By Dr. Jenny Lawler & Adrián Delgado
Apr. 06, 2020 17:10 GMT
In the midst of this global health crisis, water is an indispensable resource. To date, the only way to combat the spread of the pandemic is through isolation and hand washing.
If we look at a global map of the extent of COVID-19 we can see that it is slowly spreading to countries in the southern hemisphere where access to water for consumption, sanitation and hygiene is more complicated due to inadequate infrastructure. According to the UNICEF, only 3 out of 5 people worldwide have access to basic hand washing facilities, affecting 900 million school-age children.
Water supply is crucial for maintaining clean spaces and surfaces, as well as proper hand washing to mitigate the spread of the COVID-19 and many other infectious diseases, according to World Health Organization (WHO) recommendations. However, water supply problems in many cities and regions around the world mean that in many places they have to decide between washing their hands, drinking water or using the water for other needs. We can potentially expect to see a higher transmission rate and potentially higher mortality rates than in countries with easy access to safe water.
What does the Research tell us about Water and COVID-19?
Viruses can be classified as enveloped and non-enveloped, with most studies on the fate and transport in water focussing on the non-enveloped viruses such as noroviruses (e.g. winter vomiting bug). However a lot of high profile global disease outbreaks such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and now COVID-19 are enveloped viruses, which have a lipid or fatty type membrane layer surrounding their genetic material. This lipid layer is the reason why handwashing with soap is so successful – the soap disrupts the lipid layer like washing up liquid on a greasy pan, and the mechanical rubbing action of handwashing removes the virus from skin and surfaces. However, there is not a huge amount of research on the presence of these types of viruses in wastewater (sewage) or transmission in the environment, which has hampered the global response to these type of outbreaks. Research is more difficult due to safety concerns with working with these high risk viruses, so the majority of research has been conducted with surrogate enveloped viruses that are less likely to infect humans (such as mouse coronavirus).
Sewage & Wastewater Treatment
The virus that causes COVID-19 has been detected in the faeces of some patients diagnosed with COVID-19. However, the amount of virus released from the body via faeces, how long the virus survives, and whether the virus in faeces is infectious are not known. Generally, enveloped viruses are less stable in the environment and are more susceptible to oxidants, such as chlorine. Wastewater treatment plants treat viruses and other pathogens and are equipped with the appropriate treatment processes to effectively remove them.
The risk of transmission of COVID-19 from the faeces of an infected person is also unknown, however, based on data from previous outbreaks of related coronaviruses, such as), it is possible that the virus that causes COVID-19 could be infective if spread from faeces. There have been no reports of faecal-oral transmission of COVID-19 to date.
Because a faulty plumbing system was implicated in the spread of SARS in an apartment building in Hong Kong in 2003, the WHO recommends the use of standard, well-maintained plumbing, such as sealed bathroom drains, and backflow valves on sprayers and taps to prevent aerosolized fecal matter from entering the plumbing or ventilation system, together with standard wastewater treatment, while wastewater treatment plant operators and sludge handlers must take extra precautions and use protection barriers such as gloves and adequate face masks to prevent exposure to aerosols.
The way that viruses are detected is often based on a technique called RT-PCR (real time polymerase chain reaction) which can detect the genetic material of viruses – this has been routinely used for testing of patients. It can also be used to detect viral material in wastewater (one caveat being that it’s not possible to tell if the viral load detected is infective or not), with detection in Dutch wastewater treatment plants since the first confirmed case was announced. A technique called wastewater based epidemiology, where the amount of virus in wastewater is measured, could be used for monitoring the wastewater of a population and hence also monitoring the amount of virus in a population.
Is my drinking water safe?
COVID-19 virus may survive on surfaces several hours up to 2-3 days, with the most recent study indicating that viable virus can be found after up to 4 hours on copper, up to 24 hours on cardboard and up to 2-3 days on plastic and stainless steel. COVID-19 has not been detected in drinking water supplies globally to date. Municipal drinking water systems in Ireland have filtration and chlorination steps that are generally thought to be effective in inactivating COVID-19.
