Pest management professionals are now formally recognised as 'key workers', which highlights the importance of public health pest management during the current coronavirus (COVID-19) outbreak.
It is expected that pest management measures will be even more important both while lockdown measures continue, and as any potential easing of these allows certain food premises to re-open. There have already been reports of an increase in both rat and feral pigeon sightings in the streets following the closure of some food businesses.
Ahead of food premises re-opening, a pest management inspection (ideally by a field biologist depending on the site auditing standards) of them would be beneficial. In terms of general advice regarding what to look for in advance of them reopening, the typical proofing, hygiene and pest activity advice is available in the NPAP-CIEH publication Pest control procedures in the food industry.
As we enter the warmer temperatures of spring and summer, it is even more important that food businesses and households dispose of their food waste properly and in secure containers. We have heard of a number of local authorities that have curtailed the recycling and collection of food waste for the duration of the lockdown. This has the potential to increase the incidence of pest activity if householders do not dispose of their food waste and organic matter carefully and safely in line with local authority advice.
It is anticipated that changes in household food waste collection and processes, in conjunction with increasing temperatures, could impact on fly populations. A 2019 peer-reviewed research paper reported that of bacterial isolates taken from flying insects sampled in UK hospitals, over 50% showed resistance to at least one class of antibiotics. Almost 20% of such isolates showed resistance to more than one class of antibiotics and were defined as 'multi-drug resistant'.
It follows that risks to public health from unchecked fly problems are unacceptable, and it is imperative that fly control, particularly in sensitive situations such as health and food facilities, should continue.
In urban situations, rats harbour salmonella while over half of UK house mice are a reservoir of Toxoplasma gondii, which is a parasite posing risks to pregnant women and their unborn children. It is also recognised that pest rodents can be the main driver for salmonella infection in poultry flocks and can consume and spoil stored crops and animal feed, including causing crop damage while still in the field.
The potential and actual impact of rodent spoilage and contamination of the food chain are well documented, whether this is in relation to the food processing section of the food chain, or the food storage section or once food is on the shelf.
Rodent control is therefore imperative in preserving the 'farm-to-fork' delivery of provisions to the public during the current coronavirus crisis. Rodent activity is also estimated as being the cause of approximately 50% of fires on farms, thereby presenting a further risk to food supplies.
In December 2018, it was reported by the national press that two deaths occurred at Queen Elizabeth University hospital in connection with Cryptococcus infection. Cryptococcus was traced to feral pigeon (Columba livia) excrement onsite and had entered the ventilation system.
The efforts of Public Health England, the Non-Native Species Secretariat and the Animal & Plant Health Agency in keeping invasive insect species at bay depend on being able to access technical support and biocides including associated application equipment and personal protective equipment from suppliers.
Such species include the invasive Asian tiger mosquito (Aedes albopictus) and Asian hornet (Vespa velutina) which poses a serious threat to honeybee health. It will be vital that these agencies are able to maintain their efforts as we enter spring and summer and encounter warmer temperatures, especially with regard to monitoring and guarding against non-native mosquito species.
The role of pests as reservoirs of coronaviruses
While there is much to be determined regarding the current coronavirus, it is known that different coronavirus infections of UK rats (Rattus norvegicus) are being monitored and may pose a threat for cross-species transmission to humans. As a general comment regarding rodents, bamboo rats in China have been suggested as one of the possible intermediate host from bats to humans in the emergence of coronavirus.