Epidemiological Features of Neonates With COVID-19 Infection in Iran


 Objective: Although, the COVID-19 Pandemic has drawn the attention of physicians and researchers from all corners of the globe since it has been out broken in different countries, we have also started to invest more about the epidemiological features of neonates that had been affected by COVID-19 in Iran till now.Method: This is a cross-sectional retrospective study including all neonates from a National Registry supported by Iranian Maternal and Neonatal Network (IMaN). Since February 2020 till February 2021, data of neonates under 28 days who were diagnosed with suspected or confirmed COVID-19 has been registered in this network were collected. General data including epidemiological, clinical outcomes and infection-related information were collected. Results: In our retrospective study, data of 4015 neonates admitted to hospital all over the country and reported in IMAN is included. Totally 3725 PCR tests were performed (92.8% of admitted neonates) and from these neonates 825 (20.5%) showed positive PCR test. There were no differences between gender, weight and gestational age in neonates with positive and negative PCR test. Neonatal clinical findings were dependent to the type of admission. Respiratory distress was the most common sign in neonates, who were admitted immediately after birth (63.9%), and who were transferred from another hospital (17%); however in those who were admitted after one to several days after discharge (19.1%), the most common sign were sepsis like syndrome (31.8%) and fever (27.4%). Almost 50% of admitted neonate`s mothers had positive PCR test (25% during pregnancy and 24.3% after delivery). The most important factor of neonatal death was need for respiratory support (aOR=18.17, 95% CI; 9.24– 35.69). Gestational age of <32 weeks (aOR=2.35, 95% CI; 1.35-4.10) and birth weight of <1500 grams (aOR= 3.47, 95% CI; 1.96-6.17) were the other two factors that correlated to death. Conclusion: This is the largest study of neonatal COVID-19 diseases in Iran published to date. The most common signs of COVID-19 diseases found in neonates are respiratory distress and sepsis-like syndrome.


Introduction
In December 2019, a new outbreak of novel coronavirus from Wuhan, China has been started [1]. Coronavirus disease 2019  has spread across the world in a short time space. With increase in the number of infections, the number of neonates with COVID-19 has also rose. On Jan 30, infection was declared by WHO as a public health emergency of international concern [2]. Although the 2 types of human coronavirus cause severe and acute illnesses, the Middle East respiratory syndrome coronavirus (MERS-COV) causes Middle East respiratory syndrome (MERS) and SARS-COV causes severe acute respiratory syndrome (SARS), COVID-19 has its own clinical features and manifestations [1,3].
COVID-19 manifestations in adults are different from pediatric patients, long incubation periods, high mortality rate in elderly and atypical clinical manifestations are common in adulthood [4,5]. By knowing that SARS-COV-2 has been spread all over the world and become pandemic, and knowing that all ages are prone to the virus, even neonates, therefore COVID-19 will affect a long life period on people's health [1,5,6]. Comparing with adult studies, there are few studies on pediatrics and neonatal disease, especially for their epidemiological evaluations [7,8]. Despite the worldwide spread, the epidemiological and clinical patterns of COVID-19 remain largely unclear yet, particularly among neonates. As a result, there remains much to learn about the spectrum of neonatal disease, best methods of diagnosis, long term consequences, the mechanism of transmissions and prevention of the disease [9]. SARS-COV-2 is known to cause different signs and symptoms such as respiratory distress, shock, early and late onset sepsis, cyanosis, fever, cough, gastrointestinal presentations, pneumonia, asphyxia, disseminated intravascular coagulation (DIC), and neonatal death [10][11][12][13]. The number of neonatal patients of COVID-19 has already been rising remarkably, and they are going to be diagnosed more from the rst appearance of the disease [14]. Therefore it is important to de ne the epidemiological factors of neonates with COVID-19 disease to determine the early prevention, neonatal isolations in intensive care units, transmission of disease and limitation of the pandemic by controlling a small group of age spectrum [15]. In this study, we conducted a retrospective study, explored the epidemiological characteristics of 4015 neonatal patients with COVID-19 in Iran that could help for developing guidelines for the prevention and treatment of neonatal COVID-19 disease.

