Top Infectious Disease News of the Week— December 9, 2018

#5: HIV Persistent, but Inert, in Liver Macrophages

A new proof-of-concept study finds that although HIV persists in liver macrophages when a patient is taking antiretroviral therapy, the virus is inert in patients on long-term antiretroviral therapy, and thus is unlikely to replicate.

The findings, published in The Journal of Clinical Investigation, suggest that liver macrophages should not be considered HIV reservoirs, since it appears the cells are unable to replicate the virus.

Ashwin Balagopal, MD, an associate professor of medicine at the Johns Hopkins University School of Medicine and the study’s senior author, said his research ought to serve as a signpost for scientists developing new treatment targets for HIV.

Dr. Balagopal noted that the bulk of current research has been targeting resting memory CD4+ T cells (rmT cells), which are the most common HIV reservoirs. Although those are a clear target for scientists, less is known about whether other potential types of cells are worthwhile targets.

Read about HIV in liver macrophages.

#4: Pregnant Women Should Be a Priority When It Comes to Vaccination R&D, New Report Urges

Pregnant women have been routinely excluded from the vaccination research and development process, even though this vulnerable class is sometimes uniquely affected by infectious disease outbreaks.

In an effort to address and correct this inequity in vaccination coverage, a new report by the Pregnancy Research Ethics for Vaccines, Epidemics, and New Technologies (PREVENT) Working Group, titled Pregnant Woman & Vaccines Against Emerging Epidemic Threats: Ethics Guidance for Preparedness, Research and Response, is urging vaccination researchers, policymakers, and health groups across the globe to embark on a “paradigm shift” and change the default thinking when it comes to maternal vaccination.

Inclusion of pregnant women in vaccine research and development should be the default, not the exception, the group, funded by Wellcome Trust and made up of 17 multidisciplinary members, explained.

“There is nothing about pregnancy that makes women immune from infectious disease threats, and many infections pose increased risks to pregnant women themselves, the developing fetus, and usually both,” Carleigh Krubiner, PhD, a lead author of the report appointed at the Johns Hopkins Berman Institute of Bioethics and the Center for Global Development, told Contagion®. “[W]hen we’re developing vaccines to combat these infectious disease threats, we need to be considering pregnant women as part of the target population—when investment decisions are made and as we conduct the research to understand safety, immunogenicity, and ultimately, effectiveness.”

Read about the priorities of vaccination R&D.

#3: FDA Approves SUBA-Itraconazole for Treatment of Systemic Fungal Infections

The US Food and Drug Administration (FDA) has issued an approval for SUBA-itraconazole (Tolsura), which is indicated for the treatment of certain systemic fungal infections. The new formulation, manufactured by Mayne Pharma, combines the board spectrum antifungal drug itraconazole with a Super-BioAvailable (SUBA) drug delivery platform in a 65mg capsule.

SUBA-itraconazole is indicated for the treatment of blastomycosis (pulmonary and extrapulmonary), histoplasmosis (including chronic cavitary pulmonary disease and disseminated, non-meningeal histoplasmosis), and aspergillosis (pulmonary and extrapulmonary) in patients who are intolerant of or who are refractory to amphotericin B therapy.

Most of these infections occur in vulnerable patient populations, including people living with HIV, individuals with a history of cancer, and individuals who have undergone a solid organ or bone marrow transplants. The azole antifungal is approved for treatment of infections in adult patients.

Read about the FDA’s approval of SUBA-Itraconazole.

#2: It's Not the Neti Pot That's Dangerous, But the Water Used With It: Public Health Watch

Those dealing with sinus issues have gone to pot—as in the neti pot, a modern twist on an ancient Indian approach to nasal irrigation.

However, while some people prefer the natural benefits of “neti” (the Sanskrit word for “nasal cleansing”) to Western medical options such as prescription drugs and over-the-counter nasal sprays, the traditional method is not without risks. In fact, an extreme example of the hazards associated with neti pots is described in a case report published in the December issue of the International Journal of Infectious Diseases, in which a 69-year-old woman was diagnosed with granulomatous amoebic encephalitis caused by the Balamuthia mandrillarisamoeba found in soil and fresh water.

The authors of the report linked her condition, which proved fatal, to her use of a neti pot. Not surprisingly, and unfortunately, the consumer press has used the woman’s story as fodder for headlines warning against “brain-eating amoebas.”

“In theory, the rise in neti pot use is a good thing,” Ahmad R. Sedaghat, MD, PhD, assistant professor, department of otolaryngology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, told Contagion®. “Normal saline is natural. [But] I don’t think users are fully aware of the risks, which are primarily infectious. There are several studies in the scientific literature that have characterized just how dirty with bacteria neti pots can become.”

Read about the danger of the water used with neti pots.

#1: Asian Longhorned Tick Update: Eastern United States, Coastal Pacific Northwest Could Be Prime Survival Areas

Haemaphysalis longicornis, also called the Asian longhorned tick, is the first invasive tick to emerge in the United States in approximately 80 years. The tick has been classified as a new emerging disease threat by the US Centers for Disease Control and Prevention, and now a new study has found that the Asian longhorned tick could survive in the majority of the eastern United States and the coastal Pacific Northwest.

In the study, published today in the Journal of Medical Entomology, Ilia Rochlin, PhD, an entomologist associated with the Rutgers University Center for Vector Biology, analyzed variables such as average annual rainfall and temperature from 260 locations in Asia and Australia where the tick has been previously reported, and then developed a model that would combine this data with climate data from North America to determine suitable habitats for the tick.

“The Asian longhorned tick will most likely become established in many areas of temperate United States and southern Canada,” Dr. Rochlin told Contagion® in an interview, “[W]e know that this tick species readily feeds on humans, pets, and wildlife. All these aspects increase the likelihood that the Asian longhorned tick may become a vector species transmitting some of the numerous tick-borne pathogens already circulating over much of eastern North America.”

The study results indicated that suitable areas for habitation in North America include coastal areas from eastern Canada, such as New Brunswick and Nova Scotia; down south to Virginia and North Carolina; and from southern British Columbia to northern parts of California on the west coast. The report also notes that suitable habitats were detected through inland North America from northern Louisiana to Wisconsin and into southern Ontario and Quebec, as well as Kentucky, Tennessee, and Missouri.

Other parts of North America were excluded due to warmer temperatures, cold winters, or dry terrain.

According to Dr. Rochlin, while this model is a good prediction of potential habitats for the tick on a large scale, there is still not enough information to pinpoint specific locations of potential habitation. In order to predict potential habitats on the county or township level, investigators need to learn more about the biology and ecology of the tick.

Read about the Asian longhorned tick’s suitable habitat.