Publications

The U.S. Preventive Services Task Force (USPSTF) recently issued guidelines on screening for vitamin D deficiency. The guidelines were based on randomized trials of vitamin D deficiency screening and treatment, as well as on case-control studies nested within the Women's Health Initiative. The USPSTF concluded that current evidence is insufficient to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults. Compared with placebo or no treatment, vitamin D was associated with decreased mortality; however, benefits were no longer seen after trials of institutionalized persons were excluded. Vitamin D treatment was associated with a possible decreased risk for at least 1 fall and the total number of falls per person but not for fractures. None of the studies examined the effects of vitamin D screening versus not screening on clinical outcomes. In this Grand Rounds, 2 prominent endocrinologists debate the issue of screening for vitamin D deficiency in a 55-year-old, asymptomatic, postmenopausal woman. They review the data on which the USPSTF recommendations are based and discuss the potential benefits and risks, as well as the challenges and controversies, of screening for vitamin D deficiency in primary care practice.

BACKGROUND

Nucleic acid amplification tests (NAATs) have been used as a diagnostic tool for tuberculosis (TB) in the United States for many years. We sought to assess NAAT use in TB patients in California during a period of time when NAAT availability increased throughout the world.

METHODS

We conducted a retrospective review of surveillance data from 6051 patients with culture-confirmed pulmonary TB who were reported to the California TB registry during 2010-2013.

RESULTS

Only 2336 of 6051 (39%) TB patients had a NAAT for diagnosis before culture results. Although 90% (N = 2101) with NAAT had positive test results, 9% (N = 217) had falsely negative NAAT results, and 0.8% (N = 18) had indeterminate NAAT results. The median time from specimen collection to TB treatment initiation was shorter when NAAT was used (3 vs 14 days, < .0001), and patients with a positive NAAT result initiated treatment earlier than patients with a falsely negative result (1 vs 11 days from NAAT report, < .0001). We confirmed the increased sensitivity of NAAT compared with acid-fast bacilli (AFB) smear microscopy in our study population; 92 of 145 AFB smear-negative patients had positive NAATs. Median time from specimen collection to NAAT result report differed by health jurisdiction, from 1 to 11 working days.

CONCLUSIONS

Increased use of NAATs in diagnosis of pulmonary TB could decrease the time-to-treatment initiation and consequently decrease transmission. However, differential use and access to NAAT may prevent full realization of NAAT benefits in California.

BACKGROUND

We assessed nasopharyngeal (NP) carriage of five pathogens in febrile children with and without acute respiratory infection (ARI) of the upper (URTI) or lower tract, attending health facilities in Tanzania.

METHODS

NP swabs collected from children (N = 960) aged 2 months to 10 years, and with a temperature ≥38°C, were utilized to quantify bacterial density of S. pneumoniae (Sp), H. influenzae (Hi), M. catarrhalis (Mc), S. aureus (Sa), and N. meningitidis (Nm). We determined associations between presence of individual species, densities, or concurrent carriage of all species combination with respiratory diseases including clinical pneumonia, pneumonia with normal chest radiography (CXR) and endpoint pneumonia.

RESULTS

Individual carriage, and NP density, of Sp, Hi, or Mc, but not Sa, or Nm, was significantly associated with febrile ARI and clinical pneumonia when compared to febrile non-ARI episodes. Density was also significantly increased in severe pneumonia when compared to mild URTI (Sp, p<0.002; Hi p<0.001; Mc, p = 0.014). Accordingly, concurrent carriage of Sp+, Hi+, and Mc+, in the absence of Sa- and Nm-, was significantly more prevalent in children with ARI (p = 0.03), or clinical pneumonia (p<0.001) than non-ARI, and in children with clinical pneumonia (p = 0.0007) than URTI. Furthermore, Sp+, Hi+, and Mc+ differentiated children with pneumonia with normal CXR, or endpoint pneumonia, from those with URTI, and non-ARI cases.

CONCLUSIONS

Concurrent NP carriage of Sp, Hi, and Mc was a predictor of clinical pneumonia and identified children with pneumonia with normal CXR and endpoint pneumonia from those with febrile URTI, or non-ARI episodes.