Wild Rats, Laboratory Rats, Pet Rats: Global Seoul Hantavirus Disease Revisited.

Recent reports from Europe and the USA described Seoul orthohantavirus infection in pet rats and their breeders/owners, suggesting the potential emergence of a "new" public health problem. Wild and laboratory rat-induced Seoul infections have, however, been described since the early eighties, due to the omnipresence of the rodent reservoir, the brown rat Rattus norvegicus. Recent studies showed no fundamental differences between the pathogenicity and phylogeny of pet rat-induced Seoul orthohantaviruses and their formerly described wild or laboratory rat counterparts. The paucity of diagnosed Seoul virus-induced disease in the West is in striking contrast to the thousands of cases recorded since the 1980s in the Far East, particularly in China. This review of four continents (Asia, Europe, America, and Africa) puts this "emerging infection" into a historical perspective, concluding there is an urgent need for greater medical awareness of Seoul virus-induced human pathology in many parts of the world Given the mostly milder and atypical clinical presentation, sometimes even with preserved normal kidney function, the importance of simple but repeated urine examination is stressed, since initial but transient proteinuria and microhematuria are rarely lacking.

Discovery and Description of Ebola Zaire Virus in 1976 and Relevance to the West African Epidemic During 2013-2016.

BACKGROUND: In 1976, the first cases of Ebola virus disease in northern Democratic Republic of the Congo (then referred to as Zaire) were reported. This article addresses who was responsible for recognizing the disease; recovering, identifying, and naming the virus; and describing the epidemic. Key scientific approaches used in 1976 and their relevance to the 3-country (Guinea, Sierra Leone, and Liberia) West African epidemic during 2013-2016 are presented. METHODS: Field and laboratory investigations started soon after notification, in mid-September 1976, and included virus cell culture, electron microscopy (EM), immunofluorescence antibody (IFA) testing of sera, case tracing, containment, and epidemiological surveys. In 2013-2016, medical care and public health work were delayed for months until the Ebola virus disease epidemic was officially declared an emergency by World Health Organization, but research in pathogenesis, clinical presentation, including sequelae, treatment, and prevention, has increased more recently. RESULTS: Filoviruses were cultured and observed by EM in Antwerp, Belgium (Institute of Tropical Medicine); Porton Down, United Kingdom (Microbiological Research Establishment); and Atlanta, Georgia (Centers for Disease Control and Prevention). In Atlanta, serological testing identified a new virus. The 1976 outbreak (280 deaths among 318 cases) stopped in <11 weeks, and basic clinical and epidemiological features were defined. The recent massive epidemic during 2013-2016 (11 310 deaths among 28 616 cases) has virtually stopped after >2 years. Transmission indices (R0) are higher in all 3 countries than in 1976. CONCLUSIONS: An international commission working harmoniously in laboratories and with local communities was essential for rapid success in 1976. Control and understanding of the recent West African outbreak were delayed because of late recognition and because authorities were overwhelmed by many patients and poor community involvement. Despite obstacles, research was a priority in 1976 and recently.

Complete Genome Sequence of Seoul Virus Strain Tchoupitoulas.

Seoul virus (genus Hantavirus; family Bunyaviridae) is an emerging pathogen associated with cases of acute kidney injury in several countries across the globe. We report here the whole-genome sequence of the Tchoupitoulas strain of Seoul virus isolated in New Orleans, LA.

Chronic Q fever: different serological results in three countries--results of a follow-up study 6 years after a point source outbreak.

BACKGROUND: Acute and chronic Q fever/Coxiella burnetii infection is diagnosed principally by serology. The management of patients who have serological evidence of chronic Q fever but no other manifestation of chronic infection is challenging. METHODS: This paper describes a follow-up study of individuals 6 years after a point source outbreak. The study compares serological and polymerase chain reaction (PCR) results between 3 international reference laboratories in a well-defined cohort of Q fever patients. RESULTS: Concordance in microimmunofluorescence result interpretation from the 3 centers was only 35%. Australian and UK results had the greatest concordance and French and UK results the lowest. Serological testing revealed no chronic serological profiles when tested in either France or Australia but 10 when tested in the UK. Serological results from a patient with treated Q fever endocarditis suggested treated (France), chronic (UK), and borderline chronic (Australia) infection. PCR results on blood were universally negative. CONCLUSIONS: This study has shown that the results from Q fever micro-immunofluorescence vary according to the center in which they are carried out. This has implications for the interpretation of such tests, raises questions regarding the validity of using serological criteria alone as a means of diagnosing chronic Q fever, and affects the interpretation of epidemiological studies. We recommend that all results are interpreted according to the clinical picture and particular caution is applied in the interpretation of chronic serological profiles. In order to further our understanding of Q fever infection we propose that an international standard of Q fever serological investigation be developed.

Mitochondrial respiration and succinate dehydrogenase are suppressed early during entrance into a hibernation bout, but membrane remodeling is only transient.

