Mounir Ben Jemaa

Rickettsia felis infection, Tunisia.

We report, for the first time, serologic evidence of Rickettsia felis and R. aeschlimannii infections acquired in Tunisia from 1998 to 2003. We found that most patients with antibodies against both R. conorii and R. typhi had serologic evidence of R. felis infection.

Native Valve Infective Endocarditis in a Tertiary Care Center in a Developing Country (Tunisia)

The aim of the study was to describe the epidemiological and clinical aspects of native valve infective endocarditis (IE) in a Tunisian high-volume tertiary care center and to identify the predictors of outcome. Demographic, clinical, laboratory, and echocardiographic characteristics were examined in 134 patients who fulfilled the modified Duke criteria for native valve IE between January 1997 and December 2006. Logistic regression analysis was used to identify prognostic factors for death. Mean age was 34.22 years. Diagnosis was definite in 93% of cases. Median time to diagnosis was 21 days. Rheumatic heart disease (RHD) was the predominant (45%) underlying heart condition. One or more vegetations were detected in more than 93% of cases. The median size of vegetation was >15 mm in 28% of cases. In 66 cases (49%), cultures remained negative. Serology was positive in 15 cases, and in 4 cases leaflet culture identified the agent. The infective agent was identified in 87 cases (65%), causative microorganisms were mainly Staphylococci (n = 30, including 6 coagulase-negative Staphylococcus), and Streptococci (n = 32). Overall mortality was 19%. On multivariate analysis, congestive heart failure (hazard ratio = 5.34, 95% confidence interval 1.67 to 17.15, p = 0.005) and large vegetations (>15 mm; hazard ratio = 5.78, 95% confidence interval 1.84 to 18.32, p = 0.002) were predictive of in-hospital mortality but not neurological complications or staphylococcus IE. In conclusion, IE remains a serious disease affecting a young population in Tunisia, with RHD as still the most common underlying heart disease, and it is associated with a high mortality.

Epidemic West Nile Virus Encephalitis in Tunisia

West Nile fever (WNF) is a mosquito-borne flavivirus infection. It is epidemic in Africa and Asia. In autumn 1997, a WNF epidemic occurred in the Sfax area (southeastern Tunisia). Fifty-seven patients were hospitalized with aseptic meningitis and/or encephalitis. Search for specific anti-West Nile virus (WNV) antibodies in serum and cerebrospinal fluid (CSF) was performed using an ELISA test. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the WNV genome in CSF and brain specimens. Recent central nervous system (CNS) infection by WNV was confirmed in 30 patients, probable infection in 17 and it was excluded in 10. In the confirmed subgroup, patients with encephalitis were older than those with meningitis. CSF showed pleocytosis, high protein (47%) and normal glucose levels. Brain computed tomography-scan (CT-scan) and magnetic resonance imaging (MRI) were normal. RT-PCR disclosed WNV genome in the CSF in two cases and in a brain specimen in one. Three patients died rapidly, the remaining cases had favorable prognosis. Autopsy was performed in two cases and showed nonspecific lesions of encephalitis. No viral inclusions were seen with light microscopy. Seropositivity rate in patients’ proxies for WNV was 23.4%. Prognosis of CNS involvement during WNF seemed to be poor in older patients. This is the first WNV encephalitis epidemic report in the Sfax area of Tunisia.

Comparison of Two Quantitative Real Time PCR Assays for Rickettsia Detection in Patients from Tunisia

Background and objectives Quantitative real time PCR (qPCR) offers rapid diagnosis of rickettsial infections. Thus, successful treatment could be initiated to avoid unfavorable outcome. Our aim was to compare two qPCR assays for Rickettsia detection and to evaluate their contribution in early diagnosis of rickettsial infection in Tunisian patients. Patients and methods Included patients were hospitalized in different hospitals in Tunisia from 2007 to 2012. Serology was performed by microimmunofluorescence assay using R. conorii and R. typhi antigens. Two duplex qPCRs, previously reported, were performed on collected skin biopsies and whole blood samples. The first duplex amplified all Rickettsia species (PanRick) and Rickettsia typhi DNA (Rtt). The second duplex detected spotted fever group Rickettsiae (RC00338) and typhus group Rickettsiae DNA (Rp278). Results Diagnosis of rickettsiosis was confirmed in 82 cases (57.7%). Among 44 skin biopsies obtained from patients with confirmed diagnosis, the first duplex was positive in 24 samples (54.5%), with three patients positive by Rtt qPCR. Using the second duplex, positivity was noted in 21 samples (47.7%), with two patients positive by Rp278 qPCR. Among79 whole blood samples obtained from patients with confirmed diagnosis, panRick qPCR was positive in 5 cases (6.3%) among which two were positive by Rtt qPCR. Using the second set of qPCRs, positivity was noted in four cases (5%) with one sample positive by Rp278 qPCR. Positivity rates of the two duplex qPCRs were significantly higher among patients presenting with negative first serum than those with already detectable antibodies. Conclusions Using qPCR offers a rapid diagnosis. The PanRick qPCR showed a higher sensitivity. Our study showed that this qPCR could offer a prompt diagnosis at the early stage of the disease. However, its implementation in routine needs cost/effectiveness evaluation.

