Nelun Perera

Enteric fever in a UK regional infectious diseases unit: a 10 year retrospective review.

INTRODUCTION Enteric fever is an increasingly common diagnosis in returning travellers in the UK. METHODS We performed a retrospective descriptive study of culture-confirmed cases of enteric fever admitted to University Hospitals Leicester, UK between January 1999 and April 2009. RESULTS 100 cases of enteric fever were identified in adults (n = 76) and children (n = 24). The median age of adult subjects was 38 (range 18-71) and 55% were male. Of the 61 adult cases with notes available, 60 (98.3%) were of Asian ethnicity and 56 (92%) had a recent travel history, principally to the Indian Subcontinent. Symptoms included fever (100%), headache (62%), diarrhoea (59%) and abdominal pain (44%). Common examination findings included pyrexia and mild generalized abdominal tenderness. Mild hyponatraemia, transaminitis and a normal white cell count were commonly identified. Reduced ciprofloxacin sensitivity was common and increased over the study period. Median fever clearance time was 6 days, and treatment failure occurred in 20% of cases. Relapse occurred in 2 patients. Complications were unusual, and one patient died. DISCUSSION Patients with enteric fever presented with a non-specific febrile illness within one month after returning from travel, and most had an uncomplicated clinical course. Increasing ciprofloxacin insensitivity was the likely explanation for a high treatment failure rate and this agent can no longer recommended as empirical treatment.

Olecranon bursitis secondary to Mycobacterium kansasii infection in a patient receiving infliximab for Behçet's disease

We present a case of Mycobacterium kansasii olecranon bursitis in a woman with known immunosuppression secondary to the treatment received for her Behçets disease. We found only one other case report of olecranon bursitis caused by M. kansasii in the literature, which, unlike our case, presented in an immunocompetent adult following trauma. This case extends the range of opportunistic mycobacterial infections that are associated with anti-tumour necrosis factor therapy.

A Two-Tube Combined TaqMan/SYBR Green Assay to Identify Mycobacteria and Detect Single Global Lineage-Defining Polymorphisms in Mycobacterium tuberculosis

We have developed a novel real-time PCR assay to identify and perform preliminary genotyping of mycobacteria in a manner tailored to our local service. Within a single thermocycler run, mycobacterial 16S rDNA and the Mycobacterium tuberculosis global lineage-defining RD750 polymorphism are targeted in separate reaction tubes, each of which includes both TaqMan and SYBR Green chemistries. The results of this 16S-RD assay differentiate M. tuberculosis complex (MTBC) from nontuberculous mycobacteria (NTM) and recognize whether or not MTBC isolates belong to the East African-Indian lineage, the single most frequently isolated global MTBC lineage in our service. If required, NTM amplicons may be sequenced to provide more specific identities. We report the technical performance of this assay on 88 mycobacteria-positive cultures and discuss its use in the initial management of mycobacterial infections. The 16S-RD assay correctly identified all 70 MTBC-positive cultures and 17 NTM-positive cultures while contemporaneously recognizing 26 MTBC isolates as within and 44 outside the East African-Indian lineage. In artificial samples, the combined assay also showed limited potential to detect mixed mycobacterial infections (MTBC/NTM) and tuberculosis infections involving more than one global MTBC lineage. The approach we have established can be readily tailored to targets of particular value for any mycobacterial diagnostic service, thereby optimizing the value of the results for local clinical and public health management of mycobacterial infections.

Face mask sampling for the detection of Mycobacterium tuberculosis in expelled aerosols.

Background Although tuberculosis is transmitted by the airborne route, direct information on the natural output of bacilli into air by source cases is very limited. We sought to address this through sampling of expelled aerosols in face masks that were subsequently analyzed for mycobacterial contamination. Methods In series 1, 17 smear microscopy positive patients wore standard surgical face masks once or twice for periods between 10 minutes and 5 hours; mycobacterial contamination was detected using a bacteriophage assay. In series 2, 19 patients with suspected tuberculosis were studied in Leicester UK and 10 patients with at least one positive smear were studied in The Gambia. These subjects wore one FFP30 mask modified to contain a gelatin filter for one hour; this was subsequently analyzed by the Xpert MTB/RIF system. Results In series 1, the bacteriophage assay detected live mycobacteria in 11/17 patients with wearing times between 10 and 120 minutes. Variation was seen in mask positivity and the level of contamination detected in multiple samples from the same patient. Two patients had non-tuberculous mycobacterial infections. In series 2, 13/20 patients with pulmonary tuberculosis produced positive masks and 0/9 patients with extrapulmonary or non-tuberculous diagnoses were mask positive. Overall, 65% of patients with confirmed pulmonary mycobacterial infection gave positive masks and this included 3/6 patients who received diagnostic bronchoalveolar lavages. Conclusion Mask sampling provides a simple means of assessing mycobacterial output in non-sputum expectorant. The approach shows potential for application to the study of airborne transmission and to diagnosis.

Identification of Neisseria gonorrhoeae as the Causative Agent in a Case of Culture-Negative Dermatitis–Arthritis Syndrome Using Real-Time PCR

Sexually transmitted infections (STIs) are an increasingly common and important cause of a fever in a returning traveler. Systemic complications of STIs, human immunodeficiency virus seroconversion illness, and secondary syphilis are diagnoses that can easily be missed. We present a case of culture-negative disseminated gonococcal infection presenting with fever, malaise, polyarthralgia, arthritis, and a rash that developed following orogenital contact and was diagnosed using real-time polymerase chain reaction. This technology has major potential to improve the speed and sensitivity of diagnosis and consequent management of patients with this syndrome.

Unusual findings and diagnostic challenges in a child with Lemierre’s disease

16S rDNA polymerase chain reaction (PCR) in the diagnosis of fastidious organisms is becoming increasingly commonplace. We present the case of a child admitted to an acute paediatric unit of a university teaching hospital with otorrhoea, torticollis, and cervical lymphadenopathy. Examination revealed hepatosplenomegaly associated with pancytopenia. Radiological imaging confirmed a retropharyngeal abscess, bilateral mastoiditis, cerebellar lesions, and venous sinus thrombosis. Swabs of aural discharge grew anaerobes. Drainage of the retropharyngeal abscess and bilateral mastoidectomy were performed. Bone marrow aspiration was initially suspicious of acute leukaemia prompting further investigations, but cytogenetic analysis ruled out this diagnosis and changes were attributed to severe sepsis. Following 27 days of intravenous antibiotics and after clinical improvement, clindamycin was started. Intraoperative pus yielded no significant pathogens. A 16S rDNA PCR confirmed Fusobacterium necrophorum. The boy was discharged on a 6 week course of oral clindamycin.