Dennis Tappe

Emergence of Zaire Ebola Virus Disease in Guinea

In March 2014, the World Health Organization was notified of an outbreak of a communicable disease characterized by fever, severe diarrhea, vomiting, and a high fatality rate in Guinea. Virologic investigation identified Zaire ebolavirus (EBOV) as the causative agent. Full-length genome sequencing and phylogenetic analysis showed that EBOV from Guinea forms a separate clade in relationship to the known EBOV strains from the Democratic Republic of Congo and Gabon. Epidemiologic investigation linked the laboratory-confirmed cases with the presumed first fatality of the outbreak in December 2013. This study demonstrates the emergence of a new EBOV strain in Guinea.

First case of laboratory-confirmed Zika virus infection imported into Europe, November 2013.

In November 2013, an acute Zika virus (ZIKV) infection was diagnosed in a German traveller returning from Thailand. The patient reported a clinical picture resembling dengue fever. Serological investigations revealed anti-ZIKV-IgM and -IgG, as well as ZIKV-specific neutralising antibodies in the patients blood. In Europe, viraemic travellers may become a source of local transmission of ZIKV, because Aedes albopictus (Skuse) and Ae. aegypti (Linnaeus) are invasive mosquitoes and competent vectors for ZIKV. .

Zika virus infections imported to Italy: Clinical, immunological and virological findings, and public health implications

We report the first two cases of laboratory confirmed Zika virus (ZIKV) infections imported into Italy from French Polynesia. Both patients presented with low grade fever, malaise, conjunctivitis, myalgia, arthralgia, ankle oedema, and axillary and inguinal lymphadenopathy. One patient showed leukopenia with relative monocytosis and thrombocytopenia. The diagnosis was based on ZIKV seroconversion in both cases and on ZIKV RNA detection in one patient from acute serum sample. Sera from both patients exhibited cross-reactivity with dengue virus antigens. Our immunological analysis demonstrated that recovery from ZIKV infection is associated with restoration of normal numbers of immune cells in the periphery as well as with normal function of antigen-presenting cells. ZIKV is an emerging arbovirus, which has recently spread extensively in tourist destinations on several West Pacific islands. Returning viremic travelers may ignite autochthonous infections in countries like Italy, which are infested by Aedes albopictus, a suitable vector for ZIKV. The role of clinicians is crucial and includes early diagnosis and timely notification of public health authorities in order to quickly implement adequate focal vector control measurements.

Zika virus infection in a traveller returning to Europe from Brazil, March 2015.

We report a case of laboratory-confirmed Zika virus infection imported into Europe from the Americas. The patient developed fever, rash, and oedema of hands and feet after returning to Italy from Brazil in late March 2015. The case highlights that, together with chikungunya virus and dengue virus, three major arboviruses are now co-circulating in Brazil. These arboviruses represent a burden for the healthcare systems in Brazil and other countries where competent mosquito vectors are present.

Chronic nonbacterial osteomyelitis in childhood: prospective follow-up during the first year of anti-inflammatory treatment

IntroductionChronic nonbacterial osteomyelitis (CNO) is an inflammatory disorder of unknown etiology. In children and adolescents CNO predominantly affects the metaphyses of the long bones, but lesions can occur at any site of the skeleton. Prospectively followed cohorts using a standardized protocol in diagnosis and treatment have rarely been reported.MethodsThirty-seven children diagnosed with CNO were treated with naproxen continuously for the first 6 months. If assessment at that time revealed progressive disease or no further improvement, sulfasalazine and short-term corticosteroids were added. The aims of our short-term follow-up study were to describe treatment response in detail and to identify potential risk factors for an unfavorable outcome.ResultsNaproxen treatment was highly effective in general, inducing a symptom-free status in 43% of our patients after 6 months. However, four nonsteroidal anti-inflammatory drug (NSAID) partial-responders were additionally treated with sulfasalazine and short-term corticosteroids. The total number of clinical detectable lesions was significantly reduced. Mean disease activity estimated by the patient/physician and the physical aspect of health-related quality of life including functional ability (global assessment/childhood health assessment questionnaire and childhood health assessment questionnaire) and pain improved significantly. Forty-one percent of our patients showed radiological relapses, but 67% of them were clinically silent.ConclusionsMost children show a favorable clinical course in the first year of anti-inflammatory treatment with NSAIDs. Relapses and new radiological lesions can occur at any time and at any site in the skeleton but may not be clinically symptomatic. Whole-body magnetic resonance imaging proved to be very sensitive for initial and follow-up diagnostics.

