Since the beginning of the COVID-19 pandemic, several modelling studies have predicted negative collateral effects on the malaria burden in SSA, considering especially disrupted ITN campaigns and a limited access to antimalarial drugs. The study team of Weiss et al. created nine scenarios for different reductions of ITN coverage and access to antimalarial medication as well as regarding effects on malaria morbidity and mortality. As no ITN mass campaigns were scheduled for 2020 in Ghana, the worst-case scenario would have been a decline in access to antimalarials by 75% resulting in an increase of malaria morbidity and mortality by 12.6% and 54.6%, respectively (13). Overall, the predicted public health relevant effects of the COVID-19 pandemic on malaria include shared clinical disease manifestations leading to diagnostical challenges, disruptions of the availability of curative and preventive malaria commodities, significant effects on malaria programs, and in particular reduced access to malaria health services and health facilities in general (27).
In this study, we observed a slight but significant decline in malaria incidence during the 2nd and 3rd quarter of 2020 (April to September), and only a rebound to the average levels of previous years at the end of 2020. This pattern was visible in both, outpatient and inpatient settings, but more pronounced in the hospitalized population. The same applies to children and adults, where the reductions were also observed in both groups, but were more marked in children under five years of age. The marked decline in March/April 2020 can be explained by the extensive restrictions of movement and gathering and early stay-at-home advices for COVID-19-like symptoms unless these get severe. Such measures have likely supported the hesitancy to visit health facilities during the pandemic, which in turn poses a major risk for developing severe malaria (12, 28). The decline observed in March/April 2020 was even more remarkable in inpatients. This does not support our initial hypothesis, that in cases of more severe malaria manifestation, patients were still brought to health facilities and hospitalized, despite the pandemic. The findings from this analysis support the hypothesis, that the reported malaria burden in health facilities will shrink due to the effects of the COVID-19 pandemic in highly malaria-endemic countries (Heuschen et al. 2021). They also support results of the WHO World Malaria Report (12), and they agree with results of similar studies from other SSA countries classified as highly endemic for malaria, such as Sierra Leone, Uganda and the Democratic Republic of the Congo (29–32).
The distinct decrease of OPD visits in the health facilities of northern Ghana in September 2020 may also be explained by unusual heavy floods that started mid-August and could have further complicated the access to health services. Flooded land is a favorable habitat for Anopheles mosquitos, the malaria vector, what could have led to the observed increases of malaria incidence in October 2020.
Malaria incidence among pregnant women shows a different trend in northern Ghana. After a decline in reported malaria cases in April 2020, malaria figures have rebounded rapidly in this population and reached even higher levels compared to previous years. The most likely explanation of such an opposite trend would be the hesitancy of pregnant women to visit health facilities. This is probably due to the fear of getting infected with COVID-19, combined with initial disruptions of the provision of intermittent preventive treatment in pregnancy (IPTp) to women in antenatal care (ANC) services as well as the disruption of routine distribution of ITNs (33). The disrupted access to and delivery of ANC services is likely to explain the malaria case trend in April. However, without IPTp and ITNs, more women were at risk for malaria thereafter, which can explain the subsequent rise in malaria cases over the following months. Also, many pregnant women probably have sought the missed ANC after the initial movement restrictions were lifted with subsequent malaria diagnosis.
Ghana had already achieved high levels of ITN coverage, and no ITN mass campaign was planned for 2020 (12). However, the routine distribution of ITNs, which is usually done in health facilities during ANC sessions and in primary schools, needed to be adapted to the COVID-19 measures, which included school closure from March 2020 until January 2021 (34, 35). Also the seasonal malaria chemoprevention intervention for children and the annual indoor residual spraying of insecticides, which both require physical contact between the health workers and the community, needed to be modified (36, 37). As another consequence of the COVID-19 pandemic, the provision of rapid diagnostic tests for malaria is fragile, which may have led to under-diagnosis of cases (38). Finally, reports of hesitancy to visit health facilities due to fear of getting infected with COVID-19 are still common (33, 38). Last but not least, the malaria health care workers capacities were limited due to frequent reassignments to the control of COVID-19, to stigmatization or absence following quarantine, or to the development of COVID-19 disease or even death (13, 35, 39).
This study has strengths and limitations. A strength of the study is that the data represent a whole year of follow-up into the pandemic, which provides a more comprehensive picture of the effects compared to the previous studies with much shorter study periods. Limitations are that the surveillance system itself may have been affected by the pandemic, with a bias in the reported numbers. Moreover, it is not clear if the quality of surveillance data is fully comparable during the five years observed. Finally, much more people with malaria symptoms may have switched to self-medication during the pandemic, which may also have an albeit unknown effect on the malaria figures.
In conclusion, this study shows that the COVID-19 pandemic has been accompanied by a reduced malaria incidence in northern Ghana’s health facilities. Further data from other African countries and in particular data from community-based studies are needed to fully judge the impact of the pandemic on the global malaria situation.