Simon-Djamel Thiberville

Chikungunya fever: Epidemiology, clinical syndrome, pathogenesis and therapy

Abstract Chikungunya virus (CHIKV) is the aetiological agent of the mosquito-borne disease chikungunya fever, a debilitating arthritic disease that, during the past 7years, has caused immeasurable morbidity and some mortality in humans, including newborn babies, following its emergence and dispersal out of Africa to the Indian Ocean islands and Asia. Since the first reports of its existence in Africa in the 1950s, more than 1500 scientific publications on the different aspects of the disease and its causative agent have been produced. Analysis of these publications shows that, following a number of studies in the 1960s and 1970s, and in the absence of autochthonous cases in developed countries, the interest of the scientific community remained low. However, in 2005 chikungunya fever unexpectedly re-emerged in the form of devastating epidemics in and around the Indian Ocean. These outbreaks were associated with mutations in the viral genome that facilitated the replication of the virus in Aedes albopictus mosquitoes. Since then, nearly 1000 publications on chikungunya fever have been referenced in the PubMed database. This article provides a comprehensive review of chikungunya fever and CHIKV, including clinical data, epidemiological reports, therapeutic aspects and data relating to animal models for in vivo laboratory studies. It includes Supplementary Tables of all WHO outbreak bulletins, ProMED Mail alerts, viral sequences available on GenBank, and PubMed reports of clinical cases and seroprevalence studies.

Chikungunya Fever: A Clinical and Virological Investigation of Outpatients on Reunion Island, South-West Indian Ocean

Background Chikungunya virus (CHIKV) is responsible for acute febrile polyarthralgia and, in a proportion of cases, severe complications including chronic arthritis. CHIKV has spread recently in East Africa, South-West Indian Ocean, South-Asia and autochthonous cases have been reported in Europe. Although almost all patients are outpatients, medical investigations mainly focused on hospitalised patients. Methodology/Principal Findings Here, we detail clinico-biological characteristics of Chikungunya (CHIK) outpatients in Reunion Island (2006). 76 outpatients with febrile arthralgia diagnosed within less than 48 hours were included by general practitioners during the CuraChik clinical trial. CHIK was confirmed in 54 patients and excluded in 22. A detailed clinical and biological follow-up was organised, that included analysis of viral intrahost diversity and telephone survey until day 300. The evolution of acute CHIK included 2 stages: the ‘viral stage’ (day 1–day 4) was associated with rapid decrease of viraemia and improvement of clinical presentation; the ‘convalescent stage’ (day 5–day 14) was associated with no detectable viraemia but a slower clinical improvement. Women and elderly had a significantly higher number of arthralgia at inclusion and at day 300. Based on the study clinico-biological dataset, scores for CHIK diagnosis in patients with recent febrile acute polyarthralgia were elaborated using arthralgia on hands and wrists, a minor or absent myalgia and the presence of lymphopenia (<1G/L) as major orientation criteria. Finally, we observed that CHIKV intra-host genetic diversity increased over time and that a higher viral amino-acid complexity at the acute stage was associated with increased number of arthralgia and intensity of sequelae at day 300. Conclusions/Significance This study provided a detailed picture of clinico-biological CHIK evolution at the acute phase of the disease, allowed the elaboration of scores to assist CHIK diagnosis and investigated for the first time the impact of viral intra-host genetic diversity on the disease course.

The viral etiology of an influenza-like illness during the 2009 pandemic.

Many viruses are known to cause influenza‐like illness (ILI); however, in nearly 50% of patients, the etiologic agent remains unknown. The distribution of viruses in patients with ILI was investigated during the 2009 A/H1N1 influenza pandemic (A/H1N1p). From June 2009 to January 2010, 660 patients with suspected influenza were questioned and examined, and nasal swabs were collected. All patient samples were tested for influenza virus, and 286 negative nasal swabs were tested further for 18 other respiratory viruses using real‐time RT‐PCR. Two waves of ILI were observed in the epidemic curve (weeks 35–42 and 42–49). At least eight viruses co‐circulated during this period: human rhinovirus (HRV) (58), parainfluenza 1–4 viruses (PIV) (9), human Coronavirus (hCoV) OC43 (9), enterovirus (5), adenovirus (AdV) (4), and human metapneumovirus (hMPV) (2); however, 204 samples remained negative for all viruses tested. ILI symptoms, according to the Centers for Disease Control and Prevention criteria for ILI definition, were reported in 75% of cases. These patients had positive swabs for A/H1N1p, HRV, hCoV‐OC43, PIV, AdV, and hMPV without significant difference with non‐ILI patients. This study found that many respiratory viruses circulated during this period and that the A/H1N1p did not impact on the kinetics of other respiratory viruses. The proportion of non‐documented cases remains high. ILI could not distinguish A/H1N1p infection from that due to other respiratory viruses. However, in multivariate anlaysis, cough, chills, hyperemia, and dyspnea were associated significantly with influenza virus versus other respiratory viruses. J. Med. Virol. 84: 1071–1079, 2012.

