Mathematical model for HIV dynamics in HIV-specific helper cells

In this paper we study a delay mathematical model for the dynamics of HIV in HIV-specific CD4 + T helper cells. We modify the model presented by Roy and Wodarz in 2012, where the HIV dynamics is studied, considering a single CD4 + T cell population. Non-specific helper cells are included as alternative target cell population, to account for macrophages and dendritic cells. In this paper, we include two types of delay: (1) a latent period between the time target cells are contacted by the virus particles and the time the virions enter the cells and; (2) virus production period for new virions to be produced within and released from the infected cells. We compute the reproduction number of the model, R0, and the local stability of the disease free equilibrium and of the endemic equilibrium. We find that for values of R0<1, the model approaches asymptotically the disease free equilibrium. For values of R0>1, the model approximates asymptotically the endemic equilibrium. We observe numerically the phenomenon of backward bifurcation for values of R0⪅1. This statement will be proved in future work. We also vary the values of the latent period and the production period of infected cells and free virus. We conclude that increasing these values translates in a decrease of the reproduction number. Thus, a good strategy to control the HIV virus should focus on drugs to prolong the latent period and/or slow down the virus production. These results suggest that the model is mathematically and epidemiologically well-posed.

New findings on the dynamics of HIV and TB coinfection models

In this paper we study a model for HIV and TB coinfection. We consider the integer order and the fractional order versions of the model. Let α∈[0.78,1.0] be the order of the fractional derivative, then the integer order model is obtained for α=1.0. The model includes vertical transmission for HIV and treatment for both diseases. We compute the reproduction number of the integer order model and HIV and TB submodels, and the stability of the disease free equilibrium. We sketch the bifurcation diagrams of the integer order model, for variation of the average number of sexual partners per person and per unit time, and the tuberculosis transmission rate. We analyze numerical results of the fractional order model for different values of α, including α=1. The results show distinct types of transients, for variation of α. Moreover, we speculate, from observation of the numerical results, that the order of the fractional derivative may behave as a bifurcation parameter for the model. We conclude that the dynamics of the integer and the fractional order versions of the model are very rich and that together these versions may provide a better understanding of the dynamics of HIV and TB coinfection.

A coinfection model for HIV and HCV

We study a mathematical model for the human immunodeficiency virus (HIV) and hepatites C virus (HCV) coinfection. The model predicts four distinct equilibria: the disease free, the HIV endemic, the HCV endemic, and the full endemic equilibria. The local and global stability of the disease free equilibrium was calculated for the full model and the HIV and HCV submodels. We present numerical simulations of the full model where the distinct equilibria can be observed. We show simulations of the qualitative changes of the dynamical behavior of the full model for variation of relevant parameters. From the results of the model, we infer possible measures that could be implemented in order to reduce the number of infected individuals.

Prestadores de cuidados familiares a doentes com VIH/SIDA: perfil psico-emocional e social

