Evaluation of Surveillance System for Adverse Drug Reaction Due to Antiretroviral Drugs, Mazowe District, Zimbabwe, 2021

Godwin Choga^1,&, Owen Mugurungi², Tsitsi Patience Juru¹, Addmore Chadambuka¹, Notion Tafara Gombe^1,3, Gerald Shambira¹, Chukwuma David Umeokonkwo⁴, Mufuta Tshimanga¹

 

¹Department of Primary Health Care Sciences. Family Medicine, Global and Public Health Unit, University of Zimbabwe, Harare, Zimbabwe, ²AIDS and TB and Unit, Ministry of Health and Child Care, Harare, Zimbabwe, ³African Field Epidemiology Network, Harare, Zimbabwe, ⁴African Field Epidemiology Network, Monrovia, Liberia

 

 

^&Corresponding author
Addmore Chadambuka, Department of Primary Health Care Sciences, Family Medicine, Global and Public Health Unit, University of Zimbabwe, Harare, Zimbabwe

 

 

 

 

The use of antiretroviral drugs (ARVs) transformed the management of HIV, resulting in HIV being a chronic condition rather than a life-threatening illness. In Zimbabwe, access to antiretroviral drugs (ARVs) reduced AIDS-related deaths by 64% from 2010 to 2020. The AIDS-related deaths fell from 61000 in the year 2010 to 22000 in the year 2020[1]. Although the use of antiretroviral drugs (ARVs) has saved many lives, these drugs are not without safety concerns. They are associated with a wide range of adverse drug reactions (ADRs) which can be mild, moderate, severe, or life-threatening. The incidence of ADRs due to ARVs varies from region to region and ranges from about 32% to 85%[2]. Adverse drug reactions (ADRs) may also affect the patients´ adherence to treatment and lead to treatment failure and the emergence of drug resistance[3,4]. Therefore, there should be a system for detecting and reporting adverse drug reactions (ADRs).

 

The World Health Organization (WHO) defines pharmacovigilance as “the science and the activities relating to the detection, assessment, understanding, and prevention of adverse events or any medicine or vaccine-related problem”[5]. In Zimbabwe, the Medicines Control Authority of Zimbabwe (MCAZ) is mandated by an act of Parliament to receive and manage ADR reports from health workers to inform policy on drug safety. This ADR surveillance system heavily relies on spontaneous reporting of ADRs by health workers. It is a professional obligation for every health worker to report all suspected adverse drug reactions regardless of severity. The reports could either be in the form of a paper-based form or an electronic reporting form[6].

 

According to the 2020 District Health Information System 2 (DHIS2) data, 17 ADRs due to ARVs were reported for Mazowe District. An analysis of the Medicines Control Authority of Zimbabwe (MCAZ) statistics showed that only four ADRs due to ARVs were reported from Mazowe District in the year 2020. This reflects a gross underreporting of ARV ADRs which results in lost opportunities for reviewing ARVs´ safety profiles and coming up with public health actions to improve patient safety. Failure to improve drug safety leads to compromised patients´ quality of life, poor treatment adherence, and therefore development of drug resistance. There are limited studies in literature that assessed the attributes of ARV ADR surveillance systems in Africa. An evaluation of the ARV ADR surveillance system was last done in Zimbabwe in 2017 and was conducted at urban health facilities which is not representative of the national HIV programming. We evaluated the reasons for the underreporting of ARV ADRs, usefulness, and attributes of the ARV ADR surveillance system in Mazowe District in 2021.

 

 

Study setting

 

We conducted the study in Mazowe District which is situated in the Mashonaland Central Province of Zimbabwe. The district has 34 health facilities which include three hospitals and 31 primary health care facilities. There are four urban facilities and 30 rural facilities. Thirty-two health facilities offer HIV testing and treatment services. The district has an estimated population of 233450 people[7]. According to the DHIS2 data for the district, about 10.2% (23816/233450) of the population of Mazowe District were on antiretroviral therapy by December 2021. About 91.3% (23816/26076) of people living with HIV in Mazowe District were on antiretroviral therapy.

