The seroprevalence of IgG/IgM anti-SARS CoV- 2 antibodies in the Benadir region was 44.8%. The value is remarkably higher compared to the PCR-positive confirmed cases, as the value is slightly above 1% in Somalia (1).
The findings indicate the possibility of numerous unreported cases of COVID 19 in Somalia. The female group had a higher proportion of seropositive individuals compared to the males. However, the association of gender with seropositivity was not significant, implying it does not influence susceptibility to COVID 19. The findings are consistent with those from other regions reported seropositive cases in males (12%) were not significantly different from the females (12.8%) in India (2).
Similarly, (3) found no association between seropositivity and gender in Poland. Additionally, the study corroborated (4) who also found no significant variation in seroprevalence of males (70%) and females (71%) in Peru. Conversely, the findings were inconsistent with (5) who suggested that the males had a higher risk of acquiring COVID 19. Nonetheless, the prevalence was consistent with the global pattern of male and female cases, showing no significant variation in the number of confirmed cases (6). Therefore, gender has no association with seropositivity and does influence susceptibility to COVID 19 in Somalia.
The seropositive cases increased with age, as group 18-37 years had the lowest seroprevalence whereas 78-97 years had the highest prevalence. The findings suggest that older individuals are more susceptible to COVID 19 compared to younger ones. Immunosenescence (weakening of immunity with age) may be attributable to the high seropositivity in the elderly. It is characterized by a decrease in peripheral T cells in the blood, which may considerably increase susceptibility to COVID 19 (7). Moreover, (2) reported the same trend as the seroprevalence in individuals aged 60 years and above (12.4, 95% CI) was higher than those who were below 20 years (5.6, 95% Cl). (3) observed a similar trend as the seroprevalence at 95% confidence interval increased from 1.61% in age 18-33 to 2.60% in age 65 and above. Therefore, the age of an individual influences susceptibility to COVID 19.
Marital status had an association with the seropositivity of individuals. The single individuals had a lower positive rate compared to the married, divorced, and widowed groups. Moreover, the married people had a higher association with seropositivity compared to the widowed and divorced groups. The findings imply that married individuals are at higher risk of contracting COVID 19 than the other groups. The probable reason could be that married individuals tend to cohabit with numerous relatives compared to singles.
Additionally, most males in the Somali culture are polygamous and can marry up to four wives (8). Therefore, if a married male contracts the disease, he can transmit it to his four wives and children. Conversely, the singles are less likely to spread the disease as they tend to live alone or with fewer relatives in the house. Moreover, the divorced and widowed individuals are also expected to have children who either live with them or visit them, which increases their risk of contracting COVID 19 compared to the singles.
The groups with different levels of education had no significant variation in seroprevalence of anti-SARS CoV 2 antibodies. Ironically, the proportion of those who tested positive in the uneducated group was comparable to those at the post-graduate level. The findings were unforeseen as the educated individuals were expected to have fewer positive cases since they are more likely to adhere to COVID 19 precautionary measures than the uneducated or those with a lower level of education. The findings suggest that the level of education does not influence susceptibility to COVID 19 in Somalia, and other factors may play a role. The findings were inconsistent with (2), as the level of education significantly influenced the seropositivity in India.
Similarly, the results did not corroborate (9), who unveiled that individuals with a lower level of education had a higher likelihood of seropositivity. The high seroprevalence in the educated individuals in the study area may be due to their occupation. Notably, the findings of this study indicated that individuals in the public sector had the highest proportion of seropositive cases. Moreover, the teachers, self-employed and those working in a company also had high seroprevalence, whereas the students had the minor positive cases. Therefore, the high seropositivity may imply that the individuals work in the public sector or other high-risk areas.
The BMI status did not influence the number of seropositive cases. The findings imply that BMI is not a risk factor for seropositivity. The results are consistent with (10), who found no significant difference in seroprevalence based on BMI status.
However, behavioral habits such as smoking had a significant influence on seropositivity. The findings suggest that smoking increases the likelihood of seropositivity. Notably, smoking decreases the capacity of the lungs, which heightens the risk of acquiring respiratory illnesses, including COVID 19. Primarily, SARS CoV 2 attacks the lungs, and smoking impairs the organs, reducing one's capacity to fight the virus (1). Moreover, the odds ratio value was significantly high in individuals smoking shisha compared to those smoking khat. The findings imply that smoking shisha may increase one's susceptibility to COVID 19 compared to khat. The results are inconsistent with (11) , who found no correlation between smoking and COVID 19 susceptibility. Additionally, (12), we did not find a significant variation between smoking and COVID 19 prevalence. Therefore, other factors may have influenced the high seropositivity of smokers in Somalia.
