Jorlan Fernandes

Hantavirus Reservoirs: Current Status with an Emphasis on Data from Brazil

Since the recognition of hantavirus as the agent responsible for haemorrhagic fever in Eurasia in the 1970s and, 20 years later, the descovery of hantavirus pulmonary syndrome in the Americas, the genus Hantavirus has been continually described throughout the World in a variety of wild animals. The diversity of wild animals infected with hantaviruses has only recently come into focus as a result of expanded wildlife studies. The known reservoirs are more than 80, belonging to 51 species of rodents, 7 bats (order Chiroptera) and 20 shrews and moles (order Soricomorpha). More than 80genetically related viruses have been classified within Hantavirus genus; 25 recognized as human pathogens responsible for a large spectrum of diseases in the Old and New World. In Brazil, where the diversity of mammals and especially rodents is considered one of the largest in the world, 9 hantavirus genotypes have been identified in 12 rodent species belonging to the genus Akodon, Calomys, Holochilus, Oligoryzomys, Oxymycterus, Necromys and Rattus. Considering the increasing number of animals that have been implicated as reservoirs of different hantaviruses, the understanding of this diversity is important for evaluating the risk of distinct hantavirus species as human pathogens.

Phylogenetic analysis of the S segment from Juquitiba hantavirus: Identification of two distinct lineages in Oligoryzomys nigripes

The purpose of this study was to investigate the phylogenetic relationship of the Juquitiba virus (JUQV) carried by Oligoryzomys nigripes in endemic and non-endemic areas of Brazil. Wild rodents infected with the Juquitiba virus (JUQV) were sampled from a non-Hantavirus Cardiopulmonary Syndrome endemic area in Brazil. Three strains from O. nigripes were identified by the sequencing of the complete S segment and compared to previous studies of JUQV available in GenBank. The phylogenetic analysis of the complete S segment revealed two distinct clades; the first clade was composed of the JUQV from two non-endemic areas in Brazil and the second clade contained JUQV strains from Argentina, Paraguay and other Brazilian endemic areas.

Population Ecology of Hantavirus Rodent Hosts in Southern Brazil

In this study we analyze population dynamics of hantavirus rodent hosts and prevalence of infection over a 2-year period in Southern Brazil, a region with a high incidence of hantavirus pulmonary syndrome. The 14 small mammal species captured were composed of 10 rodents and four marsupials, the six most abundant species being Akodon serrensis, Oxymycterus judex, Akodon montensis, Akodon paranaensis, Oligoryzomys nigripes, and Thaptomys nigrita. These species displayed a similar pattern with increasing population sizes in fall/winter caused by recruitment and both, increase in reproductive activity and higher hantavirus prevalence in spring/summer. Specific associations between A. montensis/Jaborá Virus (JABV) and O. nigripes/Juquitiba-like Virus (JUQV-like) and spillover infections between A. paranaensis/JABV, A. serrensis/JABV, and A. paranaensis/JUQV-like were observed. Spillover infection in secondary hosts seems to play an important role in maintaining JABV and JUQV-like in the hantavirus sylvatic cycle mainly during periods of low prevalence in primary hosts.

Detection of the first incidence of Akodon paranaensis naturally infected with the Jabora virus strain (Hantavirus) in Brazil.

We characterised hantaviruses circulating in different Akodon rodent species collected in midwestern Santa Catarina (SC), southern Brazil, where the Jabora hantavirus (JABV) strain was first identified in Akodon montensis. Genetic and phylogenetic analyses based on a partial S segment indicated that, in SC, Akodon paranaensis and A. montensis carried the same type of hantavirus. Additionally, we conducted the first genomic characterisation of the complete S segment from the Brazilian JABV strain. This is the first report of A. paranaensis infected with the JABV.

Ecological study of hantavirus infection in wild rodents in an endemic area in Brazil.

A 3-year ecological study of small mammals was carried out in an endemic area for hantavirus pulmonary syndrome in the state of Santa Catarina in Southern Brazil. A total of 994 rodents of 14 different species corresponding to the subfamilies of Sigmodontinae, Murinae, Eumysopinae, and Caviinae were captured during 2004-2006. Oligoryzomys nigripes and Akodon montensis were the most abundant species and showed a clear seasonal pattern with higher population sizes during the winter. Rodent population outbreaks, associated within bamboo mast seeding events, were detected predominantly in areas where hantavirus pulmonary syndrome cases were notified in the state. Antibody reactivity to Hantavirus was detected in five sigmodontine species: O. nigripes (39/435), A. montensis (15/318), Akodon paranaensis (4/37), Thaptomys nigrita (1/86) and Sooretamys angouya (1/12). The highest hantavirus antibody prevalence occurred during the period of highest population size in A. montensis. For O. nigripes, hantavirus prevalence was higher in late spring, when reproduction was more frequent. Co-circulation of Juquitiba (JUQV) and Jabora (JABV) viruses was observed - JABV in A. paranaensis and A. montensis; JUQV in O. nigripes and T. nigrita. JABV occurrence was associated to gender and population size of the rodent while JUQV was related to gender, season, temperature, and locality.

