TaqMan Array Card testing of participant-collected stool smears to determine the pathogen-specific epidemiology of travellers' diarrhoea†.

BACKGROUND: We assessed the compliance with self-collection of stool smears on Whatman® FTA® Elute Card (FTA Card) and detection of travellers' diarrhoea (TD)-associated pathogens by using a quantitative Polymerase Chain Reaction (PCR) assay [customized TaqMan® array card (TAC)] in a prospective, observational cohort of travellers. METHODS: Enrolled travellers documented symptoms on a travel diary and collected an FTA Card during a diarrhoeal episode, or at the end of travel if they remained asymptomatic. TAC testing was performed on FTA Cards from TD cases and 1:1 matched asymptomatic controls and 1:1 matched loose stool cases that did not meet TD criteria. Odds ratios were used to determine the association between detected pathogens and TD. RESULTS: Of 2456 travellers, 484 (19.7%) completed an illness diary and met TD criteria, and 257 (53.1%) collected an FTA Card during the TD episode. FTA Cards were stored for a median of 2 years at room temperature (IQR: 1-4 years) before extraction and testing. The overall TAC detection rate in TD cases was 58.8% (95% CI: 52.5-64.8). Enterotoxigenic Escherichia coli was the most common pathogen in TD cases (26.8%), and 3.5% of samples were positive for norovirus. The odds of detecting TD-associated pathogens in 231 matched cases and asymptomatic controls were 5.4 (95% CI: 3.6-8.1) and 2.0 (95% CI: 1.1-3.7) in 121 matched TD and loose stool cases (P < 0.05). Enteroaggregative E. coli was the most common pathogen detected in asymptomatic controls and loose stool cases. Detection of diarrhoeagenic E. coli, Shigella/enteroinvasive E. coli and Campylobacter spp. was significantly associated with TD. CONCLUSION: FTA Cards are a useful adjunct to traditional stool collection methods for evaluating the pathogen-specific epidemiology of TD in austere environments. Qualitative detection of pathogens was associated with TD. Measures to improve compliance and quality of FTA Card collection with decreased storage duration may further optimize detection.

Diagnosis disclosure to adolescents living with HIV in rural Kenya improves antiretroviral therapy adherence and immunologic outcomes: A retrospective cohort study.

BACKGROUND & AIMS: Emphasis on adolescent HIV has increased worldwide as antiretroviral treatment has greatly extended life expectancies of HIV-positive children. Few evidence-based guidelines exist on the optimal time to disclose to an adolescent living with HIV (ALHIV); little is known about the medical effects of disclosure. This study looked to determine whether disclosure is associated with improved medical outcomes in ALHIV. Prior work has tended to be qualitative, cross-sectional, and with an emphasis on psychosocial outcomes. This paper addresses the adolescent cohort retrospectively (longitudinally), building upon what is already known about disclosure. METHODS: Retrospective, longitudinal clinical record reviews of ALHIV seen at Kericho District Hospital between April 2004 and November 2012 were performed. Patient demographics and clinical outcomes were systematically extracted. The student's t-test was used to calculate changes in mean CD4 count, antiretroviral therapy (ART), and cotrimoxazole adherence pre- vs. post-disclosure. Linear regression modelling assessed for trends in those clinical outcomes associated with age of disclosure. RESULTS: Ninety-six ALHIV (54 female, 42 male) were included; most (73%) entered care through the outpatient department. Nearly half were cared for by parents, and 20% experienced a change in their primary caregiver. The mean time in the study was 2.47 years; mean number of visits 10.97 per patient over the mean time in the study. Mean disclosure age was 12.34 years. An increase in mean ART adherence percentage was found with disclosure (0.802 vs. 0.917; p = 0.0015). Younger disclosure age was associated with significantly higher mean CD4 counts over the course of the study (p = 0.001), and a nonsignificant trend toward a higher mean ART adherence percentage (p = 0.055). CONCLUSION: ART adherence and improved immunologic status are both associated with disclosure of HIV infection to adolescent patients. Disclosure of an HIV diagnosis to an adolescent is an important means to improve HIV care.

Recurrent Nocardia Sepsis in a Patient With Sickle Cell Anemia Receiving Continuous Deferoxamine.

Nocardia species are ubiquitous soil-borne organisms that most commonly cause invasive disease in patients with defective cell-mediated immunity. We report a case of recurrent Nocardia sepsis in a patient with sickle cell disease and chronic iron overload, who was undergoing high-dose infusions of deferoxamine through a central venous catheter.

Platelets and erythrocyte-bound platelets bind infectious HIV-1 in plasma of chronically infected patients.

