Introduction

On January 30^th 2020 the World Health Organization (WHO) declared COVID-19 to be a Public Health Emergency of International Concern – the Organization’s highest level of alert –, and, on March 11^th 2020, declared it to be a pandemic.¹1. Organização Pan-Americana da Saúde - PAHO. Folha informativa – COVID-19 (doença causada pelo novo coronavírus) [Internet]. Brasília: Organização Pan-Americana da Saúde; 2020 [citado 2020 jul 9]. Disponível em: https://www.paho.org/bra/index.php?option=com_content&view=article&id=6101:covid19&Itemid=875
https://www.paho.org/bra/index.php?optio...

Measures were adopted in Brazil before the country’s first case was confirmed. On January 22^nd the Ministry of Health brought into action its Emergency Operations Center, coordinated by the Ministry’s Health Surveillance Secretariat. At that initial moment, its actions sought to promote information and communication to the population, as well as training for health workers and expansion of coverage afforded by the Brazilian National Health System (SUS), especially with regard to tertiary care, increasing intensive therapy unit (ITU) beds, respirators, personal protective equipment, among other measures.²2. Oliveira WK, Duarte E, França GVA, Garcia LP. Como o Brasil pode deter a COVID-19. Epidemiol Serv Saúde [Internet]. 2020 abr [citado 2020 jul 9];29(2):e2020044. Disponível em: https://doi.org/10.5123/s1679-49742020000200023
https://doi.org/10.5123/s1679-4974202000... On March 20^th 2020 the Ministry of Health declared community transmission of COVID-19 and thus began adoption of non-pharmaceutical measures to reduce its transmission, such as isolation and social distancing, with the aim of avoiding gatherings of people.³3. Ministério da Saúde (BR). Ministério da Saúde declara transmissão comunitária nacional [Internet]. Brasília: Ministério da Saúde; 2020 [citado 2020 maio 2], Disponível em: https://www.saude.gov.br/noticias/agencia-saude/46568-ministerio-da-saude-declara-transmissao-comunitaria-nacional
https://www.saude.gov.br/noticias/agenci...

Several studies focus physical distancing as a strategy for controlling transmission of the novel coronavirus (SARS-CoV-2) that causes COVID-19, in view of its complex dynamics and its still unknown epidemiological characteristics. A study conducted in Taiwan showed that vertical isolation of symptomatic people and people belonging to risk groups is not such an effective measure for reducing SARS-CoV-2 transmission, and that the need exists for more generalized measures, i.e. for society as a whole, such as horizontal isolation, as a social distancing measure.⁴4. Cheng H, Jian S, Liu D, Ng TC, Huang WT, Lin HH, et al. Contact Tracing Assessment of COVID-19 Transmission dynamics in Taiwan and risk at different exposure periods before and after symptom onset. JAMA Intern Med [Internet]. 2020 May [cited 2020 Jul 9]:e202020. Available from: https://dx.doi.org/10.1001%2Fjamainternmed.2020.2020
https://dx.doi.org/10.1001%2Fjamainternm... With the lockdown in Wuhan Province, China adopted extreme social distancing measures. Other countries took similar measures: lockdown of entire cities or communities, restriction of international and domestic travel, border control with screening for symptoms (health barriers), quarantine, among other measures.⁴4. Cheng H, Jian S, Liu D, Ng TC, Huang WT, Lin HH, et al. Contact Tracing Assessment of COVID-19 Transmission dynamics in Taiwan and risk at different exposure periods before and after symptom onset. JAMA Intern Med [Internet]. 2020 May [cited 2020 Jul 9]:e202020. Available from: https://dx.doi.org/10.1001%2Fjamainternmed.2020.2020
https://dx.doi.org/10.1001%2Fjamainternm... In Scotland, household isolation was effective in avoiding admission to health services. With the reduction in infected people in health services, the transmission chain was broken.⁵5. Kate M, Katie S, Janet S, Christine E, Duncan M, Lorna W, et al. Coronavirus disease (COVID-19) Community Testing Team in Scotland: a 14-day review, 6 to 20 February 2020. Euro Surveill [Internet]. 2020 Mar [cited 2020 Jul 9];25(12):pii=2000217. Available from: https://doi.org/10.2807/1560-7917.ES.2020.25.12.2000217
https://doi.org/10.2807/1560-7917.ES.202...

