The COVID-19 pandemic has become a significant global public health concern. In the present study, the frequency of COVID-19 in males (67.47%) was significantly higher than that in females (32.53%). Similarly, many studies have been conducted in different regions and have shown that males are more likely to develop COVID-19 than females [11–14]. In contrast, some reports found that females had a higher number of cases than males [7, 10, 15]
Regarding age group, the current results indicated that the burden of COVID-19 increased with increasing age of individuals, and the highest rate was among those aged ≥ 65 years, while the lowest was among children aged ≤ 5 years. This finding is in agreement with other studies in Indonesia [13], France [14], Morocco [15], South Africa [16], Saudi Arabia [17], and Australia [18].
Since the COVID-19 epidemic started in 2019, most people with COVID-19 have been older. In addition to being more susceptible to COVID-19, older people have a markedly higher risk of morbidity and mortality [19]. The combination of multimorbidity, weakness, and immunosenescence contributes to increased susceptibility to COVID-19 in individuals of advanced age. The risk of COVID-19 incidence increases with increasing age and causes serious disease among older individuals, particularly those who have weak immune systems, suffer from certain medical conditions, or unvaccinated [20].
In terms of the year of infection, 2021 was reported to have the highest rate of COVID-19 infection at 67.44%. This result is in agreement with recent studies [21–22]. In the current study, the highest rate of COVID-19 prevalence was recorded in Costal Hadhramout (26.44%), followed by Aden (23.91%), Sayon (19.82%), and Shabwah (9.11%). A similar study by Bin-Ghouth et al. [7] showed that the prevalence of COVID-19 in Aden was 27.4%. Also in Lahj and AL-Dhalea hospitals, the overall rate of COVID-19 among healthcare workers was 94.3% [10].
According to a recent Worldometer report on COVID-19 in Yemen, the highest number of cases were recorded at 119, 178, and 245, in June 2020, April 2021, and January 2022, respectively [23]. Comparable to our findings, these data show that a high number of COVID-19 cases were reported in July 2020, March 2021, and January 2022, at 571, 1851, and 759, respectively 759. This trend is in accordance with a previous report [24].
The cumulative incidence of COVID-19 was reported at 15.04 per 10,000 individuals across all the study regions. Lai et al. [19] found that the incidence rate was reported at 61.4 per 1,000,000 people in Korea, 55.06 in China, 29.47 in San Marino, 22.33 in Bahrain, 16.75 in Singapore, 14.69 in Italy, 12.54 in Hong Kong, 10.54 in Kuwait, and 4.62 in Iran. The numerous variations can be attributed to varied conditions, settings, symptoms, community transmission rates, compliance with transmission control protocols, and other factors.
The current outcomes revealed that the incidence of COVID-19 was more than two-fold higher in males than females (10.15 vs. 4.89 per 10,000 individuals). This result agrees with previous data [11, 25]. Males in Yemen are responsible for their families and providing life requirements. This means that they need to spend more time outside the house and interact with other people, especially in stores. This can expose them to infectious disease.
Regarding incidence in governorates, Socotra had the highest rate of COVID-19 incidence, followed by Costal Hadhramout, Al Maharah, Wadi Hadhramout, and Aden, whereas the remaining governorates had the lowest incidence rate. The Socotra governorate is far from the other governorates. In addition, the Al-Mahra governorate borders the Sultanate of Oman, which makes it commercially active and an area characterized by tourist attractions. Additionally, Aden and Mukalla are two of the main governorates in the study area, which have airports and ports with high trade exchange. Furthermore, weak health services, poverty, and low education levels in these governorates may have led to an increase in the incidence of COVID-19 among the population in the study area.
The overall case fatality rate in the present result was recorded at 15.05%. Globally, the rate of case fatalities ranged from 1.7–39.0% [26]. In the present study, the proportion of case fatality was significantly higher among men (10.15%) than women (4.89%). Clinical and epidemiological evidence has now revealed that almost twice as many men with COVID-19 experience severe symptoms or die, compared to women [27]. In addition, it is remarkable that men account for the majority of COVID-19 deaths worldwide, with estimates ranging from 59–75% of total mortality [28].
Furthermore, it has been suggested that the susceptibility to coronavirus infections may be attributed to the presence of female hormones, which play a pivotal role in both innate and adaptive immunity. Females have more immune-related genes because they have two X chromosomes. This makes their immune response stronger immune response [29].
These data revealed that the age group ≥ 65 years was found to be had the highest rate of case fatality, while the age group ≤ 5 has the lowest rate. The results are in consonance with those of other workers who reported higher fatality rate of COVID-19 cases was in older age-groups [5, 29]. Thera are some factors that increase the fatality risk of COVID-19 among older people such as advanced biological age, dysregulation of epigenetics, immune defects, and other factors [30].
The highest case fatality rate in this result was recorded in 2020 at 28.87%, whereas the lowest was recorded in 2022 at 7.69%. Globally, the rate of case fatalities has increased to 39.0% in 2020 and has subsequently decreased to below 0.3% by 2022 [26]. In this result, the case fatality rate was reported at 29.84%, 26.42%, 25.37%, 23.75%, and 22.36% in Abyan, Wadi Hadhramout, Shabwah, Costal Hadhramout, and Lahj, respectively, while the lowest rate was recorded in Aden (8.2%). Certain factors that may have contributed to the rise in the rate of case fatalities in the study area include the non- restriction of movement among populations during the COVID-19 pandemic, non-adherence to preventive measures, absence of travel restrictions, escalating poverty, as well as a devastation of the healthcare system, the absence of infection control facilities, and a shortage of healthcare personnel.
According to the monthly trend, the case fatality rate was more frequently reported in May 2020 (28.34%), followed by August 2021 with 24.42%, and February 2022 (16.58%). While the lowest rates were 1.09%, 8.51%, and 1.9% in October 2020, January 2021, and July 2022, respectively. Globally, the rate of case fatalities ranged from 1.7–39.0% between February and March of 2020 and subsequently declined below 0.3% during the period from July to August 2022 [26].
Limitations of this study
The most significant restriction is that there were no data on COVID-19 cases in Yemen's northern governorates for inclusion in this investigation. Another limitation of this study is that it was a retrospective evaluation of data recorded in medical facilities; thus, it lacked information on patient outcomes, signs, and symptoms.