Methods
This was a national retrospective epidemiological study that included cases from a National Registry supported by the Iranian o ce of neonatal health.
Data collections: Iranian Maternal and Neonatal Network (IMAN) registers data about all birth (live and dead) in Iran [16]. Since February 2020 till February 2021, data of neonates under 28 days who were diagnosed with suspected or con rmed COVID-19 has been registered in this network.
Data about gender, age, birth weight, gestational age, geographic location, and discharge alive or dead was collected together with clinical features on presenting symptoms, diagnosis, management and outcome.
We de ned the suspected cases as neonates who had suspected clinical presentations or had positive history of contact with con rmed patients of SARS-COV-2 and admitted in the hospital. Con rmed cases were infants with a positive PCR test. A nasopharyngeal, oropharyngeal or endotracheal swab was taken after 24 hours of age (according to the Iranian national guideline) to decrease contamination with maternal samples.
The patients were eligible to include the study if they met the following criteria: (1) from birth to the age of 28 days (2) who were suspected to be infected with coronavirus (if they had postpartum close contact to patients with SARS-COV-2, mother was infected meanwhile delivery, neonatal signs of sepsis, DIC, respiratory distress, shock, GI manifestations, poor feeding, fever or other signs or symptoms that were not related to other diseases or abnormal chest radiography or CT imaging), in association with suggestive clinical data (blood tests showing leucopenia or lymphocytopenia), and exclusion of other causes of respiratory infections.
The diagnostic criteria of COVID-19 were based on "screening protocols of neonates in COVID-19 virus epidemic of Iran" in January 2020.

Statistical Analysis:
The statistical analysis of data was done using IBM SPSS v24.0. Data were presented as mean ± SD or number (%) where appropriate. A binominal logistic regression model was conducted to detect factors associated with neonate death. In our analysis, neonate death was measured as a binary variable taking the value of one or zero. Chi-squared analysis was used to compare categorical variables when appropriate. Adjusted odds ratios (AORs) were obtained. A p value < 0.05 was considered statistically signi cant.

Ethical issue:
Anonymous data were obtained with permission from the Neonatal Health O ce of Ministry of Health and Medical Education.
The ethical issues of this study were approved in the Vice Chancellor for Research Affairs of Faculty of Medicine, Iran University of Medical Science. The ethics committee code is IR.IUMS.REC.1399.1365.

Results
In our retrospective study, data of 4015 neonates admitted to hospitals all over the country suspected of COVID-19 infection and being registered in Iranian neonatal network (IMAN) have been analyzed. Totally 3725 PCR tests were performed (92.8% of admitted neonates) and from these neonates 825 (20.5%) showed positive PCR test. Most of the admissions happened in November (617 cases) and October (589 cases) 2020. Figure 1 demonstrates the distribution of admitted cases from February 2020 to end of January 2021.

Demographic factors:
There is no difference in sex, gestational age and weight of admitted neonates with positive and negative PCR test (Table1).   Signs and symptoms: We found different signs and symptoms in three groups according to the time of admission. In the rst category, the most common clinical problems were respiratory distress (1095 cases; 42.6%), sepsis like syndrome (355; 13.8%) and cyanosis (300 cases; 11.6%). Most of these neonates needed some modes of respiratory care and our data showed 1441 (56.2%) neonates admitted after birth, needed oxygen or non-invasive or invasive respiratory care.
In the third group, the most common signs were sepsis like syndrome (244 cases; 31.8%), fever (210; 27.4%), respiratory distress (185; 24.1%) and 364 (47.5%) cases needed respiratory support. There was not a signi cant difference between groups according to their respiratory care requirements.
Respiratory Support: Totally 2331 (58%) of admitted neonates needed some type of respiratory care (ranging from oxygen therapy to non-invasive and invasive ventilation). About 55% of live neonates received respiratory support, compared with 97% of neonates who died. Most of the neonates who admitted after birth or from another hospital (1967; 60.5%) required respiratory support but in those neonates admitted after discharge, respiratory care have been provided for 364 neonates (47.5%) ( Table   1). Table 4 displays distribution of respiratory support in admitted neonates with suspected/con rmed COVID-19.  weeks was 34% compared to 6% in infants 32-36+6 weeks and 5% in term infants. This higher death rate is supposed to be mostly due to prematurity and its complications and the national death rate due to prematurity < 32 weeks is about 29% (IMAN network) that is not different from premature infants with or without COVID-19 infection. Between the group of infants who died, 21 cases (24%) which were less than 1500 grams, 25 cases (29.4%) were 1500-2499 grams and 39 cases (45.9%) were equal or more than 2500 grams (Table 2). Death rate in infants with birth weight of <1500 grams who were diagnosed with COVID-19 infection was 36% compared to 8% in infants 1500-2499 grams and 55 in infants who was born 2500 grams and more (Table5). This higher rate is mostly due to very low birth weight and the national death rate in this group is about 33% in 2019.

