The arrival of expatriates to the State in hordes and the latest developments in Wayanad where a local market place has suddenly become the hotspot of COVID-19 local transmission have made the State take the decision to intensify sentinel surveillance to detect community transmission of the disease.
Kerala had already initiated sentinel surveillance during the last week of April when it was decided to collect as many as 900 nasopharyngeal/oropharyngeal samples across all districts every week to be tested using RT-PCR (reverse transcription-polymerase chain reaction) tests in designated labs.
Now that the sentinel surveillance is being intensified, the State aims at collecting and testing 3,000 samples every week from all districts. The study is expected to provide “early warning signals as well as epidemiological information about the next phase of the pandemic.”
In the absence of reliable antibody testing kits, RT-PCR will be used for surveillance for the time being.
From seven groups
This time, samples are being collected from seven groups, based on potential risk exposure. They include patients in the general population with acute respiratory infection but are not COVID-19 suspects; health-care workers in non-COVID-19 hospitals; people with ‘high social exposure’ such as food delivery persons, community volunteers, police or media; guest workers in the State; and epidemiological samples as recommended by public health experts.
Crucial category
One of the new and crucial category included in the sentinel surveillance are natives of Kerala without any travel history who might have come into contact with interstate truck drivers (headload workers, vendors in markets, warehouse staff, people like tea sellers or repair workers at vehicle transit camps, female sex workers and men who have sex with men).
Given the current situation in Wayanad wherein an interstate truck driver is believed to have set off a chain of local transmission of COVID-19, the samples from this group would be crucial. Interstate truck movement is something the government cannot stop nor control.
Expatriates
The other new category will be expatriates who have no symptoms. Samples are to be collected from people who arrived in Kerala after May 4 from outside the country/State.
The State’s advisory specifies that the samples are to be collected from this group between the fifth and 14th day of their arrival in Kerala.
The State will be following Indian Council of Medical Research’s protocol for pooled sample collection and testing as the number of samples would be huge.