COVID-19 is also unlikely to be found in bottled water itself. However, given the suspected lifetime of COVID-19 on plastic, if buying bottled water from a supermarket, care should be taken with handling of the packaging, and (as with all groceries) the packaging should be disinfected and/or quarantined before use.
In summary, we are lucky in Ireland in that we have easy access to safe, clean drinking water and excellent wastewater treatment systems. Others are not so lucky.
I measc na géarchéime sláinte domhanda seo, is acmhainn fíor-riachtanach é uisce. Go dtí seo, is é an t-aon bhealach le leathadh na paindéime a chomhrac ná trí aonrú agus níochán láimhe.
Má fhéachaimid ar léarscáil dhomhanda de mhéid COVID-19 is féidir linn a fheiceáil go bhfuil sé ag scaipeadh go mall chuig tíortha sa leathsféar theas ina bhfuil rochtain ar uisce óil, sláintíochta agus sláinteachais níos casta mar gheall ar bhonneagar neamhleor. De réir UNICEF, níl shaoráidí bunúsacha níochán láimhe ag ach 3 as 5 dhuine ar fud an domhain, a bhaineann le 900 milliún leanbh in aois scoile.
Tá soláthar uisce ríthábhachtach chun spásanna agus dromchlaí glana a chothabháil, chomh maith le níochán láimhe i gceart chun scaipeadh an COVID-19 agus go leor galair thógálacha eile a mhaolú, de réir mholtaí na hEagraíochta Domhanda Sláinte (WHO). Mar sin féin, ciallaíonn fadhbanna soláthair uisce i go leor cathracha agus réigiúin ar fud an domhain go gcaithfidh siad cinneadh a dhéanamh idir a lámha a ní, uisce a ól nó an t-uisce a úsáid le haghaidh riachtanas eile. Is féidir linn a bheith ag súil go bhfeicfimid ráta tarchuir níos airde agus rátaí básmhaireachta a d’fhéadfadh a bheith níos airde ná i dtíortha a bhfuil rochtain éasca acu ar uisce sábháilte.
Cad a insíonn an Taighde dúinn faoi Uisce agus COVID-19?
Is féidir víreas a aicmiú mar víreas clúdaigh agus neamh-chlúdaigh, agus díríonn mórchuid na staidéar ar chinniúint agus iompar in uisce ar na víreas neamh-chlúdaigh mar noroviruses (e.g. fabht urlacan geimhridh). Is víreas clúdaigh iad a lán ráigeanna galair domhanda ardphróifíle, mar shampla siondróm géarmhíochaine riospráide (SARS), siondróm riospráide an Mheánoirthir (MERS) agus anois COVID-19, a bhfuil ciseal scannán lipid nó cineál sailleacha timpeall ar a n-ábhar géiniteach. Is é an ciseal lipid seo an fáth go n-oibríonn níocháin láimhe le gallúnach – cuireann an gallúnach isteach ar an gciseal lipid cosúil le leacht níocháin ar phaiste gréisceach, agus baintear an víreas as craiceann agus dromchlaí as an ngníomh cuimilte meicniúil a bhaineann le níocháin láimhe. Níl mórán taighde déanta ar láithreacht na gcineálacha víreas seo i bhfuíolluisce (séarachas) nó tarchur sa timpeallacht, rud a chuir bac ar an bhfreagairt dhomhanda ar ráigeanna den chineál seo. Tá sé níos deacra taighde a dhéanamh mar gheall ar imní faoi shábháilteacht maidir le bheith ag obair leis na víreas ardriosca seo, agus mar sin rinneadh an chuid is mó den taighde le víreas clúdaigh ionaid nach lú an seans go n-ionfhabhtaíonn siad daoine (mar shampla coronavíreas luch).
Cóireáil Séarachais & Fuíolluisce
Braitheadh an víreas is cúis le COVID-19 i bhfaecas roinnt othar a ndearnadh diagnóis orthu le COVID-19. Mar sin féin, ní fios méid an víreas a scaoiltear ón gcorp trí fhaecas, cá fhad a mhaireann an víreas, agus cibé an bhfuil an víreas i bhfaecas tógálach. De ghnáth, ní bhíonn víreas clúdaithe chomh seasmhach sa timpeallacht agus bíonn siad níos so-ghabhálach d’ocsaídeoirí, mar chlóirín. Déileálann ionaid cóireála fuíolluisce víreas agus pataiginí eile agus tá na próisis chóireála iomchuí acu chun iad a bhaint go héifeachtach.
