Multisite evaluation of point of care CD4 testing in Papua New Guinea.

Laboratory-based CD4 monitoring of HIV patients presents challenges in resource limited settings (RLS) including frequent machine breakdown, poor engineering support and limited cold chain and specimen transport logistics. This study assessed the performance of two CD4 tests designed for use in RLS; the Dynal assay and the Alere PIMA test (PIMA). Accuracy of Dynal and PIMA using venous blood was assessed in a centralised laboratory by comparison to BD FACSCount (BD FACS). Dynal had a mean bias of -50.35 cells/µl (r(2) = 0.973, p<0.0001, n = 101) and PIMA -22.43 cells/µl (r(2)= 0.964, p<0.0001, n = 139) compared to BD FACS. Similar results were observed for PIMA operated by clinicians in one urban (n = 117) and two rural clinics (n = 98). Using internal control beads, PIMA precision was 10.34% CV (low bead mean 214.24 cells/µl) and 8.29% (high bead mean 920.73 cells/µl) and similar %CV results were observed external quality assurance (EQA) and replicate patient samples. Dynal did not perform using EQA and no internal controls are supplied by the manufacturer, however duplicate testing of samples resulted in r(2) = 0.961, p<0.0001, mean bias =  -1.44 cells/µl. Using the cut-off of 350 cells/µl compared to BD FACS, PIMA had a sensitivity of 88.85% and specificity of 98.71% and Dynal 88.61% and 100%. A total of 0.44% (2/452) of patient samples were misclassified as "no treat" and 7.30% (33/452) "treat" using PIMA whereas with Dynal 8.91% (9/101) as "treat" and 0% as "no treat". In our setting PIMA was found to be accurate, precise and user-friendly in both laboratory and clinic settings. Dynal performed well in initial centralized laboratory evaluation, however lacks requisite quality control measures, and was technically more difficult to use, making it less suitable for use at lower tiered laboratories.

Isolated granulocytic sarcoma of the pancreas: a tricky diagnostic for primary pancreatic extramedullary acute myeloid leukemia.

We report two clinical cases of primary granulocytic sarcoma of the pancreas that were diagnosed on the surgical specimen. Atypical clinical and morphological presentations may have lead to pretherapeutic biopsies of the pancreatic mass in order to indicate primary chemotherapy. Literature review of this rare clinical presentation may help physicians to anticipate diagnostic and therapeutic strategies.

Microbial keratitis in East Africa: why are the outcomes so poor?

PURPOSE: Microbial keratitis (MK) is a major cause of blindness in Africa. This study reports the epidemiology, causative organism, management and outcome of MK in people admitted to a large referral hospital in Northern Tanzania, and explores why the outcomes are so poor for this condition. METHODS: A retrospective review of all admissions for MK during a 27-month period. Information was collected on: demographics, history, examination, microbiology, treatment and outcome. RESULTS: A total of 170 patients with MK were identified. Presentation was often delayed (median 14 days), and more delayed if another health facility was visited first (median 21 days). Appropriate intensive antibiotic treatment was prescribed in 19% before admission. Lesions were often severe (41% >5mm). Filamentary fungi were detected in 25% of all specimens (51% of specimens with a positive result). At discharge, 66% of affected eyes had a visual acuity of less than 6/60. Perforations developed in 30% and evisceration was necessary in 8%. Perforation was associated with large lesions and visiting another health facility. HIV infection was diagnosed in 16% of individuals tested, which is approximately twice the prevalence found in the wider population. CONCLUSIONS: Microbial keratitis is a significant clinical problem in this region, which generally has a very poor outcome. Delayed presentation is a critical issue. Fungal keratitis is a prominent cause and there is an indication that HIV may increase susceptibility. Prompt recognition and appropriate treatment in primary/secondary health facilities and rapid referral when needed may reduce the burden of blindness from this disease.

What is causing active trachoma? The role of nonchlamydial bacterial pathogens in a low prevalence setting.

