Malaria

• Malaria is a tropical disease caused by Plasmodium parasites
• Parasites spread to people through the bites of infected female Anopheles mosquitoes
• Over 200 parasite species but only five (5) of these species cause malaria in human
• 2 of these species –P. falciparum and P. vivax – pose the greatest threat.
• The other species are P. ovale, P. knowlesi and P. malariae.
• P. falciparum is the most prevalent malaria parasite on the African continent.

Distribution:

Time:

• Occurs all year round in endemic countries though incidence is higher during the rainy season

Place:

• About 109 countries in the world are considered endemic for malaria. These are mainly tropical and subtropical countries

Person:

• Affects everyone but those most vulnerable are the children U5 and pregnant women

Determinants

Agent:

• Plasmodium spp (vivax, falciparum, malariae, ovale, knowlesi)
• Agent undergoes an asexual cycle in human and a sexual cycle in the female anopheles mosquito

Host:

`

• Age (NB, U5), Sex (M>F), Race, Pregnancy status, SES, Housing, Population mobility, Occupation, Immune status

Environment:

• Season, Temp, Humidity (60%), Rainfall, Altitudes (<2000m)

Mosquito borne disease in humans and animals with IP of about 10 days on average

Caused by Plasmodium especially species falciparum and vivax.

The mosquitoes which act as vector for this disease are female Anopheles funestus, Anopheles moucheti, Anopheles gambiae and Anopheles arabiensis.

In 2016, nearly half of the world's population was at risk of malaria.

Most malaria cases and deaths occur in sub-Saharan Africa.

In 2016, 91 countries and areas had ongoing malaria transmission.

Some population groups are at considerably higher risk of contracting malaria, and developing severe disease, than others.

Infants, children U5, pregnant women and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travellers.

Malaria is endemic in Nigeria but the most vulnerable are the pregnant women and children under 5 years.

Major public health concern: High IMR, MMR

The major complications in pregnant women: LBW babies, fetal complications, new born death.

• Malaria affects 3.3 billion people in106 countries
• WHO estimates 216 million cases of malaria occurred in 2016, 81% in the African region, up from 211 million cases in 2015
• 655,000 malaria deaths in 2010, 91% in the African Region
• 86% were children under 5 years of age.
• Burden greater in the African Region
• In 2016, Africa had 90% of malaria cases and 91% of malaria deaths
• The major African countries contributing to the burden are: Nigeria, Democratic Republic of Congo (DRC), Ethiopia, and Uganda
• Account for nearly 50% of the global malaria deaths.
• Malaria is the second leading cause of death from infectious diseases in Africa, after HIV/AIDS.
• Malaria is the third leading cause of death for children under five years worldwide, after pneumonia and diarrheal disease
• Almost 1 out of 5 deaths of children under 5 in Africa is due to malaria, taking the life of a child every two minutes.
• The risk of HIV is increased because Malaria causes anemia which may require blood
• PLWHA are at an increased risk of clinical malaria, severe illness, hospitalization, and death
• Malaria contributes to a temporary increase in viral load among HIV-infected people
• In Nigeria, Malaria is a major public health problem where it accounts for more cases and deaths than any other country in the world
• Malaria is a risk for 97% of Nigeria’s population
• There are an estimated 100 million malaria cases with over 300,000 deaths per year in Nigeria.
• Malaria contributes to an estimated 11% of maternal mortality
• Accounts for 60% of outpatient visits and 30% of hospitalizations among children under five years of age in Nigeria
• Malaria also has the greatest prevalence, close to 50%, in children age 6-59 months in the South West, North Central, and North West regions.
• Malaria has the least prevalence 27.6 percent in children age 6-59 months in the South East region.

• Malaria is transmitted through the bites of female Anopheles mosquitoes.
• There are more than 400 different species of Anopheles mosquito
• The important vector species bite between dusk and dawn
• The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.
• Agent – Plasmodium spp
• Host – humans
• Environment
• Vector – female anopheles mosquito

• Anopheles mosquitoes lay their eggs in water
• Hatch into larvae and emerges as adult mosquitoes
• The female mosquitoes seek a blood meal to nurture their eggs.
• Transmission is more intense in places where the mosquito lifespan is longer.
• The long lifespan and strong human-biting habit of the African vector species is the main reason why nearly 90% of the world's malaria cases are in Africa.
• Transmission also depends on climatic conditions that may affect the number and survival of mosquitoes, such as rainfall patterns, temperature and humidity
• In many places, transmission is seasonal, with the peak during and just after the rainy season.
• Malaria epidemics can occur when climate favors transmission, in people with little/no immunity to malaria.
• Human immunity is an important factor, especially among adults
• Partial immunity developed over years of exposure reduce the risk of severe disease.
• For this reason, most malaria deaths in Africa occur in young children
• Whereas in areas with less transmission and low immunity, all age groups are at risk.

Acute febrile illness.

In a non-immune individual, symptoms usually appear 10–15 days after the infective mosquito bite.

The commonest symptoms are listed as follows:

• Fever
• Headache
• Joint aches
• Muscle aches
• Abdominal discomfort
• Vomiting
• Lethargy
• Anorexia

1° Prevention

Health promotion and specific protection.

• Vector control is the main way to prevent and reduce malaria
• Two forms of vector control are effective in a wide range of circumstances.
• Insecticide-treated mosquito nets
• Indoor spraying with residual insecticides
• Other adjunct measures
• Vaccines against malaria
• RTS,S/AS01 (RTS,S) – also known as Mosquirix
• Environmental sanitation, wearing long clothing.

2° Prevention

Early diagnosis and treatment of malaria reduces disease and prevents deaths

• It also contributes to reducing malaria transmission
• WHO recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before administering treatment.
• Treatment, solely on the basis of symptoms should only be considered when a parasitological diagnosis is not possible.
• Artemisinin based combination therapy (ACT) for uncomplicated malaria
• Antimalarial medicines can also be used to prevent malaria.
• For pregnant women living in moderate-to-high transmission areas, WHO recommends IPT with SP

3° prevention

Limitation of disability, rehabilitation and surveillance

• Surveillance entails tracking of the disease and programmatic responses, and taking action based on the data received
• Weak surveillance systems in Nigeria.
• Effective surveillance is required at all points on the path to malaria elimination.
• Stronger malaria surveillance systems are urgently needed to enable a timely and effective malaria response in endemic regions, to prevent outbreaks and resurgences, to track progress, and to hold governments and the global malaria community accountable

• Malaria elimination is the interruption of local transmission of a specified malaria parasite species in a defined geographical area as a result of deliberate activities
• Continued measures are required to prevent re-establishment of transmission.
• Malaria eradication is the permanent reduction to zero of the worldwide incidence of malaria infection caused by human malaria parasites as a result of deliberate activities.
• Interventions are no longer required once eradication has been achieved.

Adopted by the World Health Assembly in May 2015 with strategies:

• Reducing malaria case incidence by at least 90% by 2030.
• Reducing malaria mortality rates by at least 90% by 2030.
• Eliminating malaria in at least 35 countries by 2030.
• Preventing a resurgence of malaria in all countries that are malaria-free.

These Strategies were based on 3 key pillars:

• Ensuring universal access to malaria prevention, diagnosis and treatment;
• Accelerating efforts towards elimination and attainment of malaria-free status; and
• Transforming malaria surveillance into a core intervention.

• An estimated 65% of Nigeria’s population live in poverty and poverty is a major factor in malaria prevention and treatment.
• Vector control is highly dependent on a single class of insecticides, the pyrethroids with high resistance in 27 SSA countries
• Flouting of government policies by health care providers as well as apathy /Poor attitude of professionals
• Quantity and quality of health care providers, Relegation of Training and retraining, Staff attrition
• Inadequate funding and absence of local capacities for commodities as well as infrastructure (enabling environment)
• Logistics and security issues