According to WHO recommendations, in order for the pandemic to be considered under control, the indicator of the speed of its reproduction or transmission (Rt) needs to be below 1. The Brazilian states have not yet reached this level. Another concern is the spread of the disease to the interior regions of the country, these being places where hospital bed infrastructure is sparse, as the majority are concentrated in large urban conurbations.⁶6. Gomes CC, Cerutti Junior C, Zandonade E, Maciel ELN, Alencar FEC, Almada GL, et al. A population-based study of the prevalence of COVID-19 infection in Espírito Santo, Brazil: methodology and results of the first stage, 2020. MedRvix preprint [Internet]. 2020 [cited 2020 Jul 9]. Available from: https://doi.org/10.1101/2020.06.13.20130559
https://doi.org/10.1101/2020.06.13.20130...

This context makes it fundamental to rationalize resources and structure care flows which provide for case follow-up within the territories responsible for them and prioritize care and continuous follow-up. As such, this article proposes a flowchart to strategically assist the organization of the territory-based primary health care (PHC) service network, scaling up interventions by making the population’s everyday life the central point of care in relation to COVID-19.

Development of the flowchart

A proposal for assessment of contacts of people with tuberculosis (TB) was published in 2016.⁷7. Maciel ELN, Sales CMM. A vigilância epidemiológica da tuberculose no Brasil: como é possível avançar mais? Epidemiol Serv Saúde [internet]. 2016 jan-mar [citado 2020 jul 9];25(1):175-8. Disponível em: https://doi.org/10.5123/S1679-49742016000100018
https://doi.org/10.5123/S1679-4974201600... The proposal resulted in a territorial surveillance flowchart, the main objective of which was to break the TB transmission chain. Initially, an average distance of approximately 2,000 meters from the same spatial cluster was considered, i.e. an individual with TB and with a given genotype would be at a distance of approximately 2,000 meters from another individual with the same genotype.⁸8. Ribeiro FK, Pan W, Bertolde A, Vinhas SA, Peres RL, Riley L, et al. Genotypic and spatial analysis of Mycobacterium tuberculosis transmission in a high- incidence urban setting. Clin Infect Dis [Internet]. 2015 Sep [cited 2020 Jul 9];61(5):758-66. Available from: https://doi.org/10.1093/cid/civ365
https://doi.org/10.1093/cid/civ365... In other words, transmission is presumed between people with the same microorganism genetic material. As such, it was inferred that this would be the minimum distance for one person not to be able to transmit the disease to another.

Tuberculosis is a disease the transmission mechanisms of which have been described, for which treatment is accessible and a vaccine for preventing severe cases in children is available. This is not the case with regard to COVID-19.⁹9. Ministério da Saúde (BR). Secretaria de Vigilância em Saúde. Departamento de Vigilância das Doenças Transmissíveis. Manual de recomendações para o controle da tuberculose no Brasil [Internet] Brasília: Ministério da Saúde; 2019 [citado 2020 jul 9]. 364 p. Disponível em: https://bvsms.saude.gov.br/bvs/publicacoes/manual_recomendacoes_controle_tuberculose_brasil_2_ed.pdf
https://bvsms.saude.gov.br/bvs/publicaco... In addition, as we are in the midst of the coronavirus epidemic, the speed of its transmission is much faster than that of TB. Nevertheless, it is important to emphasize that even with all the information that exists about TB, community transmission of it still persists.

Although all the SARS-CoV-2 transmission mechanisms are not known and although there are points of disagreement about the role played by asymptomatic people, as the mechanisms of person-to-person transmission are extremely relevant for the propagation of both diseases, it can be postulated, based on surveillance, that case tracing by PHC, the organization of the community itself and isolation of symptomatic and oligosymptomatic people can play a crucial role in interrupting or reducing the SARS-CoV-2 transmission chain. As such, early identification, especially in vulnerable communities, can influence the speed of transmission.¹⁰10. Resende PC, Delatorre E, Gräf T, Mir D, Motta FC, Appolinario LR, et al. Genomic surveillance of SARS-CoV-2 reveals community transmission of a major lineage during the early pandemic phase in Brazil. bioRxiv [Internet]. 2020 Jun [cited 2020 Jul 9]. Available from: https://virological.org/t/genomic-surveillance-of-sars-cov-2-reveals-community-transmission-of-a-major-lineage-during-the-early-pandemic-phase-in-brazil/514/1
https://virological.org/t/genomic-survei...

