The Challenge of Malaria

Malaria, the disease as old as humanity itself, and often called as the ‘King of Diseases’, continues to haunt and taunt mankind. Known since millennia, malaria has played a major role in the history of mankind and it is often said that but for malaria, the history and geographical demarcations of our planet would have been different from what we have today. More than a century after identification of the causative parasites, and more than half a century after finding effective drugs and insecticides, it continues to wreak havoc on millions, particularly in the poorest parts of our world. Malaria is the fifth cause of death from infectious diseases worldwide (after respiratory infections, HIV/AIDS, diarrhoeal diseases, and tuberculosis) and the second in Africa, after HIV/AIDS. The dreaded disease is difficult to eradicate and its control is possible ONLY with coordinated efforts of the general public, healthcare personnel and government agencies. With global warming threatening to increase the mosquito density and the spread of other mosquito borne infections like Dengue and Chikungunya, time has come for all of us to wake up.

Malaria is an infectious disease caused by the parasites called Plasmodia. There are five identified species of this parasite causing human malaria, namely, Plasmodium vivax, P. falciparum, P. ovale, P. malariae and P. knowlesi. The infection is transmitted between humans by the female anopheles mosquito. It is a disease that can be treated in just 48 hours, yet it can cause fatal complications if the diagnosis and treatment are delayed. Despite centuries of efforts, malaria continues to infect millions and kill thousands.

Malaria transmission occurs in five of the six WHO regions, with Europe remaining free. Globally, an estimated 3.2 billion people continue to be at risk of being infected with malaria and developing disease, and 1.2 billion are at high risk (>1 in 1000 chance of getting malaria in a year). According to World Malaria Report 2018, in 2017, an estimated 219 million cases of malaria occurred worldwide, compared with 239 million cases in 2010 and 217 million cases in 2016. Although there were an estimated 20 million fewer malaria cases in 2017 than in 2010, data for the period 2015–2017 highlight that no significant progress in reducing global malaria cases was made in this timeframe. Most malaria cases in 2017 were in the WHO African Region (200 million or 92%), followed by the WHO South-East Asia Region with 5% of the cases and the WHO Eastern Mediterranean Region with 2%.

Globally in 2019, there were an estimated 227 million malaria cases in 85 malaria endemic countries. According to WHO’s latest World Malaria Report 2021, there were an estimated 241 million malaria cases and 627 000 malaria deaths worldwide in 2020, about 14 million more cases and 69 000 more deaths in 2020 compared to 2019. Approximately two thirds of these additional deaths (47 000) were linked to disruptions in the provision of malaria prevention, diagnosis and treatment during the pandemic. Most of the increase came from countries in the WHO African Region, with an estimated 228 million malaria cases in 2020, accounting for about 95 per cent of cases.

In 2020, twenty-nine countries accounted for 96 per cent of malaria cases globally. Six countries – Nigeria (27 per cent), the Democratic Republic of the Congo (12 per cent), Uganda (5%), Mozambique (4%), Angola (3.4%) and Burkina Faso (3.4%) – accounted for about 55 per cent of all cases globally. India accounted for 83 per cent of cases in the WHO South-East Asia Region. Sri Lanka was certified malaria-free in 2016 and remains malaria-free. It is clear that crucial milestones of the WHO Global Technical Strategy for Malaria 2016–2030 have been missed in 2020 and the 2030 targets will not be met without immediate attention.

In 2020, 29 of the 85 countries that were malaria endemic (including the territory of French Guiana) accounted for about 96% of malaria cases and deaths globally. Nigeria (26.8%), the Democratic Republic of the Congo (12.0%), Uganda (5.4%), Mozambique (4.2%), Angola (3.4%) and Burkina Faso (3.4%) accounted for 55% of all cases [WMR 2021]

Four countries accounted for just over half of all malaria deaths globally: Nigeria (31.9%), the Democratic Republic of the Congo (13.2%), the United Republic of Tanzania (4.1%) and Mozambique (3.8%).[WMR 2021]

