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Research Briefs June 2018

Tracking Down “Unusually” Resistant Germs

Last year, the Centers for Disease Control and Prevention (CDC) Antibiotic Resistance (AR) Lab Network found 221 instances of “nightmare bacteria” with unusual antibiotic resistance genes “hiding in plain sight.”

According to the study, one in four germ samples sent to the AR Lab Network for testing had special genes that allow them to spread their resistance to other germs. Further investigation in facilities with unusual resistance revealed that about one in 10 screening tests from patients without symptoms identified a hard-to-treat germ that spreads easily, meaning the germ could have spread undetected in that health care facility, the CDC said.

The CDC containment strategy includes continued infection control assessments until the spread is stopped, which takes a coordinated response among facilities, labs, health departments, and the CDC through the AR Lab Network. Health departments using the approach have conducted infection control assessments and colonization screenings within 48 hours of finding unusual resistance and have reported no further transmission during follow-up over several weeks. Estimates show that for carbapenem-resistant Enterobacteriaceae alone, the containment strategy would prevent as many as 1,600 new infections in three years in a single state—a 76% reduction.

Health care practitioners can help by using contact precautions, asking patients about recent travel or health care, and communicating about status when patients are transferred.

Source: CDC, April 2018

Islet Transplantation Improves Diabetes-Related Quality of Life

Patients with type-1 diabetes who underwent pancreatic islet transplantation showed “consistent, dramatic improvements” in a phase 3 study funded by the National Institutes of Health (NIH). The participants reported the greatest improvements in diabetes-related quality of life and better overall health status— even though they would need lifelong immune-suppressing drugs to prevent transplant rejection.

The study, conducted by the Clinical Islet Transplantation Consortium, involved 48 people with hypoglycemia unawareness who experienced frequent episodes of severe hypoglycemia despite receiving expert care. Each participant received at least one islet transplant.

One year after the first transplant, 42 participants (88%) were free of severe hypoglycemic events, had near-normal blood glucose control, and had restored awareness of hypoglycemia. About half of the recipients needed to continue on insulin to control blood glucose, but the reported improvements in quality of life were similar between those who did and those who did not. The researchers say the elimination of severe hypoglycemia and the associated fears outweighed concerns about the need for continued insulin treatment.

Islet transplantation is investigational in the United States. While the results are promising, the NIH cautions that the process is not appropriate for all type-1 patients due to risks and side effects.

Source: NIH, March 2018

U.S. Tuberculosis Rates Stagnant

Tuberculosis (TB) rates are declining too slowly—so slowly, in fact, that Centers for Disease Control and Prevention (CDC) researchers predict that TB won’t be eliminated in this century. The U.S. goal is to reduce the incidence to less than one case per one million people, but in 2017 there were 28 cases per million.

After years of decline, TB rates have stagnated among people born in the U.S. The TB rate dropped slightly (–2.5%) from 2016 to 2017. Another even slighter decrease was seen in 2017 (−1.8%). Moreover, more than one in 10 TB cases occurred among children younger than 15 years of age (a “key marker” of recent transmission, the CDC says). Half of all cases were reported in California, New York, Texas, and Florida, all four corners of the country.

As many as 13 million people in the U.S. have latent TB infection, but the vast majority do not know it. On average, 5% to 10% of people with latent TB infection progress to infectious TB. More than 80% of U.S. TB cases are associated with long-standing, untreated latent TB infections.

The CDC says reaching the elimination goal will take an “intensified, dual approach” that strengthens existing systems to prevent transmission of infectious TB disease and increases efforts to detect and treat latent infection before it progresses to infectious TB.

It is essential to ensure that every active case of TB disease is effectively detected and treated, the CDC says. Treatments can be difficult for patients to complete, and not completing them can lead to drug-resistant bacteria and even lengthier and more expensive treatment. CDC research has identified a shorter regimen for people with latent infection: 12 once-weekly doses of isoniazid and rifapentine (Priftin, Sanofi-Aventis U.S.), a simpler treatment compared with other regimens that include a 270-dose, nine-month, daily regimen of isoniazid.

Over the past 20 years, health departments and CDC TB control efforts have prevented an estimated 300,000 cases of TB disease. “Challenges remain,” says Philip LoBue, MD, Director of the CDC’s Division of Tuberculosis Elimination. But “the good news is that the path to accelerated progress is clear.” In addition to the shorter treatment regimen, recent advances include electronic directly observed therapy, which makes TB treatment less expensive and more convenient; and a diagnostic blood test that can provide accurate results in a single medical visit.

