Top Infectious Disease News of the Week—May 19, 2019

#5: Tahini Consumption Associated With Salmonella Concord Outbreak

Tahini is in the news once again as health officials have declared a multistate Salmonella Concord outbreak linked with the product. According to the US Centers for Disease Control and Prevention (CDC), this outbreak is not connected with the Salmonella outbreak resolved in February that was linked with tahini and sickened 8 individuals across 4 states.

As of May 14, 2019, 4 cases of Salmonella Concord have been reported across 3 states in the current outbreak. All 4 individuals fell ill during the month of March, with onset of illness dates ranging from March 9 to March 23. The ill range in age from 8 to 32 years, with a median age of 21 years. The outbreak notice reports that 75% of the ill are female and that 1 hospitalization has occurred in relation to the outbreak.

As part of the epidemiologic investigation, health officials conducted interviews with 3 of the ill individuals. All 3 reported eating tahini or hummus made with tahini in the week prior to becoming sick. State health officials in New York conducted a traceback investigation and interviewed restaurants where ill individuals ate and obtained samples of the products.

Read about the tahini outbreak.

#4: Investigators Discover Unknown Achilles Heel of Influenza Virus

n a study funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, investigators detail the discovery of a new site of vulnerability on the hemagglutinin (HA) of influenza virus.

The new findings offer a potential new target for antibody-based therapeutics and influenza vaccines along the HA head domain of the influenza virus prone to antigenic drift and shift. In the study, published in the journal Cell, investigators describe the unexpected discovery of a naturally occurring human antibody called FluA-20, that recognizes a previously unknown area of vulnerability on the HA that is found in most influenza A viruses, essentially uncovering influenza’s Achilles heel.

In an interview with Contagion®, Anthony S. Fauci, MD, director of NIAID, explained that the finding was surprising in a positive way. “There are a number of components of the influenza virus that are candidates for universal flu vaccine because they don’t change very much,” he said, noting that recent research has largely been directed at targeting the more stable stem of influenza’s HA, rather than the head. “However, what the investigators found was that they identified a monoclonal antibody that was able to reach into the trimer interface and wind up essentially disrupting the entire hemagglutinin, making it unable to bind to the cell. This was something that was not expected, that there would be such a vulnerable component to the hemagglutinin head that a single antibody would be able to disrupt the structural integrity of the trimer.”

According to the paper, the research team was led by investigators from The Scripps Research Institute and Vanderbilt University Medical Center. The investigators structurally characterized FluA-20 with H1 and H3 head domains to reveal a novel epitope in the HA trimer interface, after discovering the antibody in an individual who had received multiple flu vaccines and was enrolled in a different vaccine study.

Read about the discovery.

#3: Raising PrEP Awareness Could Improve Use Among Female Sex Workers in China

HIV pre-exposure prophylaxis (PrEP) has not reached its peak potential in China, according to a recent study that suggests a lack of HIV awareness and misconceptions about PrEP may be barriers to implementing prevention programs there.

The study, published in the journal AIDS Care, examined 1466 female sex workers (FSW) in China to better understand levels of awareness and willingness to use PrEP, along with factors influencing those outcomes.

“HIV pre-exposure prophylaxis has potential for use among female sex workers as a self-initiated approach to help prevent HIV in addition to traditional prevention methods such as condom use,” study author Adrienne N. Poon, MD, MPH assistant professor of medicine at the George Washington University School of Medicine & Health Sciences, told Contagion®. “We found that there was a general lack of awareness of low willingness to use PrEP among FSW in China. This is likely due to the overall low levels of HIV knowledge and awareness.”

Read about PrEP uptake.

#2: Ebola Outbreak Updates & The Role of Nosocomial Transmission

In the face of continued transmission and security issues, the Ebola outbreak in the Democratic Republic of the Congo (DRC) has challenged response efforts in new ways. On May 18, 2019, the DRC reported 15 new confirmed cases, bringing the total to 1728, with 1121 deaths.

Over the past week, 40% of the new cases were community-related and, of the total deaths, 68% occurred outside Ebola treatment centers. This leaves the community increasingly at risk, as it is the time when patients are most likely to spread infection. Safe burial has long been a challenge when it comes to Ebola outbreaks, not only because the body is contagious, but it also poses a problem for maintaining infection prevention efforts during dignified burials. Moreover, response efforts have been challenged with a “stop and go” pattern where response efforts are active for a day or 2 and then halted due to violence or security threats. Outside of the challenges for maintaining response and prevention efforts in a conflict zone, we’re also seeing a worrisome trend in Ebola cases—infection of health care workers.

During the 2013-2016 outbreak, health care workers in West Africa were 32 times more likely to be infected with Ebola. Earlier this week, a nurse was reported as the latest case in this trend, bringing the total of health care worker infections to 99. On Friday, the World Health Organization situation report noted that this number had increased to 101 and now accounted for 6% of the cases. Of these health care worker cases, there have been 34 deaths. The continued need for more health care workers, especially in the wake of frequent threats and violence, makes the possibility of nosocomial transmission that much more real. The enhanced personal protective equipment (PPE) alone is difficult for a novice and can be a considerable source of exposure. Bringing in local health care workers and staff is critical to maintaining local engagement and earning trust in this rapidly evolving environment, however, the tacit knowledge of caring for an Ebola patient is complicated on the best of days.

Read about the latest in the Ebola outbreak.

#1: Oral Gonorrhea May Be Spread Through Kissing in MSM

Oropharyngeal gonorrhea may be spread via French kissing, according to a new study out of Australia that looked at oropharynx-to-oropharynx transmission of the sexually transmitted infection (STI).

Investigators in Melbourne recruited more than 3000 gay and bisexual men who have sex with men (MSM) to participate in the study, which relied on a survey to create a mathematical model of gonorrhea transmission. Their findings were published in the journal Sexually Transmitted Infections.

Participants, who had visited a sexual health clinic in Melbourne between March 2016 and February 2017, were stratified into 3 categories of relationships: kissing-only (ie, no sex including no oral and/or anal sex), sex-only (ie, any sex without kissing), and kissing-with-sex (ie, kissing with any sex).

The median age of participants was 30 years [interquartile range (IQR): 25—37] and 6.2% (n = 229) had oropharyngeal gonorrhea. The average number of kissing-only partners in the last 3 months was 4.3, sex-only partners 1.4, and kissing-with-sex partners 5.0. Sex-only was not affiliated with oropharyngeal gonorrhea but kissing-only and kissing-with-sex were.

“The adjusted odds for having oropharyngeal gonorrhea were 1.46-fold [95% confidence interval (CI) 1.04 to 2.06] for men with ≥4 kissing-only partners and 1.81-fold (95% CI 1.17 to 2.79) for men with ≥4 kissing-with-sex partners,” investigators reported.

The research team concluded that kissing appears to be associated with the transmission of oropharyngeal gonorrhea regardless of whether sex also occurs.

“This data challenges the accepted traditional transmission routes of gonorrhea held for the past 100 years, where a partner’s penis was thought to be the source of throat infection,” lead author Eric P. F. Chow, PhD, MPH, BSc, associate professor at Monash University, told Contagion®. “A key strength of this study is that we measured ‘kissing-only partners’ for the first time. This has not been done before. We found after we controlled statistically for the number of men kissed, that ‘the number of men someone had sex with but did not kiss’ was not associated with throat gonorrhea.”

Read about the spread of oral gonorrhea.