When PAHO met EVA

Looking into the work of Lionel Gresh, PhD, consultant at the Pan American Health Organisation (PAHO).


Lionel Gresh, PhD is an old friend of EVA, with a long lasting collaboration for sourcing reference material at times of outbreak. A microbiologist by training, Lionel is now an international consultant for the Pan American Health Organisation (PAHO), the specialized health agency of the inter-american region and regional branch of the World Health Organisation (WHO) in the Americas. PAHO’s mission is to promote health equality and improve the quality and length of life of people in the Americas. 35 member states contribute to PAHO through a membership fee, while resource mobilisation for specific projects also happens through private foundations and global health partners.

Lionel did his doctoral thesis in Institut Pasteur, Paris, working on mouse models of human disease with a focus on infectious disease, such as HIV, Influenza and Tuberculosis. After completing his PhD, he worked in several countries (Austria, South Africa, Nicaragua) on the management of infectious disease (HIV, TB, Dengue among other arboviruses, Influenza and other respiratory viruses). In 2015, Lionel starts collaborating with PAHO/WHO for offering specific support to national laboratories during the Chikungunya and Zika virus outbreaks in the Americas. His work as consultant is focused on the implementation of diagnostic tests, training personnel and utilising capacity for surveillance in countries in need. In 2017 he joins the PAHO infectious hazard management unit (part of PAHO health emergencies department) and is responsible for the laboratory response team dedicated to pandemic preparedness and response. Based in the PAHO headquarters in Washington DC, he is responsible for issuing guidelines and recommendations to labs, providing technical support and assistance for the implementation of diagnostic testing, through targeted missions, as well as coordinating the provision of appropriate reagents where needed.

 ‘It is especially important to support countries in the implementation of the diagnostic techniques in their own surveillance system, as a long-term preparedness action, as well as in issuing their own guidelines that fit the reality of the country, in terms of lab capacity and epidemiological context’ Lionel highlights.


PAHO in action with the support of EVA

An example of such a country is Brazil, hit by Yellow Fever Virus in 2016. In the following years up to 2018, cases and deaths peaked, creating a public health emergency requiring localised support. The need to rapidly expand the capacity of national labs in Brazil for performing RT-PCR for rapid and high-specificity detection of yellow fever virus, as well as that of endemic and non-endemic countries, in which imported cases were observed, became imperative. In response to this outbreak, PAHO contributed by updating laboratory algorithms, while conducting training workshops in state and national laboratories and procuring and distributing diagnostic reagents for RT-PCR. The role EVA played in this rapid response was critical, as the EVA RKI partner, made possible access to yellow fever virus positive controls that were distributed to 40 laboratories across 26 countries.

During the SARS-CoV-2 outbreak, the timeline of the PAHO actions was more than swift, and involved publishing laboratory guidance, conducting trainings and distributing reagents for RT-PCR. After the announcement of the virus sequence on the 10th of Janunary 2020, the first protocol of action was published by WHO by the 14th of January 2020 and orders for reagents were placed just three days later. On the 20th of January reference material is requested from the EVA CUB partner. On the 30th of January the first training took place. Laboratory personnel from different countries was grouped in one lab to receive technical training and, within less than a month, 28 countries in the Latin America and Caribbean area received support,nine in-country missions were implemented and two hands-on workshops were organised in Brazil and Mexico for training members from 18 countries.To add to the difficulty of this feat, certain island countries in the Caribbean had to be trained remotely and the infrastructure set up from scratch!An informal help-desk started operating, in order to provide further support especially to countries in which RT-PCR infrastructure was set up for the first time.In this effort by PAHO/WHO, the EVA CUB partner was instrumental: CUB readily provided batches of controls for RT-PCR, offered through free of charge access, and shipped, within 9 days from ordering, to 36 countries and the Caribbean Public Health Agency.

Managing logistics in pandemic times is tricky. Aside from restrictions in personnel and transport, due to situations such as a confinement, material that is classed as ‘dual-use’ poses additional problems as export regulations related to biosecurity vary between countries. The MPOX outbreak in 2022 was the most recent example of such a challenge.


A continuous effort for surveillance and capacity building.


Lionel’s team has been working in ‘emergency-mode’ in the region of the Americas over a very long period of time: starting with the Chikungunya virus outbreak at the end of 2013, and followed by Zika virus in 2015, the worst outbreak of Yellow Fever Virus in Brazil in 2016, and then Covid-19 and MPOX. These outstanding circumstances have proved to be valuable lessons on pandemic response.


The rewarding aspect of the work counterbalances the adverse conditions.

‘It is satisfying to see how the capacity built perseveres through time and is, then, used for surveillance of other diseases. It is what is happening with the diagnostic capacity built during the Covid-19 pandemic’ says Lionel. ‘Working directly with the country teams, helps us learn from them on the different strategies that may work better in a certain country’, he adds.

Outside of a crisis, setting up surveillance systems based in national labs is key for ensuring pandemic preparedness. This translates to having qualified personnel for performing specialised diagnostic tests, trained in quality management systems, biosafety and biosecurity, as well as shipping protocols for different categories of agents. It also means having strong information systems in place, ready to provide data and alert the relevant authorities in case of an outbreak. At the technical level, and in parallel with serological platforms, continuing to implement molecular biology platforms for diagnostics, and especially RT-PCR, an integration breakthrough that started with the H1N1 pandemic, is key for supporting countries. A next step forward will be establishing genomic surveillance systems for whole genome sequencing, in order to detect known or new pathogens, with pandemic or epidemic potential, in wastewater or any clinical sample. This will go hand in hand with setting up a supportnetwork between countries that do not have the infrastructure for whole genome sequencing and reference labs who can perform such sequencing for genomic surveillance.Altogether, the fluent coordination between authorities at the global (WHO headquarters in Geneva), regional (PAHO has its headquarters in Washington DC and 27 offices across countries) and country-specific level, is what will continue to build optimised preparedness and response to crisis.


Text by Semeli Platsaki, PhD