‘Brandix Outbreak’ – Lessons to be learned

By Dr. Lal Jayasinghe

Recently, a few days before the present outbreak, some officials appeared on TV to warn the public not to ignore the need to practice Covid-19 safety measures, such as wearing masks and, washing hands. These are good measures to avoid respiratory disease, and most important when there is Covid spreading in the country, but the public cannot be blamed for the new wave of Covid-19 in the country following a lapse of about two months.

When the health authorities says that Covid-19 has been contained and there has been no community transmission for two months, the public cannot be convinced why they should wear masks, especially in faraway places like Moneragala. In the situation we were in, before the present outbreak, when there was no community transmission, we should have tried to prevent a Covid-19 comeback instead of limiting our efforts to preventing its spread by washing hands and wearing masks.

I mention Moneragala because there are places in Sri Lanka that are quite different. The most “dangerous” place is Katunayaka and the surrounding areas like Minuwangoda. The others are Mattala and Jaffna. Katunayaka and Mattala are the places where Covid-19 “arrives” in Sri Lanka. Jaffna is risky because of close proximality to India where the virus is abundant. Therefore, it makes sense for the authorities to treat these three areas differently from the rest of the country. For example, increasing random PCR testing in these areas is very advisable.

The other measure I hope the authorities have already adopted is to increase the surveillance of airport workers. It is good that they have protective equipment, but in my view that alone is not sufficient. I think it is worth the effort to keep all airport workers under increased close “surveillance”. Additional worthwhile measures are increased awareness training to recognise and report suspicious symptoms, lowering the threshold for testing, etc. These measures are necessary for ALL grades of workers. Particularly the lower grades like cleaners and other “minor employees”, who unfortunately often get forgotten.

It is reported that the female Brandix worker who was the first case-detected was identified by means of routine PCR testing of febrile patients or patients with respiratory symptoms, thus showing the value of such testing. However, press reports indicated that the PCR test had been performed when the patient was “being discharged”. That does not make sense. I can only hope that the press reports are not true. For maximum benefit the PCR should be performed when patients with fever or suspicious symptoms visit a health institution.

The Outbreak

The distinctive feature of this Brandix cluster is that unlike in the past where a large number of cases were discovered in an area, say Atulugama or in institution like the Welisara camp, nearly all cases were detected within a few days, in fact over about two days. Therefore, this is an explosive outbreak. Also, it was most likely a point source outbreak. In other words, one individual was responsible for transmitting the disease to a large number of people.

It is surprising that this individual has not been identified as yet. In a factory with 1,400 workers, for one individual to spread the disease to 1,000, he or she must have some special characteristics:

(1) The individual must have contact with nearly all workers. A factory with 1,400 workers must be spread over a wide area. Therefore, this individual must be someone whose job involved visiting all parts of the factory, for example a supervisor or someone who distributes material to other workers. Or, it is possible that the contact was the other way round i. e. workers visiting the individual, for example at clocking in or by visiting the canteen.

(2) Since a large number of workers were infected, presumably after only a short exposure, this individual must have been symptomatic.

(3) The third requirement is that the individual should have had exposure to a “foreigner” (by this I mean someone who has recently arrived in the country) or visited the airport to have contracted Covid-19 in the first place.

It is equally possible that this individual was a close contact of a “foreigner” as defined above, or an airport worker who was the actual initial or index case. It is then possible that this initial case was only mildly symptomatic or even asymptomatic and therefore went undetected.

Because there were a large number of cases it is easier to time the approximate date of exposure by working back from the date on which the largest number of patients reported symptoms.

There cannot be many workers who fit this criterion. Namely, someone who has contact with all or most workers, who was symptomatic during a particular period, who had access to or who is a close associate of someone who had contact with a “foreigner” or airport employee.

There is another possibility for such a large outbreak to have happened over such a short period. The source of the infection was not a single individual but a number of infectious individuals with whom nearly all or most workers had contact over a short period of a day or two. I say this because, however infectious Covid-19 is and how much a “super spreader” the individual is, it is inconceivable for one individual to infect 1,000 people in a large area. In this hypothetical situation, it is not necessary for all or even any of the alleged individuals who were the source of infection to have been symptomatic, because there were a number of sources i. e. infectious individuals, each one had to infect only a smaller number of workers. On reflection therefore, this is the most feasible explanation. However, this scenario is unlikely because with no Covid-19 transmission in the country, there is no possibility for a number of infectious individuals to come into contact with the workers during a short period.