Mpox case confirmed in India is a travel-related infection and it is not part of the current public health emergency (reported by WHO) involving clade 1 of the virus. So how is the clade 2 different and should Indians be worried?
Published Sep 09, 2024 | 8:23 PM ⚊ Updated Sep 09, 2024 | 8:23 PM
Representative image of the Mpox virus (Creative Commons)
The presence of the Mpox virus (West African clade 2) has been confirmed in an isolated patient, the Ministry of Health and Family Welfare (MoHFW) announced on Monday, 9 September.
In a statement, the MoHFW said the previously suspected case of Mpox (monkeypox) has now been confirmed and it was a travel-related infection. Laboratory tests confirmed the presence of the Mpox virus, specifically the West African clade 2, in the patient. This case is isolated, similar to the 30 cases reported in India since July 2022, and is not part of the current public health emergency (reported by WHO) involving clade 1 of the virus.
On 14 August, the World Health Organisation (WHO) declared the Mpox outbreak a Public Health Emergency of International Concern (PHEIC). This decision was based on the rising trend of Mpox cases in the Democratic Republic of Congo over the last six months, as well as the spread of cases to newer East African countries such as Burundi, Kenya, Rwanda, and Uganda.
Mpox virus Clade 1 is more infectious, causes more severe disease, and has a higher fatality rate compared to the milder Clade 2 virus. Additionally, the two clades differ in their geographic distribution and transmission dynamics.
“The individual, a young man who recently travelled from a country experiencing ongoing Mpox transmission, is currently isolated at a designated tertiary care facility. The patient remains clinically stable without systemic illness or comorbidities,” the MoHFW stated on Monday.
Media reports say that the patient is in the isolation ward of the Safdarjung Hospital in New Delhi.
The Ministry said that the case aligns with earlier risk assessments and is being managed according to established protocols. Public health measures, including contact tracing and monitoring, are actively in place to contain the situation. At this time, there is no indication of any widespread public health risk.
Experts who assessed the risk of infection spreading in India after the alert by WHO stated that India faces the possibility of a few cases being from people who had travelled to countries where the infection is reported. The risk of a large outbreak with sustained transmission within the country, however, was low.
The main differences between Mpox virus Clade 1 and Clade 2:
Virulence and severity:
Clade 1, formerly known as the Congo Basin clade, is more virulent and causes more severe illness. It has higher fatality rates, ranging from 1-10 percent in some outbreaks. Infections with Clade 1 are associated with more intense skin rashes, larger lesions, pronounced lymphadenopathy (inflammation of the lymph nodes), and higher rates of complications such as encephalitis, pneumonia, and secondary bacterial infections.
In contrast, Clade 2, previously known as the West African clade, causes milder symptoms with fewer complications. The fatality rate for Clade 2 is less than 1 percent.
Geographic Distribution:
Clade 1 is historically found in Central Africa, particularly in the Democratic Republic of Congo while Clade 2 is primarily found in West Africa, especially in Nigeria and surrounding regions.
Transmission:
Clade 1 has a higher rate of person-to-person transmission, particularly through respiratory droplets and close contact. Clade 2 on the other hand, is less infectious compared to Clade 1, with a lower rate of human-to-human transmission.
Animal models:
Studies using wild-derived inbred castaneous (chestnut-coloured) mice show that Clade 1 MPXV is the most virulent, followed by Clade IIa and Clade IIb.1, in decreasing order. The Clade IIb.1 strain, which caused the global outbreak in 2022-2023, exhibited greatly reduced replication in mice and showed no lethality even at 100 times the dose of a closely related Clade IIa virus.
On Monday, the Ministry of Health and Family Welfare (MoHFW) advised states and Union Territories to screen and test all suspected Mpox cases in the community and to identify isolation facilities in hospitals for both suspected and confirmed patients.
In a letter to states and Union Territories, Union Health Secretary Apurva Chandra urged them to prevent undue panic among the public. “No new case of Mpox (except the one) has been reported in India during the current outbreak, and none of the samples from suspected cases have tested positive,” he stated, while emphasising the need to remain vigilant.
Chandra asked states and Union Territories to review public health preparedness, particularly at the health facility level, to identify isolation facilities in hospitals, and to ensure the availability of necessary logistics and trained personnel at these facilities.
He also called for the orientation of key stakeholders, particularly surveillance units under the Integrated Disease Surveillance Programme (IDSP) at both state and district levels, to re-familiarise them with the definitions of suspected, probable, and confirmed cases, as well as contact tracing and other surveillance activities.
The letter also urged states to increase public awareness about Mpox, including its modes of transmission, the importance of timely reporting, and preventive measures, while reviewing public health preparedness and isolation facilities for suspected and confirmed cases.
In its latest situational update, WHO highlighted that the clinical characteristics of cases have largely remained consistent. Most cases involve young males, with a median age of 34 years (ranging from 18 to 44). Globally, the most commonly reported mode of transmission is sexual contact, followed by non-sexual person-to-person contact. In people who test positive for Mpox, most common symptom is rash followed by fever.
Additionally, Chandra noted that about half of the cases with available HIV status information involve individuals living with HIV. The IDSP disease surveillance network continues to monitor for any clusters of cases.
Health units at points of entry (airports) have been instructed to enhance screening of incoming travelers to detect any suspected cases. The laboratory network under the Indian Council of Medical Research (ICMR) has also been strengthened.
“Considering the disease’s epidemiology, State AIDS Control Societies have been instructed to remain on alert, detect suspected cases, and raise community awareness to promote timely reporting,” the letter said.
Chandra also outlined key public health actions needed to prevent or minimise the risk of Mpox cases or deaths in the country. He stressed the importance of widely disseminating the Ministry’s guidelines for Mpox management, as well as the updated CD-Alert on the disease issued by the National Centre for Disease Control (NCDC).
(Edited by Rosamma Thomas)
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