Replacement of neuraminidase inhibitor-susceptible influenza A(H1N1) with resistant phenotype in 2008 and circulation of susceptible influenza A and B viruses during 2009-2013, South Africa.

BACKGROUND: Data on the susceptibility of influenza viruses from South Africa to neuraminidase inhibitors (NAIs) are scarce, and no extensive analysis was done. OBJECTIVES: We aimed to determine oseltamivir and zanamivir susceptibility of influenza A and B virus neuraminidases (NAs), 2007-2013, South Africa. PATIENTS/METHODS: We enrolled participants through national influenza-like illness surveillance, 2007-2013. Influenza diagnosis was by virus isolation and quantitative polymerase chain reaction (qPCR). Drug susceptibility was determined by chemiluminescence-based NA-STAR/NA-XTD assay. Sanger sequencing was used to determine molecular markers of NAI resistance. RESULTS: Forty percent (6341/15 985) of participants were positive for influenza viruses using virus isolation (2007-2009) and qPCR (2009-2013) methods. A total of 1236/6341 (19.5%) virus isolates were generated of which 307/1236 (25%) were tested for drug susceptibility. During 2007-2008, the median 50% inhibitory concentration (IC50 ) of oseltamivir for seasonal influenza A(H1N1) increased from of 0.08 nmol/L (range 0.01-3.60) in 2007 to 73 nmol/L (range 1.56-305 nmol/L) in 2008. Influenza A isolates from 2009 to 2013 were susceptible to oseltamivir [A(H3N2) median IC50  = 0.05 nmol/L (range 0.01-0.08); A(H1N1)pdm09 = 0.11 nmol/L (range 0.01-0.78)] and zanamivir [A(H3N2) median IC50  = 0.56 nmol/L (range 0.47-0.66); A(H1N1)pdm09 = 0.35 nmol/L (range 0.27-0.533)]. Influenza B viruses were susceptible to both NAIs. NAI resistance-associated substitutions H275Y, E119V, and R150K (N1 numbering) were not detected in influenza A viruses that circulated in 2009-2013. CONCLUSIONS: We confirm replacement of NAI susceptible by resistant phenotype influenza A(H1N1) in 2008. Influenza A and B viruses (2009-2013) remained susceptible to NAIs; therefore, these drugs are useful for treating influenza-infected patients.

Evaluation of the use of plasma preparation tubes for HIV viral load testing on the COBAS AmpliPrep/COBAS TaqMan HIV-1 version 2.0.

HIV viral load monitoring forms an essential part of the management of patients receiving antiretroviral therapy, but transport of samples without loss of RNA integrity may be problematic in resource limited settings. The use of plasma preparation tubes (PPT) which can be centrifuged to separate cellular components before transport may provide a simple and cost-effective alternative to standard EDTA samples. We investigated whether PPT generated reliable results using the COBAS(®) AmpliPrep/COBAS(®) TaqMan(®) HIV-1 test version 2.0 (CAP/CTM HIV-1 v2.0). The mean difference between EDTA and PPT prepared samples (n=261) was acceptable (log 0.04 copies/ml, percentage similarity CV 3.53%). PPT can be used for viral load testing on the CAP/CTM HIV-1 v2.0.

A rare, fatal case of invasive spinal aspergillosis in an antiretroviral-naive, HIV-infected man with pre-existing lung colonization.

Infection of the central nervous system (CNS) is a rare but devastating complication of invasive aspergillosis. We report a case of invasive aspergillosis with spinal involvement in a human immunodeficiency virus (HIV)-infected patient without neutropenia. A 42-year-old, antiretroviral-naïve, HIV-infected man presented with progressive weakness in the lower limbs and urinary and faecal incontinence for 2 weeks. The patient had been prescribed broad-spectrum antibiotics and prednisone. He had upper motor neuron signs and a sensory level at T1, with accompanying neck stiffness on flexion. Magnetic resonance imaging revealed diffuse abnormal signals of the vertebral bodies in the lower cervical and thoracic areas, with cord compression in the C2 and C3 region and signal distortions of the T2 and T3 vertebral bodies. Chest X-ray and computerized tomography demonstrated post-tuberculous apical cavities with suspected fungal colonization. Histopathology of an extradural spinal lesion at T1/T2 suggested invasive aspergillosis. The patient was started on fluconazole in response to the histopathological evidence of Aspergillus infection, but died within 3 weeks. Post-mortem analysis of the biopsy sample by PCR identified the infectious agent as Aspergillus fumigatus. Atypically, his CD4(+) T-cell count was 239 cells mm(-3) and he had no evidence of neutropenia. Invasive aspergillosis should be considered as part of the differential diagnosis among HIV-infected patients with non-specific, focal CNS symptoms, even among those without classical risk factors such as neutropenia, and aggressive antifungal therapy should be instituted as early as possible.