Fatal leptospirosis and chikungunya co-infection: Do not forget leptospirosis during chikungunya outbreaks.

In endemic areas, leptospirosis can be missed by erroneous clinical or laboratory diagnosis of arboviroses or co-infections with arboviruses and an increase in mortality due to leptospirosis has already been reported during arboviruses outbreaks. During the French Polynesian chikungunya virus outbreak in 2014-2015, two leptospirosis and chikungunya co-infections were reported, one of which was fatal. Diagnosis of leptospiroses was delayed in the context of chikungunya outbreak. In the context of arbovirus outbreak, the risk of misdiagnosis of leptospirosis is maximum and clinicians should initiate early antibiotic therapy if leptospirosis is suspected. A delayed diagnosis of leptospirosis can be responsible for fatal outcome. Leptospirosis should be considered even if dengue or chikungunya virus infections are confirmed by reference molecular testing.

Analysis of risk factors for malignant Mediterranean spotted fever indicates that fluoroquinolone treatment has a deleterious effect.

OBJECTIVES: To identify risk factors for malignant Mediterranean spotted fever (MSF) caused by Rickettsia conorii conorii. PATIENTS AND METHODS: Epidemiological, clinical and biological characteristics as well as risk factors (including treatment regimens) for severe MSF cases were analysed retrospectively. A patient with two or more organ dysfunctions or patient death was defined as a severe case. RESULTS: During the study period (January 1999 to December 2009), 161 MSF cases were referred to our centre for rickettsioses. Twenty-six cases (16.1%) were considered severe, which is 3-fold higher than in our previous studies. The clinical and laboratory findings were comparable to those reported elsewhere except that the type of antibiotic treatment was associated with disease severity. Doxycycline administration prior to deterioration of disease (in 31 patients) protected patients from development of severe MSF [relative risk (RR) 0.248, 95% confidence interval (CI) 0.08-0.76] and induced earlier defervescence compared with the other treatment regimens (3.02 ± 2.2 days versus 7.1 ± 6.57 days, P = 0.021). In contrast, fluoroquinolone treatment (in 21 patients) was significantly and independently associated with MSF severity (RR 2.53, 95% CI 1.40-4.55) and was associated with a significantly longer hospital stay. CONCLUSIONS: In this retrospective study fluoroquinolone treatment was associated with increased MSF disease severity. Fluoroquinolones have been previously associated with treatment failure in typhus and scrub typhus cases. Thus, we do not recommend the use of fluoroquinolones to treat rickettsial diseases.

Rickettsia slovaca and R. raoultii in tick-borne Rickettsioses.

Tick-borne lymphadenopathy (TIBOLA), also called Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL), is defined as the association of a tick bite, an inoculation eschar on the scalp, and cervical adenopathies. We identified the etiologic agent for 65% of 86 patients with TIBOLA/DEBONEL as either Rickettsia slovaca (49/86, 57%) or R. raoultii (7/86, 8%).

Rickettsia conorii transcriptional response within inoculation eschar.

BACKGROUND: Rickettsia conorii, the causative agent of the Mediterranean spotted fever, is transmitted to humans by the bite of infected ticks Rhipicephalus sanguineus. The skin thus constitutes an important barrier for the entry and propagation of R. conorii. Given this, analysis of the survival strategies used by the bacterium within infected skin is critical for our understanding of rickettsiosis. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first genome-wide analysis of R. conorii gene expression from infected human skin biopsies. Our data showed that R. conorii exhibited a striking transcript signature that is remarkably conserved across patients, regardless of genotype. The expression profiles obtained using custom Agilent microarrays were validated by quantitative RT-PCR. Within eschars, the amount of detected R. conorii transcripts was of 55%, this value being of 74% for bacteria grown in Vero cells. In such infected host tissues, approximately 15% (n = 211) of the total predicted R. conorii ORFs appeared differentially expressed compared to bacteria grown in standard laboratory conditions. These genes are mostly down-regulated and encode proteins essential for bacterial replication. Some of the strategies displayed by rickettsiae to overcome the host defense barriers, thus avoiding killing, were also pointed out. The observed up-regulation of rickettsial genes associated with DNA repair is likely to correspond to a DNA-damaging agent enriched environment generated by the host cells to eradicate the pathogens. Survival of R. conorii within eschars also involves adaptation to osmotic stress, changes in cell surface proteins and up-regulation of some virulence factors. Interestingly, in contrast to down-regulated transcripts, we noticed that up-regulated ones rather exhibit a small nucleotide size, most of them being exclusive for the spotted fever group rickettsiae. CONCLUSION/SIGNIFICANCE: Because eschar is a site for rickettsial introduction, the pattern of rickettsial gene expression observed here may define how rickettsiae counteract the host defense.

