SARS-CoV-2 which is the causative agent for COVID-19 pandemic continues to manifest with severe acute respiratory syndrome among the adults, however, it offers a considerable signs of less severity and fatality in pediatric age group (0-18 years). The current scenario suggests that children may get infected but are less symptomatic with less mortality, concordant to earlier epidemic outbreaks of SARS-CoV and MERS-CoV, in 2002 and 2012, respectively. Although information of the adult patients with COVID-19 is in progress and published, in contrast, almost no comprehensive data or discussion about the COVID-19 in children is available. Therefore, the absence of paediatric patients with COVID-19 has perplexed clinicians, epidemiologists, and scientists. 

Epidemiology of COVID-19 in Children:

According to Chinese Centers for Disease Control and Prevention as of March 2020, only 2% cases of less than 19 years have been found affected by SARS-CoV-2 (Wu and McGoogan 2020). A study was conducted having 3 case series of SARS-CoV-2 infected children. The 1st series had 20 children from Zhejiang (until 31st Jan 2020), the 2nd series had 34 children from Shenzhen (19th Jan to 7th Feb 2020) and the 3rd series with nine infants from various provinces of China (Wang, et al. 2020; Chen, et al. 2020; Wei et al. 2020). Most of the clinical details were obtained from the 2nd series, like, no children had any underlying disease, respiratory symptoms were seen in 65% children, mild symptoms in 26% and 9% were found asymptomatic. The 1st case series was presented with mild to moderate fever, cough, rhinitis, diarrhea, headache and poor feeding, cyanosis, dyspnea in severe cases. The 3rd series presented with fever in four infants. Almost all the children with manifested symptoms recovered within couple of weeks. No death is reported in children infected with SARS-CoV-2 till date (Chen, et al. 2020). 

Clinical presentation of COVID-19 in children 

Research has proved that children develop milder symptoms compared to adults which is also seen early in outbreak of SARS-CoV and MERS-CoV infections (Chen, et al. 2020). Additionally this study is the indication that mild symptoms or absence of severe symptoms in children may lead to misdiagnosis and will lead to skip the required test for SARS-CoV-2 and therefore, asymptomatic children might spread the disease (Guan et al. 2020). A study has revealed that SARS-CoV-2 can be found in feces long after throat and nose swabs test negative. Hence negative stool sample be included in a patient's discharge criteria. However, the maximum number of SARS-CoV-2 infected children, have been found as a part of family cluster outbreak. The role of children in spreading the virus is still to be elucidated. Also, till date, there is no evidence of vertical transmission of SARS-CoV-2, from mother to the infant. 

Treatment

There is no specific treatment recommended for children by neither WHO, nor the US CDC. However, the aim of the treatment in children with COVID-19 is the prevention of organ failure,

ARDS and hospital acquired infections. This is achieved by supportive treatment, which includes

adequate intake of fluid, calories and ventilator support (Chen, et al. 2020). The recommended treatment for HCoVs infected children, is the oral lopinavir/ritonavir along with corticosteroids and aerosolized interferon alpha-2b and also intravenous immunoglobulin, in case of severe cases. Since, there is no specific recommendation from WHO and any evidence of benefit of above mentioned therapies most of the children with SARS-CoV-2 infection had been treated with only lopinavir/ritonavir without using immunoglobulins (Wang, et al. 2020). Other potential therapeutic options include monoclonal antibodies, protease inhibitors chloroquine, RNA synthesis inhibitors.

Prevention

Rapid and impactful measures for infection control are needed to minimize the spread of SARS CoV-2. One of the most challenging tasks with COVID-19, is the containment of hospital acquired transmission which is a potential threat among the children. Health care setups appear to enhance the chance of viral transmission because of infective droplets producing procedures like suctioning of the airways and intubation. Adequate and appropriate hospital sanitization is of paramount importance to control and restraint the hospital acquired COVID-19 infection. A well-known fact is the need of strict hand sanitization which can be achieved by using ethanol, isopropanol, etc. and minimal social gatherings (Bin et al. 2016). 

Possible reasons for immunity in children

One of the most common parameters for the severity of the COVID-19 is the chronic illness, like

high blood pressure, diabetes, and cardiovascular disease (Mizumoto et al. 2015). Based on this fact, children appear to be at lower risk, due to absence of such aliments at young age. Innate immunity of the human body is critical and is the first line of defense for battling the infectious diseases. This defense mechanism shows an exponential decline in the later life span, which leads to increase in the incidence of infectious disease. For example, diseases like chickenpox and measles are fatal to adults, almost 25 times more than children (Rawson, et al. 2001). Research suggests that if a child has a strong innate defense to current virus, the chances of fight against the infection is more effective, with manifestation of only mild symptoms. The fact is that children also get caught with the respiratory infection, however they fight robustly and recover faster than the adults. The probable justification could be healthy respiratory tissues due to nonsmoking, less exposure to air pollution, etc. Under normal conditions, RBCs rush into these air sacs to pick up new oxygen, however on inflammation of these alveoli, the RBCs stop functioning, making it difficult to breathe. Therefore, the people with ARDS have higher death risk of coronavirus as seen in SARS coronavirus. This is also one of the reasons that frequency of fatality of COVID-19 is less in children, owing to non-presence of complicated immunological response, compared to adults. However, it is a subject of priority for the researchers to unravel the mechanism of action and outcome in children against the CoVs infection.

References:

• Wang, XF, J Yuan, YJ Zheng, J Chen, YM Bao, YR Wang, LF Wang, H Li, JX Zeng, and YH Zhang. 2020. 'Clinical and epidemiological characteristics of 34 children with 2019 novel coronavirus infection in Shenzhen', Zhonghua er ke za zhi= Chinese journal of pediatrics, 58: E008.
• Chen, Zhi-Min, Jun-Fen Fu, Qiang Shu, Ying-Hu Chen, Chun-Zhen Hua, Fu-Bang Li, Ru Lin, Lan-Fang Tang, Tian-Lin Wang, and Wei Wang. 2020. 'Diagnosis and treatment recommendations for pediatric respiratory infection caused by the 2019 novel coronavirus', World Journal of Pediatrics: 1-7.
• Chen, Huijun, Juanjuan Guo, Chen Wang, Fan Luo, Xuechen Yu, Wei Zhang, Jiafu Li, Dongchi Zhao, Dan Xu, and Qing Gong. 2020. 'Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records', The Lancet.
• Guan, Wei-jie, Zheng-yi Ni, Yu Hu, Wen-hua Liang, Chun-quan Ou, Jian-xing He, Lei Liu, Hong Shan, Chunliang Lei, and David SC Hui. 2020. 'Clinical characteristics of coronavirus disease 2019 in China', New England Journal of Medicine.
• Bin, Seo Yu, Jung Yeon Heo, Min-Suk Song, Jacob Lee, Eun-Ha Kim, Su-Jin Park, Hyeok-il Kwon, Se mi Kim, Young-il Kim, and Young-Jae Si. 2016. 'Environmental contamination and viral shedding in MERS patients during MERS-CoV outbreak in South Korea', Clinical Infectious Diseases, 62: 755-60.
• Mizumoto, Kenji, Akira Endo, Gerardo Chowell, Yuichiro Miyamatsu, Masaya Saitoh, and Hiroshi Nishiura. 2015. 'Real-time characterization of risks of death associated with the Middle East respiratory syndrome (MERS) in the Republic of Korea, 2015', BMC Medicine, 13: 228.
• Rawson, Helen, Amelia Crampin, and Norman Noah. 2001. 'Deaths from chickenpox in England and Wales 1995-7: analysis of routine mortality data', BMJ, 323: 1091-93.