RESUMO: Com o presente estudo pretendemos identificar a sobrecarga resultante do envolvimento familiar com os doentes portadores de VIH/SIDA. Numa breve introdução teórica, procedemos à revisão dos conceitos sobrecarga familiar e dos sentimentos/emoções vivenciados pelos prestadores de cuidados. Metodologia: Estudo do tipo descritivo e exploratório, com uma amostra de 51 indivíduos, cuja finalidade consiste na caracterização dos prestadores de cuidados familiares a doentes com VIH/SIDA. Objectivos: Identificar quem o doente com VIH/SIDA, considera ser a pessoa significativa nos cuidados informais. Caracterizar, do ponto de vista sócio-demográfico, os doentes e os prestadores de cuidados familiares. Identificar sentimentos e emoções de vivências, que justifiquem o sofrimento emocional e as repercussões na sobrecarga familiar nos prestadores de cuidados informais. Instrumentos: Na avaliação da sobrecarga familiar, utilizámos o Questionário de Problemas Familiares”- FPQ (Family Problemas Questionnaire). Para identificação dos Acontecimentos de Vida, adoptámos a escala de Holmes e Rahe (Life Events); Para identificação do estrato social escolhemos escala de Graffar. Finalmente, para a caracterização sócio-demografica concebemos dois questionários: um dirigido aos doentes e o outro aos prestadores de cuidados informais. Conclusões: A sobrecarga da doença VIH/SIDA, nos prestadores de cuidados familiares, não é uniforme nas diferentes dimensões. A dimensão sobrecarga subjectiva é superior à objectiva. O suporte social revela-se fraco, relacionado com as perdas familiares, devidas a morte, pelas relações familiares disfuncionais, entre os membros da família, pela falta de apoio e informação dos técnicos de saúde. O sexo feminino é predominante nos cuidadores. As mães e esposas são o grau de parentesco dominante. Os solteiros são o grupo mais afectado pelo VIH/SIDA. Os cuidadores apresentam idade superior à dos doentes. O estrato social preponderante é o médio baixo e o baixo. Os familiares, apesar da atitude negativa dos doentes perante os cuidadores, mantêm-se envolvidos. Segundo a avaliação multiaxial proposta pelo DM-IV, constatámos, ao nível do eixo I, sintomatologia clínica do tipo das perturbações depressivas e perturbações da ansiedade. No eixo IV, os cuidadores evidenciam problemas psicossociais e ambientais, nomeadamente nas categorias problemas com o grupo de apoio primário, problemas relacionados como grupo social, problemas educacionais, problemas de alojamento, problemas económicos. Os problemas relacionados com o grupo de apoio primário, são os que mais parecem contribuir para os problemas psicossociais e ambientais.---------------------------------------ABSTRACT: This study wants to describe several problems as a result of the family’s relationship with HIV/AIDS patients, like overload. In a brief theoric introduction, we made a small revision about the concepts of family’s overload, and feelings or emotions that have been lived by the people who provide cares to the patients with this chronic disease. Methodology: This is a describing and exploratory study, with a sample with 51 individuals, with the aim to characterize the people inside the family who give care HIV/AIDS patients. Aim: To identify who are the most important people in informal cares from the patient perspective. To characterize, in a social-demographic point of view, patients and the people who take care of them. To identify feelings and emotions that could explain an emotional suffer, and some causes in the family burden. Means: to evaluate the family’s overload we used the Family Problems Questionnaire (FPQ). To identify life events we adopted the Holmes and Rahe scale. To identify the social stratum we used the Graffer scale. Finally to do a socio-economic characterization we did two kinds of questionnaire, the first one was directed for the patients, and the second one was chosen for the people who give care. Conclusions: The HIV/AIDS disease burden on the people who takes familiar cares isn’t uniform on several areas that we studied. The subjective overload it is superior to the objective. The social support is weak and poor, and related with family losses by dead, dysfunctional family relationships, and the lack of support and information by the medical staff. Mothers and wives are the dominant relative degree. And the singles are the major group with HIV/AIDS disease. The people who take care are usually older than the sick. The major social status is low or medium-low. The relatives keep evolved though the negative attitude of the sick. According with the evaluation multiaxial proposed by the DM-IV, in axle 1 we note clinic sintomatologic belonging to the type depressive perturbations and perturbations of the anxiety. Regarding with axle IV the caretakers show up psycho-social and environmental problems, namely on the categories: problems with the primary support group and problems related as social group, educational problems, accommodation problems and.

Difficulties in diagnosing atypical primary HIV-1 infection

Several cases of primary HIV-1 infection are not identified, either because the diagnosis is not suspected or because they test negative for HIV-1 antibody. This work presents an uncommon case of primary HIV-1 infection in an young parenteral drug abuser man, who presented symptoms of acute hepatitis. During the initial acute phase the serum sample of the patient tested negative for the presence of antibodies against several viruses, including HIV-1. Nevertheless, the diagnosis of primary HIV-1 infection was suspected by using an alternative method for"in vitro" induced antibody production (IVIAP), and confirmed by p24 antigen serum positivity and seroconversion in serial plasma samples of the patient. The authors suggest the use of the IVIAP and others complementary assays to help the diagnosis of acute HIV-1 infection in persons at high risk conditions.

