Trypanosoma (herpetosoma) Rangeli tejera, 1920: influence of host weight, size of inoculum, and route of infection upon experimental parasitemia

To study the influence of host age, inoculum size, and route of infection on Trypanosoma (Herpetosoma) rangeli, 12 lots of 6.0 g albino mice (NMRI strain) were infected up. with from 25x10¹ to 25x10(6) trypomastigotes/gram body weight harvested from LIT medium. The lower inocula produced low but persistent parasitemias, while the higher inocula produced high levels of parasitemia that fell quickly, suggesting the mobilization of resistance mechanisms. In other experiments, i.p. inoculation produced higher parasitemias than s.c. inoculation, and 6.0 g mice had higher parasitemias than 16.0 or 26.0 g mice. Thus, a standard methodology would seem to be necessary in the study of the various strains and/or species that may make up the T. rangeli complex.

Liver and serum soluble protein changes and pathomorphology in undernourished mice with acute Schistosomiasis mansoni

Body, liver and spleen weights; histopathology of the liver, spleen and intestines; hepatic and serum soluble proteins changes were the parameters studied in undernourished Swiss albino mice experimentally infected with S. mansoni. Non-infected deficient animab had lower liver/body weight and spleen/body weight ratios as compared to the controls (22.60% casein group). Infected mice showed higher values regardless the type of diet. Undernourished infected subgroup showed a persistent exudative periovular reaction in the liver. Soluble hepatic proteins content and serum protein fractions appeared to be lower in the deficient infected mice. A significant difference was detected in the gammaglobulin fraction between infected and non-infected animals fed the control diet with higher values for the former. Our data suggest that the effects of malnutrition, per se, are sometimes more detrimental to the host than those due to Manson 's schistosomiasis.

Human parvovirus B19 infection in HIV-positive patients

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

Clinical presentation of parvovirus B19 infection in HIV-infected patients with and without AIDS

Human parvovirus B19 replicates in erythrocyte precursors. Usually, there are no apparent hematological manifestations. However, in individuals with high erythrocyte turnover, as in patients with sickle-cell disease and in the fetus, the infection may lead to severe transient aplasia and hydrops fetalis, respectively. In AIDS patients, persistent infection may result in chronic anemia. By contrast, in HIV-positive patients without AIDS the infection evolves as a mild exanthematous disease. Two clinical descriptions exemplify these forms of presentation. In the first, an AIDS patient presented with bone marrow failure that responded to immunoglobulin. In the second, an HIV-positive patient without AIDS had a morbilliform rash, and needed no treatment. Knowing that an AIDS patient has chronic B19 anemia lessens concern about drug anemia; protects the patient from invasive diagnostic maneuvers; and prevents the patient from disseminating the infection. In AIDS patients with pure red cell aplasia, a search for parvovirus B19 DNA in the serum or in the bone marrow is warranted.

Detection of human herpesvirus-7 by qualitative nested-PCR: comparison between healthy individuals and liver transplant recipients

Diagnosis of human herpesvirus-7 active infection in transplant patients has proved difficult, because this virus is ubiquitous and can cause persistent infections in the host. The significance of viral DNA detected in leukocytes by PCR is unclear and cross-reaction in serological tests may occur. This study aimed to evaluate nested-PCR to detect human herpesvirus-7 active infection in liver transplant recipients compared to healthy individuals. human herpesvirus-7 nested-PCR was performed on leukocytes and sera of 53 healthy volunteers and sera of 29 liver transplant recipients. In healthy volunteers, human herpesvirus-7 was detected in 28.3% of leukocytes and 0% of serum. human herpesvirus-7 was detected in sera of 48.2% of the liver transplant recipients. Nested-PCR on DNA extracted from leukocytes detected latent infection and the study suggests that nested-PCR performed on serum could be useful to detect human herpesvirus-7 active infection in liver transplant recipients.

