Yellow fever in Brazil: thoughts and hypotheses on the emergence in previously free areas

This article describes and discusses factors associated to the reemergence of yellow fever and its transmission dynamics in the states of São Paulo (Southeastern Brazil) and Rio Grande do Sul (Southern) during 2008 and 2009. The following factors have played a pivotal role for the reemergence of yellow fever in these areas: large susceptible human population; high prevalence of vectors and primary hosts (non-human primates); favorable climate conditions, especially increased rainfall; emergence of a new genetic lineage; and circulation of people and/or monkeys infected by virus. There is a need for an effective surveillance program to prevent the reemergence of yellow fever in other Brazilian states.

Free-trade agreements: challenges for global health

In this study new free-trade agreements are discussed, which are based on the breaking down of tariff and technical barriers and normally exclude most of the poorest countries in the world. Considering the current context of economic globalization and its health impacts, seven controversial points of these treaties and their possible implications for global public health are presented, mainly regarding health equity and other health determinants. Finally, this research proposes a greater social and health professionals participation in the formulation and discussion of these treaties, and a deeper insertion of Brazil in this important international agenda.

A single method to stain Malassezia furfur and Corynebacterium minutissimum in scales

A single and practical method to slain Malassezia furfur and Corynebacterium minutissimum in lesions' scales is described. The scales are collected by pressing small pieces of scotch tape (about 4 cm lenght and 2 cm width) onto the lesions and following withdrawl the furfuraceous scales will remain on the glue side. These pieces are then immersed for some minutes in lactophenol-cotton blue stain. Following absorption of the stain the scales are washed in current water to remove the excess of blue stain, dried with filter paper, dehydrated via passage in two bottles containing absolute alcohol and then placed in xylene in a centrifugation tube. The xylene dissolves the scotch tape glue and the scales fall free in the tube. After centrifugation and decantation the scales concentrated on the bottom of the tube are collected with a platinum-loop, placed in Canada balsam on a microscopy slide and closed with a cover slip. The preparations are then ready to be submitted to microscopic examination. Other stains may also be used instead of lactophenol-cotton blue. This method is simple, easily performed, and offers good conditions to study these fungi as well as being useful for the diagnosis of the diseases that they cause.

Anti-phenolic glycolipid-I (PGL-I) determination using blood collection on filter paper in leprosy patients

The authors studied 70 leprosy patients and 20 normal individuals, comparing the traditional sera collection method and the finger prick blood with the conservation on filter paper for specific antibodies against the native phenolic glycolipid-I (PGL-I) from Mycobacterium leprae. The finger prick blood dried on filter paper was eluated in phosphate buffer saline (PBS) containing 0.5% gelatin. The classical method for native PGL-I was performed for these eluates, and compared with the antibody determination for sera. It was observed that there is a straight correlation comparing these two methods; although the titles found for the eluates were lower than those obtained for serology. This blood collection method could be useful for investigation of new leprosy cases in field, specially in contacts individuals.

Evaluation of three different DNA extraction methods from blood samples collected in dried filter paper in Plasmodium subpatent infections from the Amazon region in Brazil

Asymptomatic Plasmodium infection is a new challenge for public health in the American region. The polymerase chain reaction (PCR) is the best method for diagnosing subpatent parasitemias. In endemic areas, blood collection is hampered by geographical distances and deficient transport and storage conditions of the samples. Because DNA extraction from blood collected on filter paper is an efficient method for molecular studies in high parasitemic individuals, we investigated whether the technique could be an alternative for Plasmodium diagnosis among asymptomatic and pauciparasitemic subjects. In this report we compared three different methods (Chelex®-saponin, methanol and TRIS-EDTA) of DNA extraction from blood collected on filter paper from asymptomatic Plasmodium-infected individuals. Polymerase chain reaction assays for detection of Plasmodium species showed the best results when the Chelex®-saponin method was used. Even though the sensitivity of detection was approximately 66% and 31% for P. falciparum and P. vivax, respectively, this method did not show the effectiveness in DNA extraction required for molecular diagnosis of Plasmodium. The development of better methods for extracting DNA from blood collected on filter paper is important for the diagnosis of subpatent malarial infections in remote areas and would contribute to establishing the epidemiology of this form of infection.

POTENTIALLY PATHOGENIC FREE-LIVING AMOEBAE IN SOME FLOOD-AFFECTED AREAS DURING 2011 CHIANG MAI FLOOD

SUMMARYThe survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA.

