The palms of a monkeypox patient from Lodja, a city located within the Katako-Kombe Health Zone, are seen during a health investigation in the Democratic Republic of Congo in this 1997 picture. — Centers for Disease Control and Prevention/Reuters
Monkeypox was first brought to the attention of Malaysians in 2019 following the report of a case in Singapore.
In an average year, a few thousand cases occur in western and central Africa.
Cases outside Africa have been limited to a handful associated with travel to Africa or with the importation of infected animals.
In the past five years, there have been only eight confirmed cases in which travellers carried monkeypox to countries outside Africa, including two cases in 2021 in the United States.
Each of the cases in the US was associated with a person who was in Nigeria, which had seen a resurgence of monkeypox since 2017.
Human-to-human spread was limited in those cases, with two family members infected in one instance.
One health care staff who had contact with contaminated bedsheets was infected in another case.
However, the number of cases reported outside Africa in the past week alone, which is certain to increase, has already exceeded the number detected outside the continent since 1970.
This rapid spread in non-endemic Europe and North America has raised concerns and puzzles.
A DNA virus
In the early stages of monkeypox, swollen lymph nodes can be a feature to distinguish the disease from chickenpox or smallpox. — FilepicMonkeypox was first detected in laboratory monkeys in 1958 but was only first reported in humans in the Democratic Republic of Congo in 1970.
Monkeypox, cowpox and smallpox are part of the DNA virus family, Orthopoxvirus genus.
It is typically spread through close contact between an animal and a human, often through a bite, scratch, or contact with the rash.
It can also be spread via material contaminated with material from the monkeypox lesions, e.g. clothes and bedding.
Human-to human transmission has historically been less common.
When it occurs, it is believed to be due to direct contact with bodily fluids, e.g saliva, lesion material or respiratory droplets.
Compared with smallpox, which is fatal in about 30% of cases, monkeypox has a relatively low case fatality rate.
Those infected with the more virulent Central African clade, which is more easily spread by human-to-human transmission, have a case fatality rate of about 11%.
Those infected with the milder West African clade have a case fatality rate of less than 4%.
A clade is a group of organisms and all of their descendants, e.g. the shared ancestor of apes and all of that species’ descendant species would comprise a “clade”
Altered presentation
The typical early symptoms of monkeypox develop one to two weeks after a person is infected and can include fever, intense headache, back pain, muscle ache, chills, swollen lymph nodes and lack of energy.
A rash develops within one to three days of fever.
The rash is concentrated on the face (95%) and the palms and soles (75%).
The mouth (70%), genitalia (30%) and conjunctiva (20%) can also be affected.
The rash then progresses from papules and blisters to scabs, each lasting one to two days.
After the scabs fall off to reveal healthy tissue underneath, which usually lasts two to four weeks after symptom onset, the infected person is no longer infectious.
The complications of monkeypox include secondary infections, pneumonia, sepsis, encephalitis, and corneal infection with ensuing loss of vision.
Monkeypox has to be distinguished from other rash illnesses like chickenpox, measles, bacterial skin infections, scabies, syphilis and medication-associated allergies.
Swollen lymph nodes during the early stage of illness can be a feature to distinguish monkeypox from chickenpox or smallpox.
However, it has been reported that monkeypox is presenting differently among the current cases.
The early symptoms were very mild or not even noticeable at all.
In the typical case, the rash often starts in the head and progresses to the arms, legs, palms and soles.
There have been reports, in the current cases, that the rash starts in the genital and anal regions before spreading to the extremities.
Some even have proctitis, which is inflammation of the rectum.
Treatment modality
The treatment of monkeypox involves providing symptom relief, managing complications and preventing long-term sequelae.
Fluids and food will be needed to ensure adequate nutrition.
Secondary bacterial infections will be treated accordingly.
The antiviral, Tecovirimat, which was developed for smallpox, was licensed for monkeypox in 2022 but is not yet widely available.
Smallpox vaccination is about 85% effective in preventing monkeypox.
However, the first-generation smallpox vaccines are no longer available to the public.
Some laboratory staff or healthcare staff may have received a more recent smallpox vaccine to protect them in the event of exposure to Orthopoxviruses at work as there is cross protection provided by the vaccinia virus.
The newer Ankara strain vaccine based on a modified attenuated vaccinia virus was approved for monkeypox prevention in 2019.
However, there is limited availability of this two-dose vaccine.
The current thinking is that the outbreaks probably would not require containment strategies beyond ring vaccination, i.e. vaccinate close contacts of those infected with monkeypox to cut off any routes of transmission
According to the World Health Organization, monkeypox poses a moderate risk to global public health. — Reuters
Concerns and puzzles
That monkeypox has been diagnosed in people with no apparent connection to one another or who have no travel history suggests that the infection has been spreading silently, a fact that is of concern.
Monkeypox does not typically go unnoticed because of the skin lesions it causes.
However, if it spreads asymptomatically, it would make it more difficult to detect.
Many of the reported monkeypox cases in non-endemic countries include men between the ages of 20 and 50, many of whom are gay, bisexual and have sex with men (GBMSM).
Although monkeypox is not known to be sexually transmitted, sexual activity certainly involves close contact.
The most likely explanation is that the virus was introduced into the GBMSM community and has continued circulating in the community.
There will be more knowledge about the origins and risk factors of the current outbreaks in non-endemic countries when epidemiological investigations are completed.
This involves laborious contact tracing that can take weeks or months.
Whether the current outbreaks differ from that in Africa and whether the viruses in the various countries are linked to one another remains unknown.
In summary, whilst there is concern, there should be no panic.
Because monkeypox is related to smallpox, there are already treatments and vaccines available, albeit in limited supply, to curb its spread.
Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth @thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