Discussion
In this retrospective cross-sectional study using data collected from IMaN network, we have included 4015 neonates with suspected/con rmed SARS-CoV-2 infection in one year from Feb 2020 to Feb 2021 and it is one of the largest reported studies in neonates. As the infection is still spreading worldwide, this study can provide physicians and policy makers with useful information about different aspects of SARS-

CoV-2 infection in neonates.
Iran has reported its rst con rmed cases of infections in Qom on 19 February 2019 [17].  19] or other care-givers and laboratory and clinical ndings. The current gold standard to diagnose SARS-CoV-2 infection is RT-PCR on respiratory specimens [20]. Diagnosis via serological testing in neonates is particularly challenging given the transplacental transmission of maternal IgG, and that IgM assays are prone to false-positives and false-negatives, they are not the gold standard for diagnosis of congenital infections [21].
Twenty and a half percent of neonates had positive PCR test in our study which is lower than reported in another case study from Iran with 56% positive swab test [19], but higher than a Chinese study that reported 8.1% positive test in 1391 children younger than 16 years of age [22].  [22].
There was no signi cant difference between genders of neonates in our study as was shown in other reports [14,24,25]. In those neonates with positive PCR, most of them were born at term gestation which is in line with other studies [25,26,27] and in Trippella`s study with 72% term infants [8].
Most of the neonates with PCR positive tests had normal weight (> 2500 g) and a minority of neonates had very low birth weight (< 1500 grams) as was seen in the study by Christine M Salvatore, et al., with 87% of neonates with weight ≥ 2500 gram, 12% between 1500 to 2500 grams and 1%< 1000 gram [25].
In another study from Iran, no signi cant relation between COVID-19 infection and neonatal and maternal outcomes including preterm birth and low birth weight was reported but cesarean delivery and the need for ICU were higher in mothers with Covid-19 [27].
Different signs and symptoms were reported in neonatal period ranging from asymptomatic carriage to critical illness, and in this study the most frequently described symptoms showed a signi cant correlation to the time of admission. In our study, the most frequent symptoms were respiratory distress, sepsis like syndrome, cyanosis, sepsis like syndrome and fever. In other reports among symptomatic neonates, the most common clinical presentation was respiratory distress (40%), with fever (32%) and feeding intolerance (24%) [23]. In an Iranian review article the most common symptoms were shortness of breath, tachypnea, cough, apnea, temperature instability and tachycardia [19]. Respiratory changes are therefore the most common nding in studies in infected neonates.
The laboratory ndings in our study, in order of prevalence, were as follows: elevated white blood cell count, elevated creatine phosphokinase (CPK), abnormal liver enzymes, and elevated C-reactive protein and/or procalcitonin. In an Iranian review article leukopenia, lymphopenia, thrombocytopenia in, elevated CPK, elevated CRP in, elevated procalcitonin and abnormality in liver test was seen in infected infants, in order of prevalence [19]. Different types of respiratory support were needed in neonates with COVID-19 diseases. About 58% of our admitted neonates needed some kinds of respiratory support and it was more prevalent in those infants who died before discharge that showed a signi cant difference between dead and alive infants. There is a difference between our study and a study by Belén Fernández Colomer, et al. from Spain in needing some kind of respiratory support [24]. As in their study most of the neonates showed community-acquired  (Table 5).
Laboratory factors such as a positive PCR test, elevated CRP and leukocytosis were not signi cantly associated with neonatal death. (Table 5).
Among all neonates who were admitted to the hospital and required respiratory support (2331 from 4015; 58%), there is a signi cant association between death and respiratory support with OR= 18.17 and 95% CI 9.24-35.69 and p value<0.01. This difference could partially be due to more severe respiratory problem from the time of admission in those neonates who required respiratory care and died and as respiratory failure was the most common cause of death, but it could be related to other lung pathologies such as respiratory distress syndrome and pneumonia at the time of admission (Table 5).
About 58% of all neonates who were admitted to the hospital, required respiratory support which was a predictive factor for neonatal death (OR= 18.17 and 95% CI 9.24-35.69 and p value<0.01). Among those neonates who required respiratory care and died, the severity of respiratory problem at the admission was determinative. Respiratory failure was the most common cause of death along with other possible etiologies such as respiratory distress syndrome and pneumonia at the time of admission (Table 5).
There were several limitations in our study; although we had a large number of neonates with COVID-19 diseases, we were unable to screen the virus in amniotic uid, umbilical cord or vagina to study vertical transmission. We did not have required facilities in our country to detect the virus in urine, stool or blood samples to con rm the disease in suspected cases with negative PCR test. Furthermore, we used PCR test to diagnose COVID 19 which has a notable false negative rate, as only 22% of our cases showed positive test and 77% of suspected cases had negative PCR.

Conclusion
Our study was the largest study and analysis of neonatal COVID-19 diseases in Iran based on IMAN registry system. The most common signs and symptoms in neonates were respiratory distress and sepsis like syndrome. Despite the world pandemic situation, this article demonstrates that neonates are not an exception population from COVID-19 diseases and our data provides an additional guidance to enhance pre and postnatal counselling in mothers with COVID-19 diseases whilst they are pregnant and even after their delivery. Distribution of admitted cases from February 6, 2020 to January 31, 2021