Increasing findings of silent Covid cases should heighten surveillance

Thursday June 4 2020

A medical worker takes a sample

A medical worker takes a sample from a man in Kampala on May 1.PHOTO BY ABUBAKER LUBOWA 

By Deus Mwesigwa

An asymptomatic carrier is an individual that is or has become infected with a pathogen, in this case coronavirus, but presents no signs and symptoms. Although the individuals are not sufferers, studies from the John Hopkins Centre for Health Security suggest that transmission of the virus is very feasible as it is for symptomatic patients.

The asymptomatic carriers might still be contagious for half as much as symptomatic patients as per the study from Wuhan, China. That is eight days of viral shedding or transmission among asymptomatic carriers compared to 19 days for symptomatic patients. Whereas there are no irrefutable reasons why some individuals remain asymptomatic, scientists hypothesise that having a robust immune response during the incubation period of the virus can prevent the infection from cropping up; reduce the actual quantity of virus (virus inoculum) in the body and prevent it from getting to the lungs. On a crude scale, we can ascertain the strength of immunity among Ugandans.

The body’s immunity is strongest among the youth, which is why there are few hospitalisations, fewer requisitions of Intensive Care Unit treatments and even deaths from coronavirus among young people. This has statistically proven in the US by the Centers for Disease Control. Nevertheless, the overall immunity of a person depends on how healthy an individual is to mount an appropriate immune response.
This should give people hope post-lockdown as the youth statistics show that Uganda has one of the youngest population in the world; with 77 per cent of her population being under 25 years old. However, this raises other worries such as a higher possibility of having asymptomatic carriers in the population. A strong immunity is customary among youth, which pose a high risk of asymptomatic carriage in case of viral remnants post-lockdown.

To effectively prevent further transmission , there is need to ascertain the prevalence of asymptomatic carriers before full resumption of normal business. A high prevalence of asymptomatic carriers creates a gigantic predicament in public health ascendancy. There are studies in other countries showing asymptomatic Covid cases rising more than scientists had thought. Therefore, a combination of symptom-based and asymptomatic-based screening for antibodies is critical for public health interventions.

Deus Mwesigwa,