Questions on Mediterranean spotted fever a century after its discovery.

Mediterranean spotted fever (MSF) was first described in 1910. Twenty years later, it was recognized as a rickettsial disease transmitted by the brown dog tick. In contrast to Rocky Mountain spotted fever (RMSF), MSF was thought to be a benign disease; however, the first severe case that resulted in death was reported in France in the 1980s. We have noted important changes in the epidemiology of MSF in the last 10 years, with emergence and reemergence of MSF in several countries. Advanced molecular tools have allowed Rickettsia conorii conorii to be classified as a subspecies of R. conorii. New clinical features, such as multiple eschars, have been recently reported. Moreover, MSF has become more severe than RMSF; the mortality rate was as high as 32% in Portugal in 1997. Whether Rhipicephalus sanguineus is the only vector and reservoir for R. conorii conorii is a question not yet answered.

Mediterranean spotted fever.

Rickettsial disease has recently undergone an important evolution, particularly in the field of molecular genetics. This development includes Mediterranean spotted fever (MSF), a tick-borne disease caused by Rickettsia conorii. Important changes have occurred in ecologic and epidemiologic comprehension of the disease, and in the occurrence of severe forms. However, many questions still remain, including the identity of the real vector and reservoir of R conorii, and whether other risk factors exist for a severe form of MSF.

Stenotrophomonas maltophilia prosthetic valve endocarditis: a case report.

INTRODUCTION: Stenotrophomonas maltophilia is an environmental bacterium increasingly involved in nosocomial infections and resistant to most antibiotics. It is important to recognize and efficiently treat infections with this bacterium as soon as possible. CASE PRESENTATION: We present a case of Stenotrophomonas maltophilia prosthetic valve endocarditis secondary to an indwelling catheter infection. The patient was cured without surgery. We review other cases of S. maltophilia endocarditis from the literature and describe the peculiarities of this case. CONCLUSION: S. maltophilia endocarditis is a rare disease that is often hospital-acquired and related to an indwelling catheter infection. The high lethality is likely related to the intrinsic resistance of nosocomial bloodstream infections to commonly prescribed antibiotics.

The effect of a single dose of oral ivermectin on pruritus in the homeless.

BACKGROUND: Homeless people commonly present with ectoparasite-based pruritus. We evaluated the efficacy of a single dose of ivermectin to reduce the pruritus prevalence in a homeless population. METHODS: We conducted a randomized, double-blind, placebo-controlled trial from January 2006 to April 2006 in two homeless shelters in the city of Marseille, France. Homeless people complaining of pruritus were randomized to receive either ivermectin (24 mg) or placebo. Follow-up visits were planned at day 14 and day 28 after the inclusion to assess the outcome of pruritus. RESULTS: Forty-two subjects with pruritus were randomized to the ivermectin group and 40 to the placebo group. On day 14, pruritus was reported by significantly more subjects in the placebo group than those in the ivermectin group for both the per-protocol (PP) population (91.42% versus 68.57%, P = 0.014) and the intention-to-treat (ITT) population (92.5% versus 73.80%, P = 0.038). No significant effect was observed at day 28. Ivermectin was the only independent factor associated with the absence of pruritus at day 14 in both PP population [OR: 4.60 (95% CI:1.13; 18.73), P = 0.033] and ITT population [OR: 4.38 (95% CI: 1.07; 17.77), P = 0.039]. CONCLUSIONS: A single dose of oral ivermectin has a transient beneficial effect on the reduction of the prevalence of pruritus in the homeless population. More studies are required to assess the efficacy of multiple repeated treatments with ivermectin to reduce scabies and body lice endemic among homeless people with pruritus and the impact of such treatment on this population.

