New handheld device can diagnose TB without a lab in under an hour, its developers say

News brief

Child being evaluated for tuberculosis — *Stop TB Partnership*

A new smartphone-sized device can deliver tuberculosis (TB) test results at the point of care in less than an hour, an innovation that could improve diagnosis of the deadly disease in settings in which access to healthcare facilities and lab equipment is limited, its Tulane University developers reported yesterday in Science Translational Medicine.

Over 90% of new TB cases occur in low- and middle-income countries.

The battery-powered device is the first to detect Mycobacterium tuberculosis in saliva in addition to blood and sputum. The low-cost, microprocessor-controlled device uses a liquid crystal display (LCD) user interface to control test performance, automate assay analysis, and produce results.

The test uses a DNA-enrichment membrane and cellulose disc containing DNA-amplification and molecular-diagnostic reagents to provide results without a conventional lab-based DNA-isolation procedure.

High sensitivity, good specificity

The researchers used the device to test serum cell-free DNA isolated from children ages 1 to 16 years in the Dominican Republic. It detected pulmonary and extra-pulmonary TB with higher sensitivity than a costlier device (81% vs 68%, respectively) and good specificity (94%), meeting the WHO target product criteria for new non-sputum TB tests.

Saliva-based testing for TB is particularly exciting because it can be easily obtained in all patients and can be used for portable testing without the need for blood draw.

Brady Youngquist

Changes in test results for serum isolated during treatment were also highly predictive of clinical response, and the results obtained with noninvasive sputum and saliva specimens from adults with pulmonary TB were similar to those reported for reference methods.

"TB remains a critical public health concern in low-income countries and diagnosis using a cheap, simple test like we've developed is needed not only to treat patients with TB but prevent further spread of the disease," senior author Tony Hu, PhD, said in a Tulane press release.

Lead author Brady Youngquist, a graduate student, said the system makes testing more accessible. "Saliva-based testing for TB is particularly exciting because it can be easily obtained in all patients and can be used for portable testing without the need for blood draw," he said. "And sputum is often not produced in children and patients living with HIV, a common co-infection."

Nasal bacteria may boost COVID-19 infection risk

News brief

Stephanie Soucheray, MA

A new study in eBioMedicine from researchers at George Washington University suggests certain types of nasal bacteria may make someone more likely to get a COVID-19 infection.

The study was based on 1,548 self-collected nasal swabs from adults in Washington DC. The swabs were collected during two retrospective case-control studies and a nasal microbiome study. Cases were defined as those with a positive SARS-CoV-2 testand were matched with controls based on age and test date.

Researchers found those who became infected with COVID had higher levels of gene expression for two key proteins, ACE2 and TMPRSS2. Elevated nasal ACE2/TMPRSS2 expression was associated with 3.6-fold increased risk of contracting COVID-19 (95%confidence interval [CI], 1.71 to 7.47) compared to those with no detectable levels of ACE2 or TMPRSS2.

Certain proteins associated with infection

Having high densities of bacteria including Staphylococcus aureus, Haemophilus influenzae, or Moraxella catarrhalis/nonliquefaciens was linked to increased nasal ACE2/TMPRSS2 expression.

Bacteria in our noses can influence the levels of proteins that the virus uses to infect cells.

“We’ve known that the virus SARS-CoV-2 enters the body through the respiratory tract, with the nose being a key entry point. What’s new—and surprising—is that bacteria in our noses can influence the levels of proteins that the virus uses to infect cells,” said Cindy Liu, PhD an associate professor of environmental and occupational health at the GW Milken Institute School of Public Health in a press release.

Researchers said their next steps will include modifying the nasal microbiome, such as through nasal sprays or live biotherapeutics, to see if that could reduce the risk of infection.

WHO director says public health-funding independence needed amid global cuts

News brief

Stephanie Soucheray, MA

tedros WHO — Violaine Martin / Flickr cc

At a briefing today, the World Health Organization (WHO) noted that almost 75% of WHO country offices have reported health service disruptions due to recent funding cuts, 25% reported health facility closures, and 25% reported increased out-of-pocket expenditures for populations.

"They also report job losses for health and care workers, and disruptions to information systems, and the supply of medicines and health products," the WHO said. "In response, countries are revising budgets, cutting costs, and strengthening fundraising and partnerships."

In remarks made during the briefing, WHO Director-General Tedros Adhanom Ghebreyesus, PhD, said the cuts to global health funding have helped speed a transition away from aid dependency that the WHO has been encouraging for years.

Tedros says US’s absence is lose-lose

Tedros suggested countries looking for more funds must think of new ways to raise health money, such as taxes on sugary foods, alcohol, and tobacco.

Tedros also addressed the United States' retreat from the WHO, which was one of President Donald Trump's first executive orders in January. At the time, US funding made up about 15% to 20% of the WHO budget.

It's in the best interests of the US to stay in WHO.

"I said it many times that the US withdrawal from the WHO, it's a lose-lose," Tedros said. "It's in the best interests of the US to stay in WHO. It's a health security that keeps the US safe and the rest of the world safe by being in the WHO."

Indiana reports measles outbreak as cases rise in Ohio and Michigan

News brief

Lisa Schnirring

Just days after reporting its first measles case of the year, in a child, the Indiana Department of Health (IDOH) yesterday reported five more related cases.

young boy with measles — *CDC / Tatiana Lanzieri, MD, MPH*

The newly reported patients include three children and two adults who, like the first patient, are from Allen County in the northeast part of the state, an area that includes Fort Wayne.

The IDOH said the four minors were unvaccinated, and the adults' vaccination status is unknown. All patients are recovering.

Officials said though all cases are connected, there are no known links to cases in other states. "State and local public health officials are working together on the investigation to contact those with known exposure to help prevent further spread of infection. The risk to the general public remains low," the IDOH said.

More cases reported in Ohio and Michigan

Elsewhere, measles cases are rising steadily in Ohio, which in late March reported 10 cases centered in Ashtabula County, with exposures in Knox County. The Ohio Department of Health infectious disease dashboard still reflects 10 measles cases from Ashtabula County, 8 classified as locally acquired. Ashtabula County is in the far northeast corner of Ohio.

Separately, Knox County, located in central Ohio, has reported 14 cases, which include 7 Ohio residents who have links to the county’s first case, according to an update this week from Knox Public Health. Officials said the patients are isolated, with their symptoms under monitoring.

In Michigan, the Mid-Michigan District Health Department yesterday reported a measles case in a Montcalm County resident who had recently traveled outside the state. "The health department is working closely with the Michigan Department of Health and Human Services to determine points of exposure," the group said. The case lifts Michigan’s total for the year to four.