Challenges

Of Brazil’s 5,570 municipalities, 588 are located in border areas. One of the characteristics of the population living in these border areas is an intense daily movement of people across the border from their home to workplaces, schools, healthcare services and leisure activities, known as “pendulum migration.” This movement impacts the occurrence of diseases, as well as the functioning of health systems on both sides of the border.

Thus, pendulum migration must be explored when planning health services and actions due to its influence on health technology needs, on adherence to treatments and therefore on the prognosis of patients. Healthcare-oriented pendulum migration is common worldwide. In Brazil, the offer of universal free-ofcharge health services through the Sistema Único de Saúde (SUS) may increase cross-border patient mobility, especially regarding foreigners residing in twin cities located in border areas.

In Brazil, health planning is based on the principle of territoriality. Thus, foreign populations are not accounted for during planning and for financial transfers to health systems. As a result, healthcare-oriented pendulum migration affects the management and organization of health services both in Brazil and in the border countries. In particular, such migration poses challenges for the surveillance and control of diseases, programming vaccination activities, calculating population coverage estimates and patient treatment monitoring. In this context, the border areas are considered to have great vulnerability.

Toward a Solution

At the end of 2019, the Brazilian Ministry of Health’s Secretariat for Health Surveillance (SVS-MS), along with the Oswaldo Cruz Foundation (Fiocruz), with support from the Pan American Health Organization/World Health Organization (PAHO/WHO), launched the postgraduate Educational Programme on Health Surveillance at Borders (VigiFronteiras). The first edition of the programme provided courses (M.Sc. and Ph.D. training) for 75 public health workers from Brazil and neighbouring countries, free of cost.

The expected results are to strengthen health surveillance actions and services in border regions of Brazil and in neighbouring South American countries, to improve and qualify health surveillance activities in the regions along the land border, to train professionals in health systems in regions along the border of Brazil and to collaborate in developing collaborative networks to act collaboratively in response to common health problems and public health emergencies of national and international concern. Already positive results have been seen during the COVID-19 pandemic.

Since the beginning of the COVID-19 pandemic, laboratory diagnosis and knowledge of the circulation of the SARS-CoV-2 virus have been fundamental for the development of surveillance and control activities as well as the organization of the care service network. The SARS-CoV-2 has been changing over time, and some mutations or combinations

may provide the virus with a selective advantage, which contributes to increased transmissibility or the ability to evade the host’s immune response. The successful interruption of the chain of transmission of the virus, supported primarily by vaccination efforts and early detection of cases, also depends on the ability to timely detect new mutations of the virus and a potential emergence of variants of concern (VOC) and interest (VOI). The more viruses circulate, the more they may change, increasing the probability of a new VOI or VOC arising. Thus, laboratories worldwide have been tracking genomic changes in the virus at a speed and scale never seen before.

The COVID-19 Regional Genomic Surveillance Network, established in 2020 and Brazilian health authorities throughout the Fiocruz-Amazonas, with PAHO/WHO support, developed a new genome sequencing protocol and a RT-qPCR probe for rapid detection of variants such as Gamma, Alpha, Beta and Lambda of the SARS-CoV-2, allowing a massive monitoring of VOCs. The protocol was validated using more than 100,000 samples from the states of Alagoas, Minas Gerais, Pernambuco, Paraná, Rio de Janeiro, Rio Grande do Sul and Santa Catarina.

As of August 2021, around 800,000 full SARS-CoV-2 genomes were sequenced worldwide – 0.6 percent of the COVID-19 confirmed cases. In Brazil, only around 0.04 percent of COVID-19 cases were submitted to genomic sequencing. Yet, the country accounted for 59.6 percent of genomic sequencing copies in South America.

Considering the challenges imposed by the rapid spread and high prevalence of VOCs, the use of this protocol allowed greater agility in the identification of the circulation of these variants, with an increase in the number of samples sent for identification and sequencing, in addition to the simplification of work processes in laboratories. With the support of PAHO/WHO, Brazil transferred this technology and knowledge to other South American and Caribbean countries with more than 30 public health laboratories training in this new technology in a short period of time (Antigua and Barbuda, Argentina, Bahamas, Barbados, Belize, Bermuda, Bolivia CENETROP, Bolivia INLASA, Cayman Islands, Colombia,

Costa Rica, Cuba, Dominica, Ecuador, El Salvador, Grenada, Guatemala, Guyana, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Paraguay, Dominican Republic, St. Kitts, St. Lucia, St. Vincent and Grenadines, Suriname, Uruguay and Venezuela). The Ministry of Health, Fiocruz and PAHO/WHO also facilitated the distribution of reagents to implement the test. Thanks to this effort the number of variants and copies identifying in South American countries increased three times (from 14,222 to 42,414) between 1 February 2021 and 31 August 2021.