The recent announcement of a new Filipino mpox case last Aug. 19, 2024 so close to the declaration of a new PHEIC (public health emergency of international concern) by the World Health Organization triggered fears of another round of lockdowns and pandemic precautions. Health officials reassured the public that no lockdowns or other draconian measures are imminent, but it is best to be vigilant in the face of a new outbreak of a disease. With dengue and leptospirosis epidemics also looming, it is important to manage our limited resources while doing our best to prepare for the possibility of yet another local public health emergency.
Part of the difficulty in communicating the risk of mpox is that there are actually two separate clades circulating globally which behave quite differently. Clades are similar to the Covid-19 variants which, while all belong to the same species of virus, possess distinct characteristics and transmission patterns. As explained in last week’s column (https://mb.com.ph/2024/8/19/as-first-case-arrives-in-ph-should-you-be-worried-about-mpox), historically clade I has been deadlier than clade II and these clades are endemic to specific regions in the African continent. As an analogy, we can think of clade I as similar to Delta, while clade II is more like Omicron. However, mpox is nowhere near as dangerous as COVID-19 since it is not as contagious and it is easier to diagnose due to the distinctive pustular lesions.
Clade IIb (a strain under clade II), drove the 2022 PHEIC and is predominantly sexually transmitted especially in men who have sex with men (MSM). The majority of cases have been in adult men. It can still be transmitted by close contact, especially if someone touches active skin lesions. The reason for the declaration of the PHEIC in 2022 was because of how rapidly it spread among the MSM community in different countries, necessitating a quick public health response involving quick diagnosis, quarantine, isolation, and selective vaccination.
Clade I is the strain driving the current 2024 PHEIC. Clade I has been detected among children and has been particularly deadly in this population. Half of the current cases in the Democratic Republic of Congo (DRC) and the majority of the deaths have been among very young children less than 5 years old. A new lineage, clade Ib, has been confirmed to be sexually transmitted initially among heterosexuals but also seems to be spreading in the MSM community. This observation suggests that while clade Ib may spread similarly to clade IIb, some clade I viruses that end up being imported could threaten children through other routes, specifically direct contact and fomite (objects contaminated with infectious material) transmission.
The case that was detected last Aug. 19, 2024 has been confirmed to be clade II. Contact tracing revealed that this was most likely sexually transmitted and the index case did have several sexual partners at different establishments. Close contacts have been quarantined and the patient is currently completing isolation. Since he did not have any history of travel outside the country, it is likely that clade II has continued to circulate in the community in the Philippines under the radar. The current PHEIC led to the intensified testing that resulted in the detection of this case. It is highly likely that more clade II cases will be detected soon, but it is unlikely these will cause significant mortality among the population. As such, it is not a pandemic threat, which is why the 2022 PHEIC ended in May 2023 even though mpox clade IIb continued to circulate. Nevertheless, it is impossible to differentiate clade II from clade I without genomic testing, so each mpox case needs to be properly handled until clade I is ruled out.
As I write this, another mpox case has been detected in Thailand and this time with a history of travel to Africa. It was quickly confirmed to be clade Ib and is the first clade I case in Southeast Asia. Clade I is a threat not just to those who are sexually active but also to children and elderly adults. While it is unlikely that borders will be shut down, it is important to do intensified surveillance especially for those travelers coming from countries with confirmed clade I cases. Persons who have traveled from these countries need to monitor themselves for any signs of illness for up to four weeks and they should report any new skin rashes to their doctors.
The general public can protect themselves from mpox by exercising meticulous hand hygiene. Cover up any wounds or exposed skin especially if you anticipate being in crowded places where inadvertent skin to skin contact is possible. While direct contact with mpox lesions is the most likely to cause infection, indirect contact through contaminated surfaces with viable virus is a significant route of spread. Always wash your hands or sanitize with alcohol rub upon coming home, before eating, and when your hands are visibly soiled. Avoid touching your face, mouth, eyes or nose with unwashed or unsanitized hands. Practice safe sex and watch out for any new lesions especially in the genital area. While there is some evidence of respiratory droplet transmission for mpox, it is not thought to be a major route of infection and so masking is not mandatory. However, masks do provide protection against other viruses and so elderly and immunocompromised persons are encouraged to use them especially in enclosed areas.
If you develop a rash on your skin, isolate and contact your doctor to check if it is mpox. The Department of Health is increasing access to testing, and specialists like dermatologists and infectious diseases physicians are being tapped to help diagnose mpox cases quickly. It is of utmost importance to follow the advice of experts to minimize the risk of mpox spreading in our community. Please adhere to all instructions in the event you are diagnosed with mpox or you are exposed to a known case. If you are asked to isolate or quarantine at home, do so without breaking protocol. This will help shorten the outbreak and ensure that the PHEIC will end sooner rather than later.