The malaria mortality rate halved between 2000 and 2015, from about 30 to 15 per 100 000 population at risk, then reduced slightly to 14 in 2019 before increasing back to 15 in 2020. The percentage of total malaria deaths among children aged under 5 years continued to decline over the past 20 years, from 87% in 2000 to 76% in 2019, but increased slightly to 77% in 2020.[WMR 2021]

The proportion of cases due to Plasmodium vivax reduced from about 8% (18.5 million) in 2000 to 2% (4.5 million) in 2020. P. vivax caused 64-78% of cases in the WHO Region of the Americas, 34-52% of cases in the WHO South-East Asia Region, 37% of cases in the WHO South-East Asia Region, 18-35% in the WHO Eastern Mediterranean Region, 13-36% in the Western Pacific region, and 0.3-2% in the African region.[WMR 2021]

According to the World malaria report 2022 [WMR 2022], globally in 2021, there were an estimated 247 million malaria cases in 84 malaria endemic countries, an increase of 2 million cases compared with 2020. Between 2000 and 2015, case numbers steadily decreased from 245 million to 230 million across the 108 countries that were malaria endemic in 2000. Since 2016, malaria cases have increased; the largest annual increase of 13 million cases was observed between 2019 and 2020 during the first year of the COVID-19 pandemic. The increase in cases between 2020 and 2021 was considerably smaller, with 2 million additional cases. Overall, an estimated additional 13.4 million cases were attributed to disruptions during the COVID‑19 pandemic.[WMR 2022]

Most of the increase in case numbers over the past 5 years occurred in countries in the WHO African Region. Malaria case incidence declined from 82.3 per 1000 population at risk in 2000 to 57.2 in 2019, before increasing by 4% to 59.4 in 2020. There was no change in case incidence between 2020 and 2021. Despite the increase in cases, the results suggest that efforts by countries and partners averted the worst-case scenario projected at the start of the pandemic.[WMR 2022]

Since 2000, malaria deaths declined steadily from 897 000 to 577 000 in 2015, and to 568 000 in 2019. The malaria mortality rate halved between 2000 and 2015, from 30.1 per 100 000 population at risk to 15.0 per 100 000; it then continued to decline, reaching 14.0 per 100 000 in 2019. In 2020, the mortality rate increased to about 15.1 per 100 000 population at risk before decreasing slightly to 14.8 in 2021. However, in 2020, malaria deaths increased to an estimated 625 000, an increase of 57 000 deaths from 2019. The estimated deaths in 2021 were 619 000, a slight decline compared with 2020. Between 2019 and 2021 there were 63 000 deaths that were due to disruptions to essential malaria services during the COVID-19 pandemic.[WMR 2022]

The percentage of total malaria deaths among children aged under 5 years declined over the past 20 years, from 87.3% in 2000 to 76.8% in 2015, but since then it has remained unchanged. In 2021, 29 of the 84 countries that were malaria endemic (including the territory of French Guiana) accounted for about 96% of malaria cases and deaths globally.[WMR 2022]

Four countries accounted for almost half of all cases: Nigeria (26.6%), the Democratic Republic of the Congo (12.3%), Uganda (5.1%) and Mozambique (4.1%) (Fig. 3.2c). Also, four countries accounted for just over half of all malaria deaths globally: Nigeria (31.3%), the Democratic Republic of the Congo (12.6%), the United Republic of Tanzania (4.1%) and the Niger (3.9%). Nigeria accounted for 38.4% of global malaria deaths in children aged under 5 years.[WMR 2022]

