Mpox is an illness caused by a virus from the Poxviridae family, which consists of double-stranded DNA viruses capable of infecting both humans and animals (1). A related virus, variola, responsible for smallpox, was successfully eradicated in the 1980s (2).

Historically, Mpox has been found in certain regions of West and Central Africa (3, 4). However, in May 2022, a sharp rise in cases outside these endemic areas prompted the World Health Organization to declare the outbreak a Global Public Health Emergency on 23 July 2022 (5). In Burundi, the Ministry declared an outbreak on 25 July 2024.

The classic clinical manifestations of Mpox often include fever, headache, myalgia, lymphadenopathy, and skin lesions that progress through papular, vesicular, and pustular stages before ulcerating and crusting. The typical pustules of Mpox are umbilicated on an erythematous base and can occur on the face, palms, soles, and genital areas. Severe cases may include complications such as secondary bacterial infections, severe ulcerations, and prolonged illness (1).

Diagnostic confirmation is primarily achieved through molecular DNA amplification techniques applied to samples collected from skin lesions using a cutaneous swab. Polymerase chain reaction (PCR) is commonly performed, followed by clade-specific testing (6). Histology can be performed, and its utility lies in supporting the diagnosis when molecular tests are not available or in cases of atypical presentations. The histological examination reveals hyperkeratosis, acanthosis, and ballooning degeneration of keratinocytes, often accompanied by viral cytopathic effects (7).

During the 2022 outbreak, individuals with HIV were disproportionately affected, accounting for 38–50% of Mpox diagnoses (8). The majority of people living with HIV reported in the 2022 global case series had HIV viral suppression, with median CD4 counts of more than 500 cells per mm (3). Their clinical presentations, time to Mpox viral clearance, and outcomes were similar to those of people without HIV (9, 10).

This report presents the first case of Mpox in Burundi during the 2024 outbreak, involving a 50-year-old HIV-positive woman, and highlights the need for early diagnosis and intervention in such cases.

This case highlights the atypical presentation of Mpox in an HIV-positive patient with advanced disease that led to a delay in diagnosis.

Although some reports during the early Mpox outbreak in 2022 described the self-limiting clinical course in individuals with well-controlled HIV as being very similar to that in individuals without HIV, a global case series published in 2023 provided evidence of a more severe presentation among people with HIV and low CD4 cell counts (CD4 < 350 cells per mm³) (8).

Data from Nigeria and the USA suggest poor clinical outcomes in people with more HIV-related immunosuppression. Two reports from Nigeria during the 2017–2018 outbreak suggested a higher mortality rate among untreated HIV patients, along with more confluent rashes, higher rates of secondary bacterial infections, and more prolonged illness, compared to people without HIV (4, 11). During the 2022 outbreak in the USA, the US Centers for Disease Control and Prevention (CDC) supported the findings from Nigeria, reporting 47 cases of severe Mpox among people with advanced, uncontrolled HIV infection. All 47 individuals were hospitalized, had prolonged disease courses, and developed complications, and five deaths were attributed to Mpox (12). More severe rectal diseases, such as rectal bleeding and purulent or bloody stools, have been observed in individuals with Mpox and HIV, particularly among those with unsuppressed viral loads or lower CD4 counts. In the CDC series, individuals with HIV and Mpox were more likely to experience rectal pain (34 vs. 26%), tenesmus (20 vs. 12%), rectal bleeding (19 vs. 12%), purulent or bloody stools (15 vs. 8%), and proctitis (13 vs. 7%) compared to those without HIV. Among those with unsuppressed HIV viral loads, rectal bleeding (25 vs. 18%) and purulent or bloody stools (22 vs. 14%) were even more prevalent (9). The patient in our case report was hospitalized for 2 months, while non-complicated patients with Mpox typically stay for a maximum of 2 weeks. In addition, during the course of her illness, our patient developed a fulminant form of Mpox with more disseminated pustular eruptions that coalesced into large bullae and ruptured, leaving necrotic ulcers. The complication of septicemia, attributed to the secondary bacterial infection of the skin lesions and immunosuppression observed in our case, was also reported in a report from a global series of Mpox in patients with advanced HIV (8). Severe genital ulcers, characterized by painful vulvar edema, bacterial superinfection, and pus discharge, are common findings in these types of cases. Despite the lack of evidence, it is also believed that the prolonged duration and greater number of skin lesions in individuals with HIV could be associated with a longer period of infectivity.

HIV coinfection can significantly worsen Mpox outcomes, leading to more severe clinical complications, prolonged illness, and an increased risk of secondary infections. Routine HIV screening should be implemented for all Mpox patients, and clinicians must be aware of the potential complications in coinfected individuals. Similarly, Mpox should be ruled out in HIV patients with suspicious skin lesions to ensure timely diagnosis and management.