The influence of the human genome on chronic viral hepatitis outcome

The mechanisms that determine viral clearance or viral persistence in chronic viral hepatitis have yet to be identified. Recent advances in molecular genetics have permitted the detection of variations in immune response, often associated with polymorphism in the human genome. Differences in host susceptibility to infectious disease and disease severity cannot be attributed solely to the virulence of microbial agents. Several recent advances concerning the influence of human genes in chronic viral hepatitis B and C are discussed in this article: a) the associations between human leukocyte antigen polymorphism and viral hepatic disease susceptibility or resistance; b) protective alleles influencing hepatitis B virus (HBV) and hepatitis C virus (HCV) evolution; c) prejudicial alleles influencing HBV and HCV; d) candidate genes associated with HBV and HCV evolution; d) other genetic factors that may contribute to chronic hepatitis C evolution (genes influencing hepatic stellate cells, TGF-beta1 and TNF-alpha production, hepatic iron deposits and angiotensin II production, among others). Recent discoveries regarding genetic associations with chronic viral hepatitis may provide clues to understanding the development of end-stage complications such as cirrhosis or hepatocellular carcinoma. In the near future, analysis of the human genome will allow the elucidation of both the natural course of viral hepatitis and its response to therapy.

Human vaccinia-like virus outbreaks in São Paulo and Goiás States, Brazil: virus detection, isolation and identification

Since October 2001, the Adolfo Lutz Institute has been receiving vesicular fluids and scab specimens of patients from Paraíba Valley region in the São Paulo and Minas Gerais States and from São Patricio Valley, in the Goiás State. Epidemiological data suggested that the outbreaks were caused by Cowpox virus or Vaccinia virus. Most of the patients are dairy milkers that had vesiculo-pustular lesions on the hands, arms, forearms, and some of them, on the face. Virus particles with orthopoxvirus morphology were detected by direct electron microscopy (DEM) in samples of 49 (66.21%) patients of a total of 74 analyzed. Viruses were isolated in Vero cell culture and on chorioallantoic membrane (CAM) of embryonated chicken eggs. Among 21 samples submitted to PCR using primers for hemagglutinin (HA) gene, 19 were positive. Restriction digestion with TaqI resulted in four characteristic Vaccinia virus fragments. HA nucleotide sequences showed 99.9% similarity with Cantagalo virus, described as a strain of Vaccinia virus. The only difference observed was the substitution of one nucleotide in the position 616 leading to change in one amino acid of the protein in the position 206. The phylogenetic analysis showed that the isolates clustered together with Cantagalo virus, other Vaccinia strains and Rabbitpox virus.

Cutaneous anthrax in Lima, Peru: retrospective analysis of 71 cases, including four with a meningoencephalic complication

Anthrax is a zoonosis produced by Bacillus anthracis, and as an human infection is endemic in several areas in the world, including Peru. More than 95% of the reported naturally acquired infections are cutaneous, and approximately 5% of them can progress to meningoencephalitis. In this study we review the clinical and epidemiological characteristics of the patients with diagnosis of cutaneous anthrax evaluated between 1969 and 2002 at the Hospital Nacional Cayetano Heredia (HNCH) and the Instituto de Medicina Tropical Alexander von Humboldt in Lima, Peru. Seventy one patients were included [49/71 (69%) of them men], with a mean age of 37 years. The diagnoses were classified as definitive (44%) or probable (56%). The most common occupation of the patients was agriculture (39%). The source of infection was found in 63 (88.7%) patients. All the patients had ulcerative lesions, with a central necrosis. Most of the patients (65%) had several lesions, mainly located in the upper limbs (80%). Four patients (5.6%) developed meningoencephalitis, and three of them eventually died. In conclusion, considering its clinical and epidemiological characteristics, cutaneous anthrax must be included in the differential diagnosis of skin ulcers. A patient with clinical suspicion of the disease should receive effective treatment soon, in order to avoid neurological complications which carry a high fatality rate.