Efforts to control malaria are being strengthened, with gradual increase in funding, better diagnosis and treatment, and increased coverage of mosquito control measures and provision of insecticide treated bednets. According to WMR 2015, 57 of 106 countries that had ongoing transmission in 2000 have reduced malaria incidence by >75% and another 18 countries are estimated to have reduced malaria incidence by 50–75%. In 2016, 44 countries reported fewer than 10 000 malaria cases, up from 37 countries in 2010, and Kyrgyzstan and Sri Lanka were certified by WHO as malaria free. Also in 2016, WHO identified 21 countries with the potential to eliminate malaria by the year 2020.[WMR 2017] In endemic areas of Africa, infection prevalence among children aged 2–10 years is estimated to have declined from 33% in 2000 to 16% in 2015, with three quarters of this change occurring after 2005. Of the 15 countries with highest malaria incidence, Nigeria ranked at the top with an estimated 85 million cases,

More than 30000 cases of malaria are reported annually among travelers from developed world visiting malarious areas.[Leder K et al] With the shrinking globe, perennially prevalent malaria, therefore, remains an ever existing danger for humanity, in every part of the globe. In most areas, malaria and poverty co-exist, with the average GDP and average growth of per capita GDP in malarious countries being about one fifth of those in non-malarious countries.

Yet a lot more remains to be done and challenges are also increasing. Global financing for malaria control increased from an estimated US$ 960 million in 2005 to US$ 2.5 billion in 2014. International funding for malaria control, which accounted for 78% of malaria programme funding in 2014, decreased from US$ 2.1 billion in 2013 to US$ 1.9 billion in 2014 (i.e. by 8%), primarily due to changes in the funding arrangements of the Global Fund to Fight AIDS, Tuberculosis and Malaria. Most (82%) international funding was directed to the WHO African Region. Domestic funding for national malaria control programmes (NMCPs) was estimated to have increased by 1% between 2013 and 2014, from US$ 544 million to US$ 550 million. Spending on malaria control commodities (ACTs, ITNs, insecticides and spraying equipment for IRS, and RDTs) is estimated to have increased 40-fold over the past 11 years, from US$ 40 million in 2004 to US$ 1.6 billion in 2014, and accounted for 82% of international malaria spending in 2014. In that year, ITNs were responsible for 63% of total commodity spending, followed by ACT (25%), RDTs (9%) and IRS (3%).[WMR 2015] In 34 out of 41 high-burden countries, which rely mainly on external funding for malaria programmes, the average level of funding available per person at risk in the past 3 years (2014–2016) reduced when compared with 2011–2013. Exceptions were Democratic Republic of the Congo, Guinea, Mauritania, Mozambique, Niger, Pakistan and Senegal, which recorded increases. Among the 41 high-burden countries, overall, funding per person at risk of malaria remains below US$ 2.[WMR 2017]

Availability and accessibility of treatment for malaria need to be increased. Although, the proportion of children aged under 5 years, with P. falciparum malaria and who received an ACT, is estimated to have increased from less than 1% through 2005 to 16% in 2014, this proportion falls substantially short of the target of universal access for malaria case management, as envisaged in the GMAP. The number of ACT treatment courses procured from manufacturers increased from 11 million in 2005 to 337 million in 2014; the WHO African Region accounted for 98% of all manufacturer deliveries of ACT in 2014, with more than half of the total being doses for children. The number of ACT treatments delivered by manufacturers to the public sector in 2014 (223 million) was lower than the number delivered in 2013; likewise, NMCPs distributed 169 million treatments in 2014 through public sector facilities, approximately 20 million fewer than in 2013. [WMR 2015] According to WMR 2017, among 18 household surveys conducted in sub-Saharan Africa between 2014 and 2016, the proportion of children aged under 5 years with a fever who received any antimalarial drug was 41% (IQR: 21–49%). A majority of patients (70%) who sought treatment for malaria in the public health sector received ACTs, the most effective antimalarial drugs. Children are more likely to be given ACTs if medical care is sought at public health facilities than in the private sector.

Of the 78 countries reporting any monitoring data since 2010, 60 reported resistance to at least one insecticide in one malaria vector from one collection site, and 49 countries reported resistance to insecticides from two or more insecticide classes. Pyrethroid resistance was the most commonly reported; in 2014, three quarters of the countries monitoring this insecticide class reported resistance.

©malariasite.com ©BS Kakkilaya | Last Updated: May 25, 2023