Congenital tuberculosis after in vitro fertilization.

Genital tuberculosis (TB) is a major cause of infertility in the world, notably in developing countries, but its incidence is increasing in the western continents. In vitro fertilization (IVF) represents a useful treatment of infertility after TB. We report the first case of congenital TB after IVF and suggest improvement of usual screening before and after IVF.

Development of a method for recovering rickettsial RNA from infected cells to analyze gene expression profiling of obligate intracellular bacteria.

The Rickettsia genus is composed of Gram-negative bacteria responsible for Typhus and spotted fevers. Because of the limitations imposed by their obligate intracellular location, the molecular mechanisms responsible for their pathogenicity remain poorly understood. Several rickettsial genomes are now available, thus providing the foundation for a new era of post-genomic research. Here, using Rickettsia conorii as model, we developed a suitable method for microarray-based transcriptome analysis of rickettsiae. Total RNA was extracted from infected Vero cells using a protocol preserving its integrity, as observed by Bioanalyzer (Agilent) profiles. By a subtractive hybridization method, the samples were subsequently depleted of eukaryotic RNA that represents up to 90% of the whole extract and that hampers fluorochrome labeling of rickettsial nucleic acids. To obtain the amount of material required for microarray hybridization, the bacterial RNA was then amplified using random primers. Hybridizations were carried out on microarrays specific for R. conorii but containing a limited number of selected targets. Our results show that this method yielded reproducible signals. Transcriptional changes observed following exposure of R. conorii to a nutrient stress were verified by real-time quantitative PCR and by quantitative reverse transcription PCR starting from amplified cDNA and total RNA as templates, respectively. We conclude that this approach has great potential for the study of mechanisms behind the virulence and intracellular survival of members of the genus Rickettsia.

Novel chikungunya virus variant in travelers returning from Indian Ocean islands.

Chikungunya virus (CHIKV) emerged in Indian Ocean islands in 2005 and is causing an ongoing outbreak that involves >260,000 patients, including travelers returning home from these islands. We investigated cases in 4 patients returning from Mayotte and Reunion Islands with CHIKV infection and a nurse infected in metropolitan France after direct contact with the blood of a traveler. Four patients had tenosynovitis and pain at wrist pressure, and 1 had life-threatening manifestations. Four CHIKV strains were isolated, including 1 from the patient with the autochthonous case. The complete genomic sequence identified a new CHIKV variant emerging from the East/ central African evolutionary lineage. Aedes albopictus, the implicated vector of CHIKV in Indian Ocean islands, has dispersed worldwide in recent decades. High viral loads in patients returning from Indian Ocean islands to countries where Ae. albopictus is prevalent may be a source of epidemics.

Bartonella quintana coinfection with Mycobacterium avium complex and CMV in an AIDS patient: case presentation.

BACKGROUND: As a greater number of HIV-infected patients survive despite profound immunodepression due to medical progress, we face complex infection with multiple agents in AIDS-patients. CASE PRESENTATION: We report the case of an AIDS patient with a primary clinical presentation suggestive of bacillary angiomatosis. We also found in cutaneous lesions Mycobacterium avium complex and cytomegalovirus. CONCLUSION: This clinical case illustrates the possibility of multiple coinfections in AIDS patients and the need to be exhaustive in evaluating infectious diseases in severely immunocompromised patients.

