COVID-19, caused by SARS-CoV-2 virus has caused 11,903 deaths in India as of 17 June 2020. Epidemiological evidence shows that transmission and peaks of infectious diseases are associated with the timing and severity of monsoon, generally peaking towards the end of the monsoon period. Observational studies indicate that vitamin D deficiency might be a risk factor for severity and mortality of COVID-19. This blog reviews the public health consequences in India due to COVID-19 during monsoon, keeping into account emerging evidence of the possible role of vitamin D in COVID-19 severity, lifting of the lockdown and the pressure on the healthcare system due to other infectious diseases during monsoon.
Studies indicate that even in a sunnier country like India, vitamin D deficiency prevails in epidemic proportions due to reduced exposure of skin, dietary habits such as vegetarianism as well as limited fortification of food. Skin synthesis via exposure to solar Ultraviolet-B (UVB) radiation is considered as the significant source of vitamin D as dietary intake is generally insufficient. Government of India initiated a lockdown limiting the movement of 1.3 billion people from 24 March 2020 until 31 May 2020 in 4 phases (58 days) and has gradually started lifting the lockdown in a phased manner from 01 June, though COVID-19 deaths are increasing. Lockdown, although helped in reducing the transmission of SARS-CoV-2, might have led to limited sun exposure leading to an increased likelihood of vitamin D deficiency in the general population.Furthermore, the lifting of lockdown coincides with the onset of the monsoon, when the likelihood of UVB Radiation exposure is limited primarily due to lower sunshine hours, thick cloud cover and limited outdoor activities. Lifting of lockdown during monsoon may also lead to an increased viral transmission as people are more likely to stay indoors with lower ventilation as evidenced by the surge in the COVID-19 deaths.
Prior studies indicate that influenza tends to peak during the monsoon months, i.e., July-September in significant parts of India coinciding with the timing of monsoon period. Heavy rainfall and flooding, which is prevalent in monsoon, can create conditions conducive for other infectious disease outbreaks such as – dengue, malaria, influenza, diarrhea, cholera and other respiratory diseases. Simultaneous contraction of COVID-19 and these infectious diseases prevalent during monsoon may also lead to poor clinical outcomes for COVID-19 patients.
Cities like Mumbai is prone to yearly monsoon flooding, causing disruptions in traffic – severely limiting the transportation of patients needing critical care to the hospitals. Furthermore, the sudden increase of such infectious diseases during monsoon is also likely to cause strain in the healthcare system, limiting the hospital capacity available for COVID-19 patients and vice versa. Heavy rainfall may also limit the governmental response to set up additional critical care capacity. These factors may further limit the healthcare system’s ability to provide critical care to COVID-19 patients.
Healthcare providers should expect an increase in cases of COVID-19 as well as other infectious diseases and prepare for an increase in hospital capacity. Further, healthcare practitioners might need to consider factors such as diet, sunlight exposure and consider administering vitamin D supplementation to correct any vitamin D deficiency.The increased possibility of COVID-19 transmission, potential vitamin D deficiency and the increased pressure on the healthcare systems due to other infectious diseases may lead to an increased mortality rate from COVID-19 in India during monsoon. Establishing the efficacy of vitamin D supplementation/sunlight exposure would be a significant advance in the control of COVID-19 pandemic in India during monsoon. This topic in India needs urgent attention from medical researchers around the world. Additionally, government and healthcare providers need to urgently plan to mitigate the impact of COVID-19 on public health by addressing these topics as early as possible.