Widespread circulation of a new echovirus 30 variant causing aseptic meningitis and non-specific viral illness, South-East France, 2013

BACKGROUND Human enteroviruses (HEVs) are major cause of aseptic meningitis. A new outbreak of E-30 occurred between April and September 2013 in Marseille, South-East France. OBJECTIVES Better understand what happen locally when an E-30 outbreak occurs. STUDY DESIGN Laboratory data (identification and characterization of circulating E-30 strains by partial/complete genome sequencing) were analyzed together with clinical data from emergency ward of the public hospital of Marseille. RESULTS Compared with data from previous years, we observed an excess of HEV infections between April and September 2013. A total of 202 patients were tested positive of which 79% (160/202) had a cerebrospinal fluid tested positive. Because we performed genotyping using clinical specimens, we obtained representative molecular data related to patients tested positive and found a majority (105/119) of echoviruses 30 (E-30). Phylogenetic analysis revealed that E-30 circulating in Europe since 2000 belong to a unique lineage and showed at the intra-genogroup level the temporal circulation of E-30. Molecular data also indicated that majority of E-30 detected (92%) were almost identical. Compared with data from previous years, this outbreak was finally associated with an excess of patients admitted to an emergency ward for meningitis but also for non-specific viral illness. CONCLUSIONS Our data provide new insights into microevolution of E-30: almost all E-30 emerged from local circulation of one parental virus. Moreover, our findings showed that HEV outbreaks cause an excess of emergency ward consultations but probably also an excess of consultations to general practitioners who receive majority of the non-specific viral illness.

Isolation of Toscana virus from the cerebrospinal fluid of a man with meningitis in Marseille, France, 2010.

Toscana virus (TOSV; Bunyaviridae, Phlebovirus) is an emerging arthropod-borne virus transmitted by phlebotomine sandflies. TOSV is a frequent cause of central nervous system infection during the warm season in several countries bordering the Mediterranean Sea. Here, we report a case of TOSV aseptic meningitis diagnosed in 2012 in Marseille, France. The virus strain was recovered in cell culture from the cerebrospinal fluid. New-generation sequencing based on Ion Torrent technology was used to determine its complete genome sequence. Phylogenetic analysis based on the partial L segment revealed that this isolate belongs to the lineage B together with other French, Spanish, and Moroccan strains. Although several cases of TOSV meningitis are reported in the literature, few of them are diagnosed by RT-PCR combined with virus isolation and further sequence characterization. This case report supports that virus isolation should be attempted whenever possible because this remains the gold standard technique for diagnosis of arthropod-borne viral infections.

Respiratory viruses within homeless shelters in Marseille, France

BackgroundHomeless shelters are identified as places where humans are at high risk of acquiring respiratory disease. We previously reported the prevalence of the main respiratory diseases affecting a population of homeless in Marseille, France. Here, we investigated the prevalence of 10 respiratory viruses in a similar homeless population during 2 successive winter seasons.FindingsFollowing a clinical examination, we collected nasal specimens from which the RT-PCR detection of 10 respiratory viruses was performed through snapshot investigations. Among the 265 patients included, 150 (56.6%) reported at least one respiratory symptom of which 13 (8.7%) had positive swabs for at least one respiratory virus, and 115 patients reported any respiratory symptom of which 10 (8.7%) had positive swabs for respiratory virus. Overall, 23 patients had positive swabs for at least one respiratory virus. Human rhinovirus (HRV) was the predominant virus (13 isolates) followed by enteroviruses (3), human metapneumovirus (2), human coronavirus OC43 (2), 229E virus (2) and human respiratory syncytial virus subtype B (1). Among the patients infected with HRV, 10 were collected during the same snapshot.ConclusionsAlthough one half of the patients reported respiratory symptoms, the prevalence of respiratory viruses was within the range of that previously described in adult asymptomatic patients outside the homeless community. Most HRV-positive swabs were collected during the same snapshot suggesting a local outbreak. No influenza viruses were found despite the fact that one half of the patients were investigated during the peak of the seasonal influenza epidemic in Marseille.

