 2 (1.3%) for Leishmania (Leishmania) amazonensis and 2 (1.3%) for Leishmania (V.) shawi. Six (3.9%) samples were positive for Leishmania sp. but the species could not be determined, and 4 (2.6%) samples were suggestive of mixed infection by L. (V.) braziliensis and L. (V.) guyanensis. The virus was detected in L. braziliensis (N = 54), L. guyanensis (N = 5), L. amazonensis (N = 2), L. lainsoni (N = 1) and inconclusive samples (N = 6). Patients presenting with CL+ML, DL and DCL were excluded from further analysis. Association between the presence of the virus and the disease outcome were tested among the remaining 147 patients (CL = 109 and ML = 38). Of them, 71.1% (n = 27) mucosal lesions were positive for LRV1, and 28.9% (n = 11) were negative. In cutaneous lesions, 36.7% (n = 40) were positive and 63.3% (n = 69) were negative for LRV1. The ratio P(ML|LRV1+)/P(ML|LRV1-) was 2.93 (CI95% 1.57…5.46; p<0.001), thus corroborating the hypothesis of the association between LRV1 and the occurrence of mucosal leishmaniasis, as previously described in animal models; it also indicates that LRV1 is not the only factor contributing to the disease outcome.

Improvement of a PCR test to diagnose infection by Mansonella ozzardi

INTRODUCTION Mansonelliasis is caused by Mansonella ozzardi. It is widespread in the Amazon region, with a high prevalence. The common exam of thick blood smears stained with Giemsa shows low efficacy levels and has been an obstacle to diagnosing individuals with low blood parasitemia. METHODS In order to increase diagnosis efficacy, the PCR technique was improved. RESULTS AND CONCLUSIONS PCR demonstrated the best performance, with sensitivity and negative predictive values (NPV) of 100%, followed by blood filtration through membrane filters, which showed a sensitivity of 88.9% and a NPV of 84.6%, when compared to thick blood smears.

Sustained Clearance of Mansonella ozzardi Infection after Treatment with Ivermectin in the Brazilian Amazon

Therapy for mansonelliasis is challenging because there is no standard drug recommended for its treatment. This non-randomized study was conducted to evaluate the effectiveness of a single dose of 0.15 mg/kg of ivermectin to reduce Mansonella ozzardi microfilaraemia in infected persons. A total of 74 patients were studied within the municipality of Lábrea, which is located in Amazonas State, Brazil. The patients were treated with ivermectin after detection of the parasite by blood examination. Significant microfilaraemia reduction was observed and its residual effect was maintained for at least 12 months. There was no significant change in the laboratory blood count, hepatic metabolites, and nitrogen-bounding compound excreta dosage values that could compromise the use of this drug, demonstrating that ivermectin has a low toxicity level.

Cross-reactive anti-PfCLAG9 antibodies in the sera of asymptomatic parasite carriers of Plasmodium vivax.

The PfCLAG9 has been extensively studied because their immunogenicity. Thereby, the gene product is important for therapeutics interventions and a potential vaccine candidate. Antibodies against synthetic peptides corresponding to selected sequences of the Plasmodium falciparum antigen PfCLAG9 were found in sera of falciparum malaria patients from Rondônia, in the Brazilian Amazon. Much higher antibody titres were found in semi-immune and immune asymptomatic parasite carriers than in subjects suffering clinical infections, corroborating original findings in Papua Guinea. However, sera of Plasmodium vivax patients from the same Amazon area, in particular from asymptomatic vivax parasite carriers, reacted strongly with the same peptides. Bioinformatic analyses revealed regions of similarity between P. falciparum Pfclag9 and the P. vivax ortholog Pvclag7. Indirect fluorescent microscopy analysis showed that antibodies against PfCLAG9 peptides elicited in BALB/c mice react with human red blood cells (RBCs) infected with both P. falciparum and P. vivax parasites. The patterns of reactivity on the surface of the parasitised RBCs are very similar. The present observations support previous findings that PfCLAG9 may be a target of protective immune responses and raises the possibility that the cross reactive antibodies to PvCLAG7 in mixed infections play a role in regulate the fate of Plasmodium mixed infections.