 

Flow of information in the ADR surveillance system

 

When a health worker identifies or suspects an ADR, a detailed history is taken, and a reporting form is completed. The completed ADR form should be checked for completeness and sent to the national pharmacovigilance centre (MCAZ) within 15 calendar days (Figure 1). The completed ADR reporting forms will then be received at MCAZ and tabled for discussion in the Pharmacovigilance and Clinical Trials (PVCT) committee meeting for causality assessments. The PVCT committee meetings are held monthly. The PVCT committee consists of physicians, pharmacovigilance officers, disease-specific care and treatment specialists, pharmacists, epidemiologists, monitoring and evaluation officers, and public health specialists from the Ministry of Health. The PVCT committee reviews the information on the ADR form and applies the Bradford Hill criteria for causality where they assess the strength of association, consistency, temporal relationship, specificity, dose-response relationship, coherence, and biological plausibility of the ARV being responsible for the ADR[8]. The PVCT committee can also conduct the causality assessment using the WHO aide-memo on causality assessment[9]. If all the required information is available on the ADR form, most causality assessments are concluded within 1-2 hours. The outcome of the pharmacovigilance meeting is communicated to the reporting health worker or health facility within 30 calendar days[6]. If a causal relationship is established between the reported offending drug and the occurrence of the ADR, MCAZ uploads the information onto an electronic WHO database for reported ADRs which is known as the Vigibase [6].

 

Study design and study population

 

We conducted a descriptive cross-sectional study using the Updated Centre for Disease Control guidelines for evaluating public health surveillance systems[10]. Health workers who comprised doctors and nurses working in HIV clinics in Mazowe District during the year 2021 were recruited into the study. The completed ARV ADR reporting forms found at the health facilities were also reviewed.

 

Sample size and sampling technique

 

All the 32 health facilities in Mazowe District where HIV services were being offered were eligible to participate in the study. However, we reached 24 (75%) facilities due to logistical challenges. All doctors and nurses who were working in HIV clinics at the health facilities during the year 2021 and were on duty on the day of the visit were interviewed. We interviewed 81 health workers over a period of 10 days. We reviewed all the eight completed ARV ADR reporting forms that we found at the health facilities.

 

Data collection tools and techniques

 

We validated our questionnaire and checklist through a review by program coordinators in the AIDS and TB Directorate of the Ministry of Health and Child Care. We pretested them on nurses working in the HIV department at 2 clinics in Bindura District in Mashonaland Central Province of Zimbabwe. We then used the pretested interviewer-administered questionnaire to collect data from health workers to determine their knowledge of the ARV ADR surveillance system, usefulness and attributes (acceptability, simplicity, stability) of the ARV ADR surveillance system and to determine the health workers´ reasons for underreporting ARV ADRs. Checklists were used to guide the review of the ADR forms for completeness, to collect information on the timeliness of ADR reporting, and to assess the resources for operating the ARV ADR surveillance system.

 

Data management and analysis

 

Health worker knowledge: We assessed each health worker´s knowledge on five aspects of the ADR surveillance system which were:

 

• ADR surveillance system definition
• At least two out of the four objectives of the system
• ADR forms are completed in duplicate
• Timeline for reporting
• All ADRs are to be reported

 

A score of one was assigned to each of the five questions to make a total of five points. The overall knowledge rating for each health worker was assigned according to the total score obtained. (0-2 = poor, 3 = fair, 4-5 = good). We determined the proportion of health workers in each of the knowledge categories.

 

Usefulness: We determined the proportion of health facilities that had records of meetings to discuss ADR surveillance data and assessed the implementation of public health actions made from the meetings.

 

Simplicity: We determined the proportion of health workers who reported facing difficulties in completing ADR forms. A scenario of a case of ARV ADR was given to the health workers and they were asked to complete an ADR reporting form. The proportion of health workers who completed the ADR reporting form without facing any difficulties was recorded.