Paradoxical Effect of Chloroquine Treatment in Enhancing Chikungunya Virus Infection

Since 2005, Chikungunya virus (CHIKV) re-emerged and caused numerous outbreaks in the world, and finally, was introduced into the Americas in 2013. The lack of CHIKV-specific therapies has led to the use of non-specific drugs. Chloroquine, which is commonly used to treat febrile illnesses in the tropics, has been shown to inhibit CHIKV replication in vitro. To assess the in vivo effect of chloroquine, two complementary studies were performed: (i) a prophylactic study in a non-human primate model (NHP); and (ii) a curative study “CuraChik”, which was performed during the Reunion Island outbreak in 2006 in a human cohort. Clinical, biological, and immunological data were compared between treated and placebo groups. Acute CHIKV infection was exacerbated in NHPs treated with prophylactic administration of chloroquine. These NHPs displayed a higher viremia and slower viral clearance (p < 0.003). Magnitude of viremia was correlated to the type I IFN response (Rho = 0.8, p < 0.001) and severe lymphopenia (Rho = 0.8, p < 0.0001), while treatment led to a delay in both CHIKV-specific cellular and IgM responses (p < 0.02 and p = 0.04, respectively). In humans, chloroquine treatment did not affect viremia or clinical parameters during the acute stage of the disease (D1 to D14), but affected the levels of C-reactive Protein (CRP), IFNα, IL-6, and MCP1 over time (D1 to D16). Importantly, no positive effect could be detected on prevalence of persistent arthralgia at Day 300. Although inhibitory in vitro, chloroquine as a prophylactic treatment in NHPs enhances CHIKV replication and delays cellular and humoral response. In patients, curative chloroquine treatment during the acute phase decreases the levels of key cytokines, and thus may delay adaptive immune responses, as observed in NHPs, without any suppressive effect on peripheral viral load.

Sternoclavicular joint infection caused by Coxiella burnetii: a case report

BackgroundFew cases of Q fever osteoarticular infection have been reported, with chronic osteomyelitis as the most common manifestation of Q fever osteoarticular infection. Here we present the case of a sternoclavicular joint infection caused by Coxiella burnetii and localized by positron emission tomography scanning.Case presentationA 67-year-old French man from south France was hospitalized for fever and confusion. An examination revealed subclavicular and axillary lymph node enlargement. Computed tomography scanning and transesophageal echocardiogram were normal, and magnetic resonance imaging scanning did not reveal signs of infection. An immunofluorescence assay of an acute serum sample was positive for C. burnetii and he was treated with 200 mg doxycycline for 21 days. An immunofluorescence assay of convalescent serum sampled after 2 months revealed very high C. burnetii antibody titers. To localize the site of the infection, we performed positron emission tomography scanning, which revealed intense fluorodeoxyglucose uptake in his right sternoclavicular joint; treatment with 200 mg oral doxycycline daily and 200 mg oral hydroxychloroquine three times daily for 18 months was initiated.ConclusionsQ fever articular infections may be undiagnosed, and we strongly urge the use of positron emission tomography scanning in patients with high C. burnetii antibody titers to localize the site of C. burnetii infection.

Comparative analysis of rodent tissue preservation methods and nucleic acid extraction techniques for virus screening purposes.

The polymerase chain reaction (PCR) has become an essential method for the detection of viruses in tissue specimens. However, it is well known that the presence of PCR inhibitors in tissue samples may cause false-negative results. Hence the identification of PCR inhibitors and evaluation and optimization of nucleic acid extraction and preservation methods is of prime concern in virus discovery programs dealing with animal tissues. Accordingly, to monitor and remove inhibitors we have performed comparative analyses of two commonly used tissue storage methods and five RNA purification techniques using a variety of animal tissues, containing quantified levels of added MS2 bacteriophages as the indicator of inhibition. The results showed (i) no significant difference between the two methods of sample preservation, viz. direct storage at -80°C or 4°C in RNAlater, (ii) lung rodent tissues contained lower levels of inhibitor than liver, kidney and spleen, (iii) RNA extraction using the EZ1+PK RNA kit was the most effective procedure for removal of RT-PCR inhibitors.

Recurrent bilateral Mycobacterium bovis necrotizing epididymitis: a case report

BackgroundMycobacterium bovis causing tuberculosis in animals is responsible for zoonotic tuberculosis in patients. Veterinary control measures and milk pasteurization has led to a significant decrease in human cases of M. bovis infections in developed countries.Case presentationWe diagnosed recurrent M. bovis epididymitis in a 63-year old Caucasian man without any signs of pulmonary or disseminated disease. Relevant epidemiological expositions included camel milk drinking during prolonged travels in Niger, prior to initial clinical manifestations. The diagnosis was firmly established by mass spectrometry and DNA sequencing on epididymis surgical biopsy specimens. We detail therapeutic management which included surgical epididymectomy and hydrocele repair.ConclusionAs for other M. tuberculosis complex species, the genitourinary tract represents a frequent site of secondary dissemination and latency for M. bovis. Isolated epididymis infection is a newly documented manifestation of M. bovis disease.