By IDSE New Staff
The CDC issued a Health Alert Network update about an outbreak of mpox in the Democratic Republic of the Congo (DRC) that is spreading to neighboring countries.
Since January 2023, the DRC has reported the largest number of yearly suspected clade I mpox cases on record. Although clade I MPXV is endemic in the DRC, the current outbreak has resulted in clade I mpox transmission to some neighboring countries. The Republic of the Congo (ROC), which borders DRC to the west, declared a clade I mpox outbreak in April 2024, and there have been confirmed cases in the Central African Republic (CAR). In late July 2024, Burundi, Rwanda and Uganda, which sit on the eastern border of DRC, reported confirmed cases of mpox, with some cases having linkages to DRC. Mpox is not known to be endemic in these countries.
No cases of clade I mpox have been reported outside Central and East Africa, according to the CDC. Due to the limited number of travelers and lack of direct commercial flights from the region to the United States, the risk for clade I mpox importation to the United States from this outbreak is low. However, the CDC recommends clinicians maintain a heightened index of suspicion for mpox in patients who have traveled from this region and present with a rash that may be found on the hands, feet, chest, face, mouth or near the genitals; fever; chills; swollen lymph nodes; fatigue; myalgia; headache; and respiratory symptoms such as sore throat, nasal congestion and cough.
MPXV has two distinct genetic clades (subtypes of MPXV), I and II, which are endemic to Central and West Africa, respectively. Clade I MPXV has been observed to be more transmissible and cause a higher proportion of severe infections than clade II MPXV. The ongoing global mpox outbreak that began in 2022 is caused by clade II MPXV, and cases continue to be reported worldwide.
More than 22,000 suspected cases, with more than 1,200 suspected deaths, have been reported in DRC since Jan. 1, 2023—a substantial increase from the median 3,767 cases seen during 2016 to 2021. Clade I mpox cases have been reported from every DRC province. Outbreaks of clade I MPXV associated with sexual contact among men who have sex with men and female sex workers and their contacts have been reported in some provinces. In other provinces, patients have acquired infection through contact with infected dead or live wild animals, household transmission, or patient care; a high proportion of cases have been reported in children younger than 15 years of age. Mpox vaccine, which is expected to be effective against both clades, is not available in DRC. However, the country is actively working on a plan to vaccinate people.
The United States has robust mpox testing capacity, including clade-specific testing, sequencing and/or flagging high-likelihood clade I MPXV samples. The CDC also is helping communities monitor the presence of both clades of MPXV in wastewater samples, including from selected airports. Data from samples can provide an early warning of mpox activity and spread in communities.
Clinicians should follow CDC guidance on infection prevention and control for mpox to minimize transmission risk when evaluating and providing care to patients with suspected mpox.
- Consider mpox as a possible diagnosis in patients who have been to DRC or, due to the demonstrated risks of regional spread, any of its neighboring countries (ROC, CAR, Rwanda, Burundi, Uganda, Zambia, Angola, Tanzania and South Sudan) in the previous 21 days.
- Ask patients with signs and symptoms of mpox but no recent travel whether they have had contact with people who had recently been in any of the above countries and who were symptomatic for mpox.
- Consider mpox as a possible diagnosis if a clinically consistent presentation occurs, even in people vaccinated for or previously diagnosed with mpox.
- Advise all patients suspected of having mpox to isolate themselves from others.
- Evaluate all suspected cases related to DRC and its neighboring countries with laboratory testing, rather than just using a clinical diagnosis. In most situations, specimens should be sent to the appropriate state public health laboratory or a commercial laboratory for initial testing. Avoid unroofing or aspiration of lesions or otherwise using sharp instruments for mpox testing to minimize the risk for a sharps injury.
- Recommend mpox vaccine to people 18 years of age and older exposed to MPXV to help prevent the spread of mpox. Two doses of Jynneos (smallpox and monkeypox vaccine, live, non-replicating, Bavarian Nordic) vaccine offer substantial protection against mpox. Boosters are not currently recommended.
- Consider vaccinating patients with two doses of Jynneos vaccine who are eligible for mpox vaccination and planning travel to affected countries. Eligible patients who received one dose of the Jynneos vaccine more than 28 days ago should receive the second dose as soon as possible.
Medical countermeasures (e.g., brincidofovir, tecovirimat [Tpoxx, SIGA Technologies] and IV vaccinia immune globulin) used during the ongoing clade II mpox outbreak are expected to be effective for clade I MPXV infections.
Inform all patients with mpox, including those with mild disease, about the STOMP trial and recommend that they enroll. Oral tecovirimat is available through the STOMP trial. To enroll in STOMP, call (855) 876-9997.
All cases should be reported to your local health department or the CDC.