The comorbidities such as diabetes, hypertension, asthma, and cardiovascular illnesses had a significant variation between those with the condition and the healthy individuals. Notably, the odds ratio value indicated that individuals with asthma had the highest probability of testing positive for the antibody. Additionally, individuals with other illnesses, including diabetes, hypertension, and cardiac diseases, also had an increased risk of testing positive for anti-SARS CoV 2 antibody. The high seropositivity of individuals with asthma may be because the disease affects the lungs and is characterized by difficulty in breathing. Therefore, individuals with the diseases are likely to be more susceptible to the virus.
Moreover, the trend was similar in individuals who had a family history of the disease as they all showed significant variation compared to those who did not have a family history of the disease. The findings imply that chronic illnesses increase one's susceptibility to COVID 19 in Somalia. The results are inconsistent with (2), who found no significant variation between the seroprevalence of individuals with diabetes and hypertension and those who did not suffer from the illnesses. The findings were inconsistent with (13), who found no association between seropositivity and comorbidities such as diabetes and hypertension. The significant association between the comorbidities and COVID 19 observed in Somali may be due to lack of access to proper medication for individuals with an underlying condition, which increases their susceptibility to other illnesses such as COVID 19.
The clinical features, including fever, cough, loss of smell, and loss of taste, were all associated with seropositivity. The proportion of individuals who tested positive was substantially high in all groups as they were all above 70%. Hence, the symptoms could be risk factors for COVID 19 infection in Somalia. The high association between seropositivity and the clinical features implies that the individuals may have been infected with COVID 19 when they were experiencing the symptoms. The findings are consistent with (14). Who found that loss of taste and smell was associated with high seropositivity. Conversely, the same study reported that coughs and fever were not associated with seropositivity, whereas chills, fatigue, and sore throat also exhibited significant variation. Therefore, stakeholders should urge individuals experiencing the symptoms associated with COVID 19 to undertake the PCR diagnosis test for timely administration of intervention.
The prevention measures of COVID 19 were found to decrease seropositivity. However, wearing masks and regular washing of hands did not have a significant association with seropositivity. Conversely, keeping social distance and avoiding handshakes had a significant association. The results were unexpected since regular washing of hands and wearing masks are the hallmark of COVID 19 prevention measures. The findings imply that keeping social distance and avoiding handshakes are more effective in preventing COVID 19 than wearing masks and regular washing of hands in Somalia. The probable reasons could be that individuals who wore masks were less cautious with the other measures such as keeping social distance; hence, they contracted the disease.
Additionally, the individuals washing their hands regularly were probably shaking hands with other individuals or not maintaining social distance leading to the high seroprevalence. The findings are inconsistent with other studies, as (15) reported a significant association between washing hands, wearing masks, and reduction in seropositivity. Nonetheless, the findings on the reduction of seroprevalence through social distancing corroborated this study. Therefore, the Somali government should emphasize keeping social distance and avoiding handshakes as additional measures to wearing masks and washing hands to curb COVID 19 prevalence.
Close contact with individuals who tested positive for COVID 19 had an association with seropositivity. Moreover, close contact with COVID 19 patients had a higher association compared to those without contact. The seroprevalence may be high since contact is one channel of COVID 19 transmission and contact with infected individuals increases one's likelihood of contracting the illness. Moreover, keeping a social distance prevents one from contacting the infected individuals as some are asymptomatic and may be unaware of their COVID 19 positive status. Therefore, the government should sensitize citizens to self-isolate or avoid close contact with individuals who have tested positive for COVID 19 until the PCR test confirms they are negative.
Seroprevalence in Benadir districts
The seropositive cases in 16 districts in Benadir revealed substantial variation as some districts had a high prevalence of 81%, whereas, in some regions, the prevalence was as low as 16%. The findings indicate that residents in some areas are at higher risk of contracting the disease than others. Notably, the A/Aziz district (81%) had a considerably higher seroprevalence compared to the rest. The region includes port of Mogadishu, a business hub, and has a population of 2,388,000. Therefore, the high seropositivity may be due to community transmission of the disease.