Prevalence and Pattern of COVID-19 among Healthcare Workers in Rivers State Nigeria

Introduction: The evaluation of COVID-19 prevalence among healthcare workers (HCW) within the general population of COVID-19 cases is an important epidemiologic variable. The objective of this study is to describe the prevalence and patterns of COVID-19 infection in HCWs amongst a group of patients receiving care for COVID-19 in Rivers state, Nigeria. Methods: This study was a prospective descriptive study of all consenting patients who re-ceived care through hospitals, designated for COVID-19 treatment in Rivers state either as in-patient or out-patient following a laboratory-confirmed diagnosis of COVID-19 based on a positive SARS-CoV-2 RT-PCR from April to September 2020. Results: A total number of 646 COVID-19 patients were enrolled over the study period with 98 (15.2%) HCWs in the patient population. The HCWs with COVID-19 consisted largely of Doctors 47 (47.9%), Nurses 30 (30.6%), and socio-sanitary and hygiene workers 10 (10.2%). There were 46 (46.9%) female HCWs, compared to Non-HCWs with 112 (21.1%), females, p = 0.000. Sixty-eight (69.4%) HCWs had a source of contact for infection established compared to Non-HCWs with an established source of contact in 181 (34.2%), p = 0.000. Eight (8.2%) HCWs had Severe disease compared to 52 (9.8%) Non-HCWs


Introduction
The response to the COVID-19 pandemic as declared by the World Health Organisation (WHO) in March 2020 [1], elevated global cognizance of the role of healthcare workers as a critical resource for the world. This acknowledgement was accentuated as healthcare workers (HCWs) became frontline combatants across all pillars of the COVID-19 response with the attendant risk of infection.
Healthcare worker infection, therefore, became an issue of concern in the early period of the pandemic response with documentation of alarming rates of HCW infections [2] [3]. A report from the WHO joint mission to China in February 2020 reported 2055 COVID-19 laboratory-confirmed cases of HCW healthcare infections in 476 hospitals across China [2]. Correspondingly Wang et al. [3], reported that 29% of patients with COVID-19 infection were HCWs from a cohort of 138 patients treated in a hospital in Wuhan. The study [3] also referred to the risk of widespread transmission in healthcare settings as evidenced by a super spreader patient who infected over 10 HCWs in the hospital. Similar observations regarding HCW infections were also noted in Spain as of 31st March 2020 with over 9400 HCWs consisting of approximately 15% of all confirmed cases infected with COVID-19 [4]. The WHO Africa region office also reported that over 10,000 HCWs had been infected with COVID-19 in Africa as of July 2020, with an average rate of 10% of infections in some key countries [5].
The evaluation of healthcare worker's prevalence among the general population of COVID-19 cases has therefore become an important variable in the epidemiologic analysis of the pandemic; with studies around the world documenting a range of 3% -19% prevalence of HCWs among the populations infected with SARS-CoV-2 [6] [7] [8] [9]. Wu et al. [10] in a Chinese centre for disease control (CDC) report, documented that 3.8% of 44,672 cases were healthcare workers; while two studies [11] [12] from Italy reported that HCWs accounted for 9% [11] and 9.8% [12] of cases in March 2020. Elimian et al. [13]

Study Design, and Population
This study was a prospective descriptive study of all consenting patients who re-

Data Collection
A data extraction form built on the open data kit (ODK) tool was used to collect

Ethical Considerations
The Ethical approval was obtained from the Research Ethics Committee of the University of Port Harcourt Teaching Hospital, Rivers state before the commencement of the study. Confidentiality was maintained by the removal of patient identifiers from the dataset and ensuring that only researchers involved in this study had access to the extracted data.

Statistical Analysis
The data was exported from the Microsoft Excel spreadsheet into IBM Statistical This accounts for limitations arising from the sample size.

Results
A total number of 646 patients were enrolled over the study period with 98    Table 2).
The age group distribution of HCWs, with comparison to Non-HCWs, is as displayed in Table 2. The majority of the HCWs were in the 31 -40 (40.8%) and 41 -50 (23.5%) year age groups, there was no significant difference in comparison with non-healthcare workers p = 0.202, χ 2 = 9.777 (see Table 2).
The pattern of contact source, comorbidity, disease severity, and outcome variables are presented in Table 3.   Comorbidities: The pattern of comorbidities is as displayed in Table 3. The leading comorbidities in HCWs were hypertension 20.4%, diabetes 10.2%, and asthma 2.0%. Hypertension 25.7% and diabetes 7.7% were also the leading comorbidities in non-healthcare workers. There were no significant differences in the proportions of comorbidity in both groups. The pattern of symptoms: The pattern of symptoms is shown in Table 4 and Figure 2. The leading symptoms