 

Acceptability: We determined the proportion of health workers who reported their willingness to participate in the ARV ADR surveillance system and those who felt that it was their professional obligation to complete ADR reporting forms. We also determined the proportion of health workers who reported a history of identifying an ADR and failed to complete the ADR reporting form. The proportion of ADRs recorded in the health facility statistics but not reported to MCAZ was calculated.

 

Stability: We determined the proportion of trained health workers and the proportion of health facilities with adequate resources (ADR reporting forms, ARV ADR surveillance system reference materials, communication platforms, and transport) for use in the ADR surveillance system.

 

Data quality: We calculated the proportion of completed ARV ADR reporting forms with missing information on either of the following mandatory sections:

 

• The initials of the patient
• The name of the reporting health worker
• The name of the offending drug
• Full details of the adverse drug reaction and the clinical course
• The outcome of the patient

 

Timeliness: The proportion of the completed ARV ADR forms that were sent to MCAZ within the recommended 15 days was calculated.

 

Permission and ethical consideration

 

Permission was obtained from the Mashonaland Central Provincial Medical Directorate, the Mazowe District Health Executive, and the University of Zimbabwe. The study was reviewed and approved by the Mashonaland Central Provincial Ethics Committee (MC/IEC/05/2022). All the study participants signed informed consent forms before participating in the study. Confidentiality was assured to the study participants throughout the study. Their names were not written on the data collection tools and were stored under lock and key.

 

 

Demographic characteristics of health workers

 

We interviewed 81 health workers, with 61 (75.3%) of them being female. There were 40 (49.4%) registered general nurses, 36 (44.4%) primary care nurses, and five (6.2%) medical doctors among the interviewed health workers. The median years in service was nine years (IQR:6,13) (Table 1).

 

Health workers´ knowledge of the ADR surveillance system

 

Most health workers knew the definition of ADR surveillance (85.2%, 69/81) and that all ADRs must be reported (77.8%, 63/81). There were 36 (44.4%) respondents who knew at least two of the four objectives of the ADR surveillance system, while 25 (30.9%) knew that the ADR reporting forms were completed in duplicate. Only five (6.3%) of the respondents knew the reporting timelines of 15 days for identified ADRs. On assessing the overall knowledge rating, 43 (53.1%) respondents had poor knowledge, while 28 (34.6%) and 10 (12.4%) had fair and good knowledge of the ADR surveillance system respectively (Table 2).

 

Usefulness of the ADR surveillance system

 

No facility was found to have records of meetings held to discuss ADR surveillance data and to have any documented public health actions.

 

Simplicity

 

Out of the 81 health workers, 31 (38.3%) reported having completed an ARV ADR form before. Of the 31 health workers who had completed an ARV ADR form previously, six (19.4%) reported facing problems with completing the forms. When they were given exercises to complete ARV ADR forms, 67 (82.7%) health workers did not face any difficulties whilst 14 (17.3%) health workers faced difficulties in completing the ARV ADR forms.

 

Stability

 

Two (2.5%) of the respondents were formally trained on the ARV ADR surveillance system but all of them had been sensitized on the system. All the health facilities had ADR reporting forms available. None of the health facilities had an electronic reporting platform. All the facilities had National Antiretroviral Therapy guidelines as reference material for ARV ADR surveillance. All the facilities had a telephone for communication with the district level. All the facilities were supported by motorcycle couriers who visited the respective health facilities at least twice per week as part of an integrated transport system between the health facilities and the district hospital (Table 3). The maximum time that an ARV ADR form would take before reaching the district health hospital from a health facility was four days. There were three vehicles at the district hospital and usually, a vehicle from the district traveled to Harare, where MCAZ is located, at least twice a week. The maximum time required for an ARV ADR form to be transported from the district hospital to MCAZ was four days.

 

Acceptability

 

There were 78 (96.3%) health workers who reported that it was their duty to report the ARV ADRs and 76 (93.8%) reported that they were willing to participate in the surveillance system. However, 54 (66.7%) reported that they had previously failed to report an identified ADR. There were 25 ARV ADRs that were recorded in the health facilities´ statistics for the year 2021 and no ARV ADR forms were sent to MCAZ.