Source: CDC, March 2018

The “Other” Risks of High Blood Pressure

In general, people are aware of the possible “traditional” outcomes of cardiovascular disease: heart attack, heart failure, and stroke. But other outcomes, such as kidney disease and dementia, are less known. In a Centers for Disease Control and Prevention study of 4,166 adults, only 38.5% of those with self-reported hypertension were aware of the risk of kidney disease versus 24.8% of normotensive adults. Awareness of the risk of dementia was “markedly low” at 8.7% and 7.9%, respectively.

The researchers found “notable” socioeconomic and racial/ethnic differences in awareness of risks. For example, high-income respondents had greater awareness of the association between uncontrolled hypertension and kidney disease, stroke, and dementia compared with low-income respondents. Non-Hispanic whites had greater awareness of risk than non-Hispanic blacks (who have a higher prevalence of hypertension and uncontrolled hypertension).

Nearly 35 million people have uncontrolled hyper tension, the researchers note. To educate more diverse patient populations about the risks, they recommend expanding current initiatives, such as the “Mind Your Risks” program (https://mindyourrisks.nih.gov), promoted by the National Institute of Neurological Disorders and Stroke, and the “Measure Up, Pressure Down” program (www.measureuppressuredown.com.), sponsored by the American Medical Group Association.

Source: Preventing Chronic Disease, April 2018

Clinical Puzzle: Lung Cancer Or Hodgkin’s Lymphoma?

Patients with Hodgkin’s lymphoma have a 15% to 40% likelihood of pulmonary involvement (e.g., a solitary lung mass or cavitary lung lesion). But clinicians at Bassett Healthcare in Cooperstown, New York, were faced with an extremely rare case of another presentation: an endobronchial obstructing mass.

Their patient, a 40-year-old man, reported having had cough, fatigue, and progressive weight loss (despite a good appetite) for eight months. Because he had a history of smoking, he was treated for bronchitis, but the cough worsened. He had no fever, night sweats, dyspnea, or chest pain (common features of Hodgkin’s lymphoma).

Auscultation revealed clear lungs, with no crackles or wheeze, and no dullness to percussion. The patient’s blood work was negative except for eosinophilia. A subsequent chest radiograph showed an irregular left hilar lung opacity. A computed tomography scan showed a cavitary consolidation of the left upper lobe of the lung. Fiber-optic bronchoscopy with tissue from the endobronchial mass indicated an obstructing lesion in the left upper-lobe bronchus. The clinicians suspected lung cancer. However, they also found inflammatory cells, and immunohistochemistry revealed findings consistent with Hodgkin’s lymphoma.

They started the patient on chemotherapy. After six cycles, his symptoms resolved. Follow-up at eight months showed no clinical evidence of recurrence.

As the clinicians found out, radiologically, Hodgkin’s lymphoma can mimic lung cancer. Thus, they advise histopathological diagnosis for patients presenting with a lung mass.

Source: BMJ Case Reports, March 2018

Which Comes First: The Mood Disorder or the Inflammation?

Mood disorders and cardiovascular disease (CVD) are often linked—one mechanism may be common underlying low-grade inflammation. Specifically, studies have found a consistent association between circulating levels of proinflammatory cytokines with both mood disorders and CVD, say researchers from Lausanne University Hospital, Bern University Hospital, and the National Institute of Mental Health. However, they suggest, that influence may be one-way: Mood disorders may lead to inflammation, but inflammation may not be a risk factor for the onset of mood disorders.

Noting that much of the research on inflammatory markers and CVD has focused on major depression, the researchers decided to conduct a study to investigate any association between atypical subtype of depression and increased levels of inflammatory markers. They analyzed data from 3,118 participants who underwent comprehensive somatic and psychiatric evaluations at baseline and a mean of 5.5 years later. Current and remitted mood disorders included bipolar and major depressive disorders (MDD); subtypes included atypical, melancholic, and combinations of those.

After adjusting for confounders, they found current combined MDD was associated with increased high-sensitivity C reactive protein (hsCRP) levels and decreased interleukin (IL)-6 levels. Current atypical MDD was associated with increased hsCRP levels at follow-up. Moreover, remitted melancholic MDD was associated with decreased IL-6 levels at follow-up.

The major finding, the researchers say, was the association between the current atypical subtype of MDD at baseline with increased levels of hsCRP at follow-up. In contrast, inflammatory levels at baseline were not associated with subsequent atypical MDD at follow-up. What this suggests is that the disorder is causally related to increased inflammation, rather than inflammation increasing the mood disorder.

Their finding of unidirectional association appears to be specific to the atypical subtype of MDD, they add, which is characterized by somatic symptoms including sleep, energy, and eating behavior.

Source: Psychological Medicine, April 2018