The malarial impact on the nutritional status of Amazonian adult subjects

The anthropometric (body weight, height, upper arm circumference, triceps and subescapular skinfolds; Quetelet index and arm muscle circunference) and blood biochemistry (proteins and lipids) parameters were evaluated in 93 males and 27 females, 17-72 years old voluntaries living in the malarial endemic area of Humaita city (southwest Amazon). According to their malarial history they were assembled in four different groups: G1-controls without malarial history (n:30); G2 - controls with malarial history but without actual manifestation of the disease (n:40); G3 - patients with Plasmodium vivax (n:19) and G4 - patients with Plasmodium falciparum (n:31). The malarial status was stablished by clinical and laboratory findings. The overall data of anthropometry and blood biochemistry discriminated the groups differently. The anthropometric data were low sensitive and contrasted only the two extremes (G1>G4) whereas the biochemistry differentiated two big groups, the healthy (G1+G2) and the patients (G3+G4). The nutritional status of the P. falciparum patients was highly depressed for most of the studied indices but none was sensitive enough to differentiate this group from the P. vivax group (G3). On the other hand the two healthy groups could be differentiated through the levels of ceruloplasmin (G1G2). Thus it seems that the malaria-malnourishment state exists and the results could be framed either as a consequence of nutrient sink and/or the infection stress both motivated by the parasite.

Evaluation of nutritional status in patients with endemic pemphigus foliaceus

Sixteen patients with endemic pemphigus foliaceus were submitted to nutritional evaluation. Ten had the localized form of the disease (Group G1) and six the disseminated form (Group G2). The patients were submitted to anthropometric measurements (weight, height, Quetelét index, tricipital skin fold, subscapular skin fold, arm circumference, arm muscle circumference, arm area, arm muscle area, and arm adipose area) and to laboratory evaluation by protein electrophoresis. Arm circumference, arm area and arm muscle area showed lower values in G2 than in G1. Weight and arm muscle circumference tended to the lower in G2 than in G1. Protein electrophoresis showed decreased albumin levels in both groups, with lower values in G2. Overall analysis of the results permits us to conclude that patients with endemic pemphigus foliaceus present signs and symptoms of protein, but not calorie, malnutrition and that this malnutrition is more marked in patients with disseminated pemphigus foliaceus.

Equidade na saúde e nos cuidados de saúde : migrantes e não migrantes na infecção de VIH/SIDA em Portugal

RESUMO - Este estudo tem como objectivo analisar a questão da equidade em saúde e nos cuidados de saúde entre migrantes e não migrantes no contexto da infecção de VIH/SIDA. A equidade em saúde e nos cuidados de saúde são valores de justiça distributiva. Este princípio representa um direito essencial para atingir uma melhor saúde e preocupa-se com a redução das desigualdades injustas em saúde e nos cuidados de saúde entre classes socioeconómicas. Os migrantes podem ser mais propensos a piores níveis de saúde do que os não migrantes devido a desigualdades sociais, na infecção por VIH/SIDA. Há escassez de estudos sobre a equidade em saúde e nos cuidados de saúde entre migrantes e não migrantes, aplicado ao contexto de VIH/SIDA em Portugal. Este é um país recente de migração e apresenta um aumento do número de casos de VIH/SIDA. O desenvolvimento deste estudo é importante para uma melhor compreensão da realidade da equidade em saúde e cuidados de saúde entre migrantes e não migrantes. Para a metodologia deste estudo, foram utilizados os dados da notificação obrigatória dos casos de VIH/SIDA em Portugal. A nacionalidade foi utilizada como aproximação ao estatuto de migrante. Através deste estudo empírico, foi possível constatar que os não nacionais estão sobre-representados nos casos notificados com um aumento no número de casos nos últimos anos. Estes dados sugerem uma iniquidade na saúde e nos cuidados de saúde a favor dos nacionais. Os portugueses representam. ----- ABSTRACT - The main goal of this work was to analyze the equity in health and health care between migrants and non migrants in the HIV/AIDS context. Equity in health and health care is a value of distributive justice. Is a primary right in order to achieve a better health and is concerned with a reduction in unfair inequality in health and health care between socioeconomic classes. Migrants are more susceptible to worse health levels due to socio inequalities, especially in the HIV/AIDS disease, when compared to non migrants. There is a scarcity of studies about health and health care between migrants and non migrants applied to the HIV/AIDS context in Portugal. Migration in Portugal is a recent, but increasing, phenomenon regarding the number of HIV/AIDS cases. This study brings a new overview over the equity of health and health care between migrants and non migrants. The methodology of this study uses mandatory notification of the HIV/AIDS cases detected in Portugal, and the nationality was used as a proxy to the migrant status. This empirical study allowed, detect that non nationals are overrepresented among notified cases, although the number has increased in the last years. This data suggests an inequity in health and health care in favor of nationals. Portuguese people’s represent the majority of notified cases, and the PALOP citizens come in second place.