 

Timeliness and data quality

 

Of the 25 ARV ADRs identified in the health facilities´ statistics, there were eight forms that were completed in the year 2021 that were not sent to MCAZ by March 2022. Out of the eight completed forms found at the health facilities, five had missing information on mandatory fields. Two forms had missing patient initials and three forms had missing descriptions of the ADRs.

 

Reasons for underreporting ARV ADRs

 

There were 47 (58.0%) respondents who indicated that they failed to report ARV ADRs because the ADRs were minor while 45 (55.6%) failed to report due to high workload. Fourteen (17.3%) health workers reported that they failed to report ADRs because of fear of being blamed for causing the ADR.

 

 

The study findings show that the health workers´ knowledge of the ARV ADR surveillance system was poor. The poor knowledge could have emanated from the lack of training as only two health workers had received formal ADR surveillance system training in the district. This resulted in the underreporting of ARV ADRs and the surveillance system failing to meet its objectives[11]. Lack of knowledge of the objectives of the surveillance system means that there is limited understanding of the reasons for ADR reporting and using the surveillance data. This was similar to the findings by Muringazuva et al in 2015, whereby health worker knowledge of the objectives of the ADR surveillance system led to low ADR reporting rates in Kadoma City[12]. The lack of knowledge on the timelines for reporting could also have resulted in the eight ARV ADR reports completed in the year 2021 still being at the facilities in March 2022. Backstrom et al in 2000 found that lack of knowledge of the regulations for ADR reporting negatively affected reporting in northern Sweden[13].

 

Although there was a lack of formal training on the ARV ADR surveillance system, all the health workers were sensitized about ARV ADR reporting during support visits by the District Pharmacist. The sensitizations coupled with the availability of the ADR reporting forms, national antiretroviral therapy guidelines for reference, and a reliable communication and transport system make the surveillance system stable. All facilities had telephones for easy communication with the district level. Twice weekly visits to health facilities through the motorcycle courier system and twice weekly vehicle visits to Harare where MCAZ is located enable ADR forms to be transported from health facilities to MCAZ within the stipulated timeline of 15 days. The motorcycle courier system is partner-supported rather than government-funded, and this could reflect on lack of sustainability of the transport system. Our findings were consistent with a study by Muringazuva et al in 2015 which showed that the ADR surveillance system in Kadoma was stable as the health facilities always had reporting forms and a reliable communication system available[12].

 

A surveillance system should not be very complex to operate. The ARV ADR surveillance system was found to be simple. This is most likely due to having no confirmatory procedures required for an ARV ADR to be reported and that the reporting form is only one page long and self-carbonated. It does not take long to complete the ADR form. This was consistent with the findings from the study by Mugauri et al in 2017 which revealed that the few health workers who completed ARV ADR forms faced little or no challenges during the process[14]. Despite the ADR form being short and easy to complete, most of the completed forms at the facilities had missing mandatory sections. Completeness of data is key in the interpretation of the reports and missing data negatively affects the process of causality assessment at the national pharmacovigilance center.

 

Most of the health workers had previously identified patients experiencing ARV ADRs and they failed to complete the ADR reporting forms. Furthermore, there were ARV ADR cases noted in the facility records which were not reported to MCAZ. This is happening despite 93.8% of the health workers reporting that they are willing to participate in the surveillance system and 96.3% of them reporting that it was their duty to complete ARV ADR reporting forms. The reported willingness to report ARV ADRs by the health workers did not translate to increased ADR reporting in Mazowe District. Khoza et al, in a study done at Parirenyatwa in 2004 revealed that 75% of the health workers reported that it was their professional obligation to report ADRs although there was gross underreporting of ADRs at the hospital[15]. The discrepancy between the reported willingness to report and the actual reporting of ADRs could be due to too much workload. Having too much workload was reported as the major reason for the failure to report ARV ADRs by the health workers in Mazowe District.