Oral ivermectin in the treatment of body lice.

The mainstays of treatment of body-louse infestation in humans in a community setting are insecticides and the removal of infested clothing. We report here the dramatic effect that 3 doses of oral ivermectin (12 mg each), administered at 7-day intervals, have in reducing the total number of body lice in a cohort of homeless men from a shelter in Marseilles, France. We identified a baseline total of 1898 lice in the cohort. Over a 14-day period, this number fell to 6 lice; the prevalence of infested individuals fell from 84.9% to 18.5%. Although this effect was not sustained at day 45, it establishes that ivermectin plays a novel role in the control of body-louse infestation in humans.

Acute cytomegalovirus infection complicated by venous thrombosis: a case report.

BACKGROUND: CMV-induced vasculopathy and thrombosis have been reported, but they are rare conditions usually encountered in immunocompromised patients. However more and more complications of CMV infections are recognized in immunocompetent patients. CASE PRESENTATION: We present a case report of a previously healthy adult with cytomegalovirus infection that was complicated by tibiopopliteal deep venous thrombosis and in whom Factor V Leiden heterozygous mutation was found. CONCLUSION: This new case report emphasizes the involvement of cytomegalovirus in induction of vascular thrombosis in patients with predisposing risk factors for thrombosis. It is necessary to screen for CMV infection in patients with spontaneous thrombosis and an history of fever.

Veillonella montpellierensis endocarditis.

Veillonella spp. rarely cause infections in humans. We report a case of Veillonella endocarditis documented by isolating a slow-growing, gram-negative microbe in blood cultures. This microbe was identified as the newly recognized species Veillonella montpellierensis (100% homology) by 16S RNA gene sequence analysis.

Diagnosis of infectious endocarditis in patients undergoing valve surgery.

PURPOSE: Histologic examination of valve samples is considered as the gold standard for the diagnosis of infectious endocarditis. Molecular tools are also very promising for patients with negative-culture endocarditis. Thus, we studied the contribution of valvular histology, culture, and 16S rRNA PCR amplification plus sequencing to the diagnosis of infectious endocarditis in patients undergoing valve surgery. SUBJECTS AND METHODS: We performed culture, histological examination, and broad-range PCR amplification plus sequencing on valve samples taken from 127 patients with infectious endocarditis and from 118 patients without endocarditis. The sensitivity and specificity of these tests for the diagnosis of endocarditis in patients undergoing valve surgery were studied. RESULTS: The sensitivity of PCR was of 61% (64/105) whereas that of histological examination was of 63% (62/98) and that of valve culture was of only 13% (14/105). All 68 positive PCR results considered reliable according to an interpretation scheme were from patients with infectious endocarditis, resulting in a 100% (118/118) specificity of the interpreted molecular approach. The specificity of histology was also of 100% (118/118) when using stringent criteria (ie, presence of vegetation, microorganisms, and/or valvular inflammation with mainly polymorphonuclear cells). PCR identified an etiological agent in 38% (5/13) of definite blood culture-negative infectious endocarditis. CONCLUSION: We show that valvular histology with stringent criteria is the gold standard for the diagnosis of infectious endocarditis. Broad-range amplification of 16S rRNA gene is indicated for infectious endocarditis of unknown etiology, whereas valve culture is of limited sensitivity.

Transcriptional response of Rickettsia conorii exposed to temperature variation and stress starvation.