Multispacer typing of Rickettsia isolates from humans and ticks in Tunisia revealing new genotypes.

BackgroundRickettsioses are important remerging vector born infections. In Tunisia, many species have been described in humans and vectors. Genotyping is important for tracking pathogen movement between hosts and vectors. In this study, we characterized Rickettsia species detected in patients and vectors using multispacer typing (MST), proposed by Founier et al. and based on three intergenic spacers (dksA-xerC, rmpE- tRNAfMet, mppA-pruC) sequencing.MethodsOur study included 25 patients hospitalized during 2009. Ticks and fleas were collected in the vicinity of confirmed cases. Serology was performed on serum samples by microimmunofluorescence using Rickettsia conorii and Rickettsia typhi antigens. To detect and identify Rickettsia species, PCR targeting ompA, ompB and gltA genes followed by sequencing was performed on 18 obtained skin biopsies and on all collected vectors. Rickettsia positive samples were further characterized using primers targeting three intergenic spacers (dksA-xerC, rmpE- tRNAfMet and mppA-purC).ResultsA rickettsial infection was confirmed in 15 cases (60%). Serology was positive in 13 cases (52%). PCR detected Rickettsia DNA in four biopsies (16%) allowing the identification of R. conorii subsp israelensis in three cases and R. conorii subsp conorii in one case. Among 380 collected ticks, nine presented positive PCR (2.4%) allowing the identification of six R. conorii subsp israelensis, two R. massiliae and one R. conorii subsp conorii. Among 322 collected fleas, only one was positive for R. felis. R. conorii subsp israelensis strains detected in humans and vectors clustered together and showed a new MST genotype. Similarly, R. conorii subsp conorii strains detected in a skin biopsy and a tick were genetically related and presented a new MST genotype.ConclusionsNew Rickettsia spotted fever strain genotypes were found in Tunisia. Isolates detected in humans and vectors were genetically homogenous despite location differences in their original isolation suggesting epidemiologic circulation of these strains.

Spinal brucellosis in South of Tunisia: review of 32 cases

BACKGROUND CONTEXT Brucellosis remains an important economic and public health problem in some parts of the world. The spine is the most common site of musculoskeletal involvement of brucellosis. PURPOSE Assess the clinical, laboratory, radiological findings, and outcomes of vertebral involvement in brucellosis. STUDY DESIGN A retrospective study. PATIENT SAMPLE Thirty-two patients with spinal brucellosis during a period of 21 years (1990-2010) were included. OUTCOME MEASURES Clinical and radiological improvement. METHODS Diagnosis made on clinical presentation, laboratory findings, radiographic evidence, and the Brucellar etiology was considered when seroagglutination tests were positive at a titer of 1/160 or higher, and/or Brucella spp were isolated in the blood or sample cultures. RESULTS The mean age of patients was 51±15.85 years (23 males, 9 females; age range, 19-74 years). The median diagnostic delay was 3 months. Back or neck pain (100% of patients), fever (78%), and sweats (68.6%) were the most common symptoms. Cultures of blood specimens from five patients (15.6%) were positive for Brucella melitensis. Four patients (12.5%) had motor weakness or paralysis. Magnetic resonance imaging was performed in 24 (75%) cases. Paravertebral masses, epidural masses, and psoas abscesses were detected in 65.6%, 59.4%, and 28.1% of patients, respectively. The lumbar vertebra was the most frequently involved region with the rate of 68.7%, followed by thoracal (18.7%), cervical (6.3%), lumbosacral (6.3%), and thoracolumbar (3.1%) segments. The duration of antimicrobial therapy of brucellosis (median, 6 months; range, 3-13 months) varied according to clinical response and the presence of epidural and paravertebral masses. There were no deaths or severe sequelae in this study. CONCLUSIONS Brucellar spondylitis should be considered in patients with back pain and fever in endemic areas. A high index of suspicion and clinical, laboratory, and radiological examinations help to confirm the diagnosis of vertebral involvement.

