Epidemiology of COVID-19 in Yemen: A Descriptive Study

In Yemen, the rst COVID-19 conrmed case was reported on 10 April 2020. The OBJECTIVE of this study is to identify the epidemiological characteristics of COVID-19 patients in Yemen. METHODOLOGY: From May 20 to 31, 2020, the data were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. A retrospective study used to determine the epidemiological characteristics of the rst 53 conrmed cases of patients with COVID-19. This data includes the date of diagnosis, gender, age, governorates, and clinical symptoms. Data analyzed using SPSS version 22. RESULTS: A total number of 53 conrmed cases were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. The majority of the participants were male (72%), their age were less than 39 years (40%) and from Aden governorate (43%). The commonest symptoms reported among the participants were fever (%), sore throat and cough. Conclusion: Male, less than 39 years old and from Aden is the trend of COVID-19 in Yemen. The ndings of this study may help provide guidance for frontline medical staff in the clinical management of the outbreak. the A retrospective study used to determine the epidemiological characteristics of the rst 53 conrmed cases of patients with COVID-19 in Yemen. Conrmed cases dened as polymerase chain reaction assay (PCR) positive. Only cases included in this study are laboratory positive cases. The ethics The data This data date Data were key-in into Data accomplished before Analytical into


Introduction
Coronaviruses are a family of viruses transmitted through mammals and birds, with humans being particularly susceptible to infection and transmission of the virus (1). The earlier two coronaviruses outbreaks are the Middle East Respiratory Syndrome Coronavirus (MERS) and Severe Acute Respiratory Syndrome (SARS) in 2015 and 2003; respectively and another outbreak reported in China in December 2019 which showed similarities to the novel coronavirus and is now a pandemic disease affected most countries worldwide (2). WHO declared on January 30, 2020, declared COVID-19 is a global public health concern and collaborative efforts of all countries to prevent the rapid spread of COVID-19 are needed (3).
The main known transmission method of coronavirus is from person-to-person through sneezing or coughing, touching a contaminated surface (4). The clinical features of COVID-19 are cough, fever, fatigue, pneumonia, and shortness of breath (5,6). There is no particular antiviral treatment or vaccine so far (4). Hence, the prevention measures should be practiced rmly such as physical distancing, wearing face masks, and wear eye protection are associated with a great reduction in COVID-19 infection. In addition to hand hygiene practices to reduce the spread of coronavirus infection (5).
WHO reported that 80% of COVID-19 patients with mild symptoms recovered without any medication showed mild symptoms and. About 20% of COVID-19 infected cases showed serious symptoms such as shortness of breath, multi-organ failure and septic shock. Around 2% of cases can be fatal (3). Recent studies suggested that COVID-19 infected those with a weak immune system such as obese, older males, with chronic comorbidities, HIV patients, pregnant women, and long-term users of immunosuppressive medications (7)(8)(9)(10). According to a recent systematic review reported that the most common comorbidities affected by COVID-19 are cardiovascular diseases, hypertension and diabetes (11).
The recent mortality rate of COVID-19 infection is predictable to be approximately 4.8% throughout the globe (12).
Different mortality rates were recorded in different countries, in Germany was 1%, and Italy 11.4% (12). The possible explanation is due to the overestimated mortality rate and health authorities selected severe cases but not mild cases and no symptoms cases. Although overall fatality rate for clinical cases ranged from 2-5% globally than the previous outbreaks related to viruses such as H7N9 (39.0%), MERS (34.4%), and SARS (9.5%) pathogens continue to emerge and spread to the population at risk, hence there is an urgent need to move from responsiveness nations to proactive management (6,13).
The greatest way of prevention is not exposing to COVID-19 through washing hands using soap and water, wearing face masks, quarantining suspected and con rmed cases (4,14). Prevention measures are very important and curtail especially there is no vaccine available yet (15). Some measures were taken in the whole country to minimize the exposure and transmission of COVID-19 by closing schools, universities, and activities of large crowed. In Yemen, schools, universities and wedding halls were closed before any COVID-19 con rmed cases reported and the ight to the main airport [Aden] also closed as a prevention measure. WHO endorses the main personal protective actions against the COVID-19 which washes your hands regularly, maintain physical distancing, no touching the nose, eyes, and mouth, practice respiratory hygiene and if sick stay home (14).
Yemen's health system is already greatly breakable due to the con ict for more than 5 years. In Yemen, the rst con rmed case was reported on 10 April 2020 in Hadhramout, Yemen (16). The challenges that faced Yemen to reduce COVID-19 cases are many, one is a very limited number of national laboratories and the lack of PCR reagents and machines for COVID-19 detection. Second, the di culties of implementations of international health strategies of the COVID-19 outbreak due to the civil war and con ict. The government also failed to formulate enough isolation locations at the country entry. Third, due to the long and uncontrollable coastal borders that some refugees and immigrants may enter the country without COVID-19 testing (17). WHO representative in Yemen reported that approximately 65000 deaths and 494000 will be hospitalized will occur in Yemen if there are no protection measures that take place at the right time. WHO representative added that it is extremely alarming circumstances if the Yemeni people do not make thoughtful changes in their behavior to face the COVID-19 infection (18). Therefore, the objective of this study is to identify the epidemiological characteristics of COVID-19 patients in Yemen.

