Historical analysis of the records of sylvan yellow fever in the State of Amazonas, Brazil, from 1996 to 2009

IntroductionYellow fever is a non-contagious infectious disease, highly lethal, transmitted by the Aedes, Haemagogus and Sabethes.MethodsDescriptive retrospective study of the yellow fever cases in Amazonas, between 1996 and 2009.ResultsForty two cases of yellow fever were confirmed, with 30 deaths, 10% of which were foreigners.ConclusionsThe presence of Aedes aegypti and Aedes albopictus in both rural Amazonas and its capital demonstrates the dispersion of these vectors and underscores the need for better and continuous epidemiological and entomological control.

First report of yellow fever virus in non-human primates in the State of Parana, Brazil

Sylvatic yellow fever is a zoonosis associated mainly with wild animals, especially those in the genus Alouatta, that act as the source of infection. Once infected, these animals pass the disease on to humans by way of an infected mosquito belonging to the genera Aedes, Haemagogus, or Sabethes. The present study is the first report of a case of yellow fever in non-human primates (NHP) in the State of Paraná, Brazil. After the case was diagnosed, several prophylactic measures were adopted to prevent outbreaks of the disease in humans.

Ecological aspects of mosquitoes (Diptera: Culicidae) in the gallery forest of Brasilia National Park, Brazil, with an emphasis on potential vectors of yellow fever

Introduction We analyzed the vertical and monthly distributions of culicid species in the gallery forest of Brasília National Park, with an emphasis on the potential vectors of yellow fever (YF). Methods Between September 2010 and August 2011, mosquitoes were captured on the ground and in the canopy of the forest for five consecutive days per month, from nine to 15 hours. The mosquitoes were examined to verify natural infection with flaviviruses by isolation in Aedes albopictus Skuse, 1864 cells followed by indirect immunofluorescence. Results We identified 2,677 culicids distributed in 29 species. Most of the mosquitoes were captured at ground level (69%) during the rainy season (86%). The most abundant species were Sabethes (Sabethes) albiprivus Theobald, 1903; Limatus durhamii Theobald, 1901; Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon, 1924; Haemagogus (Haemagogus) janthinomys Dyar, 1921; Aedes (Ochlerotatus) scapularis Rondani, 1848; Psorophora (Janthinosoma) ferox Von Humboldt, 1819; and Aedes (Ochlerotatus) serratus Theobald, 1901. Limatus durhamii, Limatus durhamii, Psorophora ferox, Aedes scapularis and Aedes serratus showed significant differences (p<0.05) in their habitat use. Limatus durhamii was found more often in the canopy, unlike the other species. During the rainy season, the most abundant species were Sa. albiprivus, Haemagogus leucocelaenus and Limatus durhamii. During the dry season, the potential YF vectors exhibited a very low frequency and abundance, except Aedes scapularis and Aedes serratus. No flavivirus was detected in the 2,677 examined mosquitoes. Conclusions We recommend continued and systematic entomological monitoring in areas vulnerable to the transmission of YF in the Federal District of Brazil.

Ludwig's angina after severe thrombocytopenic purpura associated with dengue fever

Here, we report a case of Ludwig's angina, which required surgery because of toothache. The patient had dengue and severe thrombocytopenia as confirmed by clinical and laboratory diagnoses. However, dengue is not included among the predisposing factors for Ludwig's angina.

Molecular identification of the agent of Q fever – Coxiella burnetii – in domestic animals in State of Rio de Janeiro, Brazil

Introduction Over the last recent years, the number of Q fever cases have has increased throughout the world. An epidemiological investigation was performed in the area in which the first molecular documentation of Q fever in Brazil was previously reported. Methods Indirect immunofluorescence assay (IFA) and PCR of Coxiella burnetii targeting the htpAB gene were performed in samples from 14 dogs (blood); 1 cat (blood); 10 goats (blood, milk, vaginal swab and anal swab); 3 sheep (blood); and 2 horses (blood). Results Two dogs, two sheep and five goats were seroreactive. DNA was amplified from 6 milk and 2 blood samples from goats and from dogs, respectively. The sequence of the amplicons exhibited 99% sequence similarity with the homologous sequence of the htpAB gene of C. burnetii RSA 331 (GenBank - CP000890). Conclusions The results confirm C. burnetii infection in animals in Rio de Janeiro and reinforce the need for the surveillance of Q fever in Brazil.

Risk factors associated with the transmissionof Brazilian spotted fever in the Piracicaba river basin, State of São Paulo, Brazil

INTRODUCTION : Brazilian spotted fever (BSF) is a disease transmitted by ticks for which the etiological agent is Rickettsia rickettsii. The present essay evaluates the risk factors associated with the transmission of cases of BSF in the time period between 2003 and 2013 in the Piracicaba river basin, state of São Paulo. METHODS : This essay presents a retrospective study to identify the factors associated with the transmission of cases of BSF among all suspected cases identified by the System for Epidemiological Surveillance of São Paulo (CVE). After the description of temporal distribution (onset of symptoms) and the environmental and demographic variations of the confirmed and discarded cases, a multiple logistic regression model was applied. RESULTS : We searched 569 probable locations of infection (PLI) with 210 (37%) confirmed cases of BSF and 359 (63%) discarded cases. The associated variables for the confirmation of BSF in the multiple logistic model using a confidence interval (CI) of 95% were age (OR = 1.025 CI: 1.015-1.035), the presence of Amblyomma sculptum in the environment (OR = 1.629 CI: 1.097-2.439), the collection of ticks from horses (OR = 1.939 CI: 0.999-3.764), the presence of capybaras (OR = 1.467 CI: 1.009-2.138), an urban environment (OR = 1.515 CI: 1.036-2.231), and the existence of a dirty pasture (OR = 1.759 CI: 1.028-3.003). CONCLUSIONS : The factors associated with the confirmation of BSF cases included an urban environment, age, presence of the A. sculptum vector, the collection of ticks from horses, the presence of a capybara population, and a dirty pasture environment.

