To our knowledge, this study is the first one conducted in Yemen, particularly in the Taiz governorate. From April 2020 to March 2023, 1933 COVID-19 cases confirmed by molecular were included in this study. In the current results, the prevalence of cases was observed to be significantly higher among males (66.3%) as compared to females (33.7%). Similar reports have been conducted in different countries in the world showing COVID-19 infections are more in males than females [15–19]. These data were in disagreement with the results of several studies [11, 14, 20].
Females have stronger immune systems, including antiviral interferon and humoral and adaptive immunity that fight against viruses, particularly SARS-CoV-2 infections [21]. The results of the 2017 research revealed that female mice were less susceptible to the SARS-CoV virus than their male counterparts. However, after having an ovariectomy, the differences between genders' vulnerability to the virus disappeared. This means that estrogen may have been responsible for the differences in vulnerability [22].
In addition, the X-chromosome in women, unlike the Y-chromosome in men, contains the majority of immune-associated genes, giving them a stronger immune system. Males having higher levels of angiotensin-converting enzyme-2, the primary SARS-CoV-2 receptor, than females [23–24].
At the beginning of the 2019 pandemic COVID-19 outbreak, most COVID-19 cases were observed among elderly individuals [25]. The age groups 25–34 had the highest proportion of COVID-19 cases (22.9%), while those aged ≤ 5 years (0.1%) had the lowest rate. These results were different from a study that found more cases of COVID-19 cases were more prevalent in the older people than the younger people [15, 19–20]. On the contrary, a study by Sallam et al. [13] found a higher rate of COVID-19 cases among the age group of subjects aged 19–49 years. Similarly, the highest frequency rates were observed among the age group of 15–29 years [11]. In Australia, adults aged 20 to 29 have a higher infection rate [26].
Older individuals are more vulnerable to COVID-19 and are at a meaningfully increased risk for morbidity and death [27]. Infections in older adults frequently manifest in an atypical manner, thereby complicating their identification and management. The physiological changes associated with old age, several age-related co-morbid diseases like diabetes and heart and lung disease, and the use of related medications are all factors contributing to poor health status [23].
Regarding the period of infection, the highest rate of cases was in 2021, and the lowest in 2023. This study was supported by some reports [28–29]. The continuous conflict in the governorate since 2015 that led to the destruction of the healthcare infrastructure, increased poverty, inadequate health resources, and the escape of healthcare staff to another area are all factors contributing to the increase in COVID-19 cases in 2021.
Recently, the Worldometer reporting COVID-19 in Yemen revealed that the high cases were reported at 119, 178, and 245 cases, respectively, in June 2020, April 2021, and January 2022 [30]. These data are similar to our results showed that a high rate of COVID-19 cases was recorded at 9.47%, 27.78%, and 5.59% in June 2020, March 2021, and June 2022, respectively.
Four waves were the result of the global COVID-19 pandemic: the first, which lasted from January 2020 to February 2021; the second, which lasted from March 2021 to June 2021; the third, which lasted from July 2021 to October 2021; and the fourth, which lasted from November 2021 to March 2022 [28].
The seasonal trends in COVID-19 cases were estimated to be between November and April for all outcomes and in all countries [31]. Many viruses that infect the respiratory system have different patterns during the winter months [32]. It is widely acknowledged that factors such as the host, pathogen, and environmental factors, such as an increase in indoor activity and seasonal weather fluctuations, have a significant impact on the viral stability beyond the host [33].
In this finding, the overall incidence rate of COVID-19 was 6.31 per 10,000 people in Taiz. A report by Lai et al. [34] found that the incidence varied from 0.0002 per 1,000,000 populations in India to 61.4 per 1,000,000 populations in Korea. According to the results based on districts, the high incidence rate of COVID-19 was 35.22 and 13.34 per 10,000 people among males who live in Al Mukha. In addition, The Al Mukha district exhibited the highest incidence of COVID-19. This could be attributed to the fact that the majority of the nearby residents were moved to the Al Mukha district during the armed conflict.
This investigation revealed an average 14.12% rate of fatality cases. Recently, the overall case fatality rate was 22.9% in Yemen [5]. Globally, the case fatality rate was recorded at 1.0% [5]. The case fatality rate was reported at 2.3% in China [15] and between 3.3 and 4% in Africa [18, 35], 0.16% in Australia [26], 2.92% in Germany [36], 1–20% in Ethiopia [37], and 3.72% in Latin America [38].
The present data showed the fatality rate was significantly higher in males (13.35%) compared to females (11.3%). This result aligns with the recent findings that documented that the fatality case rate was higher in males than females [15, 38–39].
The fatality rate was higher among individuals aged ≥ 65 years. This finding is in agreement with the results of previous studies [15, 40]. COVID-19 is more likely to cause serious illness or death in older adults if they are unvaccinated, have a disability, have an impaired immune system, or have certain medical conditions. Therefore, they are more likely to need hospitalization, intensive care, or a ventilator breath; otherwise, they may succumb to death [41].
Limitations of this study
This study has several limitations. First, there are no data on COVID-19 cases in the Mawiyah and Hayfan districts, which are under the control of the Sana’a authorities, and this is considered the most important limitation. Second, some cases were clinically diagnosed as being infected with COVID-19 but without laboratory confirmation and were excluded from this study. Third, there is a weakness in the data documentation and recording in health centers, which is another limitation of this study.