BY
Godday O. Aghedo (AMIIM)
Public Health Analyst
1.0 Background
The novel coronavirus was originated
from Wuhan in China and was first reported to World Health Organization (WHO)
officially on December 31th, 2019, hence now known as Coronavirus disease 2019
(COVID-19). It is from the family of the SARS-Coronavirus and it is very
infectious, being a respiratory disease, it spreads very fast too. It has an incubation
period of between 2 – 14 days (that is the time between actual infection and
the appearance of clinical symptoms). It is on records that COVID-19 affects
all age groups but older people, immune-compromised individuals and those with
underlying health conditions like Asthma, Cardiovascular Diseases (CVD), Diabetes
Mellitus (DM), cancer, HIV/AIDS, Tuberculosis etc., appear to become more vulnerable
to being critically ill from the virus. According to China’s National Health
Commission (NHC), 80% of those that died were 60 years and above while 71% had
pre-existing chronic health conditions. Something similar may be indicated for
the overwhelming deaths recorded in Italy too.
Severe Acute Respiratory Syndrome (SARS)
had affected a total of 8,096 people worldwide but on January 30th, 2020, the
novel coronavirus (nCOV) recorded a surpassing total case count. Consequently,
on same day, the World Health Organization declared the coronavirus outbreak
a Global Public Health Emergency.
The Centre for Disease Control
confirmed the first US case of human to human transmission on January 30th,
2020 and the number had continued to multiply since then. Human to human
transmission, otherwise known as domestic or local transmission is very
worrisome, according to WHO.
1.1.0 The Degree of Danger COVID-19 Poses
To
understand how dangerous this virus is, there are three factors of
considerations:
1.1.1
Transmission Rate
(Ro) –
that is the number of newly infected people from a single case, and this is
determined by its reproductive number (Ro). For COVID-19, on January 23rd, 2020
WHO estimated its Ro to be between 1.4 to 2.5, while other independent studies
have pegged it at between 3.6 to 4.0; but obviously, the Ro appears to be far
more than these estimates. Note that, when an outbreak has a Ro that is less
than 1, it will disappear gradually, but it is not so with COVID-19, which even
surpassed the Ro for common flu (1.3) and for SARS (2.0).
1.1.2
Case Fatality Rate
(CFR) –
that is the percentage of cases that culminate in death of patients. WHO press
conference of January 29th, 2020 placed the CFR at 2%, though it was too early
to determine that since the total number of people infected worldwide at that
time could be correctly determined. Epidemiologists believe that CFR can change
with time since viruses can undergo mutation as in the case of COVID-19. So,
arguably, the CFR of COVID-19 appears to be greater than the officially
projected 2%. For SARS, it was 10% and 34% for MERS. The current Hantavirus
still in China has a CFR of 38%.
1.1.3
Possibility of asymptomatic
transmission
– between the estimated 2 – 14 days incubation period, COVID-19 could be
asymptomatic but definitely transmissible. This even makes it more dangerous,
as carriers can go on infecting other people without the knowledge of both
parties.
1.2.0 Mode
of Transmission
COVD-19
is transmitted from person to person through contaminated droplets from
coughing or sneezing. These can be inhaled from the air or picked up from
common surfaces. In a nutshell, there are two major transmission routes:
1.2.1 Direct
Inhalation – this
happens when the droplets or aerosols are inhaled by someone in a close range
when an infected person coughs or sneezes. This is while social distancing (at
least two meters away from people) is a recommended means of prevention.
1.2.2 Indirect
Transmission – this
happens when contaminated secretions (droplets and/or aerosols) that dropped on
common surfaces like the railings, knobs, handles of objects, tables, metallic
surfaces, closes etc., are picked up unknowingly by hand and transferred to the
mouth, nose, eyes and face. This is why constant hand washing and refrain from
touching one’s face is recommended.
1.3.0 Categorization
of Transmission
It is noteworthy that not all locations within a given
country/territory/area are equally affected. Consequently, the following terms
are used in describing the categories of infection burden across various
locations:
1.3.1 Interrupted transmission – this indicates locations where
interruption of transmission has been demonstrated or recorded. Most times, it
may require the determination of details in later dates.
1.3.2 Under investigation – this refers to locations where the type of transmission
has not been determined for any cases. An example includes when samples have
been taking to the laboratory and results awaited.
1.3.3 Imported cases only – this refers to locations where all cases have been
acquired outside the location of reporting. For instance, as at when Nigeria
recorded her first COVID-19 case, the nation’s status was regarded as imported
case only; but that should have changed now.
1.3.4 Local transmission – this indicates locations where the source of infection is
within the reporting location. I think that Nigeria is now here, because those
infected by the imported cases have started infecting others in their contacts
too. For instance, Mr A got infected in UK, returned to Nigeria and infected Mr
B. Mr A was identified and linked to treatment while NCDC commences index
contact tracing. Meanwhile, before Mr B could be traced, he has infected Mr C,
who in turn infected Mr D. In a nutshell, local transmission began at the point
Mr C was infected by Mr B.
1.3.5 Community transmission - this is evidenced by the inability to
relate confirmed cases through chains of transmission for a large number of
cases, or by increasing positive tests through sentinel samples (routine
systematic testing of respiratory samples from established laboratories). This
is a dangerous point of disease transmission, as we see happening in Italy. Nigeria must do everything possible not to
get to this level of transmission, it can be overwhelmingly catastrophic.
2.0
Impact Comparisons of Covid-19 with
Similar Viruses
The
have been outbreaks of other highly infectious diseases previously, in the same
family of Corona Virus.
2.1 The seasonal Influenza (flu) virus is estimated to
claim 290,000 to 650,000 lives annually. This brings the figure to 795 to 1,781
deaths per day.
2.2 The Severe Acute Respiratory Syndrome (SARS) reigned from November
2002 to July 2003. It was also a coronavirus but originated from Beijing,
China, and spread to 29 countries. It infected 8,096 people with 774 deaths (that
is a fatality rate of 9.6%). On January 30th, 2020 the novel coronavirus
(2019-nCoV) cases surpassed even the 8,096 cases worldwide which were the final
SARS count in July 2003.
2.3 The Middle East Respiratory Syndrome (MERS) broke out in April 2012,
infected 2,494 people worldwide and lead to the death of 858 people (that is a fatality
rate of 34.4%). It was first reported in Jordan.
Deductively, the
fatality rate of COVID-19 seems to vary from country to country, but on a
global scale, it is perhaps higher than 2%. With the sophistications in the
medical sciences of the developed countries, the transmission rates and death
records for COVID-19 are alarming. Africa and particularly Nigeria must
therefore be very proactive in other to effectively curtail this deadly virus. Globally,
COVID-19 has infected a total of 711,325 people leading to the death of 33,562
people; with a day’s new infection and death records of 48,243 and 2,706
respectively. However, 150,825 people have fully recovered and subsequently
discharged. CLICK HERE TO DOWNLOAD THE COMPLETE PDF VERSION.