Emerging & Re-Emerging Viruses
by Prof. Hervé Fleury, MD-PhD | Ventum Biotech Scientific Board Member
These viruses are very numerous and come largely from animal reservoirs; will be mentioned here filoviruses (Marburg, Ebola), hantaviruses (Hantaan, SNV), prions, retroviruses (HTLV-I, HIV), influenza viruses (in humans and birds), arenaviruses, hénipavirus (Hendra, Nipah), coronaviruses (including SARS CoV, MERS CoV, SARS CoV 2), enteroviruses, measles virus, rabies virus, Mpox, hepatitis E virus and of course arboviruses carried by mosquitoes, ticks or sandflies. Only some examples will be discussed in more detail such as SNV, Nipah, Kyasanur Forest Disease and West Nile.
Among the viruses of the animal reservoir some may reach a pandemic power as was the case of HIV, SARS CoV 2 and influenza H1N12009; in the short term an influenza pandemic (based on the H5N1 avian or recombinant virus) could arise while localized outbreaks of arboviruses will multiply in Europe.
The need for the construction of specialized laboratories at the P4 level (BSL-4) is becoming important to handle hazardous specimens and isolate associated viruses; India, for example, is building a new BSL-4. These work units require suitable premises (filtered air), hoods, protective equipment for manipulators (diving suits) as well as procedures for decontamination of premises, work surfaces and exit airlocks (showers of protective clothing). However, there have been contamination accidents in these BSL-4 including SARS CoV, the smallpox virus and potentially SARS CoV 2. Indeed, some experiments have been or are being conducted in these units which use what is called the "Gain Of Function" (GOF) and which aim to adapt animal viruses to human cells; thus a few years ago a controversy broke out around the H5N1 virus; similarly, it may have been around a GOF experiment concerning a bat coronavirus that the SARS CoV 2 strain was generated. In any case, international regulatory needs should prevail for the management of these BSL-4.
It is also necessary to take into consideration the needs of decontamination of the premises for the future, especially with regard to the places of medical practice; thus, a patient infected with Ebola or MERS CoV will represent a significant potential source of contamination of premises and equipment (including automated laboratory chains) as well as medical personnel. One example is the first SARS-CoV patient in Hong Kong in 2003 who was hospitalized at the French Hospital in Hanoi where he infected 35 health care workers. We can also recall the role of surfaces contaminated with SARS CoV 2 for viral transmission and not forget the example of Mpox which can keep its infectious power on supports such as mattresses and towels. Also, to take into account the spread of viruses by air conditioning systems in residences and even in hospitals as we can provide references.
In conclusion, pandemics have an unavoidable future, and the hygiene response will have to be equal to the threats that will be present, particularly in hospital areas, laboratories and land or air transport vehicles.