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon

BackgroundThe purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection.MethodsThe arthropods were collected from the healthy Indian population and by flagging vegetation in grassland or woodland along the peridomestic environment of the Indian reserve. Wild rodents were live-trapped in an area bordering the reserve limits, due the impossibility of capturing wild animals in the Indian reserve. The wild rodents were identified based on external and cranial morphology and karyotype. DNA was extracted from spleen or liver samples of rodents and from invertebrate (tick and louse) pools, and the molecular characterization of the rickettsia was through PCR and DNA sequencing of fragments of two rickettsial genes (gltA and ompA). In relation to hantavirus, rodent serum samples were serologically screened by IgG ELISA using the Araraquara-N antigen and total RNA was extracted from lung samples of IgG-positive rodents. The amplification of the complete S segment was performed.ResultsA total of 153 wild rodents, 121 louse, and 36 tick specimens were collected in 2010. Laguna Negra hantavirus was identified in Calomys callidus rodents and Rickettsia bellii, Rickettsia amblyommii were identified in Amblyomma cajennense ticks.ConclusionsZoonotic diseases such as HCPS and spotted fever rickettsiosis are a public health threat and should be considered in outbreaks and acute febrile illnesses among Indian populations. The presence of the genome of rickettsias and hantavirus in animals in this Indian reserve reinforces the need to include these infectious agents in outbreak investigations of febrile cases in Indian populations.

Detection of different South American hantaviruses

Hantaviruses are the etiologic agents of Hemorrhagic Fever with Renal Syndrome (HFRS) in Old World, and Hantavirus Pulmonary Syndrome (HPS)/Hantavirus Cardiopulmonary Syndrome (HCPS), in the New World. Serological methods are the most common approach used for laboratory diagnosis of HCPS, however theses methods do not allow the characterization of viral genotypes. The polymerase chain reaction (PCR) has been extensively used for diagnosis of viral infections, including those caused by hantaviruses, enabling detection of few target sequence copies in the sample. However, most studies proposed methods of PCR with species-specific primers. This study developed a simple and reliable diagnostic system by RT-PCR for different hantavirus detection. Using new primers set, we evaluated human and rodent hantavirus positive samples of various regions from Brazil. Besides, we performed computational analyzes to evaluate the detection of other South American hantaviruses. The diagnostic system by PCR proved to be a sensible and simple assay, allowing amplification of Juquitiba virus, Araraquara virus, Laguna Negra virus, Rio Mamore virus and Jabora virus, beyond of the possibility of the detecting Andes, Anajatuba, Bermejo, Choclo, Cano Delgadito, Lechiguanas, Maciel, Oran, Pergamino and Rio Mearim viruses. The primers sets designed in this study can detect hantaviruses from almost all known genetics lineages in Brazil and from others South America countries and also increases the possibility to detect new hantaviruses. These primers could easily be used both in diagnosis of suspected hantavirus infections in humans and also in studies with animals reservoirs.

Characterization of Juquitiba Virus in Oligoryzomys fornesi from Brazilian Cerrado

The Juquitiba virus, an agent of Hantavirus Cardiopulmonary Syndrome, is one of the most widely distributed hantavirus found in South America. It has been detected in Oligoryzomys nigripes, Akodon montensis, Oxymycterus judex, Akodon paranaensis in Brazil and in O. nigripes, Oryzomys sp. and Oligoryzomys fornesi rodents in Argentine, Paraguay and Uruguay. Here, we report the genomic characterization of the complete S segment from the Juquitiba strain, isolated from the lung tissues of O. fornesi, the presumed rodent reservoir of Anajatuba virus in Brazilian Amazon, captured in the Cerrado Biome, Brazil.

Rio Mamore Virus and Hantavirus Pulmonary Syndrome, Brazil

Hantavirus pulmonary syndrome (HPS) is an acute, severe, frequently fatal disease associated with cardiopulmonary failure; it is caused by hantaviruses naturally hosted by wild rodents. Rio Mamore virus (RIOMV) was first described in 1996 in Bolivia; it was associated with the small-eared pygmy rice rat, Oligoryzomys microtis (1). Subsequently, 1 strain of RIOMV was isolated from O. microtis rats in Peru, designated HTN-007 (2); and 2 strains were recovered in the Brazilian Amazon from O. microtis rats (RIOMV-3) and uncharacterized species of rodents of the genus Oligoryzomys (RIOMV-4) (3). Recently, HPS cases associated with RIOMV have been reported: 2 cases in Peru (4) and 1 case in French Guiana (caused by a variant named Maripa virus) (5). We report isolation of a strain of RIOMV from a patient with fatal HPS in Brazil....

Hantavirus pulmonary syndrome in a highly endemic area of Brazil.

Hantavirus pulmonary syndrome (HPS) is the most frequently reported fatal rodent-borne disease in Brazil, with the majority of cases occurring in Santa Catarina. We analysed the clinical, laboratory and epidemiological data of the 251 confirmed cases of HPS in Santa Catarina in 1999-2011. The number of cases ranged from 10 to 47 per year, with the highest incidences in 2004-2006. Gastrointestinal tract manifestations were found in >60% of the cases, potentially confounding diagnosis and leading to inappropriate therapy. Dyspnoea, acute respiratory failure, renal failure, increased serum creatinine and urea levels, increased haematocrits and the presence of pulmonary interstitial infiltrate were significantly more common in HPS patients who died. In addition, we demonstrated that the six cases from the midwest region of the state were associated with Juquitiba virus genotype. The case-fatality rate in this region, 19·2%, was lower than that recorded for other mesoregions. In the multivariate analysis increase of serum creatinine and urea was associated with death by HPS. Our findings help elucidate the epidemiology of HPS in Brazil, where mast seeding of bamboo can trigger rodent population eruptions and subsequent human HPS outbreaks. We also emphasize the need for molecular confirmation of the hantavirus genotype of human cases for a better understanding of the mortality-related factors associated with HPS cases in Brazil.