Seroprevalence of HIV, HTLV-I/II and other perinatally-transmitted pathogens in Salvador, Bahia

Generation of epidemiological data on perinatally-transmitted infections is a fundamental tool for the formulation of health policies. In Brazil, this information is scarce, particularly in Northeast, the poorest region of the country. In order to gain some insights of the problem we studied the seroprevalence of some perinatally-transmitted infections in 1,024 low income pregnant women in Salvador, Bahia. The prevalences were as follow: HIV-1 (0.10%), HTLV-I/II (0.88%), T.cruzi (2.34%). T.pallidum (3.91%), rubella virus (77.44%). T.gondii IgM (2.87%) and IgG (69.34%), HBs Ag (0.6%) and anti-HBs (7.62%). Rubella virus and T.gondii IgG antibodies were present in more than two thirds of pregnant women but antibodies against other pathogens were present at much lower rates. We found that the prevalence of HTLV-I/II was nine times higher than that found for HIV-1. In some cases such as T.cruzi and hepatitis B infection there was a decrease in the prevalence over the years. On the other hand, there was an increase in the seroprevalence of T.gondii infection. Our data strongly recommend mandatory screening tests for HTLV-I/II, T.gondii (IgM), T.pallidum and rubella virus in prenatal routine for pregnant women in Salvador. Screening test for T.cruzi, hepatitis and HIV-1 is recommended whenever risk factors associated with these infections are suspected. However in areas with high prevalence for these infections, the mandatory screening test in prenatal care should be considered.

Detection of Cryptococcus neoformans capsular polysaccharide antigen in asymptomatic HIV-infected patients

Serum samples from 242 HIV-positive persons were studied for the detection of capsular polysaccha-ride antigen of Cryptococcus neoformans; 193 of these patients presented less than 300 CD4+ cells/µl of blood and 49 patients had more than 300 CD4+ cells/µl. None of them had symptoms or signs characteristic of cryptococcosis. The capsular antigen of C. neofarmans was detected by latex agglutination technique with pronase pre-treatment (IMMY, Crypto-Latex Antigen Detection System, Immunomycologics Inc., OK, USA); in 61% of the samples, ELISA technique was also used (Premier, Cryptococcal Antigen, Meridian Diagnostic Inc., Cincinatti, Oh, USA). The comparative study of both methods showed that the results obtained were similar in 96.9% of the cases. The capsular antigen was detected in 13 out of 193 (6.7%) patients with less than 300 CD4+ cells/µl. Cryptococcosis was confirmed mycologically in 3 of these 13 cases (23%) by the isolation of C. neoformans in CSF or blood cultures. Three patients, who had presented negative results of both tests for capsular antigen, suffered disseminated cryptococcosis 4 to 8 months later. The predictive diagnostic value of capsular antigen detection of C. neoformans seems tobe low and we believe that it should not be done routinely in asymptomatic HIV-positive persons.

Drug resistance of M. Tuberculosis isolated from patients with HIV infection seen at an AIDS Reference Center in São Paulo, Brazil

M. tuberculosis-positive cultures were obtained from 228 patients seen in our service and drug sensitivity assays were carried out from January 1992 to December 1994. A survey of the medical records of these patients showed resistance to one or more drugs in 47 (20.6%), 25 of whom (10.9%), who reported previous treatment, were considered to have acquired resistance. Among the antecedents investigated, only previous treatment and alcoholism were the factors independently associated with the occurrence of resistance. The survival of patients with resistant strains was lower than that of patients attacked by non-resistant M. tuberculosis. We conclude that in the present series M. tuberculosis resistance to tuberculostatic agents was predominantly of the acquired type.