MOLECULAR CHARACTERIZATION OF AMERICAN CUTANEOUS LEISHMANIASIS IN THE TRI‑BORDER AREA OF ASSIS BRASIL, ACRE STATE, BRAZIL

SUMMARY In this study, Leishmaniaspecies were identified by Polymerase Chain Reaction (PCR). The epidemiology of patients suspected of having American Cutaneous Leishmaniasis in the municipality of Assis Brasil, Acre State, located in the Brazil/Peru/Bolivia triborder was also investigated. By PCR, the DNA of Leishmaniawas detected in 100% of the cases (37 samples) and a PCR-Restriction Fragment Length Polymorphism (RFLP) of the hsp 70gene identified the species in 32 samples: Leishmania (Viannia) braziliensis (65.6%) , L. (V.) shawi (28.1%) , L. (V.) guyanensis (3.1%) and mixed infection L. (V.) guyanensis and L. (Leishmania) amazonensis (3.1%)This is the first report of L. (V.) shawiand L. (L.) amazonensis in Acre. The two predominant species were found in patients living in urban and rural areas. Most cases were found in males living in rural areas for at least three years and involved in rural work. This suggests, in most cases, a possible transmission of the disease from a rural/forest source, although some patients had not engaged in activities associated with permanence in forestall areas, which indicate a possible sandflies adaptation to the periurban setting.

Asymptomatic infection with Plasmodium falciparum and Plasmodium vivax in the Brazilian Amazon Basin: to treat or not to treat?

In this study, we determined whether the treatment of asymptomatic parasites carriers (APCs), which are frequently found in the riverside localities of the Brazilian Amazon that are highly endemic for malaria, would decrease the local malaria incidence by decreasing the overall pool of parasites available to infect mosquitoes. In one village, the treatment of the 19 Plasmodium falciparum-infected APCs identified among the 270 residents led to a clear reduction (Z = -2.39, p = 0.017) in the incidence of clinical cases, suggesting that treatment of APCs is useful for controlling falciparum malaria. For vivax malaria, 120 APCs were identified among the 716 residents living in five villages. Comparing the monthly incidence of vivax malaria in two villages where the APCs were treated with the incidence in two villages where APCs were not treated yielded contradictory results and no clear differences in the incidence were observed (Z = -0.09, p = 0.933). Interestingly, a follow-up study showed that the frequency of clinical relapse in both the treated and untreated APCs was similar to the frequency seen in patients treated for primary clinical infections, thus indicating that vivax clinical immunity in the population is not species specific but only strain specific.

Sandfly fauna (Diptera: Psychodidae) from caves in the state of Rondônia, Brazil

This study had the aim of ascertaining the sandfly fauna and possible presence of Leishmania in these insects, collected in caves in the state of Rondônia, Brazil. Collections were conducted in eight caves located in two different areas of this state. Leishmania in the sandflies collected was detected using the polymerase chain reaction (PCR). This was the first study on sandflies from caves in Rondônia and, among the total of 1,236 individuals collected, 24 species and 10 genera were identified. The species Evandromyia georgii was collected for the first time in Rondônia and the most abundant species were Trichophoromyia ubiquitalis with 448 individuals (36.2%), followed by T. octavioi with 283 (22.9%) and E. georgii with 179 (14.5%). For the PCR, 17 pools were analyzed and five pools were positive (forT. auraensis in three pools and for Nyssomyia shawi and N. antunesi in one pool each). The kDNA region was amplified and the presence of Leishmania DNA was confirmed. The sandfly fauna in these caves can be considered diverse in comparison with similar studies in other regions. It may be that some species use caves as a temporary shelter and breeding site, while other species live exclusively in this environment. The detection of Leishmania DNA indicates that this pathogen is circulating in cave environments and that further studies are needed in order to ascertain the risks of infection by leishmaniasis in these locations with high touristic potential.