A Variegated Squirrel Bornavirus Associated with Fatal Human Encephalitis

Between 2011 and 2013, three breeders of variegated squirrels (Sciurus variegatoides) had encephalitis with similar clinical signs and died 2 to 4 months after onset of the clinical symptoms. With the use of a metagenomic approach that incorporated next-generation sequencing and real-time reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), the presence of a previously unknown bornavirus was detected in a contact squirrel and in brain samples from the three patients. Phylogenetic analyses showed that this virus, tentatively named variegated squirrel 1 bornavirus (VSBV-1), forms a lineage separate from that of the known bornavirus species. (Funded by the Federal Ministry of Food and Agriculture [Germany] and others.).

Acute Zika Virus Infection after Travel to Malaysian Borneo, September 2014

To the Editor: Zika virus (ZIKV), a mosquito-borne flavivirus, causes Zika fever, a self-limiting febrile and exanthematic arthralgia syndrome closely resembling dengue fever. Most often, signs and symptoms are maculopapular rash, fever, arthralgia, myalgia, headache, and conjunctivitis; edema, sore throat, cough, and vomiting occur less frequently (1). The virus, which was initially isolated from a rhesus monkey (Macaca mulatta) in 1947 in Uganda, has come to attention recently after a large outbreak occurred in the western Pacific region, including French Polynesia, New Caledonia, Easter Island, and the Cook Islands (2). Travel-related imported infections have thus been increasingly reported from the western Pacific and sporadically also in travelers to other regions of the world, including Thailand, Indonesia, and Senegal (2,3). ZIKV is transmitted by different Aedes mosquito species, and nonhuman primates play a role as reservoirs (1). After the beginning of the ZIKV epidemic in late 2013, a 20-fold increase of Guillain-Barre syndrome incidence was noted in French Polynesia; 1 patient was infected a week before neurologic symptoms started (4). We report an acute ZIKV infection in a traveler returning from Malaysian Borneo who experienced bilateral hearing difficulties during the course of illness. On September 1, 2014, a 45-year-old woman was seen in an outpatient clinic in Heidelberg, Germany for fever of up to 39°C and maculopapular rash covering her trunk, arms, and legs. Fever had started on August 30, which was 6 days after she had returned from a 3-week vacation to peninsular Malaysia and Sabah, Malaysian Borneo. Laboratory analyses showed a slightly elevated C-reactive protein level of 5.2 mg/L (reference range <5.0), but liver function test and complete blood count results were within reference range. During the next 3 days, the fever subsided, but the patient experienced a sore throat, bilateral conjunctivitis, and a burning sensation of the palms and soles. These symptoms were accompanied by swelling of the hands and increasing arthralgia of the wrists, palms, and fingers. There was no lymphadenopathy. An indirect immunofluorescence assay for ZIKV (3) demonstrated an IgM titer of 1:640 and an IgG titer of 1:320 (cutoff <1:20) on day 6 of illness (Figure). An indirect immunofluorescence assay for dengue virus demonstrated an IgG titer of 1:80 and no IgM (cutoff <1:20). Figure Clinical course and laboratory results (reverse transcription-PCR [RT-PCR]) for a patient with Zika virus (ZIKV) infection acquired from Malaysian Borneo. Two days later, the patient experienced sudden bilateral dull and metallic hearing; in her left ear, she experienced a very short delay between a sound and her perception of the sound. Follow-up ZIKV serologic testing on day 11 of illness showed a decreased IgM titer of 1:160 and an increased IgG titer of 1:2,560 (Figure). Viral neutralization testing (3) of the same sample demonstrated the presence of ZIKV-specific neutralizing antibodies. Chikungunya virus serology results were negative. An archived serum sample from day 3 of illness studied by ZIKV serology and a ZIKV-specific real-time reverse transcription PCR (3) was negative (Figure). Hearing difficulties lasted for 10 days and resolved gradually (Figure). During her journey to several cities and villages in Sabah, Malaysian Borneo, the patient had noticed several mosquito bites even though she had used repellents. She had stayed in hotels, private homes, and remote church homes under various conditions (Technical Appendix). In Asia, Zika fever has been described sporadically in Cambodia, Thailand, and Indonesia (Java and Lombok) (1,3,5,6). On the basis of the incubation time of ≈6 days in returning travelers (2,3), we assumed that the patient became infected in Keningau or surrounding villages, in northern Borneo. Although ZIKV was detected in Ae. aegypti mosquitoes in peninsular Malaysia in 1969 (7) and antibodies against ZIKV were demonstrated in serum samples from 15 of 79 patients on peninsular Malaysia and 9 of 50 patients in Borneo in 1953 (8), Zika fever in peninsular Malaysia or Borneo has not been reported. In 2001, ZIKV seropositivity was demonstrated in a native Bornean, 2 migrants to Borneo, and 2 Bornean orangutans (Pongo pygmaeus) (9). A later study found an additional 8 Bornean orangutans to be seropositive for antibodies against ZIKV (10). Thus, in Borneo, either the virus only rarely infects humans or the disease is mistaken for dengue fever. Neurologic complications of ZIKV infections had previously been reported only as Guillain-Barre syndrome, and hearing difficulties in Zika fever patients have not been reported. Because this symptom resolved spontaneously, no audiometry or auditory brainstem response testing was performed, and the cause of the disorder remains unclear. Because of increasing travel and migration and heightened clinical and laboratory awareness, more ZIKV infections are likely to be diagnosed outside of epidemic events. Technical Appendix: Travel itinerary of a patient with Zika fever. Click here to view.(217K, pdf)