Rat hepatocyte invasion by Listeria monocytogenes and analysis of TNF-alpha role in apoptosis

Listeria monocytogenes, etiological agent of severe human foodborne infection, uses sophisticated mechanisms of entry into host cytoplasm and manipulation of the cellular cytoskeleton, resulting in cell death. The host cells and bacteria interaction may result in cytokine production as Tumor Necrosis Factor (TNF) alpha. Hepatocytes have potential to produce pro-inflammatory cytokines as TNF-alpha when invaded by bacteria. In the present work we showed the behavior of hepatocytes invaded by L. monocytogenes by microscopic analysis, determination of TNF-alpha production by bioassay and analysis of the apoptosis through TUNEL technique. The presence of bacterium, in ratios that ranged from 5 to 50,000 bacteria per cell, induced the rupture of cellular monolayers. We observed the presence of internalized bacteria in the first hour of incubation by electronic microscopy. The levels of TNF-alpha increased from first hour of incubation to sixth hour, ranging from 0 to 3749 pg/mL. After seven and eight hours of incubation non-significant TNF-alpha levels decrease occurred, indicating possible saturation of cellular receptors. Thus, the quantity of TNF-alpha produced by hepatocytes was dependent of the incubation time, as well as of the proportion between bacteria and cells. The apoptosis rate increased in direct form with the incubation time (1 h to 8 + 24 h), ranging from 0 to 43%, as well as with the bacteria : cells ratio. These results show the ability of hepatocyte invasion by non-hemolytic L. monocytogenes, and the main consequences of this phenomenon were the release of TNF-alpha by hepatocytes and the induction of apoptosis. We speculate that hepatocytes use apoptosis induced by TNF-alpha for release bacteria to extracellular medium. This phenomenon may facilitate the bacteria destruction by the immune system.

Serological markers and risk factors for hepatitis B and C viruses in patients infected with human immunodeficiency virus

Both hepatitis B and hepatitis C viruses (HBV and HCV) infection are common in HIV-infected individuals as a result of shared risk factors for acquisition. A serological study for HBV and HCV was performed in 251 HIV-positive individuals from Medellín, Colombia. A qualitative RT-PCR for HCV was done in 90 patients with CD4+ T-cell count < 150 per mm³. Serological markers for HBV infection were present in 97 (38.6%) patients. Thirty six of them (37.1%) had isolated anti-HBc. A multivariate analysis indicated that the following risk factors were significantly associated with the presence of these markers: age (OR = 1.05, 95% CI: 1.01-1.08), pediculosis pubis (OR = 1.83, 95% CI: 1.01-3.33), men who have sex with men and women (OR = 3.23, 95% CI: 1.46-7.13) and men who have sex only with men (OR = 3.73, 95% CI: 1.58-8.78). The same analysis restricted to women showed syphilis as the only significant risk factor. Thus, HBV infection was considerably associated with high risk sexual behavior. HCV was present in only two (0.8%) of HIV patients. Both of them were positive by RT-PCR and anti-HCV. This low frequency of HIV/HCV coinfection was probably due to the uncommon intravenous drug abuse in this population. The frequent finding of isolated anti-HBc warrants molecular approaches to rule out the presence of cryptic HBV infection.

Salivary gland proteins of the human malaria vector, Anopheles dirus B (Diptera: Culicidae)

Salivary gland proteins of the human malaria vector, Anopheles dirus B were determined and analyzed. The amount of salivary gland proteins in mosquitoes aged between 3 - 10 days was approximately 1.08 ± 0.04 µg/female and 0.1 ± 0.05 µg/male. The salivary glands of both sexes displayed the same morphological organization as that of other anopheline mosquitoes. In females, apyrase accumulated in the distal regions, whereas alpha-glucosidase was found in the proximal region of the lateral lobes. This differential distribution of the analyzed enzymes reflects specialization of different regions for sugar and blood feeding. SDS-PAGE analysis revealed that at least seven major proteins were found in the female salivary glands, of which each morphological region contained different major proteins. Similar electrophoretic protein profiles were detected comparing unfed and blood-fed mosquitoes, suggesting that there is no specific protein induced by blood. Two-dimensional polyacrylamide gel analysis showed the most abundant salivary gland protein, with a molecular mass of approximately 35 kilodaltons and an isoelectric point of approximately 4.0. These results provide basic information that would lead to further study on the role of salivary proteins of An. dirus B in disease transmission and hematophagy.

