SOCIETAL AND PUBLIC HEALTH MEASURES AGAINST THE EFFECTS OF SARS-COV-2 ON THE TRANSMISSION DYNAMICS OF MALARIA: A MATHEMATICAL MODELLING APPROACH

INTRODUCTION: Human beings are at constant risk of infectious diseases. No human can be exempted from the menace of epidemic disease (Ademola and Odeniran 2016) . The continuous reports from emerging and re-emerging infectious diseases remain a global concern. Transmission mecha-nisms of epidemic disease can only be properly understood by developing potent prophylactic tools for existing and emerging organisms (CDC 2019). Micro-organisms are usually the main causes of infectious diseases, depending on their virulence and pathogenic state. The major causal organisms causing infectious diseases are those of parasites, viruses and bacteria. The in-fectious attribute of pathogens connotes ”transmission of organism from an infected individual to a non-infected individual”. At this juncture, our discussion is limited to malaria, Lassa fever and malaria-Lassa fever co-infection diseases which are the main focus of this study.

Malaria, a common parasitic disease in some parts of sub-Saharan Africa, Asia and Latin America, is caused by the genus Plasmodium. There are several known species, however, hu-mans are often affected through the bite of the female Anopheles mosquito vector. Global esti-mates of malaria show 80 percent cases from Africa, and malaria is responsible for more than a million annual death in affected developing countries(WHO, 2012; CDC, 2019). Among chil-dren under five years of age, malaria seems to be the leading cause of mortality, with similar incidence among pregnant women (WHO, 2012). In pregnant women, severe malaria cases have been reported to cause maternal death, still birth, severe anaemia, congenital malforma-tions and low birth weights (WHO, 2012; Olaniyi et al 2018). The problem of chemotherapeutic drug resistance against the Plasmodium organism and insecticidal resistance on the mosquito vector has been widely reported and also linked to the growing incidence rate of malaria dis-ease in endemic communities (CDC, 2019). Therefore, the transmission dynamics can only be better understood by developing cogent parameters in the disease transmission coupled with strategically analysing the control measures to stem its spread.

The emergence of coronavirus disease (COVID-19) pandemic caused by severe acute respi-ratory syndrome coronavirus 2 (SARS-COV 2) has caused an unprecedented global societal and public health crisis (Rothan et al. 2020). The World Health Organization (WHO) declared the outbreak a public health emergency of international concern on 30 January 2020 and a pandemic on 11 March 2020. This was due to the aftermath of basic reproduction number of the novel coronavirus significantly larger than 1 (ranges from 2.24 to 3.58) (Zhao et al. 2020). While malaria and COVID-19 can have similar presentation, common symptoms they share include but not limited to: fever, breathing difficulties, tiredness and acute onset headache, which may lead to misdiagnosis of malaria for COVID-19 and vice versa, particularly when clinician relies mainly on symptoms. Malaria testing and treatment are also disturbed due to the risks faced by health workers who provide health care services during the pandemic. Decision-makers will need to make difficult choices to ensure that COVID-19 and other urgent, ongoing public health problems- including malaria endemics—are addressed while minimizing

The current data showed a lower incidence of SARS-COV 2 in developing countries, al-though the number of positive cases kept increasing on daily basis in these areas. Incidentally, malaria disease is quite endemic in most of these developing countries especially Africa, of which the overburdened health systems and societal measures aimed at curbing the SARS-COV 2 pandemic could have necessitated a negative impact on the control of malaria and subsequently leading to more deaths. As of 19th August 2020, Africa COVID-19 statistics showed that there have been 874,036 cases; 18,498 deaths and 524,557 recoveries, while global reports showed 22 million cases, 777,000 deaths and 14 million recoveries. Meanwhile, WHO malaria cases showed that there are 228 million cases and 405,000 deaths globally in 2018, of which 94% are from Africa (WHO 2019).

The person-to-person transmission of COVID-19 infection led to the isolation of patients that were administered a variety of treatments at the onset of outbreak. At present, there are no specific antiviral drugs or vaccine against COVID-19 infection for potential therapy of humans. The commonly adopted option was strategically using broad-spectrum antiviral drugs like Nu-cleoside analogues and also HIV-protease inhibitors that could attenuate virus infection until the specific antiviral becomes available (Lu et al. 2020). The treatment that have so far been attempted showed that 75 patients were administrated existing antiviral drugs. Some of the treat-ment options include, twice a day oral administration of 75 mg oseltamivir, 500 mg lopinavir, 500 mg ritonavir and the intravenous administration of 0·25 g ganciclovir for 3–14 days (Chen et al.2020). Broad-spectrum antiviral remdesivir and chloroquine have been observed to be highly effective in the control of COVID-19 infection in vitro. These antiviral compounds have been used in human patients with a safety track record. Hence, these therapeutic agents can be consid-ered to treat COVID-19 infection (Wang et al. 2020). However, the inclusion of chloroquine, a known malaria drug has drawn global debates on its effectiveness against the novel coronavirus, leading to scarcity of the drug in pharmacy especially in malaria-endemic countries.

COVID-19 intervention strategies such as city lockdown, restrictions of movements, supply chain interruptions, closure of shops and institutions, minimal contact between healthcare ser-vice providers and patients amongst others could have led to malaria prevention activities being disrupted (Sherrard-Smith, et al. 2020). Malaria prevention activities include seasonal malaria chemoprevention (SMC), mass distribution of long-lasting insecticidal nets (LLIN) and indoor residual spraying of insecticides (IRS), most of which are distributed in gatherings in form of lo-cal workshops, which could have been cancelled during COVID-19 lockdown rules. Restriction of vehicular movements could have negatively impacted the accessibility to antimalaria drugs in pharmacy for those who could afford it. Hoarding of medicines and preparations were com-mon occurrence during the pandemic and the cost of antimalaria drugs in some countries were unaffordable due to shortages in supply.

Therefore, this study investigated the impact of societal measures such as city lockdown against COVID-19 spread in malaria-endemic countries. It also estimates the proportionate in-crease or decrease of malaria due to insufficient access to antimalaria drugs during the pandemic and its global impact on the public health risk.