Discussion
Healthcare worker infection with SARS-CoV-2 has been a global source of concern since the onset of the pandemic with alarming prevalence rates of HCW in-  [9]; it is a source of concern as it is higher than the 9.3% prevalence reported by Elimian et al. [13], in a descriptive study of COVID-19 from all states in Nigeria. The understanding that Rivers state is one of the high burden states for COVID-19 infection may also explain the higher prevalence of HCWs infection above a National average value in this study. The prevalence of HCW infection in this study is similar to 15% reported in Spain [4] and lower than 19% from the USA [7], which were both within the early phases of the pandemic in March and April 2020 respectively. In further comparison with other studies, the prevalence of HCWs with COVID-19 in this study is above 2.8% and 2.5% observed by Shararidad et al. [18] and Giesen et al. [19] from Iran and Spain respectively among hospitalised patients. A systematic review of global studies [8] reported HCW infection prevalence of 3.9% consisting of an estimated 152,888 of 3,912,156 cases as of 8 may 2020; while Wu et al. [10] from China found a prevalence of 3.4%. Two other studies [11] [12], from Italy reported a prevalence of 9% and 9.8% respectively while a study in Qatar [6] found a prevalence of 10%. The prevalence of the above studies, is lower than the finding in this index study. It is therefore evident that HCWs contribute significantly to the burden of COVID-19 in the study location with prevalence rates above what is general observed from many other studies.
In the professional group of HCWs the most affected by COVID-19 in this study were doctors (47.9%), nurses (30.6%), and WASH/Environmental health, health attendants (10.2%). This shows that medical and clinical staff who have direct contact with patients and support staff who are in contact with the patient's environment are most at risk for infection. This pattern corresponds with the findings of Zheng et al. [20] in a study from the London teaching hospital which found that clinical staff groups had higher infection rates 7.3% compared to non-clinical staff with 2.8%, with medical and dental and nursing and midwifery as the professional groups with the highest rates of infections. A similar pattern was also observed by Sotgui et al. [21] at an Italian forefront hospital in a serologic prevalence study for SARS-CoV-2 with doctors (47.0%), Nurses (26.2%), and socio-sanitary workers (5.5%), having the highest prevalence of D. D. Alasia, O. Maduka Occupational Diseases and Environmental Medicine SARS-CoV-2 infection. Other studies have also corroborated this pattern as shown in a systematic review of global studies [8] which had nurses (38.6%) and Doctors (31.3%) as the leading professional category in correspondence with the findings of this study. Lombardi et al. [22] in Italy also reported Doctors, Health technicians, Nurses, and Health assistants 10.5%, 9.4%, 8.4%, and 8% were the leading professional groups with SARS-CoV-2 infection. Fusco et al. [11] also reported a higher proportion of nurses (50%) and doctors (23%) in their cohort.
Alajmi et al. [6] from a Qatar national surveillance study reported the highest infection rates in Nurses (33.2%) and non-clinical support staff with (31.3%) with physicians consisting 5% of infections. Maskari et al. [23] from Oman reported Nurses with 38% of infections while doctors and paramedics had 13% of infections each with administrative/support staff making up 36%. The pattern of reported by Alajmi [6] and Maskari [23] differs slightly from our pattern with nurses, non-clinical support, and paramedics having higher rates of infections compared to doctors. The variations may be due to a higher proportion of community-acquired infections over hospital-acquired infections documented in those studies. The summary of all studies still shows that clinical workers especially doctors and nurses and support staff with contact to patient environments have a higher risk of infection. Clinical staff are therefore at higher risk and require an emphasis on risk communication prevention messages, provision of PPEs, and surveillance for infection. There were no significant differences in the mean age and age group distribution profile of HCWs and non HCWs in this study, with the mean age of 40.22 years above the national average of or mean of 37.1 years explained by the exclusion of people under 18 in the comparisons. Similar age means and median and age group distribution have also been reported by other studies [8] [11] [21] [23].
There was a significant difference in the gender distribution between healthcare and non-healthcare workers in this study, with a higher female prevalence among healthcare workers compared to non-healthcare workers, this reflects the high preponderance of females in healthcare occupations in Nigeria especially nursing which accounted for over 30% of the HCWs and doctors. Other studies show a similar trend of female HCWs proportions above general population figures with Fusco et al. [11], Bandyopadhyay [8], Lombardi et al. [22], Maskari et al. [23] reporting proportions of 49%, 71.6%, 62.4%, and 64% respectively.
In this study, the majority of HCWs (69.4%) with COVID-19 had a source of contact established compared to non-healthcare workers with a predominantly unknown source of disease indicating higher levels of community transmission in Non-HCWs. Also, the majority of HCWs had their contacts within the hospital environment from patients and other healthcare workers. These findings correspond with that of Wang et al. [3] who reported a higher rate of hospital-associated transmission in HCW of 29% compared to 12.3% in hospitalized non-HCWs. This finding shows the need for better infection prevention and control practice and appropriate PPE use among HCWs in this environment to reduce transmission of SARS-CoV-2 among HCWs. There was no significant Wang et al. [3] reported hypertension and diabetes as the leading comorbid disease conditions, while Maskari et al. [23] reported diabetes as the leading comorbid disease condition over hypertension. The range of comorbidity presence of 22.9% to 46.4% among HCWs reported by Wang et al. [3] and Maskari et al. [23] respectively is comparable to the 33.7% reported in this study.
The pattern of symptoms among the HCWs in this study was similar and did not differ significantly from non-HCWS, with fever, dry cough, fatigue, headaches, myalgia, anosmia, ageusia, and shortness of breath as the leading symptoms in line with the existing symptom pattern and other studies involving the general population [25] and HCWs [3] [6]. The presence of anosmia among HCWs as the second most common symptom in this study is a finding of interest as anosmia is predictive of less severe disease, reduced hospitalizations', and lower in-hospital mortality in COVID-19 patients [26] [27].

Conclusion
The study has shown that the prevalence of COVID-19 among HCWs in the study location is high and a cause of epidemiologic concern as HCWs contribute