Benefícios auxílio-doença concedidos aos trabalhadores empregados no ramo de carne e pescado no Brasil em 2008

This study aims to analyze factors associated with sick leave rates among workers in the meat, fish, and seafood industries in Brazil. The study analyzed all sick leave benefits granted by the countrys social security system to workers in these industries in 2008. Incidence of sick leave per 10 thousand jobs was stratified by sex, age, diagnosis, job position, State, and nature and length of benefits. The study analyzed 31,913 sick leaves, with an annual incidence of 788.7. Meat processing and packaging showed the highest incidence, and fish and seafood processing and packaging showed the longest mean length of sick leave. Women showed a higher sick leave incidence, while men received longer average sick leaves. Injuries, musculoskeletal disorders, and mental disorders accounted for 67.2% of sick leaves. The most common diagnoses were lower back pain, first-trimester bleeding in pregnancy, and depression. The data suggest poor job protection and adverse working conditions in these industries.Este estudo objetivou identificar fatores associados a incidencia de concessao de beneficios entre trabalhadores na atividade de carne e pescado no Brasil. Foram estudados os beneficios auxilio-doenca concedidos pela Previdencia Social aos empregados em carne e pescado no Brasil em 2008. As incidencias por 10 mil vinculos empregaticios foram estratificadas por sexo, idade, diagnostico, atividade economica, unidade federada, especie e duracao dos beneficios auxilio-doenca. Foram concedidos 31.913 beneficios auxilio-doenca, com incidencia de 788,7. O ramo abate de bovinos, equinos, ovinos e caprinos apresentou a maior incidencia (1.223,2); o pescado, a maior duracao (61 dias) de beneficios auxilio-doenca. As mulheres apresentaram maior incidencia, enquanto os homens, maior duracao de beneficios auxilio-doenca. Os grupos Lesoes, doencas osteomusculares e transtornos mentais representaram 67,2% dos beneficios auxilio-doenca. Os diagnosticos mais incidentes foram as dorsopatias, hemorragia no inicio da gravidez e episodios depressivos. O ramo de atividade, sexo, e a idade representaram importantes fatores associados a incidencia de beneficios auxilio-doenca, sugerindo uma precarizacao das condicoes/relacoes de trabalho.

Occurrence of Mansonella ozzardi diagnosed using a polycarbonate membrane in a riverside population of Lábrea in the Western Brazilian Amazon

INTRODUCTION Mansonella ozzardi is a widely distributed filaria worm in the Amazon region. This study aimed to determine the prevalence of M. ozzardi infection in riverine communities of Lábrea municipality, Amazonas State, Brazil. METHODS A diagnostic blood filtration method in a polycarbonate membrane was used. RESULTS M. ozzardi was found in 50.3% of the sample, with the highest prevalence in farmers/fishermen (69.4%; χ 2 = -19.14, p<0.001). The prevalence was higher in longer-term residents (≥11 years; 60.2%). CONCLUSIONS M. ozzardi infection rates are high near the Purus River, much greater than those previously reported based on diagnosis using thick blood smears.

New insights into the genetic diversity of Leishmania RNA Virus 1 and its species-specific relationship with Leishmania parasites

Cutaneous leishmaniasis is a neglected parasitic disease that manifests in infected individuals under different phenotypes, with a range of factors contributing to its broad clinical spectrum. One factor, Leishmania RNA Virus 1 (LRV1), has been described as an endosymbiont present in different species of Leishmania. LRV1 significantly worsens the lesion, exacerbating the immune response in both experimentally infected animals and infected individuals. Little is known about the composition and genetic diversity of these viruses. Here, we investigated the relationship between the genetic composition of LRV1 detected in strains of Leishmania (Viannia) braziliensis and L. (V.) guyanensis and the interaction between the endosymbiont and the parasitic species, analyzing an approximately 850 base pair region of the viral genome. We also included one LRV1 sequence detected in L. (V.) shawi, representing the first report of LRV1 in a species other than L. braziliensis and L. guyanensis. The results illustrate the genetic diversity of the LRV1 strains analyzed here, with smaller divergences detected among viral sequences from the same parasite species. Phylogenetic analyses showed that the LRV1 sequences are grouped according to the parasite species and possibly according to the population of the parasite in which the virus was detected, corroborating the hypothesis of joint evolution of the viruses with the speciation of Leishmania parasites.