Can Monkeypox patients remain asymptomatic like COVID, ICMR plans sero-survey to assess

Monkeypox is a disease that causes fevers and skin lesions.

The Indian Council of Medical Research (ICMR) is set to initiate a time-bound serological (blood serum) survey on close contacts of monkeypox patients to assess the proportion of people who remain asymptomatic for the viral infection.

“We want to conduct a sero survey for monkeypox antibodies among close contacts of laboratory-confirmed cases of monkeypox in India. The reason behind this is (that) till today we don’t know what is the proportion of people who remain asymptomatic for this infection,” a top ICMR official told Moneycontrol.

Monkeypox is a rare viral infection similar to human smallpox, which was eradicated in 1980. Although monkeypox is much milder than smallpox, with most infected people recovering within a few weeks, it can in rare cases be fatal.

Symptoms of the viral disease too are similar to smallpox, including fever and rash. It is followed by intense headache, back pain, muscle aches, lack of energy and swollen lymph nodes.

India has so far reported 10 cases of monkeypox and one fatality from the infection.

“Those who have come in contact with currently monkeypox- infected patients are definitely exposed individuals and our sero-survey would look into assessing the antibodies in them,” the senior official cited above added.

The officials said the study will test the close contacts of the confirmed cases and look for the presence of monkeypox antibodies in them; people with mild infection may test negative for the infection after an RT-PCR test.

Also read: 31 companies express interest in developing Monkeypox vaccines, kits; Serum, Biological E in race

“The close contacts are also getting tested by RT-PCR for this infection and there are cases where they have tested negative. There is a threshold of a molecule-based test; below that threshold, the test won’t be able to detect (infection),” the official said.

Molecule based RT-PCR tests are conducted to specifically detect the monkeypox infection.

World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus on July 23 declared the current monkeypox outbreak a Public Health Emergency of International Concern (PHEIC), overriding the WHO Emergency Committee, which decided 6-9 against recommending the tag of a PHEIC.

Non-availability of commercial serological kits

There is one problem that could impede the plan to conduct serological tests on contacts of monkeypox patients: non-availability of antibody detection kits for the infection.

“The antibody detection assays are not available globally. Some countries have them but they are not available for commercial purpose,” said the senior official.

Also read: Government in talks to drug firms for making monkeypox vaccine: Covid task force head

Even the Centers for Disease Control and Prevention (CDC) in the United States doesn’t have the serological kits, the official said.

The National Institute of Virology, Pune, is working on developing the assays and manufacturing commercial kits.

“If we are able to develop a good test, then we may go for sero-survey in at-risk or high-risk population groups, but all depends on the success and availability of the test that we are still developing,” the official added.

 Testing labs doubled

The senior official said surveillance conditions for nonkeypox had improved with the help of the Integrated Disease Surveillance Programme (IDSP). Samples of  suspected monkey patients get assessed on a priority basis.

“We had 15 labs earlier for testing for the monkeypox virus, now the number has gone up to 20 labs and there are an additional 10 labs kept on standby. If there is a need, we can activate these 10 also. We have doubled the number of labs now,” the senior official added.

When asked about a rise in the number of samples coming for testing, the official linked it to increased surveillance and number of labs.

“The number of suspected cases has also gone up, but that doesn’t mean India is witnessing a rise in the number of monkeypox cases,” the official added.

 According to the official, the situation is not alarming.

“The situation is in fact under control. Whenever there is a public health emergency declaration, we augment the surveillance program, prepare labs,” the official added.

According to one source, ICMR scientists have also planned research programmes on monkeypox on which discussions are underway.