Children younger than 5 years exposed to maternal syphilis in utero, including those with congenital syphilis detected at birth, were at higher risk for all-cause hospitalization and had longer hospital stays, according to a study conducted in Brazil and published yesterday in JAMA Network Open.

Led by researchers from the London School of Hygiene and Tropical Medicine, the study involved data from the Center of Data and Knowledge Integration for Health Birth Cohort on 8.3 million single births from January 2011 to December 2015, with a 3-year follow-up. Of all children, 30,039 had been exposed to maternal syphilis, and 36,443 had congenital syphilis.

The incidence of syphilis, a bacterial infection caused by Treponema pallidum, has increased more than 200% among women of child-bearing age in high-income countries in recent years, the researchers noted.

"Syphilis can be transmitted sexually or vertically from mother to child during pregnancy, affecting the developing fetus," they wrote. "It is estimated that globally, maternal syphilis has caused 350,000 adverse birth outcomes every year, including stillbirth, preterm birth, low birth weight, neonatal deaths, and congenital infection." 

Congenital cases carry 6 times the risk

During the study, 65.1% of children with congenital syphilis and 31.3% with maternal syphilis were hospitalized at least once, compared with 19.0% in the unexposed group. 

These results suggest the need for close monitoring of exposed children and stress the importance of preventing syphilis in women of childbearing age.

Relative to unexposed children, those with congenital syphilis were at a 6-fold increased risk for first hospitalization (hazard ratio [HR], 6.19), and those exposed to maternal syphilis were at nearly twice the risk (HR, 1.90). The highest risk of hospitalization was noted in the first month of life among congenital syphilis patients (HR, 11.53). 

Although risk declined with increasing age, syphilis-exposed children had higher hospitalization rates than the unexposed group until age 36 months. Those exposed to syphilis in utero also had more and longer hospital stays.

"These results suggest the need for close monitoring of exposed children and stress the importance of preventing syphilis in women of childbearing age," the study authors wrote.

Health authorities in the Democratic Republic of the Congo (DRC) are scaling up the response to an anthrax outbreak in North Kivu province that has so far resulted in 16 suspected cases, 1 confirmed case, and 1 death, according to a statement today from the World Health Organization (WHO), which is supporting the efforts.

The epicenter is four health districts around Lake Edward that border Uganda, where seven related suspected anthrax cases have been reported on the other side of the lake. In an April weekly disease update, the WHO’s African regional office said seven people in Uganda’s Kabale district had signs of cutaneous anthrax after slaughtering cattle.

Infections follow reports of animal deaths, including hippos

In the DRC, initial alerts on March 22 were posted after dozens of buffalos and hippopotamuses died in Virunga National Park, which includes part of Lake Edward.

The WHO said efforts are under way to vaccinate livestock in communities near rivers and that veterinary teams are working to safely dispose of animal carcasses. Health officials are also conducting public awareness campaigns to enhance preparedness.

Anthrax is a bacterial disease that mainly affects animals, but people can contract the disease directly or indirectly from infected animals or from exposure to contaminated animal products. The disease manifests as three forms in humans, and cutaneous infections are most common, occurring when spores come into contact with broken skin. Gastrointestinal infections result from eating contaminated meat, and inhalational anthrax—the rarest type—results from breathing in spores.

In 2023, an anthrax outbreak in Zambia resulted in nearly 700 cases, 4 of them fatal. The outbreak was tied to eating or butchering meat from infected carcasses, including dead hippos.

• Federal food-safety officials are investigating the source of a new Listeria monocytogenes outbreak that has been linked to 10 illnesses so far, the US Food and Drug Administration (FDA) said yesterday on its foodborne illness investigation website. The US Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) and the FDA are both involved in the probe.
• Burkina Faso has reported its first Zika case, which involves a 6-year-old girl from Ziniare who was hospitalized for a suspected dengue infection but was negative for the disease, according to the latest weekly infectious disease bulletin from the Africa Centre for Disease Control and Prevention (Africa CDC). Follow-up testing at the country’s reference lab confirmed the Zika infection. The patient had no history of travel in the 15 days before her symptoms began.
• The USDA Animal and Plant Health Inspection Service (APHIS) today reported one more H5N1 avian flu detection in poultry, which involves a commercial layer facility in Aurora County, South Dakota. The farm has 700,000 birds. Since the virus began striking poultry in February 2022, outbreaks have led to the loss of 169 million birds across all 50 states and Puerto Rico.