As per a recent safety communication published on 15 July 2022, the FDA has advised people to utilize swab samples collected directly from lesion (growth or rash) while testing for monkeypox virus, a type of orthopoxvirus. The FDA is unaware of any clinical evidence in the favor of using other sample types, like blood or saliva, to test for monkeypox virus. False test findings could come from using alternate sample types that were not collected from a lesion.

 

FDA SAFETY SUGGESTIONS:

The FDA has disseminated this information to aid in educating test users, caregivers, medical professionals, test developers, laboratory staff, and the general public as well as to lessen the possibility of erroneous test findings that could contribute to an increase in the monkeypox virus's spread.

 

(a) For Caregivers and Test users:

• Be informed about all the information about monkeypox as per Center for Disease Control and Prevention (CDC).
• Primary care provider must be consulted if a person had interaction with anyone who had monkeypox or if the person is experiencing signs of the disease.
• Healthcare provider must be consulted if the monkeypox virus was detected using a sample other than the lesion swab.

(b) For Health care personnel:

• Recognize CDC's guidelines for healthcare workers, which encompass clinician frequently asked questions (FAQs) and instructions on how to prepare /gather samples for monkeypox virus testing.
• Consider retesting the patient using direct lesion swab sample if there is an erroneous result from the monkeypox virus test conducted using a substitute sample type.

(c) For Laboratory personnel and test developers:

• Be informed of the CDC's Guidelines for Laboratory Personnel, which provides guidance for doctors and information on protocols, testing, preparation and collection of specimens.
• For discussing novel test development and substitute testing strategies, and for sharing validation data from saliva, blood, or any other sample types, FDA may be contacted.

(d) Any kind of issues, including possible false positives, experienced with monkeypox virus tests must be reported to FDA.

 

Monkeypox Test Description

Tests for the monkeypox virus are used to identify if an individual is infected with the monkeypox virus. The CDC's non-variola orthopoxvirus test, which has FDA clearance, may identify monkeypox from a sample of a lesion. To increase monkeypox testing capacity and accessibility, this test is carried out in numerous laboratories that fall under CDC's public health Laboratory Response Network (LRN) along with additional large reference labs.

The FDA hasn't approved any laboratory developed tests (LDTs) that are available for the orthopoxvirus or especially the monkeypox virus. A single Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory that satisfies the criteria for carrying out tests of high complexity may design, produce, and use LDTs. Unless specifically required, the FDA normally does not use its authority to implement the legal requirements for these devices. This is known as the "enforcement discretion" approach. The FDA is still keeping an eye on the situation in terms of the best practices for monkeypox tests.

 

Potential Risk of False Monkeypox Test Results

False-negative test results for monkeypox indicate that the individual does not have monkeypox. However, they do have monkeypox.  Such kind of finding could result in a delayed diagnosis or ineffective care. False-negative outcomes can also result in the sick individual failing to take precautions to reduce their exposure to others. This, in turn, could enhance the monkeypox virus's ability to spread. False-positive test results for monkeypox indicate that the individual has monkeypox. However, they do not have monkeypox. Such kinds of results could prevent timely identification or treatment of the patient's actual illness, which might be a condition other than monkeypox.

The FDA has collaborated with the CDC, private laboratories, and producers to boost the accessibility of monkeypox diagnostics for individuals and healthcare professionals who require them. To escalate the production and distribution of the CDC non-variola orthopoxvirus test, which has FDA clearance, the FDA and the CDC are collaborating closely.

In order to expand the testing capacity of labs utilizing the CDC test, the FDA has also authenticated the usage of additional chemicals and automation. The FDA has been exercising enforcement discretion as usual with regard to LDTs for monkeypox. Regarding the non-variola orthopoxvirus test, the FDA and CDC are collaborating to speed up distribution and magnify testing capacity.