Frequency of histopathological changes in Howler monkeys ( Alouatta sp.) naturally infected with yellow fever virus in Brazil

Abstract: INTRODUCTION: Due to the importance that Howler monkeys have on the yellow fever (YF) epidemiological sylvatic cycle in Brazil, more accurate morphological diagnostic criteria needs to be established, especially considering the differences that may exist between the genera of Brazilian non-human primates (NHPs) involved in yellow fever virus (YFV) epizootics. METHODS: Records of YF epizootics in NHPs in Brazil between 2007 and 2009 were obtained from the Brazilian Ministry of Health database to select YF positive (n=98) Howler monkeys (Alouatta sp.) for this study. The changes described in the histopathological reports were categorized by organ and their frequencies calculated. RESULTS: The most frequent lesions observed in the animals with YF were hepatocyte apoptosis (Councilman body formation), midzonal hepatocyte necrosis, steatosis, liver hemorrhage, inflammatory mononuclear cell infiltration of the liver, renal acute tubular necrosis and interstitial nephritis. Midzonal hepatocyte necrosis, steatosis and hemorrhage presented positive correlations with apoptosis of hepatocytes, suggesting strong YFV pathogenic effect association; they were also the main histopathological changes in the Alouatta sp. A pronounced negative correlation between apoptosis of hepatocytes and hepatic mononuclear cell infiltration pointed to significant histopathological differences between YFV infection in Howler monkeys and humans. CONCLUSIONS: The results warn that NHPs may exhibit different response patterns following YFV infection and require a more careful diagnosis. Presumptive diagnosis based on primate histopathological lesions may contribute to public health service control.

Rheumatic fever: a multicenter study in the State of São Paulo

Rheumatic fever is still the most commonly seen rheumatic disease in Brazilian pediatric rheumatology clinics. It remains a significant health problem since subsequent cardiac sequelae represent one of the most important causes of chronic heart disease in children. We reviewed the clinical manifestations of rheumatic fever in 786 patients, followed at seven pediatric rheumatology clinics in the state of São Paulo, Brazil. All patients were diagnosed according to revised Jones' criteria. Regarding major criteria, 396 (50.4%) children exhibited carditis, 453 (57.6%) polyarthritis, 274 (34.8%) chorea, 13 (1.6%) erythema marginatum, and 12 (1.5%) subcutaneous nodules. Valvular lesions documented by echocardiography in the absence of accompanying auscultatory findings were found in 144 (18.3%) patients. Migratory polyarthritis was observed in 290 (64.0%) patients with articular involvement. Documented previous streptococcal infection assessed by serum antistreptolysin (ASO) titers occurred in 531 (67.5%) patients. Even though prophylaxis with benzathine penicillin was recommended to all patients, recurrent attacks were observed in 147 (18.7%). We emphasize the high frequency of chorea, silent carditis and recurrences in our series as well as the variable clinical presentation of arthritis in rheumatic fever. Multicenter studies should be encouraged to improve our understanding of the clinical features of rheumatic diseases in children and adolescents.

The thermal stability of yellow fever vaccines

The assessment of yellow fever vaccine thermostability both in lyophilized form and after reconstitution were analyzed. Two commercial yellow fever vaccines were assayed for their thermal stability. Vaccines were exposed to test temperatures in the range of 8 (graus) C to 45 (graus) C. Residual infectivity was measured by a plaque assay using Vero cells. The titre values were used in an accelerated degradation test that follows the Arrhenius equation and the minimum immunizing dose was assumed to be 10 (ao cubo) particles forming unit (pfu)/dose. Some of the most relevant results include that (i) regular culture medium show the same degradation pattern of a reconstituted 17D-204 vaccine; (ii) reconstituted YF-17D-204 showed a predictable half life of more than six days if kept at 0 (graus) C; (iii) there are differences in thermostability between different products that are probably due to both presence of stabilizers in the preparation and the modernization in the vaccine production; (iv) it is important to establish a proper correlation between the mouse infectivity test and the plaque assay since the last appears to be more simple, economical, and practical for small laboratories to assess the potency of the vaccine, and (v) the accelerated degradation test appears to be the best procedure to quantify the thermostability of biological products.

Molecular analysis of yellow fever virus 17DD vaccine strain

The Oswaldo Cruz Foundation produces most of the yellow fever (YF) vaccine prepared world wide. As part of a broader approach to determine the genetic variability in YF l7D seeds and vaccines and its relevance to viral attenuation the 17DD virus was purifed directly from chick embryo homogenates which is the source of virus used for vaccination of millions of people in Brazil and other countries for half a century. Neutralization and hemagglutination tests showed that the purified virus is similar to the original stock. Furthermore, radioimmune precipitation of 35S-methionine-labeled viral proteins using mouse hyperimmune ascitic fluid revealed identical patterns for the purified 17DD virus and the YF l7D-204 strain except for the 17DD E protein which migrated slower on SDS-PAGE. This difference is likely to be due to N-linked glycosylation. Finally, comparison by northern blot nybridization of virion RNAs of purified 17DD with two other strains of YF virus only fenome-sized molecules for all three viruses. These observations suggest that vaccine phenotype is primarily associated with the accumulation of mutations.