It would therefore be possible to infer that the space in which SARS-CoV-2 is propagated would also be in spatially delimited social circles. Based on this assumption, the proposal mentioned above was adapted to COVID-19 case tracing in a wider territory, as demonstrated in flowcharts 1 and 2. The term territory as used here, as affirmed by Milton Santos,¹²12. Santos M. A natureza do espaço: técnica e tempo, razão e emoção. São Paulo: Hucitec; 1996. is defined as the interdependent locus of the form of production and socioeconomic formation where people’s social relations and networks occur and is not restricted just to geographic space.

The overriding objective of this form of territory-based surveillance would be to map individual-individual and individual-space social network interaction with COVID-19, considering certain social determinants of health (SDH). It also proposes the carrying out of active tracing of new cases of the disease so as to keep suspected cases in isolation and control the disease’s transmission chain. In the flowchart, 2,000 meters is considered as being the distance in which potential transmission can occur between two people in a household, at work or during leisure activities.

The COVID-19 territorial surveillance flowchart addresses the tracing of flu-like syndrome (FLS) cases, based on identification of an individual’s social relations and SDH. According to the Ministry of Health, FLS is defined as: “An individual with an acute respiratory clinical picture, characterized by febrile sensation or fever, even if reported, accompanied by coughing OR sore throat OR runny nose OR breathing difficulty.”¹³13. Ministério da Saúde (BR). Secretaria de Atenção Primária à Saúde. Protocolo de manejo clínico do coronavírus (COVID-19) na atenção primária à saúde: versão 7 [Internet]. Brasilia: Ministério da Saúde; 2020 [citado 2020 Jul 9]. Disponível em: https://www.cremeb.org.br/index.php/normas/protocolo-de-manejo-clinico-do-coronavirus-covid-19-na-atencao-primaria-a-saude-versao-7/
https://www.cremeb.org.br/index.php/norm...

Two flowchart proposals are presented, one for the pandemic period and the other for the post-pandemic period, assuming that in the latter period it will also be necessary to trace cases and contacts.

Flowchart application

The flowchart should be used in PHC when assessing a suspected COVID-19 case. PHC is one of the entry points to SUS and should reorganize the flow of service users, taking on health service protagonism.¹⁴14. Sarti TS, Lazarini WS, Fontenelle LF, Almeida APC. Qual o papel da Atenção Primária à Saúde diante da pandemia provocada pela COVID-19? Epidemiol Serv Saúde [Internet]. 2020 abr [citado 2020 jul 9];29(2):e2020166. Disponível em: https://doi.org/10.5123/s1679-49742020000200024
https://doi.org/10.5123/s1679-4974202000... In this pandemic period, COVID-19 cases are attended to by doctors and nurses, but in the post-pandemic period community health agents, who are the link between the health center and the community,¹⁵15. Quirino TRL, Silva NRB, Machado MF, Souza CDF, Lima LFS, Azevedo CC. O trabalho do agende comunitário de saúde frente à pandemia do COVID-19. Rev Port Saúde Sociedade [Internet]. 2020 [citado 2020 jul 9];5(1):1299-1314. Disponível em: http://www.seer.ufal.br/index.php/nuspfamed/article/download/10406/7481
http://www.seer.ufal.br/index.php/nuspfa... can work on identification of possible contacts.

In the pandemic period (Figure 1), the flowchart provides guidance on identification of each contact of a person diagnosed as having COVID-19, observation of social networks and SDHs and, based on this, seeking places where the individual coexists with other people, with the aim of identifying new FLS cases. However, before clinical investigation, an important item of SDHs is taken into account, namely access to the water supply network. If the individual does not have access to the network, the case is referred to the social services to verify possibilities of help. Clinical assessment begins by looking for presence of comorbidities and FLS. If FLS are present, ideally diagnostic assessment for COVID-19 should be conducted with testing and isolation for 14 days, if there are no comorbidities, or referral to a reference service. Individuals who do not have FLS should receive guidance on the disease and its symptoms.