Methodology
From May 20 to 31, 2020, the data were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. A retrospective study used to determine the epidemiological characteristics of the rst 53 con rmed cases of patients with COVID-19 in Aden, Yemen. Con rmed cases de ned as polymerase chain reaction assay (PCR) positive. Only cases included in this study are laboratory positive cases. The ethics committees of Al-Hikma University, Sana'a-Yemen approved this study. The data were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. This data includes the date of diagnosis, gender, age, governorates, and clinical symptoms. Data were key-in into SPSS software in the principal investigator computer and protected with a PIN at Al-Hikma Research Center, Al-Hikma Univerity, Sana'a-Yemen. Data cleaning and validation were accomplished before the data analysis. Analytical datasets were created in an anonymized manner and categorical variables into percentages using SPSS version 20.

Results
A total number of 53 con rmed cases were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. This data collected from 20 May 2020 until 31 May 2020. The majority of the participants were male (72%), their age was less than 39 years (40%) and from the Aden governorate (43%). The commonest symptoms reported among the participants were fever and cough (90%), followed by the sore throat (81%) ( Table 1). The number of cases con rmed on the 20th of May 2020 was one case, three days later the con rmed cases jumped into 14 cases. The con rmed cases then dropped again on 24th of May 2020, with two con rmed cases, 5 days later the con rmed cases jumped again to 14 cases. These may due to the behavior of the residents and their carelessness [ Figure 1].