Hepatitis C: sexual or intrafamilial transmission? Epidemiological and phylogenetic analysis of hepatitis C virus in 24 infected couples

The role of sexual or intrafamilial transmission of hepatitis C is controversial. A phylogenetic analysis was performed on the non-structural region 5B of the hepatitis C virus (NS5B-HCV). High percentages of homology (mean of 98.3%) were shown between the couples. Twenty (83.3%) of the 24 men but only two of the women (8.3%) reported having had sexually transmitted diseases during their lives. The risk factors for HCV acquisition were blood transfusion (10 couples), use of illegal injected drugs (17), use of inhalants (15), acupuncture (5) and tattoos (5). The shared use of personal hygiene items included toothbrushes between six couples (25%), razor blades between 16 (66.7%), nail clippers between 21 (87.5%) and manicure pliers between 14 (58.3%). The high degree of similarity of the hepatitis C virus genome supports the hypothesis of hepatitis C virus transmission between these couples. The shared use of personal hygiene items suggests the possibility of intrafamilial transmission of infection.

Visceral leishmaniasis in Rio de Janeiro, Brazil: eco-epidemiological aspects and control

From 1977 (index case) to 2006, 87 cases of visceral leishmaniasis were confirmed in the municipality of Rio de Janeiro, Brazil, in periurban areas on the continental and coastal slopes of the Pedra Branca massif and the continental slopes of the Gericinó massif. The majority (65.5%) of the patients were more than five years old, predominantly males (61.5%), but without any difference between the sexes below the age of 14 years. The overall fatality rate was 10.4%. Two cases of visceral leishmaniasis/human immunodeficiency virus coinfection were detected. Leishmania chagasi was isolated from human and canine cases. The associations between the presence of phlebotomines and human and canine migrations, disorderly occupation involving degradation of environmental preservation areas and poor socioeconomic conditions may have created a favorable setting for the establishment and propagation of the disease. Close epidemiological surveillance associated with traditional control measures and others (active case researches, land clearing and health education), reduced the incidence of human cases from 2.8 per 100,000 inhabitants in 1981 to less than 0.01 per 100,000 since 1997. The canine infection rates decreased from 4.6% in 1984 to 1.6% in 2008. Lutzomyia longipalpis was not detected in some locations where human and canine cases occurred. In the years 2007 and 2008, no new human cases were reported, but there is a persistent and worrisome residual canine seroprevalence.

Level of behavior and knowledge concerning human papillomavirus among university students of a nursing college

INTRODUCTION: Human pappilomavirus is one of the most common sexually transmitted diseases, and persistent HPV infection is considered the most important cause of cervical cancer. It is detected in more than 98% of this type of cancer. This study aimed to determine the level of knowledge concerning human papillomavirus among nursing college students of a private educational institution located in the City of Bauru, SP, and correlate their knowledge according to the course year. METHODS: A descriptive study with a quantitative approach, performed with a questionnaire that permitted the quantification of data and opinions, thus guaranteeing the precision of the results without distortions in analysis or interpretation. The survey was applied to randomly selected 1st, 2nd, 3rd, and 4th-year nursing college students. Twenty students from each level were selected during August 2009, totaling 80 students of both genders. RESULTS: Observation revealed that 4th-year students had greater knowledge than 1st-year students, reflecting the greater period of study, the lack of knowledge of 1st-year students was due to the low level of information acquired before entering college. CONCLUSIONS: The need for complementary studies which determine the profile and knowledge of a larger number of teenagers in relation to HPV was established. The need for educational programs that can overcome this lack of information is undeniable, especially those aimed at making adolescents less susceptible to HPV and other STDs.

