Evaluation of GeneXpert MTB/RIF for detection of Mycobacterium tuberculosis complex and rpo B gene in respiratory and non-respiratory clinical specimens at a tertiary care teaching hospital in Saudi Arabia.

OBJECTIVES: To assess the performance of Xpert MTB/RIF, an automated molecular test for Mycobacterium tuberculosis (MTB) and resistance to rifampin (RIF), against smear microscopy and culture method for diagnosis of MTB infection. Methods: This is a retrospective analysis of 103 respiratory and 137 non-respiratory patient specimens suspected of tuberculosis at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia performed between April 2014 and March 2015. Each sample underwent smear microscopy, mycobacterial culture, and GeneXpert MTB/RIF test. Results: Fifteen out of 103 respiratory samples were smear and culture positive, whereas 9 out of 137 non-respiratory samples were smear positive. Out of 9 smear positive specimens, 8 were also culture positive. All 15 culture positive respiratory samples were detected by Xpert MTB/RIF (sensitivity  and positive predictive value [PPV]=100%). Similarly, all 8 culture positive non-respiratory specimens were identified by Xpert MTB/RIF (sensitivity 100%; PPV 88.8%). The Xpert MTB/RIF detected only one false positive result in 88 smear negative respiratory specimens (specificity 98.9%; negative predictive value [NPV]= 100%). All 125 smear negative non-respiratory specimens tested negative by culture and Xpert MTB/RIF (sensitivity, specificity, PPV, NPV= 100%). Conclusion: The performance of Xpert MTB/RIF was comparable to the gold standard culture method for identification of MTB in both respiratory and non-respiratory clinical specimens.

Acute septic arthritis in children.

BACKGROUND: Acute septic arthritis is a health-care problem in growing children. The aim of the present study was to determine the demographic features, clinical presentation, diagnostic evaluation, treatment and outcome of children suffering from acute septic arthritis. METHODS: Retrospective review of consecutive admissions of children < or =14 years of age with a bacteriologically and/or radiologically confirmed diagnosis of septic arthritis during the 10 year period, January 1997-December 2006 at King Fahad Hospital, King Abdulaziz Medical City was undertaken. RESULTS: Sixty-five patients (male : female, 2.4:1), 10 days-14 years of age (mean +/- SD: 3.3 +/- 3.2 years), met the inclusion criteria. More than half of the patients were under 2 years. The most frequent clinical features were pain (92%), fever (77%), limitation of joint movement (77%) and joint swelling (72%). Joint involvement was monoarticular in 97% of knees, and hips were affected in 75% of patients. Bacteria were isolated from joint aspirate or blood in 28 patients (43%), and Staphylococcus aureus was the most common organism, comprising 39% of the total bacterial isolates. Radiological diagnostic findings were observed in 19 (32%) of 60 patients with plain radiographs, nine (69%) of 16 patients with sonograms of the hip, 36 (80%) of 45 patients with Tc-labeled bone scan and nine (100%) of nine patients with magnetic resonance imaging. The joint infection resolved with no sequelae in 46 patients who were followed up for 6-36 months, but two had bone deformity and 17 were lost to follow up. CONCLUSION: According to the present series, septic arthritis is most common in young infants, mainly monoarticular, and is frequently localized in the knee and hip joints. Early diagnosis and appropriate treatment are associated with excellent outcome.

Conjugated pneumococcal vaccine for children in saudi arabia: following the footsteps of hib vaccine.

This study was conducted to assess the impact of Hib vaccination on the Haemophilus influenzae type b incidence and occurrence of Streptococcus pneumoniae in the University Hospital of Riyadh, Saudi Arabia. The study also meant to consider the need for the introduction of routine conjugated pneumococcal vaccine for children. It was a retrospective study during the period of January 1996 to July 2007 reviewing all positive blood and CSF in children up to 18 years of age who were admitted to the hospital with a diagnosis of invasive disease with Haemophilus influenzae type b and Streptococcus pneumoniae. Eighty cases with invasive disease due to Haemophilus influenzae were admitted between 1996 and 2000. Hib conjugated vaccine has become routine in Saudi Arabia since the year 2000 and since then a significant steady drop of Haemophilus influenzae type b cases was observed with only 36 cases occurring between June 2001 and July 2007. On the other hand, no change was observed in the incidence of Streptococcus pneumoniae invasive disease. This study suggests that the prevention of invasive pneumococcal disease by immunization may be an attractive proposition. These results should initiate health authorities to encourage similar local and nation wide studies to support this suggestion.

Rare but fatal complication of umbilical venous catheterization.

Umbilical venous catheterization in neonates is an intravascular infusion route for resuscitation and maintenance fluids, blood and blood products, parenteral nutrition, and hypertonic solutions that can be used as an alternative when peripheral venous access is not possible. When used, special precautions should be taken and guidelines followed to prevent rare but often fatal complications.

Penicillin resistance in serogroups/serotypes of Streptococcus pneumoniae causing invasive infections in Central Saudi Arabia.

OBJECTIVE: To determine the minimum inhibitory concentrations (MICs) of penicillin, ceftriaxone and vancomycin of serogroups/serotypes of Streptococcus pneumoniae (S. pneumoniae) from invasive diseases in all age groups from major hospitals in Riyadh, Kingdom of Saudi Arabia (KSA). METHODS: All isolates of S. pneumoniae from patients with invasive pneumococcal infections between February 2000 and November 2001 were prospectively collected from 8 major hospitals in Riyadh, KSA. The isolates were confirmed as S. pneumoniae at the King Khalid University Hospitals, Riyadh, KSA and then serogrouped/serotyped using the agglutination method. The MICs for penicillin, ceftriaxone and vancomycin were carried out using the E-test. RESULTS: Forty-three percent of the isolates were resistant to penicillin mostly of the intermediate type (97%). The resistant strains were mainly confined to serogroups/serotypes 6, 23, 19 and 15 and the 7-valent conjugate vaccine covers 76% of the penicillin-resistant strains. Only one isolate was resistant to ceftriaxone. CONCLUSION: In view of the rather insignificant level of highly resistant-penicillin strains and the virtual absence of resistance to ceftriaxone we would like to suggest using ceftriaxone for treating invasive pneumococcal infections outside the central nervous system. We recommend that the conjugate vaccine would be a useful adjunct to penicillin prophylaxis in patients at risk in our community.