We examined respiration and lipid composition of liver mitochondria purified from a hibernator (Ictidomys tridecemlineatus) in different stages of a torpor bout. Between interbout euthermia (body temperature, T (b), 37°C) and early entrance (T (b) 30°C), state 3 and state 4 respirations, fueled by 6 mM succinate, fell by over 50%. Mitochondrial respiration did not decline any further in the late entrance and torpor stages (T (b) 15 and 5°C, respectively). Succinate dehydrogenase (SDH) activity declined in a similar pattern as mitochondrial respiration, and there was a significant positive correlation between state 3 respiration and SDH activity. However, unlike during arousal from torpor, oxaloacetate was not a major factor in inhibition of SDH. Analysis of mitochondrial lipids showed little change in neutral lipids or phospholipid classes, except for a transient decrease in phosphatidylethanolamine content in early entrance. In the transition from interbout euthermia to early entrance, we found transient increases in some saturated phospholipid fatty acids (16:0, 18:0) and decreases in some unsaturates (18:2, 20:4). These changes resulted in transient increases in total saturates and the ratio of saturates to unsaturates, and transient decreases in total unsaturates, total polyunsaturates, total n-6, the ratio of monounsaturates to polyunsaturates, and unsaturation index. None of these changes persisted into late entrance or torpor, nor did they correlate with mitochondrial respiration. We conclude that mitochondrial metabolic suppression during entrance into a torpor bout occurs very early and is likely related to acute regulation of electron transport chain enzymes rather than changes in membrane phospholipid composition.

Mopeia virus-related arenavirus in natal multimammate mice, Morogoro, Tanzania.

A serosurvey involving 2,520 small mammals from Tanzania identified a hot spot of arenavirus circulation in Morogoro. Molecular screening detected a new arenavirus in Natal multimammate mice (Mastomys natalensis), Morogoro virus, related to Mopeia virus. Only a small percentage of mice carry Morogoro virus, although a large proportion shows specific antibodies.

Case report: Eastern equine encephalitis virus imported to the UK.

Eastern equine encephalitis (EEE) is rare, but the most severe of the mosquito-borne encephalitides in the United States with a high case fatality rate of 30%. Here, we present a patient with EEE. EEE virus causes sporadic human disease in the Eastern parts of the United States, but the case we describe was a Scottish tourist who acquired the disease from mosquito bites while in holiday in the United States. This is a first report of an imported case to Europe.

Diagnostic reverse-transcription polymerase chain reaction kit for filoviruses based on the strain collections of all European biosafety level 4 laboratories.

A network of European biosafety level 4 laboratories has designed the first industry-standard molecular assay for all filoviruses species, based on the strain collections of all participants. It uses 5 optimized L gene primers and 3 probes, as well as an internal control with a separate detection probe. Detection limits (probit analysis, 95% detection chance) were as follows: Zaire ebolavirus, 487 copies/mL of plasma; Sudan ebolavirus Maleo, 586 copies/mL; Sudan ebolavirus Gulu, 1128 copies/mL; Cote d'Ivoire ebolavirus, 537 copies/mL; Reston ebolavirus, 4546 copies/mL; Lake Victoria marburgvirus Musoke, 860 copies/mL; and Lake Victoria marburgvirus Ravn, 1551 copies/mL. The assay facilitates reliable detection or exclusion screening of filovirus infections.

Molecular diagnosis and analysis of Chikungunya virus.

BACKGROUND: In March 2005 a Chikungunya fever outbreak began on the islands of the Indian Ocean. The number of cases of this disease dramatically rose amongst these islands before affecting over a million people in India. Travellers to these regions have returned to the UK with the disease leading to a greater than 15-fold increase in the annual number of Chikungunya virus (CHIKV) sero-positive samples in 2006. OBJECTIVES: A real-time RT-PCR test was developed for CHIKV and designed to detect currently circulating strains of virus as well as other genotypes. Its sensitivity was compared with an existing standard RT-PCR assay and a previously published real-time assay. STUDY DESIGN: A real-time RT-PCR assay was optimised and evaluated using a panel of 55 clinical serum samples and a synthetic RNA transcript as a positive control. Nucleotide sequencing of part of the E1 gene of CHIKV was used to investigate the relatedness of the samples. RESULTS: The real-time RT-PCR was 10-fold more sensitive than a conventional block-based RT-PCR and could detect as low as 20 copies of RNA transcript. The assay also had 10-fold improved sensitivity in detecting the outbreak strain of virus when compared to another published TaqMan assay. Analysis of sequences from patients that had travelled to India, Mauritius or the Seychelles showed high similarity with published sequences from the Indian Ocean island of Réunion. CONCLUSIONS: A sensitive and rapid real-time RT-PCR assay has been developed for CHIKV and tested against current isolates.

Co-evolutionary patterns of variation in small and large RNA segments of Crimean-Congo hemorrhagic fever virus.