Restriction enzyme analysis of the human cytomegalovirus genome in specimens collected from immunodeficient patients in Belém, State of Pará, Brazil

INTRODUCTION: Human cytomegalovirus is an opportunistic betaherpesvirus that causes persistent and serious infections in immunodeficient patients. Recurrent infections occur due to the presence of the virus in a latent state in some cell types. It is possible to examine the virus using molecular methods to aid in the immunological diagnosis and to generate a molecular viral profile in immunodeficient patients. The objective of this study was to characterize cytomegalovirus genotypes and to generate the epidemiological and molecular viral profile in immunodeficient patients. METHODS: A total of 105 samples were collected from immunodeficient patients from the City of Belém, including newborns, hemodialysis patients, transplant recipients and HIV+ patients. An IgG and IgM antibody study was completed using ELISA, and enzymatic analysis by restriction fragment length polymorphism (RFLP) was performed to characterize viral genotypes. RESULTS: It was observed that 100% of the patients had IgG antibodies, 87% of which were IgG+/IgM-, consistent with a prior infection profile, 13% were IgG+/IgM+, suggestive of recent infection. The newborn group had the highest frequency (27%) of the IgG+/IgM+ profile. By RFLP analysis, only one genotype was observed, gB2, which corresponded to the standard AD169 strain. CONCLUSIONS: The presence of IgM antibodies in new borns indicates that HCMV continues to be an important cause of congenital infection. The low observed genotypic diversity could be attributed to the small sample size because newborns were excluded from the RFLP analysis. This study will be continued including samples from newborns to extend the knowledge of the general and molecular epidemiology of HCMV in immunodeficient patients.

Epidemiology of malaria in the municipality of Cruzeiro do Sul, State of Acre, Brazil, in 2010: uses of a control chart at the local level

INTRODUCTION: This study describes the uses of a control chart in the malaria surveillance at the local level, signaling whether there is a need to intensify or adapt control measures. METHODS: The districts of Cruzeiro do Sul (n=14), State of Acre, Brazil, were classified into three groups: I) those with an incidence lower than expected; II) those with an incidence within the expected range; and III) those with an epidemic. RESULTS: Thirteen of the fourteen districts had outbreaks of malaria at some point in 2010, and six districts showed persistent malaria epidemic throughout the year. CONCLUSIONS: The control chart may help the malaria control at the local level.

Clinical and hepatic evaluation in adult dengue patients: a prospective two-month cohort study

INTRODUCTION: To analyze the liver dysfunction and evolution of signs and symptoms in adult dengue patients during a two-month follow-up period. METHODS: A prospective cohort study was conducted in Campos dos Goytacazes, Rio de Janeiro, Brazil, from January to July, 2008. The evolution of laboratory and clinical manifestations of 90 adult dengue patients was evaluated in five scheduled visits within a two-month follow-up period. Twenty controls were enrolled for the analysis of liver function. Patients with hepatitis B, hepatitis C, those known to be human immunodeficiency virus (HIV) seropositive and pregnant women were excluded from the study. RESULTS: At the end of the second month following diagnosis, we observed that symptoms persisted in 33.3% (30/90) of dengue patients. We also observed that, 57.7% (15/26) of the symptoms persisted at the end of the second month. The most persistent symptoms were arthralgia, fatigue, weakness, adynamia, anorexia, taste alteration, and hair loss. Prior dengue virus (DENV) infection did not predispose patients to a longer duration of symptoms. Among hepatic functions, transaminases had the most remarkable elevation and in some cases remained elevated up to the second month after the disease onset. Alanine aminotransferase (ALT) levels overcame aspartate aminotransferase (AST) during the convalescent period. Male patients were more severely affected than females. CONCLUSIONS: Dengue fever may present a wide number of symptoms and elevated liver transaminases at the end of the second month.