Chronic HIV-1 infection is associated with persistent viremia in most patients, but it remains unclear how free virus may survive the potential hostile effects of plasma. We investigated whether sites might exist on the surfaces of circulating blood cells for protection of infectious HIV-1 particles. Red blood cells (RBC) either from blood of uninfected normal individuals, or from blood obtained without EDTA from chronically infected HIV-1 patients, invariably contained a small number of RBC having attached platelets as determined by flow cytometry, light microscopy, and immunofluorescence microscopy. After mixing normal RBC with platelet-rich plasma, discrete populations of RBC, platelets, and complexes of platelets attached to RBC were purified by fluorescence-activated cell sorting. Upon incubation of purified cells or platelets with HIV-1 followed by washing and co-incubation with CD4-positive peripheral blood mononuclear cells (PBMC), platelets, and platelet-RBC complexes, but not platelet-free RBC, caused infection of PBMC. Infection was prevented by pre-treating the platelet-RBC complexes with EDTA. Plasma and RBC (comprising a RBC/platelet-RBC mixture) from chronically infected patients with low viral loads were also co-incubated with PBMC ex vivo to determine the presence of infectious HIV-1. All freshly isolated plasmas from the HIV-1-infected donors, obtained in the absence of anticoagulant, were noninfectious. Interestingly, the RBC from most of the patients caused cell-cell infection of PBMC that was prevented by stripping the RBC with EDTA. A monoclonal antibody to DC-SIGN partially inhibited cell-cell HIV-1 infection of PBMC by normal RBC pre-incubated with platelets and HIV-1. We conclude: (a) platelet-free EDTA-free plasma from chronically infected HIV-1 patients, although containing viral RNA, is an environment that lacks detectable infectious HIV-1; (b) platelets and platelet-RBC complexes, but not purified RBC, bind infectious HIV-1; (c) DC-SIGN, and possibly other C-type lectins, may represent binding sites for infectious HIV-1 on platelets and platelet-RBC complexes.

Impact of fluoroquinolone resistance mutations on gonococcal fitness and in vivo selection for compensatory mutations.

BACKGROUND: Quinolone-resistant Neisseria gonorrhoeae (QRNG) arise from mutations in gyrA (intermediate resistance) or gyrA and parC (resistance). Here we tested the consequence of commonly isolated gyrA(91/95) and parC86 mutations on gonococcal fitness. METHODS: Mutant gyrA(91/95) and parC86 alleles were introduced into wild-type gonococci or an isogenic mutant that is resistant to macrolides due to an mtrR(-79) mutation. Wild-type and mutant bacteria were compared for growth in vitro and in competitive murine infection. RESULTS: In vitro growth was reduced with increasing numbers of mutations. Interestingly, the gyrA(91/95) mutation conferred an in vivo fitness benefit to wild-type and mtrR(-79) mutant gonococci. The gyrA(91/95), parC86 mutant, in contrast, showed a slight fitness defect in vivo, and the gyrA(91/95), parC86, mtrR(-79) mutant was markedly less fit relative to the parent strains. A ciprofloxacin-resistant (Cip(R)) mutant was selected during infection with the gyrA(91/95), parC86, mtrR(-79) mutant in which the mtrR(-79) mutation was repaired and the gyrA(91) mutation was altered. This in vivo-selected mutant grew as well as the wild-type strain in vitro. CONCLUSIONS: gyrA(91/95) mutations may contribute to the spread of QRNG. Further acquisition of a parC86 mutation abrogates this fitness advantage; however, compensatory mutations can occur that restore in vivo fitness and maintain Cip(R).

Emerging resistant Gram-negative aerobic bacilli in hospital-acquired infections.

The increasing emergence of serious multidrug-resistant (MDR) Gram-negative infections has led to a new health-care crisis. These infections predominately include MDR Pseudomonas aeruginosa, extended-spectrum beta-lactamase-producing Enterobacteriaceae and MDR Acinetobacter baumannii. These organisms are present in a variety of clinical settings, but there is a distinct paucity of antibiotics to effectively treat these infections. The increasing use of broad-spectrum antibiotics and lack of good stewardship have contributed to the increase in these MDR organisms. This review focuses on the main MDR Gram-negative infections contributing to the current crisis in health care, their mechanisms of resistance and various treatment options for empiric therapy.

The role of adenovirus in respiratory tract infections.

Adenovirus plays a significant role in respiratory tract disease in pediatric and adult patients. It has been linked to outbreaks and epidemics in various patient populations, resulting in considerable morbidity and mortality. In this article, we discuss the epidemiology, pathogenesis, respiratory tract illnesses and complications, and roles of potential treatment options. The role of the past oral adenovirus vaccine and the military implications of its withdrawal from routine use in military recruits is discussed as well.

Necrobacillosis: A case report of complicated Fusobacterium necrophorum septicemia.

Necrobacillosis due to Fusobacterium necrophorum is an uncommon anaerobic infection. It has a wide range of presentations and commonly presents as Lemierre's syndrome. We present a case of necrobacillosis defined by F. necrophorum bacteremia with epidural and pararectal fluid collection without evidence of internal jugular vein thrombophlebitis.

Case of Clostridium perfringens bacteremia after routine colonoscopy and polypectomy.

Bacteremia is an uncommon complication after polypectomy and colonoscopy. We report one of the first cases of Clostridium perfringens bacteremia after polypectomy. Our patient was a four years old boy with congenital polyposis, who underwent colonoscopy and polypectomy without complication. Approximately 12h later he developed a fever and tachycardia with no other clinical symptoms. His blood cultures grew out penicillin susceptible C. perfringens and Enterococcus faecalis. He responded to antibiotic therapy and remained clinically asymptomatic for the duration of his course. There are a few reports of bacteremia after routine polypectomy, but no reported cases of C. perfringens bacteremia in the pediatric population. Clostridial sp. bacteremia can be fatal with devastating consequences if appropriate antibiotics and/or surgical debridement are delayed. Polymicrobial infection, as illustrated in our patient, is also common and can be a poor prognostic risk factor. Therefore, for patients with a history of polypectomy and new onset fever, anaerobic infections should be considered and empiric antibiotic therapy should include coverage for these organisms.