The amount of Covid-19 detected in Greymouth wastewater last week went up tenfold.
With people now reporting their own test results — and many not logging negative tests — wastewater testing gives scientists another clue as to what is happening.
ESR has been testing water in Greymouth, Westport, Reefton and Hokitika and has detected Covid-19 in all four towns for multiple weeks.
ESR said on Friday the readings were still at very low levels in Westport and Hokitika — below the level at which it can be quantified.
In Greymouth, levels were quantifiable, and were tenfold higher than the previous week.
Exact case numbers cannot be determined from wastewater results alone — just that the number of new cases is increasing, decreasing or remaining the same.
West Coast District Health Board emergency co-ordination centre incident controller Dr Helen Skinner said it was now assumed everyone coming into hospital could be Covid-positive, and that some of them would be asymptomatic.
"We are only testing patients who present to our emergency department or who are being admitted to hospital who are symptomatic."
The result was recorded in patient records, therefore the DHB could not say how many people turning up at hospital had the virus.
"We currently have no Covid-positive patients receiving hospital-level care in Te Nikau [Grey Hospital]."
Modelling estimated the Coast would start to reach peak numbers at least four to five weeks after the first cases were confirmed, which was about two weeks ago.
"We have not yet reached the point where we need to reduce surgery or other services, however when this peak occurs we will only be providing essential services."
Meanwhile, as Covid-19 cases creep up throughout the West Coast, only four country schools in the Grey district are free of the virus at present.
Barrytown, Awahono, Paparoa Range and Lake Brunner Schools are the only ones to escape so far.
Cobden School this week joined eight other schools with its first confirmed case. Gloriavale Christian Community School has also confirmed cases.
The West Coast’s first case of Covid-19 in this outbreak was announced on February 19. Six days later it was in Greymouth High School and has since spread to nine of the 13 schools.
Ministry of Education figures are not available for the West Coast, but the region’s largest primary school, Grey Main, yesterday had 22 cases among children, plus three staff members. Overall, 35 children have had the virus and 13 have recovered.
Cobden School principal Noula Markham said everyone was coping well after being alerted of the school’s first case on Monday. — Greymouth Star
By Laura Mills and Viv Logie