Rickettsia conorii is an obligate intracellular bacterium transmitted to humans by Rhipicephalus sanguineus ticks. The success of this microorganism at surviving in nature implicates the ability to efficiently adapt to different environments, including the arthropod vector and the mammalian host. Numerous bacterial species possess a highly evolved system for stress adaptation. This so-called stringent response is mediated by guanosine 3',5'-bispyrophosphate and guanosine 3'-diphosphate 5'-triphosphate which are under spoT control in some Gram-negative bacteria. Interestingly, annotation of the R. conorii genome evidenced 5 spoT paralogs. We hypothesized that these spoT genes play a role in adaptation to environmental changes specifically encountered by rickettsiae during their different life cycles. Transcription of the spoT paralogs was examined by RT-PCR from infected Vero cells maintained in rich or deficient culture media, from infected C6/36 insect cells cultured at various temperatures and from infected ticks. Our results demonstrated that the 5 spoT genes can be transcribed. SpoT1 (RC0374) is only transcribed upon stringent response. Transcription of spoT3 (RC0888) was never observed in arthropod cells or ticks, but was specific to R. conorii RNA extracted from infected Vero cells. These results indicate that rickettsial spoT paralogs are independently transcribed, depending on the different infected hosts and the adaptive capacity of the pathogen. Bioinformatics analysis of these possibly encoded proteins is also reported.

PCR detection of bacteria on cardiac valves of patients with treated bacterial endocarditis.

We used broad-range PCR amplification and sequencing to detect and identify bacterial DNA in 156 valves of patients treated for infective endocarditis (IE). Bacterial DNA was found more frequently in patients who underwent valve replacement while on antibiotic treatment for IE (60%) than in patients who had completed antibiotic treatment for IE (37%; P = 0.02). We found specific bacterial DNA in valves removed from 11 of 30 patients who had completed antibiotic treatment for IE. Six had no histological evidence of IE. The presence of DNA was significantly correlated with the presence of histologic lesions (P = 0.001) and with the presence of bacteria detected by Gram staining (P < 0.001). Bartonella and streptococci were detected for much longer after antibiotic treatment by PCR than other species (P = 0.047 and 0.04, respectively), and coagulase-negative staphylococci were detected for much shorter periods (P = 0.02). The finding that bacterial DNA was more likely to be detected in valves of patients with active IE than in patients who had completed antibiotic treatment for IE shows that bacterial DNA is cleared slowly. There was no significant correlation between the duration of antibiotic therapy and the presence of bacterial DNA in valves. Since the persistence of bacterial DNA in valves does not necessarily indicate the persistence of viable bacteria, the detection of bacterial DNA in valves from IE patients should be interpreted with caution, in particular in those patients with a past history of treated IE.

Shell vial culture as a tool for isolation of Brucella melitensis in chronic hepatic abscess.

A 50-year-old man was admitted with a liver abscess and positive serology for Brucella spp. Liver pus and blood cultures remained sterile on conventional culture. Inoculation of liver pus onto eukaryotic cells by the centrifugation-shell vial technique yielded Brucella melitensis, identified by 16S rRNA gene amplification and sequencing.

Hand antisepsis: evaluation of a sprayer system for alcohol distribution.

OBJECTIVE: To evaluate the usefulness of a new alcohol sprayer by comparing it with an individual bottle of alcohol. Patterns of use and perceptions among healthcare personnel were compared for the two products. DESIGN: Observational study recording the volume of alcohol used and the compliance rate (frequency of hand antisepsis per number of opportunities), and a survey of healthcare workers' perceptions of the different hand hygiene strategies. SETTING: A 20-bed medical unit in a public hospital in Marseille, France. PARTICIPANTS: Healthcare workers of an infectious disease unit INTERVENTIONS: Hand hygiene alcohol systems (sprayer vs individual bottle, 70% ethyl alcohol). RESULTS: The sprayer was used more frequently than the individual bottle (12.6 vs 9.7 hand washes per day). With the sprayer system, compliance was 91% for physicians, 28% for nurses, and 8% for housekeeping personnel. Alcohol hand antisepsis was preferred to washing hands with soap and water in low-risk situations such as simple entrance into a room (91% vs 36%; P < 10(-6)) or simple contact with a patient (69% vs 40; P < .005). The sprayer system was considered easier to use (95%), more hygienic (90%), and faster (92%), with a better tolerance than the individual bottle. CONCLUSION: The new alcohol sprayer should improve rapid hand antisepsis.