The World Health Organization (WHO) announced late last week that the gangrenous disease noma has been added to its official list of neglected tropical diseases (NTDs).

Also known as gangrenous stomatitis or cancrum oris, noma is a rapidly progressive bacterial infection of the face and mouth. It begins as inflammation of the gums, and, if not treated early with antibiotics, spreads quickly to destroy facial tissue and bone, frequently leading to death or severe disfigurement. Diagnosis and treatment in the early stages of the infection can lead to proper wound healing.

The official request to have noma added to the NTD list was submitted to the WHO in January on behalf of 32 member states.

More than a disease

Primarily found in sub-Saharan Africa, noma mainly affects malnourished children between the ages of 2 and 6 years. Poor oral hygiene, malnutrition, weakened immune systems, and extreme poverty are among the risk factors.

"Noma is more than a disease, it is a social marker of extreme poverty and malnutrition, affecting the most vulnerable populations," WHO Director-General Tedros Adhanom Ghebreyesus, PhD, said in a press release. "By classifying noma as a neglected tropical disease, we are shining a light on a condition that has afflicted marginalized communities for centuries."

Current efforts to control the disease in endemic areas are often managed by oral health programs. The WHO says recognition of noma as an NTD aims to boost those efforts through multisectoral and multipronged approaches, amplifying global awareness of the disease, and stimulating research and funding.

"We are committed to working with affected countries and communities to address the drivers of noma, and alleviate the suffering it causes," Tedros said.

By classifying noma as a neglected tropical disease, we are shining a light on a condition that has afflicted marginalized communities for centuries.

With 72 new cases, the US Salmonella outbreak linked to cantaloupe has now topped 300 cases, and another person has died, bringing the death total to 4. So far, half of patients interviewed were hospitalized, the Centers for Disease Control and Prevention (CDC) said in an update late last week.

"CDC is concerned about this outbreak because the illnesses are severe and people in long-term care facilities and childcare centers have gotten sick. Do not eat pre-cut cantaloupes if you don’t know whether Malichita or Rudy brand cantaloupes were used," the CDC warned.

CDC is concerned about this outbreak because the illnesses are severe.

Salmonella can be most dangerous for the elderly, children under age 5, and those with compromised immune systems. So far in this outbreak, 40 sick people resided in long-term care facilities, and 30 children attended childcare centers before they got sick.

Mexican fruit plant closed

In total 302 people in 42 states have been sickened, and news media reported that a plant in Mexico is closed because of the outbreak. A Reuters story says five people in Canada have died in this outbreak, as well. In the United States, three people have died in Minnesota, and one person in Oregon.

Illnesses started on dates ranging from October 16, 2023, to November 28, 2023, and 129 people have been hospitalized.

Malichita and Rudy brand whole cantaloupes have been identified in both the United States and Canada as the sources for the outbreak and have been recalled. The affected fruit may have stickers that say "4050," and "Product of Mexico/produit du Mexique."

Pre-cut cantaloupe sold at a number of vendors, including Kwik Trip, Aldi, Vinyard, Kroger, and Sprouts, has also been recalled.

A survey of US healthcare providers found that those who more commonly treat sexually transmitted infections (STIs) are more likely to prescribe prophylactic (preventive) doxycycline for STI prevention, Centers for Disease Control and Prevention (CDC) researchers reported late last week in Emerging Infectious Diseases.

The analysis of survey responses from a sample of 1,504 US healthcare providers (30.4% family physicians, 36.2% internists, 16.7% obstetricians/gynecologists, and 16.7% nurse practitioners/physician assistants) showed that providers whose practice includes 10% or more STI care were more than 2.5 times more likely to have used doxycycline prophylactically for STI prevention than non-STI providers (adjusted odds ratio [aOR], 2.76; 95% confidence interval [CI], 2.20 to 3.48). STI providers were more than 50% more likely (aOR, 1.54; 95% CI, 1.24 to 1.89) to agree that the benefits of prescribing prophylactic doxycycline for patients who are at high risk for STIs outweigh the possibility of increasing antimicrobial resistance (AMR).

STI providers were no more likely than non–STI providers to agree that they had seen an increase in AMR among their patients over the past 5 years (aOR, 1.00; 95% CI, 0.81 to 1.23) or that the prophylactic use of doxycycline contributes to AMR (aOR, 1.09; 95% CI, 0.88 to 1.35).

Forthcoming CDC guidelines weigh risks, benefits

The CDC is currently working on guidelines for who should be eligible for doxycycline post-exposure prophylaxis, or doxy-PEP, which involves taking a dose of doxycycline within 72 hours of unprotected sex. A trial conducted at sexual health clinics in San Francisco and Seattle found that, among a cohort of men who have sex with men (MSM) and transgender women, the intervention reduced incidence of chlamydia by 88%, syphilis by 87%, and gonorrhea by 55%.

Concern about the impact that doxy-PEP could have on AMR is among the issues that the CDC is weighing. Trial investigators say they didn't see marked changes in AMR at 12 months follow-up but note that resistance will need to be monitored.

"Additional education on this topic for providers who routinely treat STIs and for providers who routinely prescribe doxycycline will help minimize any potential AMR threats," the CDC researchers wrote.

The effectiveness of unregulated botanical blacklegged-tick repellants and killers varies widely, with some offering minimal protection against bites and the pathogens they transmit to humans, according to a Centers for Disease Control and Prevention (CDC) study.

Published last week in Emerging Infectious Diseases, the study summarized the evidence on products used in the United States and their efficacy compared with that of products registered with the Environmental Protection Agency (EPA) as safe and effective. The bite of the blacklegged, or deer, tick (Ixodes scapularis) can cause Lyme disease, ehrlichiosis, and other diseases.

The author, Lars Eisen, PhD, noted that while the availability of unregulated anti-tick products, many based on botanical oils, is proliferating, assessments of such products are limited. These products are EPA-exempt because their active and inactive ingredients are considered to pose limited risk to human health or the environment when applied to skin, clothing, or vegetation.

"Evaluations of minimum risk tick repellents have typically focused on individual active ingredients rather than formulated products, which often combine multiple active ingredients," he wrote.

Repellent effect much shorter with botanicals

Some products killed blacklegged ticks at rates similar to chemical pesticides, while others had little effect. In addition, different products based on the same active ingredients (eg, rosemary oil) varied considerably in their tick-killing ability.

Evaluations of minimum risk tick repellents have typically focused on individual active ingredients rather than formulated products, which often combine multiple active ingredients.

One study that compared the ability to repel ticks in the United States among 19 minimum-risk active ingredients showed that total protection ranged from under 10 minutes (eg, castor oil) to less than 1 hour (eg, citronella oil) and 1 or 2 hours (eg, cinnamon oil), compared with the entire 6-hour observation period with the chemical DEET.

"Consumers should be aware that effectiveness to kill and repel ticks can differ among unregulated minimum risk products," Eisen wrote. "There also is a need to better understand the reasons why members of the public choose to use EPA-registered versus minimum risk 25(b) exempt tick toxicant and repellent products, based on perceptions about effectiveness and safety for humans, pets, and the environment."