DETECTION OF Leptospira spp. AND Brucella abortus ANTIBODIES IN FREE-LIVING JAGUARS (Panthera onca) IN TWO PROTECTED AREAS OF NORTHERN PANTANAL, BRAZIL

 This study aimed to assess the exposure of free-living jaguars (Panthera onca) to Leptospira spp. and Brucella abortus in two conservation units in the Pantanal of Mato Grosso, Brazil. The presence of antibodies in blood samples of eleven jaguars was investigated using autochthonous antigens isolated in Brazil added to reference antigen collection applied to diagnosis of leptospirosis by Microscopic Agglutination Test (MAT). The Rose Bengal test was applied for B. abortus antibodies. Two (18.2%) jaguars were seroreactive for the Leptospira spp. antigen and the serovar considered as most infective in both animals was a Brazilian isolate of serovar Canicola (L01). All jaguars were seronegative for B. abortus. These data indicate that the inclusion of autochthonous antigens in serological studies can significantly increase the number of reactive animals, as well as modify the epidemiological profile of Leptospira spp. infection.

SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated.

Seroepidemiological study of human cysticercosis with blood samples collected on filter paper, in Lages, State of Santa Catarina, Brazil, 2004-2005

INTRODUCTION: Human serofrequency of antibodies against Taenia solium antigens was determined and risk factors for cysticercosis transmission were identified. METHODS: Individuals (n=878) from periurban and rural locations of Lages, SC, were interviewed to gather demographic, sanitary and health information. Interviews and blood sample collections by finger prick on Whatman filter paper were performed from August 2004 to May 2005. Observation determined that 850 samples were suitable for analysis and were tested by ELISA using vesicular fluid of Taenia crassiceps heterologous antigen. To ensure the reliability of the results, 77 samples of the dried blood were matched with sera. The reactive samples were submitted to a serum confirmatory immunoblot (IB) test using purified Taenia crassiceps glycoproteins. RESULTS: The ELISA results for the dried blood and serum samples were statistically consistent. ELISA was positive in 186 (21.9%) out of 850 individuals. A group of 213 individuals were asked to collect vein blood for IB (186 with positive result in ELISA and 27 with inappropriate whole blood samples) and 130 attended the request. The IB was positive in 29 (3.4%) out of 850 individuals. A significant correlation (p = 0.0364) was determined among individuals who tested positive in the IB assay who practiced both pig rearing and kitchen gardening. CONCLUSIONS: ELISA with dried blood eluted from filter paper was suitable for cysticercosis population surveys. In Lages, human infection was associated with pig rearing and kitchen gardening. The prevalence index was compatible with other Latin American endemic areas.

Cat infected by a variant of bat rabies virus in a 29-year disease-free urban area of southern Brazil

INTRODUCTION: After 29 years, rabies was detected in a cat in Curitiba, southern Brazil. METHODS: The fluorescent antibody test (FAT) and mouse inoculation test (MIT) were performed on central nervous system (CNS) samples. RESULTS: Direct immunofluorescence was negative, but the biological test was positive and rabies virus was characterized as variant 4 (from Tadarida brasiliensis). CONCLUSIONS: Reappearance of rabies in domestic animals warns of sylvatic-aerial risk of infection and the necessity of monitoring bats in historically rabies-free areas.

Detection of arboviruses of public health interest in free-living New World primates (Sapajus spp.; Alouatta caraya) captured in Mato Grosso do Sul, Brazil

Introduction A sero-epidemiological survey was undertaken to detect the circulation of arboviruses in free-living non-human primates. Methods Blood samples were obtained from 16 non-human primates (13 Sapajus spp. and three Alouatta caraya) that were captured using terrestrial traps and anesthetic darts in woodland regions in the municipalities of Campo Grande, Aquidauana, Jardim, Miranda and Corumbá in the State of Mato Grosso do Sul, Brazil. The samples were sent to the Instituto Evandro Chagas (IEC) in Ananindeua, Pará, Brazil, to detect antibodies against 19 species of arboviruses using a hemagglutination inhibition test (HI). Results Of the 16 primates investigated in the present study, five (31.2%) were serologically positive for an arbovirus. Of these five, two (12.5%) exhibited antibodies to the Flavivirus genus, one (6.2%) exhibited a monotypic reaction to Cacipacoré virus, one (6.2%) was associated with Mayaro virus, and one (6.2%) was positive for Oropouche virus. Conclusions Based on the positive serology observed in the present study, it was possible to conclude that arboviruses circulate among free-living primates. The viruses in the areas studied might have been introduced by infected humans or by primates from endemic or enzootic areas. Studies of this nature, as well as efficient and continuous surveillance programs, are needed to monitor viral activities in endemic and enzootic regions.