Seroprevalence of human toxocariasis in Andean communities from the Northeast of Lima, Peru

The aim of this study was to assess the seroprevalence of human toxocariasis in three Andean communities from the Northeast of Lima, Peru. A total of 303 subjects including children and adults were studied and blood samples were collected to detect anti-Toxocara antibodies by ELISA-IgG test and by hematological examination; stool samples were collected also for parasitological examination. The overall seroprevalence of toxocariasis observed in the total population was 20.46%, with a significant high proportion in children from one to 10 years old (p = 0.034). Among the subjects with positive serology, 32.26% of them had respiratory disturbances, 22.58% hepatomegaly, 17.74% ocular signs or symptoms, 14.51% abdominal pain, 9.68% neurological involvement, and 4.84% cutaneous signs, but none of these clinical features were associated to a positive serology by multivariate analysis. Furthermore, 79.03% of seropositive subjects also harbored at least one intestinal parasite, which was associated to a positive serology (p < 0.05). The presence of pets within the houses, a previous history of pica or geophagia and the use of public places were also present in this population, but only the latter was associated to the serology (p < 0.05). In conclusion, clinical, serological, and epidemiological evidences for larval Toxocara infection were found in the studied population.

Human toxocariasis: a seroepidemiological survey in the Amazonian city of Yurimaguas, Peru

The aim of this study was to determine the seroprevalence of the infection by Toxocara in the general population of the Amazonian city of Yurimaguas, Peru. From March to August 2008, a total of 300 subjects were sampled and tested by means of a Toxocara ELISA-IgG test. A clinical and epidemiological questionnaire was used to assess the symptomatology and risk factors associated with human toxocariasis. The overall rate of seropositivity was 35.66%, with a significant high proportion in children (p < 0.001). The clinical evaluation revealed that 95.33% of the seropositive group had some type of symptomatology: headache (66.36%), respiratory compromise (63.55%), abdominal pain (54.21%), cutaneous signs (40.19%) and ocular manifestations (36.45%), and almost all of them were statistically significant (p < 0.001). Furthermore, 56.07% of the seropositive subjects presented at least one intestinal pathogen parasite with predominance of helminthes, but without significant association (p = 0.334). The analysis of risk factors showed only that the use of public places and geophagia exhibited a significant association with the seropositivity (p < 0.001). Clinical, serological and epidemiological findings associated to infection with Toxocara were observed in the present study and future studies should be done to assess this serious health problem.

Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil

The Ministry of Health's National Human Rabies Control Program advocates pre-exposure prophylaxis (PEP) for professionals involved with animals that are at risk of contracting rabies. We report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. The antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. The veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. After onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by RT-PCR. Genetic sequencing showed that the infection was caused by variant 3 (Desmodus rotundus), a finding confirmed by tests on the brain sample. It is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. This study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.

