Malaria control efforts

The 2014-16 Ebola outbreak in West Africa dealt a “heavy blow to malaria control efforts”. As a consequence, the number of patients with malaria went up then, which could also happen now. The impact of Ebola on malaria control was further discussed in a BugBitten blog post by Vera Unwin in 2015. 

Examination of mosquito nets. Credit: Gabriel Ponce de León, M.P.H. / CDC

Today, the COVID-19 pandemic is affecting malaria control efforts, although the case numbers in Africa, the continent with the highest malaria burden, is still fairly low (17,578 confirmed COVID-19 cases and 916 deaths in all of Africa as of 16 April 2020). Insecticide-treated net (ITN) and indoor residual spraying (IRS) campaigns have already been suspended in several malaria endemic countries due to concerns around COVID-19 and supply issues.

The importance of “sustaining malaria prevention and control interventions” during the COVID-19 pandemic will be one of the topics highlighted next week during World Malaria Day (on 25 April 2020).

Diagnosis, treatment and outcome

During the 2014-2016 Ebola outbreak, the number of patients who received appropriate treatment for malaria went down – despite the above mentioned increase in cases. One reason was that patients started to avoid health care facilities due to the fear of contracting Ebola there. Consequently, there was a significant increase of malaria deaths. 

In addition, the presence of malaria could complicate the diagnosis of COVID-19 due to similar symptoms at the onset of both diseases, says Dr. Chikwe Ihekweazu, the director of the Nigerian CDC. His colleague Dr. Ifeanyi Nsofor of Nigeria Health Watch mentioned in a conversation with me that he had observed patients with symptoms like fever asking to get tested for COVID-19 before malaria. As a result, malaria diagnosis and treatment get delayed. Also, “disruptions in the supply chains of essential malaria commodities“, including rapid diagnostic tests and antimalarial medicines, have been reported as an indirect conseqence of the COVID-19 pandemic.

As COVID-19 mortality is higher among people with underlying health conditions, Dr. Ngozi Erondu, an associate fellow in the Global Health Program at Chatham House in London, hypothesizes that malaria may increase the percentage of severe COVID-19 cases.  

Class 3 biosafety cabinet for samples to be tested for COVID-19. Credit: Nigeria Health Watch

Malaria vaccine candidates

2019 saw the start of a large trial of a malaria vaccine candidate in Malawi, Ghana and Kenya planned to last four to five years; another one was suppossed to start in Equatorial Guinea in 2020. Even without an ongoing pandemic, the vaccince candidate whose trial started last year was facing quite a few challenges: the limitation of the candidate (only partial protection over a limited time), the feasibility of administering several doses according to schedule, claims that parents were not sufficiently informed about potential risks, rumours about the candidate causing infertility and the discussion whether written consent should have been gotten from the parents.

The WHO had intentions to decide after 24 months whether the use of the currently tested vaccine candidate should be extended to other African countries. Already before the COVID-19 pandemic, this timeline was under critique, especially due to “higher risks of meningitis, cerebral malaria, and doubled female mortality” associated with the vaccine.

Due to the COVID-19 pandemic, malaria vaccine candidates will be facing even more obstacles. By now, a consortium established for testing malaria vaccines has joined the fight against COVID-19, thus possibly decreasing their resources for malaria vaccines. External funds might be diverted for the same reason. Avoidance of health care facilities (mentioned above) means a decrease of participants. Most likely, other challenges will also rise. 

Now what? 

Computer monitors at the Nigerian CDC showing surveillance trends for various diseases and conversations on social media that can be relevant to the control of COVID-19. Credit: Paul Adepoju / Nature Medicine

The WHO recommends a continuation of malaria control efforts, delivery of intermittent preventive treatment in pregnancy (IPTp), seasonal malaria chemoprevention (SMC), and intermittent preventive treatment in infants (IPTi) as well as systematic malaria diagnostics as part of fever management and measures for early detection and treatment of malaria. At the same time, best practices must be observed to protect health workers.

As the situation is dynamic, it is likely that modifications to current strategies will become necessary – such as “a temporary return to presumptive malaria treatment, or the use of mass drug administration.” Although not mentioned specifically in this report by the WHO, the impact on malaria vaccine trials should be watched carefully and minimized where possible.

In addition, there is a need to distribute accurate information, such as the basic WHO-recommended protective measures, and to (re)build trust in the health care system.