The genus Nairovirus of the family Bunyaviridae includes the Crimean-Congo haemorrhagic fever (CCHF) species group. The species is predominated by the hazard-group 4 pathogens, from which the name and majority of strain entries are derived. Additionally, the species embraces hazard-group 2 viruses that are classified as members by antigenic cross-reactivity. CCHF viruses have a tripartite RNA genome consisting of large (L), medium (M) and small (S) segments. Here, the sequence characterization of previously undescribed L and S segments from novel strains originating in the Middle East and Africa is reported. Further scrutiny of this data with phylogenetic tools, in the context of other publicly available sequence information, reveals analogous grouping patterns between the L and S segments. These groups correlate with the geographical distribution of strain isolation and indicate that the L and S segments of CCHF viruses have evolved together.

Development of a multi-pathogen oligonucleotide microarray for detection of Bacillus anthracis.

An oligonucleotide microarray system has been specifically designed to detect and differentiate Bacillus anthracis from other bacterial species present in clinical samples. The pilot-scale microarray initially incorporated probes to detect six common species of bacteria, which were fully evaluated. The microarray comprised long oligonucleotides (50--70-mer) designed to hybridise with the variable regions of the 16S rRNA genes. Probes which hybridised to virulence genes were also incorporated; for B. anthracis, these initially included the pag, lef, cap and vrrA (for partial genotyping) genes. Hybridisation conditions were initially optimised to be run using 5 x SSC, 0.1% SDS, 50 degrees C for 16 h. The detection limits of the microarray were determined under these conditions by titration of chromosomal DNA and unlabelled amplicons followed by hybridisation to determine the levels of sensitivity that could be obtained with the microarray. Two different amplification methodologies were also compared-specific-primer based PCR and random PCR (with the labelling stage incorporated). Higher sensitivity was obtained using specific PCR primers, however, since one of the desired outcomes of a microarray-based detection system was the high discrimination that it offered, random amplification and labelling was used as the amplification method of choice. The length of hybridisation was investigated using a time-course, and 1--2h was found to give optimal and higher signals than 16 h incubation. These results indicate that microarray technology can be employed in a diagnostic environment and moreover, results may be obtained in a similar time-scale to a standard PCR reaction, but with the advantage that no a priori knowledge of the infectious agent is required for detection.

Q fever outbreak in industrial setting.

An outbreak of Q fever occurred in South Wales, United Kingdom, from July 15 through September 30, 2002. To investigate the outbreak a cohort and nested case-control study of persons who had worked at a cardboard manufacturing plant was conducted. The cohort included 282 employees and subcontractors, of whom 253 (90%) provided blood samples and 214 (76%) completed questionnaires. Ninety-five cases of acute Q fever were identified. The epidemic curve and other data suggested an outbreak source likely occurred August 5-9, 2002. Employees in the factory's offices were at greatest risk for infection (odds ratio 3.46; 95% confidence interval 1.38-9.06). The offices were undergoing renovation work around the time of likely exposure and contained straw board that had repeatedly been drilled. The outbreak may have been caused by aerosolization of Coxiella burnetii spore-like forms during drilling into contaminated straw board.

Dengue hemorrhagic fever with fulminant hepatic failure in an immigrant returning to Bangladesh.

An immigrant from Bangladesh living in the United Kingdom presented with a nonspecific febrile illness after visiting his homeland and subsequently developed fulminant hepatic failure accompanied by hypotension, ascites, a generalized coagulopathy, and thrombocytopenia. Serology and detection of dengue virus serotype 3 by PCR established a postmortem diagnosis of hepatic failure secondary to dengue hemorrhagic fever.

Poliovirus type 1 in working stocks of typed human rhinoviruses.

After eradication of circulating polioviruses, reintroduction might arise from cultured laboratory stocks, or from collections of patients' or environmental samples. In an example of a further class of risk, we recorded poliovirus type 1 in at least four working stocks of what had been identified as various serotypes of human rhinovirus. This finding emphasises the need to urgently assess the possibility of presence of poliovirus, even in apparently well-characterised stocks of other viruses, to screen for the virus where necessary, and to destroy materials in which risk outweighs potential benefit.

Phylogenetic relationships and differential selection pressures among genotypes of dengue-2 virus.

To elucidate the processes controlling the emergence and spread of dengue-2 virus (DEN-2) we examined the evolution of viral isolates sampled from both local (Viet Nam) and global populations. Our phylogenetic analysis, incorporating envelope (E) glycoprotein sequences from 147 isolates of DEN-2, provided a more complete picture of viral diversity, with a newly defined "Cosmopolitan" genotype having a near global distribution and two other genotypes restricted to Asia. By analyzing rates of synonymous and nonsynonymous substitution we determined that genotypes have experienced different selection pressures, with some evidence of positive selection in the Cosmopolitan genotype and one of the two Asian genotypes, but that the transition from sylvatic to human transmission was not accompanied by adaptive evolution of the E gene. Although there was no association between selection pressures acting on the E gene and proposed virulence differences among genotypes, some putatively selected amino acid sites have previously been implicated in changing viral pathogenicity, most notably E-390, and may also affect transmittability. These findings have implications for the future spread of DEN-2.