Discussion
Coronaviruses are large, RNA viruses, and enveloped (19). Coronaviruses considered insigni cant pathogens until the early twenty-rst century where we experienced two major outbreaks from MERS and SARS. As of May 28, 2020, 5·85 million people infected with COVID-19 and 359000 deaths worldwide (20). To the best of our knowledge, this is the rst epidemiological study about COVID-19 in Yemen. This analysis of early con rmed COVID-19 cases in Aden, Yemen provides insight into the epidemiological characteristics and clinical features. Cases are con rmed using PCR testing which is a universal golden standard.
Our study showed that the number of men is greater than women of COVID-19 infection (72%). Similar ndings reported by previous studies reported that COVID-19 infection was more likely to affect males (6,21). A previous study indicated that 56% of infection with COVID-19 were males (2). Another study found that 50.7% were males (22). An Italian study reported that men represent 58% of COVID-19 infected patients and 70% of COVID-19related deaths (23). SARS has infected more men than women (24). The possible explanation is that fewer females infected with COVID-19 may due to the X chromosome protection, in addition to sex hormones which reported to have a signi cant role in the immunity of women (10,25,26). Other possible factors such as behavioral and cultural habits have also contributed such as smoking in particular has been implicated as a signi cant contributor to disease severity (27,28). Overall, men are more likely to involve health-related risks (29).
The mean age of con rmed cases of COVID-19 patients in our study is 44.4. The mean age in Yemen is lower than several studies reported in systematic review which showed that the mean age of COVID-19 patients was 52.0 years (30). Also lower than the mean age of COVID-19 patients presenting in Chines study was 46.5 years (24). The highest affected age group was those ≤ 39 years old. Our ndings supported by a previous study reported that COVID-19 infection affects mostly those in the age group of 30-65 (31). Similar ndings reported in previous studies during SARS outbreaks that age was a very important factor in both mortality and morbidity of SARS infection (32). United Nation reported that the growth rate of the Yemeni population is one of the highest in the world, at 3%. Approximately 50% of the Yemen population is below 15 years of age (33).
In this study, the highest number of COVID-19 con rmed cases were recorded in Aden governorate. The possible explanation is that Aden is the temporary capital of Yemen. It's the only international entry of the country by Air. There may be some imported cases that came with the local citizens who preferred to back home during this pandemic that hit the whole world. On 11 May 2020, Aden city which is the interim capital of Yemen declared "infested city" after the ooding hit Aden which contributed to the spread of diseases like Dengue, Malaria, Cholera and the new disease COVID-19 (34). In addition to the governmental and political con icts in Aden obstructing national and international efforts to ght the new pandemic COVID-19 infection.
Since we are only able to access to the Aden data from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. Furthermore, we only got cases from the 20th of May until the 31st of May 2020. The number of cases con rmed on the 20th of May 2020 was one case, three days later the con rmed cases jumped into 14 cases. The con rmed cases then dropped again on 24th of May 2020, with two con rmed cases, 5 days later the con rmed cases jumped again to 14 cases. These may due to the behavior of the residents and their carelessness. Furthermore, most people not able to buy the masks, not able to stay home because of the nature of their work which is a daily earned income.
The common symptoms of COVID-19 infections included fever, shortness of breath and cough, sometimes these followed by headache, sore throat, insomnia, frequent urination and nasal congestion. Some severe cases experienced GIT symptoms such as diarrhea, nausea, and vomiting. Our study also reported that 90% of the COVID-19 con rmed cases suffer from fever, cough (90%), followed by the sore throat (81%). Similar ndings reported in previous studies that 90% of hospitalized patients were suffering from fever (5,35). Similar ndings reported in Chinese study where they reported that fever is the most common symptom (91.7%) then cough (75%) (22).
The limitation of this study is the small sample size with only 53 patients with con rmed COVID-19 were included. Obtaining data from other centers was not possible at this time due to political reasons. More data about the clinical outcome of the COVID-19 was not available at this moment, though, the available data in our study documented an early epidemiological assessment of COVID-19 in Yemen. Patient comorbidities were also not documented. Another limitation is that this study conducted in a short duration and limited by Aden as geographical location is due to some political and logistics reasons. Despite the limitation of our study, the study might offer guidance for policymakers in Yemen and medical staff to manage this outbreak and speci c conclusions can be drawn from this study and further studies are needed to be built in this study. More epidemiological studies in multicentre in Yemen are urgently needed which can empower epidemiologists to build the COVID-19 model for the Yemen context.

Declarations
Ethics approval and consent to participate: The ethics committees of Al-Hikma University, Sana'a-Yemen approved this study.

Consent for publication:
Not applicable Availability of data and materials: The data were obtained from the National Center of Public Health Laboratories, Ministry of Health and population, Aden, Yemen. The datasets generated during and/or analysed during the current study are not publicly available because the National Center of Public Health Laboratories don't have online database but this data are available from the corresponding author on reasonable request.

Figure 1
The frequency of cases per day during the study period