Morphological changes in the digestive system of 93 human immunodeficiency virus positive patients: an autopsy study

Involvement of the digestive system in patients with acquired immunodeficiency syndrome (AIDS) is frequent and many changes in these patients are diagnosed only at autopsy. There are few studies of autopsy with detailed analysis of this system and only one was conducted in Brazil. We evaluated each segment of the digestive system in 93 consecutive autopsies of patients infected with human immunodeficiency virus (HIV) and the importance of these lesions to death. Of these, 90 (96.8%) patients had AIDS. We reviewed medical records, autopsy reports and histological sections from tongue to rectum stained with hematoxylin-eosin. When necessary, we analyzed special stains and immunohistochemistry to investigate infections. There was damage to the digestive system in 73 (78.5%) cases. The most common infections were candidiasis (42%), cytomegalovirus (29%), histoplasmosis (11.8%), toxoplasmosis (9.7%) and mycobacterial infection (9.7%). Malignancies were rare, present in four (4.3%) cases (two Kaposi's sarcoma, one adenocarcinoma and one metastatic embryonal carcinoma). All segments showed lesions: tongue (48.6%), esophagus (44.8%), stomach (44.7%), colon (43.2%) and small intestine (28.9%). The lesions found were immediate cause of death in five (5.4%) cases. In another 36 (38.7%) cases the basic disease was systemic and also compromised the digestive system.

TESTING A SUBTYPE-SPECIFIC GP41 AMPLIFICATION METHOD FOR GENOTYPING INDIVIDUALS INFECTED BY HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 IN THE BRAZILIAN POPULATION OF ITAJAÍ, SOUTH BRAZIL

The method used by YAGYU et al. for the subtype-specific polymerase chain reaction (PCR) amplification of the gp41 transmembrane region of the human immunodeficiency virus type-1 (HIV-1) env gene, was tested. HIV-1 proviral DNA from 100 infected individuals in Itajaí, South Brazil was used to analyze this method. Seventy individuals were determined according to this method as having PCR products at the expected size for subtypes B, C, D and F. Of these individuals, 26 (37.1%) were observed as having the expected amplification for subtype C, and 42 (60%) were observed as having the expected products for subtypes B and D. Of the subtype B and D amplicons, 16 (22.9%) were classified as subtype D, and 26 (37.1%) were classified as subtype B. Two individuals (2.9%) had amplicons that were observed after subtype F-specific amplification was performed. Sequencing and comparing the patient sequences to reference sequences confirmed the classification of sequences of subtypes C and B. However, sequences that were falsely determined as being D and F in the PCR assay were determined as being subtypes C and B, respectively, by sequence analysis. For those individuals from whom no amplified products were obtained, a low viral load that was indicated in their patient history may explain the difficulty in subtyping by PCR methods. This issue was demonstrated by the results of ANOVA when testing the effect of viral load on the success of PCR amplification. The alignment of the obtained sequences with HIV-1 reference sequences demonstrated that there is high intra-subtype diversity. This indicates that the subtype-specific primer binding sites were not conserved or representative of the subtypes that are observed in the Brazilian populations, and that they did not allow the correct classification of HIV-1 subtypes. Therefore, the proposed method by YAGYU et al. is not applicable for the classification of Brazilian HIV-1 subtypes.

FIRST CASE OF HUMAN INFECTION BY Bertiella studeri (Blanchard, 1891) Stunkard,1940 (Cestoda; Anoplocephalidae) IN BRAZIL

SUMMARY Cestodes of the Bertiella genus are parasites of non-human primates found in Africa, Asia, Oceania and the Americas. Species Bertiella studeri and Bertiella mucronatacould, accidentally, infect human beings. The infection occurs from ingestion of mites from the Oribatida order containing cysticercoid larvae of the parasite. The objective of this report is to register the first case of human infection by Bertiella studeri in Brazil. Proglottids of the parasite, found in the stool sample of a two-and-a-half-year-old child, were fixed, stained and microscopically observed to evaluate its morphological characteristics. Eggs obtained from the proglottids were also studied. The gravid proglottids examined matched the description of the genus Bertiella. The eggs presented a round shape, with the average diameter of 43.7 µm, clearly showing the typical pyriform apparatus of B. studeri. The authors concluded that the child was infected with Bertiella studeri,based on Stunkard's (1940) description of the species. This is the fifth case of human Bertiellosis described in Brazil through morphometric analysis of the parasite, the third in Minas Gerais State and the first diagnosed case of Bertiella studeriin Brazil.