Intestinal microsporidiosis in HIV-positive patients with chronic unexplained diarrhea in Rio de Janeiro, Brazil: diagnosis, clinical presentation and follow-up

After the diagnosis of two cases of microsporidial intestinal infection in 1992, in Rio de Janeiro, we have started looking for this parasite in HIV-infected patients with chronic unexplained diarrhea. We have studied 13 patients from Hospital Evandro Chagas, IOC-FIOCRUZ. Fecal specimens from these patients were examined for the presence of Cryptosporidia and Microsporidia, in addition to routine examination. Spores of Microsporidia were found in the stools of 6 (46.1%) of the 13 patients studied, with 2 histological jejunal confirmations. The Microsporidia-infected patients presented chronic diarrhea with about 6 loose to watery bowel movements a day. Five infected patients were treated with Metronidazole (1.5 g/day). They initially showed a good clinical response, but they never stopped eliminating spores. After about the 4th week of therapy, their diarrhea returned. Two patients utilized Albendazole (400 mg/day-4 weeks) with a similar initial improvement and recurrence of the diarrhea. Intestinal Microsporidiosis seems to be a marker of advanced stages of AIDS, since 5 of our 6 infected patients were dead after a 6 month period of follow-up. The present study indicates that intestinal microsporidiosis may be a burgeoning problem in HIV-infected patients with chronic diarrhea in Brazil, which deserves further investigation.

Immunological status of ENL (Erythema Nodosum Leprosum) patients: its relationship to bacterial load and levels of circulanting IL-2R

Recent data suggest that the clinical course of reactional states in leprosy is closely related to the cytokine profile released locally or systemically by the patients. In the present study, patients with erythema nodosum leprosum (ENL) were grouped according to the intensity of their clinical symptoms. Clinical and immunological aspects of ENL and the impact of these parameters on bacterial load were assessed in conjunction with patients' in vitro immune response to mycobacterial antigens. In 10 out of the 17 patients tested, BI (bacterial index) was reduced by at least 1 log from leprosy diagnosis to the onset of their first reactional episode (ENL), as compared to an expected 0.3 log reduction in the unreactional group for the same MDT (multidrug therapy) period. However, no difference in the rate of BI reduction was noted at the end of MDT among ENL and unreactional lepromatous patients. Accordingly, although TNF-alpha (tumor necrosis factor) levels were enhanced in the sera of 70.6% of the ENL patients tested, no relationship was noted between circulating TNF-alpha levels and the decrease in BI detected at the onset of the reactional episode. Evaluation of bacterial viability of M. leprae isolated from the reactional lesions showed no growth in the mouse footpads. Only 20% of the patients demonstrated specific immune response to M. leprae during ENL. Moreover, high levels of soluble IL-2R (interleukin-2 receptor) were present in 78% of the patients. Circulating anti-neural (anti-ceramide and anti-galactocerebroside antibodies) and anti-mycobacterial antibodies were detected in ENL patients' sera as well, which were not related to the clinical course of disease. Our data suggest that bacterial killing is enhanced during reactions. Emergence of specific immune response to M. leprae and the effective role of TNF-alpha in mediating fragmentation of bacteria still need to be clarified.

Status of Non-Technical Losses of Electricity in Brazil

The electricity demand in Brazil has been growing. Some studies estimate that through 2035 the energy consumption (the power consumption) should increase 78%. Two distinct actions are necessary to meet this growth: the construction of new generating plants and to reduce electrical losses in the country. As the construction of power plants have a high price, coupled with the growth of (current) environmental concern, electric utilities are investing in reducing losses, both technical and non-technical. In this context, this paper aims to present an overview of nontechnical losses in Brazil and to raise a discussion on the reasons that contribute to energy fraud.

Prevalence of HTLV-I and HTLV-II infections among HIV-1-infected asymptomatic individuals in São Paulo, Brazil

Human immunodeficiency virus (HIV-1)-infected subjects with acquired immunodeficiency syndrome (AIDS) are often infected with multiple pathogens. In particular, HTLV-I and HTLV-II infections have been found more frequently in AIDS patients than in asymptomatic individuals in Europe and Japan. We carried out a serosurvey among asymptomatic HIV-1-infected subjects in São Paulo, Brazil and compared our results with those of other investigators. In this study, we found HTLV infection in 1.5% of 266 asymptomatic and 14% of 28 AIDS patients. Epidemiological data obtained from patients pointed out the use of intravenous drugs as the principal risk factor for acquiring retroviruses. In conclusion, our results are in accordance with other studies done in Brazil and elsewhere where the principal risk group for HIV/HTLV-I/II coinfection was IDU