Ventriculoperitoneal shunts for treating increased intracranial pressure in cryptococcal meningitis with or without ventriculomegaly

Introduction Cryptococcosis is an opportunistic mycosis, especially in patients that are human immunodeficiency virus (HIV)-positive, and frequently involves the central nervous system. Methods We assessed the potential of ventriculoperitoneal shunting (VPS) in preventing mortality due to uncontrollable intracranial hypertension (ICH) in 15 patients with acquired immunodeficiency syndrome (AIDS)-related cryptococcal meningitis. Results After 2 weeks of antifungal therapy consisting of amphotericin B deoxycholate with or without fluconazole, patients with persistent ICH underwent VPS, despite having persistent Cryptococcus neoformans infection. In 12 patients, the uncontrollable ICH was resolved by VPS. Conclusions Patients with cryptococcal meningoencephalitis who have ICH must be considered for VPS even with positive cerebrospinal fluid cultures.

Description of microsporidia in simulids: molecular and morphological characterization of microsporidia in the larvae of Simulium pertinax Kollar (Diptera: Simuliidae)

IntroductionMicrosporidia constitute the most common black fly pathogens, although the species' diversity, seasonal occurrence and transmission mechanisms remain poorly understood. Infections by this agent are often chronic and non-lethal, but they can cause reduced fecundity and decreased longevity. The objective of this study was to identify microsporidia infecting Simulium (Chirostilbia) pertinax (Kollar, 1832) larvae from Caraguatatuba, State of São Paulo, Brazil, by molecular and morphological characterization.MethodsLarvae were collected at a single point in a stream in a rural area of the city and were kept under artificial aeration until analysis. Polydispyrenia spp. infection was characterized by the presence of at least 32 mononuclear spores measuring 6.9 ± 1.0 × 5.0 ± 0.7µm in persistent sporophorous vesicles. Similarly, Amblyospora spp. were characterized by the presence of eight uninucleate spores measuring 4.5 × 3.5µm in sporophorous vesicles.ResultsThe molecular analysis confirmed the presence of microsporidian DNA in the 8 samples (prevalence of 0.51%). Six samples (Brazilian larvae) were related to Polydispyrenia simulii and Caudospora palustris reference sequences but in separate clusters. One sample was clustered with Amblyospora spp. Edhazardia aedis was the positive control taxon.ConclusionsSamples identified as Polydispyrenia spp. and Amblyospora spp. were grouped with P. simulii and Amblyospora spp., respectively, corroborating previous results. However, the 16S gene tree showed a considerable distance between the black fly-infecting Amblyospora spp. and the mosquito-infecting spp. This distance suggests that these two groups are not congeneric. Additional genomic region evaluation is necessary to obtain a coherent phylogeny for this group.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará, Northeastern Brazil

INTRODUCTION: Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD) to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. METHODS: The susceptibility reference lineage (SRL) was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph) of the SRL. RESULTS: The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50) that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. CONCLUSIONS: We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil

AbstractINTRODUCTION:Despite chemical and physical vector control strategies, persistent infestations of Triatoma sordida have been reported in a large part of Minas Gerais, Brazil, and the cause for this is little investigated. We aimed to characterize the deltamethrin toxicological profile in peridomestic T. sordidapopulations from Triângulo Mineiro area of Minas Gerais.METHODS:Susceptibility to deltamethrin was assessed in seventeen peridomestic T. sordida populations. Serial dilutions of deltamethrin in acetone (0.2µL) were topically applied on the first instar nymphs (F1; five days old; fasting weight, 1.2 ± 0.2mg). Dose response results were analyzed using Probit software, and the lethal doses, slope and resistance ratios were determined. Qualitative tests were also performed.RESULTS:The deltamethrin susceptibility profile of T. sordida populations revealed resistance ratios ranging from 0.84 to 2.8. The percentage mortality in response to a diagnostic dose was 100.0% in all populations.CONCLUSIONS:From our results, the lack of resistance to insecticides but persistent T. sordida infestations in the Triângulo Mineiro area may be because of: 1) environmental degradation facilitating dispersion of T. sordida , allowing colonization in artificial ecotopes; 2) operational failures; and 3) complexity of the peridomicile in the study area.These variables are being investigated.