Ní fios freisin an riosca go dtarchuirfear COVID-19 ó fhaecas duine ionfhabhtaithe, áfach, bunaithe ar shonraí ó ráigeanna roimhe seo de coronavíreas gaolmhara, mar shampla), is féidir go bhféadfadh an víreas is cúis le COVID-19 a bheith tógálach más rud é leathadh ó fhaecas. Ní dhearnadh aon tuairiscí ar tharchur faecach-béil COVID-19 go dtí seo.
Toisc go raibh baint ag córas pluiméireachta lochtach le scaipeadh SARS i bhfoirgneamh árasán i Hong Cong i 2003, molann an WHO úsáid a bhaint as pluiméireacht chaighdeánach, dea-chothaithe, mar dhraenacha seomra folctha séalaithe, agus comhlaí sreabhadh siar ar spraeirí agus sconnaí chun cosc a chur ar ábhar feacach aerasóilithe ó dhul isteach sa chóras pluiméireachta nó aerála, chomh maith le cóireáil chaighdeánach fuíolluisce, agus caithfidh oibreoirí ionaid cóireála fuíolluisce agus láimhseálaithe sloda réamhchúraimí breise a dhéanamh agus bacainní cosanta a úsáid mar lámhainní agus maisc aghaidhe chun nochtadh d’aerasóil a chosc.
Is minic a bhíonn an bealach a mbraitear víreas bunaithe ar theicníc ar a dtugtar RT-PCR (imoibriú slabhrúil polaiméaráise fíor-ama) atá in ann ábhar géiniteach víreas a bhrath – úsáideadh é seo go rialta chun othair a thástáil. Is féidir é a úsáid freisin chun ábhar víreasach a bhrath i bhfuíolluisce (fainic amháin nach féidir a rá an bhfuil an t-ualach víréasach a bhraitear ionfhabhtaíoch nó nach bhfuil), agus é a bhrath in ionaid cóireála fuíolluisce Ollainnise nuair a bhfógraíodh an chéad chás dearbhaithe. D’fhéadfaí teicníc ar a dtugtar eipidéimeolaíocht fuíolluisce-bhunaithe a úsáid, ina dtomhaistear méid an víreas i bhfuíolluisce, chun monatóireacht a dhéanamh ar fhuíolluisce daonra agus mar sin monatóireacht a dhéanamh ar mhéid an víreas i ndaonra.
An bhfuil m’uisce óil sábháilte?
Féadfaidh víreas COVID-19 maireachtáil ar dhromchlaí cúpla uair an chloig suas le 2-3 lá, agus tugann an staidéar is déanaí le fios gur féidir víreas inmharthana a fháil tar éis suas le 4 uair an chloig ar chopar, suas le 24 uair ar chairtchlár agus suas le 2-3 lá ar phlaisteach agus cruach dhosmálta. Níor aimsíodh COVID-19 i soláthairtí uisce óil ar fud an domhain go dtí seo. Tá céimeanna scagacháin agus clóirínithe ag córais uisce óil chathrach in Éirinn a gceaptar go ginearálta go bhfuil siad éifeachtach chun COVID-19 a dhíghníomhachtú.
Ní dócha go mbeidh COVID-19 le fáil in uisce i mbuidéil ach an oiread. Mar sin féin, i bhfianaise shaolré amhrasta COVID-19 ar phlaisteach, má tá tú ag ceannach uisce i mbuidéil ó ollmhargadh, ba cheart a bheith cúramach agus an pacáistiú á láimhseáil, agus (mar atá le gach earraí grósaera) ba cheart an pacáistiú a dhíghalrú agus / nó a choraintín sula n-úsáidtear é.
Mar achoimre, tá an t-ádh linn in Éirinn sa mhéid is go bhfuil rochtain éasca againn ar uisce óil sábháilte, glan agus ar chórais cóireála fuíolluisce den scoth. Níl an t-ádh ar roinnt dhaoine eile.