Fatal outcome of chikungunya virus infection in Brazil.

BACKGROUND: Chikungunya virus (CHIKV) emerged in the Americas in 2013 and has caused ~2.1 million cases and over 600 deaths. A retrospective investigation was undertaken to describe clinical, epidemiological and virus genomic features associated with deaths caused by CHIKV in Ceará state, northeast Brazil. METHODS: Sera, cerebrospinal fluid (CSF) and tissue samples from 100 fatal cases with suspected arbovirus infection were tested for CHIKV, dengue (DENV) and Zika virus (ZIKV). Clinical, epidemiological and death reports were obtained for patients with confirmed CHIKV infection. Logistic regression analysis was undertaken to identify independent factors associated with risk of death during CHIKV infection. Phylogenetic analysis was conducted using whole genomes from a subset of cases. RESULTS: 68 fatal cases had CHIKV infection confirmed by RT-qPCR (52.9%), viral antigen (41.1%), and/or specific-IgM (63.2%). Co-detection of CHIKV with DENV were found in 22% of fatal cases, ZIKV in 2.9%, and DENV and ZIKV in 1.5%. A total of 39 CHIKV-deaths presented with neurological signs and symptoms, and CHIKV-RNA was found in the CSF of 92.3% of these patients. Fatal outcomes were associated with irreversible multiple organ dysfunction syndrome. Patients with diabetes appear to die at a higher frequency during the sub-acute phase. Genetic analysis showed circulation of two CHIKV-East Central South African (ECSA) lineages in Ceará and revealed no unique virus genomic mutation associated with fatal outcome. CONCLUSION: The investigation of the largest cross-sectional cohort of CHIKV-deaths to date reveals that CHIKV-ECSA strains can cause death in individuals from both risk and non-risk groups, including young adults

Parasite Specific Antibody Increase Induced by an Episode of Acute P. falciparum Uncomplicated Malaria.

There is no approved vaccine for malaria, and precisely how human antibody responses to malaria parasite components and potential vaccine molecules are developed and maintained remains poorly defined. In this study, antibody anamnestic or memory response elicited by a single episode of P. falciparum infection was investigated.This study involved 362 malaria patients aged between 6 months to 60 years, of whom 19% were early-diagnosed people living with HIV/AIDS (PLWHA). On the day malaria was diagnosed and 42 days later, blood specimens were collected. Parasite density, CD4+ cells, and antibodies specific to synthetic peptides representing antigenic regions of the P. falciparum proteins GLURP, MSP3 and HRPII were measured.On the day of malaria diagnosis, Immunoglobulin (IgG) antibodies against GLURP, MSP3 and HRP II peptides were present in the blood of 75%, 41% and 60% of patients, respectively. 42 days later, the majority of patients had boosted their serum IgG antibody more than 1.2 fold. The increase in level of IgG antibody against the peptides was not affected by parasite density at diagnosis. The median CD4+ cell counts of PLWHAs and HIV negative individuals were not statistically different, and median post-infection increases in anti-peptide IgG were similar in both groups of patients.In the majority (70%) of individuals, an infection of P. falciparum elicits at least 20% increase in level of anti-parasite IgG. This boost in anti-P. falciparum IgG is not affected by parasite density on the day of malaria diagnosis, or by HIV status

Thermotolerance of Fungal Conidia

Conidia of entomopathogenic fungi (EF) are the propagules most frequently used in arthropod biocontrol programs. This anamorphic form is essential for the infection process, including spore germination, penetration, vegetative growth, conidiogenesis and dissemination. Most EF are mesophilic and can develop between 10 and 40 °C, but optimal growth is between 25 and 35 °C. Abiotic factors, especially temperature (high or low) can determine their viability, virulence and success or failure of infection process. Temperature has the highest impact on conidial stress inhibiting metabolic processes, such as decreased morphogenesis during germination, protein denaturation and membrane disorganization. Several studies show that some strains of Beauveria spp., Metarhizium spp., and Isaria spp. exhibit conidial survival even when grown at high temperatures, indicating a relationship between conidial thermotolerance and their geographical isolation origin. Moreover, the high variability in fungal thermotolerance is also dependent of the culture media composition and growth condition. EF that grow at high temperatures do not grow at low temperatures and vice versa. Moreover, when growth conditions are not set at optimal temperatures, EF development is affected and their effectiveness in biological control programs of arthropods is reduced. Thermal stress directly impacts on fungal strains ability to target arthropods and their environmental activity performance. The screening for fungal strains with a higher thermotolerance and the improvement on conidial formulations may aid in optimizing the conditions for biocontrol agent application.Fil: Paixão, Flávia R. S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Fernandes, Éverton. Universidade Federal de Goiás; BrasilFil: Pedrini, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentin