MALARIA Flashcards
What is Malaria
Malaria is a tropical infectious disease caused by transmission of plasmodium parasites from the anopheles mosquito vector to the human host. It is an an ecological hazard, a biological or chemical hazard that has the potential to impacts adversely on the well being of people or on the environment more generally. There are two infectious vectors plasmodium (p.) falciparum and p. Vivax.
Magnitude of Malaria
Incidence:
• 94% of all malaria cases globally occur in Sub-Saharan Africa.
• In 2019, there were 213 million malaria cases reported in Africa.
• Most cases are concentrated in 16 African countries, including Nigeria, the Democratic Republic of the Congo, and Uganda.
Mortality:
• In 2020, 229,000 deaths from malaria occurred in Africa, accounting for more than 60% of global malaria deaths.
• Children under 5 years old account for around 67% of malaria deaths in Africa.
Regional Variations:
• West and Central Africa are the most affected regions, with Nigeria accounting for about 25% of global malaria cases and deaths.
• East and Southern Africa have also reported significant numbers of malaria cases, though some countries, like South Africa, have made strides in reducing transmission.
Economic Impact:
• Malaria costs Africa an estimated $12 billion annually in lost productivity.
• Malaria-related illness and death reduce workforce productivity and affect agricultural output, particularly in rural areas.
Vulnerable Populations:
• Pregnant women and young children are especially vulnerable, with malaria causing 11,000 maternal deaths annually in Sub-Saharan Africa.
• Malaria is also one of the leading causes of illness among travelers in Africa.
Prevention and Treatment:
• Insecticide-treated nets (ITNs) and malaria treatment programs have reduced malaria deaths by 60% in some African countries.
• Despite progress, resistance to malaria treatments, including artemisinin, is increasing in parts of Southeast Asia, which could potentially spread to Africa.
Duration of BSB
Seasonality and Malaria Transmission
• Malaria transmission is highly seasonal, typically peaking during the rainy season. • Rainfall creates breeding sites for malaria-carrying mosquitoes, especially in stagnant water such as puddles, ponds, or ditches. • Wet season (usually 3-6 months depending on the region) encourages mosquito larvae to thrive and multiply. • During the dry season, mosquitoes’ breeding habitats dry up, leading to a decline in malaria transmission.
Temperature and Malaria Duration
• Malaria transmission is highly dependent on temperature, with an optimal range of 20°C to 30°C. • At temperatures below 20°C, mosquito activity and parasite development slow down, reducing transmission. • At temperatures above 32°C, mosquito larvae may die off or develop slower, and the malaria parasite inside the mosquito takes longer to mature. • Hotter temperatures (especially in tropical regions) can cause mosquitoes to breed more rapidly, increasing the duration of malaria transmission in some areas.
Rainfall and Mosquito Breeding
• Rainfall plays a crucial role in malaria transmission because it creates temporary standing water where mosquitoes can lay their eggs. • During the wet season, large amounts of rainfall flood areas with stagnant water, providing ideal breeding grounds for the Anopheles mosquito (vector of malaria). • Irrigation systems, reservoirs, and swamps are artificial breeding sites that increase mosquito populations and extend the malaria season, especially when water is stagnant. • In areas with irregular rainfall patterns, sudden heavy rains can cause outbreaks in regions that may not typically experience malaria transmission.
Frequency of Malaria
General Probability:
• Rural Areas in Sub-Saharan Africa, including Nigeria, face higher probabilities of malaria transmission due to favorable conditions for mosquito breeding. In rural settings, malaria transmission is 3-4 times more likely compared to urban settings.
• Urban Areas, while not immune, have a lower probability of malaria transmission due to better living conditions, healthcare access, and mosquito control measures.
Rural Areas:
• In rural Nigeria, 70-80% of malaria cases occur in these areas. The likelihood of contracting malaria in rural areas can be as high as 50-70% during peak transmission seasons, particularly the rainy months.
• Infection rates in rural Nigerian children under five are approximately 5-7 times higher than in urban children. In rural areas of Nigeria, malaria incidence rates are as high as 300-400 cases per 1,000 people annually, especially in remote villages.
Urban Areas:
• The probability of malaria in urban areas is significantly lower, but not negligible. In Nigerian cities such as Lagos, Abuja, and Kano, malaria rates are typically around 100-200 cases per 1,000 people annually, lower than in rural areas but still significant.
• Urban slums still have higher malaria rates compared to other urbanized zones, with up to 40-50% of residents in slum areas being affected due to poor infrastructure and sanitation.
Malaria in Nigeria:
• In Nigeria, 97% of the population is at risk for malaria, with rural areas having a greater probability of exposure. However, urbanization and population movement between rural and urban areas contribute to the spread of malaria even in cities.
• Malaria incidence in rural regions is approximately 250-350 cases per 1,000 people, while in urban areas it is 100-200 cases per 1,000.
• According to Nigeria’s National Malaria Control Programme (NMCP), about 50 million people in Nigeria are affected by malaria each year, with the majority living in rural areas where prevention and treatment are less accessible.
Infection Risk by Location:
• The probability of contracting malaria can also depend on specific locations within rural or urban settings:
• In rural Nigeria, the risk is highest during the rainy season (April to October), with a 2-3 fold increase in mosquito breeding grounds.
• In urban areas, the risk is typically higher in poorer neighborhoods, where sanitation systems may not be well-managed, providing breeding grounds for mosquitoes. The malaria transmission rate in these areas can be 10-20% higher than in wealthier urban districts.
Scale of Impact
Health Impact
• Prevalence: • Malaria remains one of the leading causes of illness and death in Sub-Saharan Africa, with Nigeria being one of the countries most affected. • In Nigeria, approximately 97% of the population is at risk of malaria, with 50 million cases reported annually. • Sub-Saharan Africa accounts for around 90% of global malaria cases and deaths, making it the region with the most significant burden of the disease. • Death Toll: • Malaria is responsible for approximately 200,000 deaths annually in Nigeria, which is the highest number in the world. • In Sub-Saharan Africa, malaria leads to an estimated 600,000 deaths per year, with children under five and pregnant women being the most vulnerable. • Children Under Five: • Malaria is a leading cause of death in children under five in Africa, with over 200,000 child deaths annually due to the disease. • In Nigeria, it is estimated that 25-30% of all childhood deaths are caused by malaria, highlighting the critical public health burden on younger populations. • Hospitalizations: • Malaria leads to millions of hospitalizations in both rural and urban areas of Nigeria and Africa. • In Nigeria, up to 11 million cases of malaria result in hospital visits each year, placing a substantial strain on the healthcare system.
Economic Impact
Lost Productivity:
• The economic costs of malaria in Africa are staggering. It is estimated that malaria causes economic losses of $12 billion per year across Sub-Saharan Africa due to lost productivity, healthcare costs, and early deaths.
• In Nigeria, malaria accounts for a 5% loss in GDP annually, as a significant portion of the working-age population is affected by illness, reducing overall productivity.
Impact on Agriculture:
• Malaria has a disproportionate impact on agricultural workers in rural areas. These workers are more likely to fall ill during peak transmission seasons, leading to a reduction in agricultural output.
• In Nigeria, malaria-related absenteeism among agricultural workers contributes to an estimated loss of $1 billion annually in the agricultural sector.
Healthcare Costs:
• The financial burden of malaria on healthcare systems is immense. In Nigeria, malaria-related treatment accounts for around 40% of total healthcare expenditure, further straining an already under-resourced health sector.
• Many families spend a significant portion of their income on treating malaria, with out-of-pocket costs often resulting in economic hardship.
Social Impact
Loss of Workforce:
• Malaria affects both men and women in Nigeria and Sub-Saharan Africa, but it particularly impacts women of childbearing age and pregnant women, who face higher risks of severe illness and complications.
• In rural areas, where healthcare access is limited, the impact of malaria-related illness is more pronounced as it contributes to high levels of absenteeism from work and school, impacting family income and children’s education.
Education:
• Malaria is a significant barrier to education in Africa, particularly in rural areas. Children who are frequently ill with malaria are often unable to attend school, leading to poor academic performance and dropout rates.
• In Nigeria, millions of school days are lost each year due to malaria, affecting the educational prospects of children, especially in rural regions.
Mental Health:
• The long-term social impact of malaria also includes mental health challenges, particularly for families who experience the loss of a child or breadwinner due to malaria.
• The burden of malaria on households also leads to stress, anxiety, and increased rates of depression, particularly in communities where there are limited support systems.
- Environmental Impact
Climate and Habitat Changes:
• Climate factors, such as temperature, rainfall, and humidity, significantly influence the prevalence and distribution of malaria. In rural areas with poor sanitation, the spread of malaria is exacerbated by environmental changes that increase mosquito breeding grounds, especially in rural wetlands and flood-prone areas.
• Environmental impacts of malaria are also connected to the ongoing efforts to improve clean water and sanitation, which indirectly help reduce the spread of malaria by limiting mosquito breeding sites.
Public Health Response
Control and Prevention Programs:
• A range of interventions, including insecticide-treated nets, indoor spraying, antimalarial medications, and education programs, have been implemented across Sub-Saharan Africa, including Nigeria.
• The World Health Organization (WHO) has been working with African governments and NGOs to reduce malaria prevalence through campaigns aimed at increased use of insecticide-treated nets and diagnostic testing. These efforts have been partially successful in reducing malaria cases, but challenges remain due to funding gaps, inadequate infrastructure, and resistance to antimalarial drugs.
Causes of Malaria (Climate)
Tropical Climate:
• Nigeria has a tropical climate with distinct rainy (April–October) and dry (November–March) seasons.
• Rainy season leads to stagnant water, providing breeding grounds for Anopheles mosquitoes.
Temperature Range:
• Temperatures range from 22°C to 33°C year-round, ideal for the Plasmodium falciparum parasite lifecycle.
• These temperatures allow the parasite to complete its development in 7–10 days in the mosquito.
Prevalence by Region:
• South and South-East zones: Prevalence of 16% due to higher rainfall but better healthcare access and urbanization.
• North-West zone: Prevalence of 34% due to hotter temperatures, lower rainfall, and limited healthcare access.
Breeding Grounds:
• Rainy season increases the accumulation of stagnant water in puddles, ponds, and ditches, which are breeding grounds for mosquitoes.
• The mosquitoes lay their eggs in water, where larvae hatch and develop into adults that transmit malaria.
Impact of Climate Change:
• Climate change may increase flooding, irregular rainfall, and more intense storms, expanding breeding grounds and worsening malaria transmission.
Optimal Conditions for Transmission:
• Warm temperatures and seasonal rainfall make Nigeria’s climate highly conducive to year-round malaria transmission.
• Regional Variations:
• Southern regions have slightly lower malaria rates (16%) due to urbanization and better healthcare.
• Northern regions face higher malaria prevalence (34%) due to hotter climates and poorer healthcare infrastructure.
Causes of malaria (Mosquitoes)
Primary Malaria Vector - Anopheles gambiae:
• The primary mosquito vector across most of Nigeria is Anopheles (An.) gambiae.
• An. gambiae is one of the world’s most significant malaria vectors due to its susceptibility to the Plasmodium parasite and its preference for humans as a host.
• Known for its indoor-feeding behaviour, which increases human exposure to infected mosquitoes at night.
High Population Density:
• Nigeria’s high population density increases the likelihood of close contact between people and mosquitoes, enhancing the efficiency of parasite transmission.
• People living in crowded urban and rural settings are at greater risk of malaria due to the close proximity of hosts and more frequent interactions with mosquitoes.
Plasmodium falciparum - Primary Parasite:
• P. falciparum is the dominant Plasmodium species responsible for the majority of malaria cases in Nigeria.
• Known for its severe symptoms, higher mortality rates, and resistance to treatment in some regions, making it particularly concerning.
Malaria Transmission:
• Malaria transmission is most efficient where high mosquito populations exist, and human populations are large and dense, especially in areas with poor sanitation and lack of proper vector control measures.
• Anopheles gambiae’s nocturnal and indoor-feeding habits, combined with Nigeria’s climate and population density, create ideal conditions for malaria spread.
Causes of malaria (economic)
Low GDP per Capita:
• Nigeria’s GDP per capita is 2,097.09 USD (2020), indicating a low national income.
• A low GDP results in limited government resources to implement malaria reduction measures, including prevention programs, healthcare access, and vector control.
• Limited funding hinders the ability to control and treat malaria effectively across the population.
• High Poverty and Unemployment Rates:
• 40% of Nigerians live below the poverty line, and the unemployment rate stands at 33%, which significantly impacts people’s ability to combat malaria.
• Low-income households may lack the financial resources to afford necessary malaria treatments, adequate housing, or sanitation measures that help reduce the risk of contracting the disease.
• These conditions contribute to higher vulnerability to malaria, especially in rural and disadvantaged areas.
Lack of Education and Awareness:
• Poverty often correlates with low education levels, resulting in limited knowledge about malaria prevention and treatment.
• People in poverty may not have access to information on how to protect themselves or may not be aware of the availability of effective treatments.
Economic Impact of Malaria on Businesses:
• Malaria negatively impacts businesses due to employee absenteeism, increased healthcare costs, and decreased productivity.
• 72% of companies reported a negative malaria impact, with 39% perceiving these impacts as serious.
• Employee absenteeism reduces productivity, affecting business profitability and reputation.
Impact on Household Income:
• In malaria-endemic regions, households lose up to 25% of their income due to the direct and indirect costs of malaria, including treatment, prevention, and lost work hours.
• Economic losses are further exacerbated by unproductive days spent by family members caring for sick individuals or recovering from illness.
Malaria’s Impact on National Economic Growth:
• Leading economists estimate that malaria causes an “economic growth penalty” of up to 1.3% per year in malaria-endemic African countries like Nigeria.
• Malaria discourages investments, especially in sectors like tourism, agriculture, and business development.
• The disease affects land use, crop selection, and agricultural productivity, leading to sub-optimal production.
Impact on Education and Human Capital:
• Malaria is responsible for 15% of health-related absenteeism from school in some areas.
• In malaria-endemic regions, it is estimated that up to 60% of schoolchildren’s learning ability is impaired due to the disease.
• This hampers the development of human capital, leading to long-term economic consequences due to a less educated workforce.
High Healthcare Costs:
• Malaria accounts for over 40% of the total monthly curative healthcare costs in Nigeria, diverting resources from other areas of healthcare.
• The high cost of treating malaria reduces the availability of funds for preventative healthcare and public health infrastructure improvements.
Social impacts of malaria
High Poverty and Unemployment Rates:
• 40% of Nigerians live below the poverty line, with an unemployment rate of 33%.
• Low-income households are less able to afford malaria treatments, adequate housing, or sanitation measures, increasing malaria risk.
• Vulnerable groups, particularly in rural and disadvantaged areas, face a higher vulnerability to malaria due to these financial constraints.
Lack of Education and Awareness:
• Poverty often correlates with low education levels, limiting knowledge about malaria prevention and treatment options.
• Limited access to information means many people are unaware of how to protect themselves from malaria or may not know effective treatments are available.
• This lack of health literacy contributes to higher disease prevalence and continued transmission.
Economic Impact of Malaria on Businesses:
• Malaria leads to employee absenteeism, increased healthcare costs, and decreased productivity, damaging businesses.
• 72% of companies report a negative impact due to malaria, with 39% considering it a serious issue.
• Absenteeism affects the profitability and reputation of businesses, especially in areas with high transmission rates.
Impact on Household Income:
• Households in malaria-endemic regions lose up to 25% of their income due to the direct and indirect costs of the disease, including treatment costs, prevention, and lost work hours.
• Economic losses are compounded by unproductive days spent by family members either recovering from illness or caring for sick relatives.
Malaria’s Impact on National Economic Growth:
• Malaria is estimated to cause an economic growth penalty of up to 1.3% per year in malaria-endemic countries like Nigeria.
• The disease discourages investment in key sectors such as tourism, agriculture, and business development.
• Malaria also impacts land use and crop selection, resulting in sub-optimal agricultural production and economic inefficiency.
Impact on Education and Human Capital:
• Malaria accounts for 15% of health-related absenteeism from school in some regions.
• In malaria-endemic areas, it is estimated that up to 60% of schoolchildren’s learning ability is impaired due to malaria.
• Impaired education leads to long-term economic consequences, contributing to a less skilled workforce and slower economic development.
High Healthcare Costs:
• Malaria represents over 40% of total monthly curative healthcare costs in Nigeria, placing a heavy burden on the health system.
• The high costs of treating malaria limit the resources available for preventative healthcare and critical public health infrastructure improvements.
• The strain on healthcare systems further limits access to essential services, making it harder for people to prevent or treat malaria effectively.
Environmental impacts of malaria
DDT Usage in Nigeria
• Indoor Residual Spraying (IRS) with DDT is a part of malaria control in Nigeria, especially in high-transmission areas.
• Research in regions with DDT spraying has shown detectable residues: soil samples recorded concentrations ranging from 0.5 mg/kg to 3.2 mg/kg, exceeding global safety thresholds.
• Studies have found that 10%-20% of food samples (especially vegetables) tested near treated areas contained DDT residues above permissible levels, raising public health concerns.
• Persistent contamination of water bodies near IRS-treated areas shows levels of DDT residues ranging from 0.1 µg/L to 1.0 µg/L, which can affect aquatic life and pose risks to human populations dependent on these water sources.
Larval Source Management (LSM) in Nigeria
• Efforts to drain stagnant water sources for malaria control in rural Nigeria have significantly reduced mosquito breeding habitats.
• In one study in Anambra State, swamp drainage reduced mosquito breeding sites by approximately 60%, correlating with a 40% reduction in malaria prevalence in the surrounding community.
• However, environmental modifications have disrupted natural habitats, affecting species diversity: surveys indicated a 30% decline in populations of certain fish and amphibian species due to the destruction of wetlands.
• The loss of wetland areas due to LSM practices also poses risks for local biodiversity and ecosystem services, with up to 25% of small wetlands altered or lost in some regions.
Explain the means by which the activities of people intensified the impacts of Malaria
Malaria remains one of the most significant public health challenges in Nigeria, particularly in urban areas like Lagos. The intensification of malaria’s impact can be better understood through an analysis of various human processes, behaviors, and socio-environmental conditions:
- Urban Settlement and Living Conditions
Rapid urbanization in cities like Lagos has resulted in high population density, with over 60% of residents living in more than 100 slums and informal settlements. In areas like Makoko, a third of the community lives on stilts above water. These slums are plagued by poor housing, inadequate sanitation, limited healthcare access, and lack of basic infrastructure. Such conditions provide ideal breeding grounds for malaria-carrying Anopheles mosquitoes. In Lagos, malaria accounts for more than 70% of outpatient visits to public health facilities. Crowded environments and insufficient resources exacerbate the spread of the disease, trapping vulnerable populations in cycles of poverty and poor health.
- Human Behavior and Risk Management Challenges• Misuse and Non-Compliance with Antimalarial Treatment: Malaria treatment is often hindered by improper medication usage. Non-compliance and incorrect dosing, particularly among children, contribute to treatment failure. Educating the public about the correct use of antimalarial drugs is essential to improving outcomes.
• Counterfeit Medicines: In 2001, counterfeit drugs made up 67% of all antimalarial medications in Nigeria. Although this figure has decreased to 16%, counterfeit or substandard medicines remain a significant problem. These fake drugs contribute to drug resistance and treatment failures, exacerbating malaria’s impact.
• Antimalarial Resistance: Misuse and non-compliance with antimalarial medications lead to the development of resistance in the Plasmodium parasite. This resistance reduces the effectiveness of treatments, increasing morbidity and mortality rates and further burdening public health systems. - Cultural and Behavioral Normalization of Malaria
In many Nigerian communities, malaria has become normalized, with people accepting it as an inevitable part of life. This mindset discourages individuals from engaging in preventive measures like using insecticide-treated nets (ITNs) or participating in Indoor Residual Spraying (IRS) campaigns. This cultural normalization weakens public health efforts aimed at controlling and eradicating malaria.
• Perception as a Common Ailment: Malaria is often treated as a common, flu-like illness, and many people self-diagnose and self-medicate without seeking professional medical advice. This can lead to incorrect treatment and contribute to the growing problem of drug resistance. • Stigma and Beliefs Surrounding Malaria Prevention: Cultural beliefs in some areas discourage people from using preventive measures like ITNs and IRS. There is a mistrust of these measures, with some believing the chemicals used are more dangerous than the disease itself. This mistrust is often fueled by a lack of education, fear of new technologies, or negative past experiences with public health campaigns. • Impact on Malaria Campaigns: The normalization of malaria undermines public health campaigns. Communities that view malaria as inevitable are less likely to participate in prevention initiatives, such as IRS, ITN distribution, or environmental management programs aimed at eliminating mosquito breeding grounds.
- Socio-Economic Factors• Poverty: Malaria’s economic burden is severe, with households losing up to 25% of their income to medical expenses and productivity losses. The disease affects agricultural labor, with workers often unable to perform effectively due to illness. This cycle of illness and poverty continues to hinder economic development in endemic regions.
• Education: Malaria is a significant cause of school absenteeism, impacting children’s learning abilities. In some regions, malaria negatively affects up to 60% of schoolchildren’s learning potential, hindering their educational development and future prospects. - Environmental and Sanitation Issues• Stagnant Water and Mosquito Breeding Grounds: Poor drainage systems, improper waste management, and unregulated water storage practices create stagnant water pools, which are prime breeding sites for mosquitoes. Efforts to improve sanitation and water management, such as ensuring water is stored in closed containers and implementing indoor bathrooms with running water, are essential to reducing mosquito populations.
• Farming Practices: Agricultural practices, such as flood irrigation, increase the number of standing water bodies near settlements, creating additional mosquito breeding sites. Proximity to livestock and their water sources also contributes to malaria transmission.