Cytokine kinetics of Zika virus-infected patients from acute to reconvalescent phase

Abstract Zika virus is an emerging mosquito-borne flavivirus currently causing large epidemics in the Pacific Ocean region and Brazil. Clinically, Zika fever resembles dengue fever, but is less severe. Whereas the clinical syndrome and laboratory diagnostic procedures have been described, little attention was paid to the immunology of the disease and its possible use for clinical follow-up of patients. Here, we investigate the role of cytokines in the pathogenesis of Zika fever in travelers returning from Asia, the Pacific, and Brazil. Polyfunctional T cell activation (Th1, Th2, Th9, and Th17 response) was seen during the acute phase characterized by respective cytokine level increases, followed by a decrease in the reconvalescent phase.

Long-term in vitro cultivation of Echinococcus multilocularis metacestodes under axenic conditions

We report here on the development of an in vitro system for the long-term cultivation of Echinococcus multilocularis larvae under axenic conditions. In the absence of feeder cells from the host, long-term survival of the parasite depended strictly on low oxygen conditions and the presence of reducing agents in the medium. Host serum supported survival of the parasite but the growth of metacestode vesicles and differentiation towards the protoscolex stage only occurred in the presence of culture medium that was preconditioned by hepatoma cells or several other immortal cell lines. On the basis of this in vitro system, future analyses on the identification of host-derived growth factors for E. multilocularis will be greatly facilitated.

Gastroenteritis in childhood: a retrospective study of 650 hospitalized pediatric patients

BACKGROUND Acute diarrhea continues to be an important cause of hospitalization in young children, and deaths still occur as a result. We reviewed a large cohort of hospitalized children affected by gastroenteritis. The hypothesis of our study was that clinical characteristics and a limited set of laboratory data can differentiate between the different causative pathogens of diarrhea. METHODS A chart review was performed of 650 patients with pathogen-proven diarrhea treated between April 2005 and May 2008 in the childrens hospital of the University of Würzburg. Clinical presentation at the time of admission and during hospital stay, laboratory findings, stool pathogen results, and epidemiological data were collected and compared. A severity score was generated. RESULTS Rotavirus was the most common gastroenteritis pathogen identified, followed by norovirus, adenovirus and Salmonella spp. Nosocomial infections were caused most commonly by norovirus. Rotavirus was the most common agent when there was simultaneous detection of two or more viruses. Rotavirus infections were significantly more severe, with a higher frequency of diarrhea and elevated liver enzymes. Infections due to Salmonella spp showed significantly higher values for C-reactive protein, erythrocyte sedimentation rate, and body temperature. A seasonal distribution was noted, with the peak for rotaviruses/noroviruses in winter/spring, the peak for adenoviruses in November/December, and the peak for Salmonella spp in the summer months. Younger children and toddlers had significantly higher gastroenteritis and airway inflammation scores. Of note, respiratory symptoms and parameters of systemic inflammation differed between the different pathogens. CONCLUSIONS Gastroenteritis is a common reason for hospital admission in previously healthy children during the first years of life. Rotaviruses were found to be the most common pathogens in our cohort. On the basis of clinical and laboratory parameters it appears possible to distinguish between the different causative agents. This may have implications for hospital hygiene management and for the identification of predictive markers of a severe course.