Building the Future of Biodefense

Recommendation: Powassan virus disease is a rare tick-borne disease. Organizations in Winnebago County, Illinois, with employees working outdoors in grassy or wooded areas should remind them that tick bite prevention is important for minimizing exposure risk. Wearing protective clothing, using insect repellent, and conducting tick checks after being in grassy, agricultural, or forested areas protects employees from tick-borne diseases.

Situation: Illinois health officials reported that ticks in Winnebago County tested positive for the Powassan virus for the first time. This follows a September 2025 report of Illinois’ first confirmed human Powassan virus case (see PHC alert 9/24/25). With no vaccine available and risk of serious complications, health officials urged residents to prevent tick bites and monitor for symptoms after outdoor exposure. [Confidence: Very High]

Recommendation: Organizations in Osaka, Japan, should provide flexible work schedules to allow sick employees (or those with caregiving duties) to stay home until 48 hours after gastrointestinal symptoms have stopped. Encourage robust hand and food hygiene.

Situation: According to media sources, over 600 students across 8 elementary and junior high schools in Kumatori Town, Osaka Prefecture, were ill with food poisoning linked to bread served in school lunches. An unnamed manufacturer in Izumisano City was the supplier of bread. Norovirus was detected in some students, as well as in an employee of the company that supplied bread. Health officials ordered the bread manufacturer to suspend operations for 5 days while investigations continue. [Confidence: Very High]

Recommendation: Argentina reported a resurgence of locally acquired chikungunya in recent years, following multiple years of low to no activity. Organizations in Argentina should reduce mosquito populations at their facilities by eliminating standing water. Employees can prevent mosquito bites by wearing protective clothing, using insect repellent, and eliminating standing water near their homes. Organizations should inform employees with planned work travel to Argentina and support pregnant employees who opt not to travel. Employees should consult a doctor about vaccination against chikungunya before traveling to affected areas. Vaccine eligibility and availability may vary by country.

Situation: Argentina reported 3,202 suspected chikungunya cases, of which 199 were confirmed and probable cases, from August 2025 to mid-March 2026. Of the confirmed and probable cases, 54 were in individuals who recently traveled internationally, mostly in Bolivia, Brazil, Paraguay, and Cuba. 145 cases were locally acquired, clustered in the northern part of Argentina, near the border with Bolivia, though locally acquired cases were recorded in more southern regions as well. Regionally, most cases were reported from Salta (126), followed by Jujuy (6), Tucuman (4), Catamarca (4), Santiago del Estero (3), Buenos Aires (1), and Chaco (1). The outbreak in Salta may have emerged following importation of the disease from Bolivia, where transmission is ongoing (see PHC alert on 3/10). Health officials noted that the rise of locally acquired cases in Argentina follows a sustained regional increase in chikungunya activity across the Americas. [Confidence: Very High]

Recommendation: Over 8 million people worldwide are infected with the Chagas disease parasite. It is most common in rural areas of Mexico and Central and South America. It usually spreads through bites from triatomine bugs, known as kissing bugs, but can also be transmitted through oral ingestion of food or beverages, like açaí, contaminated with the feces of infected triatomine bugs or crushed insects. Oral infection is associated with local outbreaks and often results in more severe acute disease, including fever, acute myocarditis, and severe heart issues, with mortality rates reaching up to 33% in some cases. Employees should avoid consuming açaí products in the South Zone of Macapá, Brazil, during the ongoing outbreak and exercise caution regarding the source of any açaí purchased.

Situation: Health officials are responding to an acute Chagas disease outbreak in southern Macapá, Brazil, with 6 confirmed cases. Affected neighborhoods include Jardim Marco Zero, Zerão, Buritizal, and Universidade. Officials activated a contingency plan focused on containment, case investigation, and patient care. While the source of the outbreak remains under investigation, officials are inspecting açaí processing sites and temporarily closing establishments that cannot verify proper sanitization, as contaminated açaí juice is a known oral transmission source. Businesses are allowed to reopen once compliance is confirmed. The public was also provided guidance on Chagas symptoms. Earlier this year, consumption of improperly prepared açaí was the suspected source of infection of a Chagas disease outbreak in Ananindeua, Brazil (see PHC alert on 1/27). [Confidence: Very High]