By Glenn Laverack and Sergio Fernando Jaime

The Comarca is a micro-region which borders the provinces of Rio Negro and the province of Chubut, Patagonia, Argentina and is situated close to the border with Chile. It is served by an international airport, being a popular destination for tourists and seasonal agricultural workers. Permanent residents live in small towns or in households along the roads or in isolated areas. The hantavirus is endemic in the region which is mountainous and has natural forests that provide a habitat for mice that are a specific rodent host species. Hantavirus infections typically have a long incubation period, making surveillance difficult, with symptoms of headache, fever, muscle aches, nausea, vomiting, and diarrhoea. Hantaviruses are spread from mice to humans via urine, faeces, and saliva in an aerosol and less frequently by a bite. People can become infected in forest areas when collecting products to sell or to eat such as mushrooms and the ¨rosa mosqueta¨, also a favourite food source of mice. 

In Argentina, hantavirus cases are officially reported as part of the basic indicators of morbidity. In 2021, an incident of 5 positive cases (3 females and 2 males) with one death of hantavirus infection were registered in Salta province in the northwest of Argentina. The Ministry of Public Health recommended that the local population keep their homes and lots clean and to block holes where rodents could enter houses [1]. Broader public health measures have also been used including population ¨lock-downs¨ and travel restrictions.

Andes orthohantavirus is a major causative agent of hantavirus pulmonary syndrome, a more severe infection that is capable of spreading through droplets in close contact between people with a 30-35% mortality rate. It is also called the Andes virus, as it is found in Andean region in Argentina and Chile and is the only hantavirus that has shown an interpersonal transmission. The symptoms are coughing, shortness of breath and fluid on the lungs and there is currently no treatment or a vaccine.  In late 2018, an outbreak of Andes virus swept through a small town in the Chubut region in Patagonia infecting 34 and killing 11 people. An investigation attributed the size of the outbreak to a super spreader event at large social gatherings in 4 clusters [2].  In 2018 the first recorded imported human case of the Andes hantavirus also occurred in the United States [3] demonstrating that there is a real risk of an international outbreak starting from a localised and remote event. A feature of hantavirus outbreaks in Patagonia has been the lack of coordination between the top-down clinical and epidemiologic response with community involvement.

Community involvement

The Comarca includes the municipalities of Epuyen, El Hoyo, Lago Puelo and El Maitén (Chubut side), and El Bolsón (Rio Negro side). The residents in El Bolson, Lago Puelo, El Hoyo and Epuýen live close to the forest environment. However, it is in Epuýen, the poorest community,  where hantavirus cases have been most prevalent and in which, for economic and social reasons, people often enter the forest. Lago Epuýen is close to Epuýen and is an area of high-risk, partly because of a change in forest habitat leading to a concentration of natural forest, and because it is a popular recreational area with residents and tourists. ¨Hotspots¨ such as Lago Epuýen do not warn about the risk from hantavirus or restrict access to forested areas, especially during seasonal periods of high population density of mice. The hantavirus is not perceived to be a significant risk and usually only presents a few cases each year which reduces local sensitivity and discourages preventive action by local authorities because of potential bad publicity that could affect the tourism sector.

Image/Glenn Laverack

It is essential that the epidemiological, the clinical and the municipal work more closely with local people to prevent future hantavirus outbreaks. However, the four communities have distinct socio-ecological characteristics. Lago Puelo, for example, has established neighbourhood associations which can be used to engage the local population. El Hoyo has the experience of local cooperatives supporting initiatives to provide public transport and care for the elderly. Epuýen is less cohesive and has a history of community frustration and tension with local authorities, a situation made worse by COVID and recent forest fires. Communities such as Epuýen require targeted support by local authorities to encourage better community involvement. 

Encouraging community-based strategies

Community-based strategies increase local skills and knowledge to help people to be better organised and mobilised towards protecting their health. The evidence suggests that community-based strategies are not commonly utilised for prevention programs in the Andean region [4]. However, the following steps have provided a simple way forward to encourage local authorities to better work with communities to manage future outbreaks:

  1. Identify who will represent the community, either through existing leaders or newly selected people, for example, members of neighbourhood associations or cooperatives.
  2. Establish a local coordinating group, such as a committee structure, in each community with the purpose to discuss problems and solutions and to share resource ideas regarding local disease outbreaks. The priority of Andes hantavirus can then be developed as a priority. The local coordinating committee (LCC) is comprised of representatives from local services (hospital, municipality, police etc) and the selected representatives of the community. The LCC should meet on a regular basis, such as every 3 months, and have a membership of approximately 10 – 15 persons. 
  3. Establish a central coordinating committee (CCC) with an overarching responsibility to discuss broader issues and solutions across the Rio Negro and Chubut regions and to coordinate activities across of the LCCs. The CCC meets every 6 months and has at least one representative from each of the LCC plus a representative from epidemiology and other relevant regional services.  
  4. Develop a training plan to build the competencies of the both the LCC and CCC. For example, strategic planning is a systematic technique that uses a simple three step process of problem identification, planning and resource allocation within a realistic timeframe to address a specific problem.
  5. It is important to regularly review the progress of both the LCC and the CCC towards achieving their goals, for example, a community plan for an outbreak, stronger social and professional networks and evidence of a better working relationship between the community and local authorities.

The international evidence on community health workers (CHWs) shows that they can be effective in interacting with householders and communities to inform, to collect data and to develop local competencies [5]. CHWs provide a bridge between the health system and the community and it is important that new skill sets are developed for capacity building and evaluation activities. The roles and responsibilities of CHWs in the Andean region must ensure a balance of work that allows them to spend as much time as possible in the community to help prevent future outbreaks, for example, by working with local neighbourhood associations and cooperatives. Local volunteers can also be recruited to help with providing information to householders or with organising local events to raise awareness about the importance of hantavirus prevention.

Conclusions

We conclude that poverty, population movement, ready access to high-risk areas and a perceived low risk of an endemic disease presents the necessary conditions for future Andes hantavirus outbreaks in the Comarca, Patagonia. To prevent an outbreak, it is important to understand the behavioural factors that lead to the spread of the disease and how communities can play a crucial role in containment and local surveillance. It is important to engage with communities to facilitate their cooperation to report suspected cases and case contacts and to prevent cross-infection beyond the local level.

Complex social factors that contribute to the spread of a range of infectious diseases in the Latino American context demand an innovative response that can quickly provide clarity to enable programs to be better prepared and implemented. A fast and simple (quick & dirty) approach to assess community-based involvement in the prevention of the Andes hantavirus in the Comarca proved to be very useful.  A quick & dirty approach can provide a fresh perspective to help public health authorities to better understand how communities can be actively involved in the control of localised disease outbreaks. The approach used site visits and observations, face-to-face and group interviews, preceded by a desk-based review of the literature. The information was collected over a short time frame and was used to develop relevant recommendations for local decision-makers.

We conclude that this type of an approach should be integrated into all public health programs by providing in-service training for CHWs and public health professionals working at the community level. It is a rapid and discreet intervention that can be carried out by a small team with minimal interference in the community. This will provide valuable information to public health authorities to help make promotion and prevention more relevant and cost effective in the Comarca.