PURPOSE: In low prevalence settings, clinically active follicular trachoma (TF) is often found in the absence of detectable Chlamydia trachomatis. The reasons for this persistent follicular phenotype are not well understood; one possible explanation is that other bacterial species are provoking the inflammatory response. This study investigated the relationship between TF, C. trachomatis, and nonchlamydial bacterial infection. METHODS: A cross-sectional survey was conducted in a trachoma endemic village in Tanzania. All available children were examined for trachoma and swabs were collected for microbiologic culture (blood and chocolate agar) and C. trachomatis PCR (Amplicor). RESULTS: Four hundred seventy-three children under 10 years of age were recruited for this study. The prevalences of TF and C. trachomatis were 13.7% and 5.3%, respectively, and were not associated. Bacteria were cultured from 305 (64.5%) swab samples; 162 (34.3%) grew a pathogen (with or without a commensal organism) and 143 (30.2%) grew commensal bacteria only. The most common pathogens were Streptococcus pneumoniae and Haemophilus influenzae (type B and non-type B). The presence of bacterial pathogens was associated with TF (odds ratio, 4.68; 95% confidence interval, 2.31-9.50; P < 0.001). CONCLUSIONS: In regions with low levels of endemic trachoma, it is possible that much of the TF that is observed is attributable to nonchlamydial bacterial pathogens. It is plausible that individuals who have previously developed a follicular conjunctivitis in response to C. trachomatis may more readily reform conjunctival follicles when challenged with certain other bacterial species.

Bacterial infection in scarring trachoma.

PURPOSE: To assess whether non-chlamydial bacterial infection is associated with trachomatous scarring in adults. METHODS: This was a case-control study of 360 cases with trachomatous scarring but without trichiasis, and 360 controls without scarring. All participants underwent clinical examination, and a swab was taken from the inferior conjunctival fornix. Samples were inoculated onto blood and chocolate agar later that day. RESULTS: Bacterial isolates were identified in 54.0% of cases compared with 34.6% of controls (P < 0.001). A multivariate logistic regression model adjusted for age and lack of education showed that scarring was associated with the presence of commensal organisms (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.01-2.09) and was strongly associated with the presence of pathogenic organisms (OR, 4.08; 95% CI, 1.59-10.45). There was an increasing prevalence of all bacterial isolates with increasing severity of scarring (P(trend) < 0.001). CONCLUSIONS: Trachomatous scarring is strongly associated with non-chlamydial bacterial infection compared with controls. The role of such infection with regard to scarring progression should be investigated and may have important implications for trachoma control strategies and prevention of blindness.

Evaluation of a dried blood spot HIV-1 RNA program for early infant diagnosis and viral load monitoring at rural and remote healthcare facilities.

OBJECTIVE: To assess technical and operational performance of a dried blood spot (DBS)-based HIV-1 RNA service for remote healthcare facilities in a low-income country. DESIGN: A method comparison and operational evaluation of DBS RNA against conventional tests for early infant diagnosis of HIV and HIV RNA quantitation under field conditions in Tanzania. METHODS: DBSs were prepared and plasma was frozen at -80 degrees C. DBSs were mailed and plasma couriered to a central laboratory for testing using the Abbott m2000 system. Infant diagnosis DBSs were also tested for HIV-1 DNA by ROCHE COBAS AmpliPrep/COBAS TaqMan System. Results of DBS RNA were compared with conventional tests; program performance was described. RESULTS: Among 176 infant diagnosis participants, using a threshold of at least 1000 copies/ml, sensitivity and specificity of DBS versus plasma RNA were 1.00 and 0.99, and of DBS RNA versus DBS DNA were 0.97 and 1.00. Among 137 viral load monitoring participants, when plasma and DBS RNA were compared, r value was 0.9709; r value was 0.9675 for at least 5000 copies/ml but was 0.7301 for less than 5000 copies/ml. The highest plasma RNA value at which DBS RNA was not detected was 2084 copies/ml. Median (range) turnaround time from sample collection to result receipt at sites was 23 (4-69) days. The Tanzania mail service successfully transmitted all DBS and results between sites and the central laboratory. CONCLUSION: Under program conditions in Tanzania, DBS provided HIV-1 RNA results comparable to conventional methods to remote healthcare facilities. DBS RNA testing is an alternative to liquid plasma for HIV-1 RNA services in remote areas.