In this way, a person with COVID-19 sets the contact control strategy in motion, which is based on looking for FLS in different social environments, such as at home, at work, in shelters, among others. If the person lives alone, does not have fixed employment or does not practice leisure activities with other people, there is no one to be specifically investigated (Figure 1).

If contacts have had or report fever (≥37.8ºC), dyspnea, myalgia and fatigue, and upper respiratory symptoms,¹³13. Ministério da Saúde (BR). Secretaria de Atenção Primária à Saúde. Protocolo de manejo clínico do coronavírus (COVID-19) na atenção primária à saúde: versão 7 [Internet]. Brasilia: Ministério da Saúde; 2020 [citado 2020 Jul 9]. Disponível em: https://www.cremeb.org.br/index.php/normas/protocolo-de-manejo-clinico-do-coronavirus-covid-19-na-atencao-primaria-a-saude-versao-7/
https://www.cremeb.org.br/index.php/norm... their symptoms should be observed and they should be kept in isolation. Monitoring of these people should take place until they are fit to come out of isolation and if they get worse they should be advised to go to the nearest referral or urgency/emergency health service. In crowded places in which a person diagnosed as having COVID-19 may have interacted with a lot of people, health education actions should be carried with contacts with the aim of avoiding greater propagation of the disease and alerting as to symptoms.

Identification of prior diseases among cases and their contacts can be considered to be a guidance measure in relation to severity markers. Health professionals should ask about any prior diseases, such as diabetes, arterial hypertension, cancer, and other recent communicable diseases, such as dengue and Chikungunya, among others. At this time, any information about recent or chronic illnesses is relevant and should be taken into consideration and reported to the health team.

In the post-pandemic period, a person’s social networks tend to increase, when places that were closed during the pandemic begin to reopen, such as churches and schools. A collective health education strategy is therefore proposed, providing information on signs and symptoms, as well as guidance on health care, in order to identify the needs of each family member. Clinical investigation follows the same steps as those contained in the individual flowchart, in accordance with Ministry of Health recommendations (Figure 2).

Final considerations

The flowcharts presented for active tracing of symptomatic COVID-19 cases in PHC can be useful for preventing the disease transmission chain from being maintained and thus reduce the demand for ITU beds, principally in places where there are few hospital beds. As such, identifying people with FLS, performing diagnostic tests and promoting isolation early can stop transmission to individuals belonging to groups at greater risk of developing severe forms of COVID-19.

Health education, conducted using language, information and guidance easily understandable by the population, is highly necessary in order to avoid the negative effect of fake news in circulation on the internet, in addition to reaching a larger number of people who, once they have received guidance, can become spreaders of quality information.¹⁶16. Ministério da Saúde (BR). Ministério da Saúde lança serviço de combate à Fake News [Internet]. Brasília: Ministério da Saúde; 2018 [citado 2020 jul 9]. Disponível em: https://www.saude.gov.br/noticias/agencia-saude/44139-ministerio-da-saude-lanca-servico-de-combate-a-fake-news
https://www.saude.gov.br/noticias/agenci...

Accompanying cases considered to be milder and monitoring their evolution, with adequate referral, when necessary, to the network of clinical and social services, can ensure more immediate health care for symptomatic individuals and create conditions for isolation of those in vulnerable situations, in accordance with WHO recommendations.¹³13. Ministério da Saúde (BR). Secretaria de Atenção Primária à Saúde. Protocolo de manejo clínico do coronavírus (COVID-19) na atenção primária à saúde: versão 7 [Internet]. Brasilia: Ministério da Saúde; 2020 [citado 2020 Jul 9]. Disponível em: https://www.cremeb.org.br/index.php/normas/protocolo-de-manejo-clinico-do-coronavirus-covid-19-na-atencao-primaria-a-saude-versao-7/
https://www.cremeb.org.br/index.php/norm...

The flowcharts presented here can and should be adapted to concomitant surveillance of other endemic and epidemic diseases in Brazil, since COVID-19 comes on top of the diseases already in existence in the country, stressing the need to reorganize health services, given that the pandemic has altered PHC’s way of working.

In conclusion, we believe that the actions proposed can provide significant advancement with COVID-19 health surveillance, given that this approach takes into consideration transmission in the community and in its social spaces, with contact tracing and adequate health guidance and education. As such, implementing the flowcharts can assist PHC organization, providing benefits for affected people and for the community as a whole.

References

Publication Dates