 

Limitation

 

We reached 24 (75%) of the 32 targeted health facilities offering HIV services. Nevertheless, we think that reaching three-quarters of the intended facilities could be representative of the district health facilities. We also relied on interviews with health workers which could result in some information bias. The health workers may have withheld negative information to protect the image of their health facilities and avoid potential disciplinary action. We reassured the health workers that the information that they provided would be confidential and would not be used for any purposes other than for the study.

 

 

Health worker knowledge of the ARV ADR surveillance system was poor. The surveillance system was simple and stable, but it was not acceptable, not timely, and not useful. There was poor data quality on the completed forms. The reported reasons for underreporting ARV ADRs by the health workers were mainly, perceiving the ADRs as minor and being overwhelmed with too much workload.

 

We recommend pharmacovigilance training for health workers in Mazowe District. The training should focus more on electronic reporting, which is less expensive for the district and improves on timeliness of reporting. There should be an investment in health facility phones that are compatible with electronic reporting platforms. The District Pharmacist should review monthly ADR statistics and follow up with health facilities that recorded ARV ADRs so that they also complete ADR reporting forms. Adverse drug reaction reporting should also be emphasized during support and supervision visits to health facilities. The facilities that would have reported ARV ADRs to MCAZ should be recognized during district review meetings to motivate others to start reporting. The health workers in charge of health facilities should include ARV ADR surveillance data in their institutional data analysis meetings and make use of the information.

 

The results of the evaluation were disseminated to the Mazowe District Health Executive, and the AIDS and TB Unit officials in the Ministry of Health. On-the-job training on the completion of the ADR forms, the objectives of the pharmacovigilance system, and the reporting timelines for ADR reporting were conducted to fifty health workers as part of public health actions after the evaluation.

 

 

The authors have no competing interests to declare. AD and CDU were members of the JIEPH editorial team; however, they did not play any role in the editorial decision process of the manuscript.

 

Declarations

 

Ethics approval and consent to participate

 

The study was reviewed and approved by the Mashonaland Central Provincial Ethics Committee. All the study participants signed informed consent forms before participating in the study. The names of the study participants were not written on the data collection tools.

 

Consent for publication

 

Not applicable

 

Availability of data and materials

 

The data used for analysis during the study is available from the corresponding author upon reasonable request.

 

Funding

 

We did not receive any funding for this work.

 

 

 

Conceptualization: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira, Addmore Chadambuka, Chukwuma D Umeokonkwo. Data curation: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru. Formal analysis: Godwin Choga, Mufuta Tshimanga, Tsitsi Juru, Gerald Shambira, Addmore Chadambuka, Notion Gombe, Chukwuma D Umeokonkwo. Investigation: Godwin Choga, Owen Mugurungi. Methodology: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira, Addmore Chadambuka. Project administration: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira. Resources: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru. Supervision: Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira, Addmore Chadambuka. Validation: Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru. Writing – original draft: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira, Addmore Chadambuka, Chukwuma D Umeokonkwo. Writing – review & editing: Godwin Choga, Mufuta Tshimanga, Owen Mugurungi, Tsitsi Juru, Notion Gombe, Gerald Shambira, Addmore Chadambuka, Chukwuma David Umeokonkwo. All authors read and approved the final manuscript.

 

 

We would like to express our sincere gratitude to the staff at MCAZ for their support. Special thanks go to the staff in the Family Medicine, Global and Public Health Unit, Department of Primary Health Care Sciences at the University of Zimbabwe for the guidance and support that they rendered to us. Many thanks go to the Mazowe District Health Executive and all the participants for their consent to take part in the study.

 

 

Table 1: Demographic characteristics of health workers, Mazowe District, Zimbabwe, 2021

Table 2: Health workers knowledge on the ARV ADR surveillance system, Mazowe District, Zimbabwe, 2021

Table 3: Stability of the ARV ADR surveillance system in Mazowe District, Zimbabwe, 2021

Figure 1: Flowchart for ADR reporting in Zimbabwe, designed from the Zimbabwe National Pharmacovigilance Policy Handbook, Second Edition, 2016

 

 

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