HUMAN T-LYMPHOTROPIC VIRUS 1 (HTLV-1) AND HUMAN T-LYMPHOTROPIC VIRUS 2 (HTLV-2): GEOGRAPHICAL RESEARCH TRENDS AND COLLABORATION NETWORKS (1989-2012)

Publications are often used as a measure of research work success. Human T-lymphotropic virus (HTLV) type 1 and 2 are human retroviruses, which were discovered in the early 1980s, and it is estimated that 15-20 million people are infected worldwide. This article describes a bibliometric review and a coauthorship network analysis of literature on HTLV indexed in PubMed in a 24-year period. A total of 7,564 documents were retrieved, showing a decrease in the number of documents from 1996 to 2007. HTLV manuscripts were published in 1,074 journals. Japan and USA were the countries with the highest contribution in this field (61%) followed by France (8%). Production ranking changed when the number of publications was normalized by population (Dominican Republic and Japan), by gross domestic product (Guinea-Bissau and Gambia), and by gross national income per capita (Brazil and Japan). The present study has shed light on some of the defining features of scientific collaboration performed by HTLV research community, such as the existence of core researchers responsible for articulating the development of research in the area, facilitating wider collaborative relationships and the integration of new authors in the research groups.

Human immune responses during schistosomiasis mansoni

Studies of immune responses as they occur in patients with schistosomiasis appear to progress relative to corrent technological advances, and to advance despite the understandable inability to pursue in vivo manipulations in this host/parasite system. Emphasis is most often placed on making immunological comparisons between such patient groups as reinfected/non-reinfected, intestinals/hepatosplenic, high/low intensities of infection, infected/uninfected within endemic areas, and those born of infected/uninfected mothers. Based on these types of comparisons, reasonable conjectures can be made regarding the immunological occurrences during this chronic exposure condition. Some consideration is now being given to the immune mechanisms of some of the observations made, and while some of these must then be carried back to experimental models for further manipulation-based analysis, new technological developments continue to assist in the field/bench ability to ask questions that might assist our understanding to a point where this knowledge can be applied to shaping developmental approaches to vaccine development and the goal of alleviating morbidity.

Histopathology of human American cutaneous leishmaniasis before and after treatment

Chemical therapy for the treatment of leishmaniasis is still inadequate, and a number of drugs and therapeutic programs are being tested. Besides treatment, the ultimate goal is an effective cure, and histopathological analyses of the lesion cicatrices constitute an important measure of treatment success, or otherwise, in this respect. In this paper, we describe histopathological patterns in cases of American cutaneous leishmaniasis in 32 patients from the municipality of Caratinga, Minas Gerais, Brazil, before and after treatment with the following therapeutic methodos: l) leishvacin + glucantime; 2) leishvacin + BCG associated with glucantime; 3) glucantime; 4) leishvacin + BCG. Lesion fragments were collected from all patients by biopsy prior to, and approximately 30 days after, each treatment which resulted in a clinical diagnosis of cure. Following the analysis of slides, the preparations were described from a histopathological point of view and grouped taking into account the prevalence or significance of the characteristic elements. This process resulted in the following classification: 1. exsudative reaction (ER); 2. exsudative giant cell reaction (EGCR); 3. exsudative productive reaction (EPR); 4. exsudative productive giant cell reaction (EPGCR); 5. exsudative productive necrotic reaction (EPNR); 6. necrotic exsudative reaction (NER); 7. productive exsudative reaction (PER), 8. productive giant cell reaction (PGCR); 9. productive exsudative giant cell reaction (PEGCR); 10. productive exsudative giant cell granulomatous reaction (PEGCGR); 11. productive reaction (PR) and 12. productive cicatricial (cure) reaction (PCR). After this analysis, it was noted that clinical cure did not always coincide with histopathological cure.