Acute pancreatitis as initial manifestation of adult Henoch-Schönlein purpura: report of a case and review of literature

Abdominal pain observed in Henoch-Schönlein purpura (HSP) is usually attributed to edema and hemorrhage in the small bowel wall, secondary to a small-vessel vasculitis. Pancreatitis secondary to HSP is extremely rare. Here we report a 53-year-old man presented with acute pancreatitis that developed into characteristic rashes seen during HSP at the second day of the clinical onset, together with arthritis and glomerulonephritis. HSP is a rare and benign cause of acute pancreatitis. This complication can occur as an initial manifestation of HSP. Elevated serum amylase level can be considered as the early diagnostic tool for HSP pancreatitis. The patients with HSP who have abdominal pain as their chief complaint should be evaluated for pancreatitis, by routine serum amylase and abdominal computed tomography scan, to plan the specific treatment and avoid unnecessary surgery.

Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

ABSTRACT Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia.

Short- and long-term outcomes of surgery for active infective endocarditis: a Tunisian experience

From January 1997 to December 2006, all patients with a Duke criteria-based definite diagnosis of infective endocarditis (IE) operated on during the active phase in a Tunisian high volume tertiary-care centre were included. Among the 186 patients with IE identified during the study period, 88 (48.35%) required surgery in the active phase. Mean age was 34.9 years, 54 (61.4%) were men. The infected valve was native in 70 cases (79.5%) and prosthetic in 18 (20.5%). Streptococcus sp. were the most common causative microorganisms. The most frequent indication for operation was congestive heart failure. There were 24 in-hospital deaths (27.27% early mortality). By multivariate analysis, severe congestive heart failure (HR=13.82, 95% CI [3.38-38.15], P<0.001) and large >15 mm vegetations (HR=6.02, 95% CI [1.48-18.52], P=0.03) were predictive of in-hospital mortality. Survivors were followed-up from 3 to 120 months, mean of 28.6. Actuarial 5- and 10-year survivals free from the combined endpoint of recurrent IE, cardiovascular death and late surgery in survivors were 69+/-5% and 63+/-7%, respectively. In conclusion, despite medical progress, surgery for endocarditis in Tunisia remains challenging and yields high mortality rates. Severe heart failure is the most powerful predictor of mortality. Long-term outcome is, however, satisfactory.

Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of Chlamydophila pneumoniae IgA antibodies

BackgroundSerologic diagnosis of Chlamydophila pneumoniae (Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measurement of Cpn antibodies. While commercial enzyme linked immunosorbent assays (ELISA) have been developed, they have not been fully validated. We therefore evaluated and optimized a commercial ELISA kit, the SeroCP IgA test, for the detection of Cpn IgA antibodies.MethodsSerum samples from 94 patients with anti-Cpn IgG titers ≥ 256 (study group) and from 100 healthy blood donors (control group) were tested for the presence of IgA antibodies to Cpn, using our in-house MIF test and the SeroCP IgA test. Two graph receiver operating characteristic (TG-ROC) curves were created to optimize the cut off given by the manufacturer.ResultsThe MIF and SeroCP IgA tests detected Cpn IgA antibodies in 72% and 89%, respectively, of sera from the study group, and in 9% and 35%, respectively, of sera from the control group. Using the MIF test as the reference method and the cut-off value of the ELISA test specified by the manufacturer for seropositivity and negativity, the two tests correlated in 76% of the samples, with an agreement of Ƙ = 0.54. When we applied the optimized cut-off value using TG-ROC analysis, 1.65, we observed better concordance (86%) and agreement (0.72) between the MIF and SeroCP IgA tests.ConclusionUse of TG-ROC analysis may help standardize and optimize ELISAs, which are simpler, more objective and less time consuming than the MIF test. Standardization and optimization of commercial ELISA kits may result in better performance.