Malaria

Eco-epidemiology of Malaria

Three important factors

•The agents (parasite) and

•The host (man and mosquito)

•The environment (abiotic and biotic)

Human Factor

•Susceptibility to infection

•Genetic factors

•Human behavior:

  Sleeping behavior

  occupation (in time & space)

  population migration

Vector factor

•Density

•Longevity (sporogony)

•Man – vector contact

•Susceptibility to malaria infection

Parasite factor

(adaptation to vector & man)

•Parasite Species P.v , P.f ,……

*Strains of the parasite

Facts on Malaria in the World.

•About 3.3 billion people - half of the world's population - are at risk of malaria. Every year, this leads

to about 250 million malaria cases and nearly one million deaths. People living in the poorest countries are the most vulnerable.

•Malaria is especially a serious problem in Africa, where one in every five (20%) childhood deaths is due to the effects of the disease.

•An African child has on average between 1.6 and 5.4 episodes of malaria fever each year. And every 30 seconds a child dies from malaria.

Environmental factors

Abiotic factors: which affect different life history stages of mosquitoes:-

For adult mosquitoes

•Environmental temperatures

•Environmental humidity

•Rainfall

•Wind

Abiotic factors

For immature stage

•Sunlight

•Permanent/ temporary nature of breeding places

•Soil conditions

•Physico-chemical conditions of breeding places 

Biotic factors

Biotic factors that affect vector bionomics are.

•Vegetation – trees , shrubs, herbs, total vegetation cover, aquatic flora & fauna

•Host availability and accessibility (man and animal) cattle, sheep, goat, buffalo, other domestic animals.

•Predators parasites & pathogens affect aquatic & adult life of vector.

Eco-epidemiological characteristics

1.  Perennial-intense transmission-  Forest areas.

2.  Seasonal transmission- I rural areas. (Open terrain agro-climatic zones).

3.  Seasonal transmission-II urban areas.

Intense Transmission

•Several infective mosquito bites every year.

•Transmission occurs for few months (6 months)

•More than one species of vectors  responsible  for transmission.

•Low vector densities & high transmission.

•Adult generally asymptomatic. Low grade parasitaemia in asymptomatic carriers.

Intense Transmission

•Young children, pregnant women suffer most due to malaria.

•Prone to faster precipitation of drug resistance as well as insecticide resistance.

•P. falciparum is the dominant species in such areas.

•These areas are stable malaria areas. 

Seasonal transmission- rural areas:

•Infective mosquito bites per person/year, are very few/ few and/ or even none in some areas.

•Active transmission may vary from few days to few weeks in a transmission season.

•Generally one species of vector like Anopheles culicifacies (in India) is mainly involved in transmission

Seasonal transmission

•Higher vector density is required for effective transmission, as the density fluctuates seasonally.

•Human population in these areas are generally susceptible or may have low grade immunity to malaria parasite & therefore all age-groups show high parasitaemia in peripheral blood.

•Asymptomatic parasite carriers are not usually seen in these areas due to poor/ no immunity to malaria.

Seasonal transmission

•All age groups can contribute to malaria transmission during transmission season or during outbreaks.

•All age groups are equally susceptible to the disease.

•Drug resistance and insecticide resistance develop at a slower pace than in intense transmission areas.

•All age groups can contribute to malaria transmission during transmission season or during outbreaks.

•All age groups are equally susceptible to the disease.

•Drug resistance and insecticide resistance develop at a slower pace than in intense transmission areas.

•These are low transmission/ epidemic prone areas with unstable malaria

•Predominantly P. vivax transmission is common  however few pockets of P. falciparum in certain localities/ villages.

Malaria- Strategy

•PARASITE ELIMINATION AND DISEASE MANAGEMENT

 •Early case detection and complete treatment with effective combination of drugs like CQ and  SP-  

   ACT

•Strengthening of referral services

•Epidemic preparedness and rapid response

INTEGRATED VECTOR MANAGEMENT (FOR TRANSMISSION RISK REDUCTION)

 •Indoor Residual Spraying in selected high risk areas

•Use of Insecticide treated bed nets

•Use of Larvivorous fish

•Anti larval measures in urban areas including biolarvicides.

•Minor engineering/environmental methods.

•SUPPORTING INTERVENTIONS

•Behavior Change Communication

•Public Private Partnership & Inter-sectoral convergence

•Human Resource Development through capacity building

•Monitoring and evaluation through periodic reviews/field visits and web based Management Information System

Malaria- Constraints

ØSurveillance - Inadequate in many districts.

ØDiagnosis & treatment – delay in diagnosis by blood slides at PHCs. 

ØHuman Resource - Inadequate especially shortage of MPW (Male), Supervisors,   Lab. Technicians etc.

ØDrug Resistance  - Emerging Chloroquine resistance in parasites

ØSpraying – Routinely poor implementation

ØInadequate IEC/BCC and capacity  resulting in less involvement of local self-govt, Corporate sector and community towards mosquitogenic conditions

ØMonitoring -  Poor monitoring & supervision mainly due to shortage of technical supervisors and mobility.

Malaria- Innovations

•Linkage with NRHM and use of NRHM Institutions for VBDCs

•Early diagnosis and treatment by

–Strengthening of human resource

–Introduction of RDK for remote and inaccessible Pf predominant areas

–Introduction of ACT combination in drug resistant areas

•GIS mapping for focused intervention in high risk prioritized districts

•Up-scaling the use of bed-nets

•Intensive monitoring & supervision

•Intensified IEC activities to involve community, PRIs, District administration for improved acceptance of the programme 

Suspected Malaria case

  A patient with fever in an endemic area during transmission season or who has recently visited an endemic area with out any other obvious cause of fever like :

—Cough and other signs of respiratory infection

—Running nose and other signs of cold

—Diarrhea

—Pelvic inflammation indicated by severe low back ache, with or with out vaginal discharge and urinal symptoms.

—Skin rash suggestive of eruptive illness.

—Skin infections e.g. boils, abscess, infected wounds

—Painful swelling of joints

—Ear discharge

Clinical malaria

  A patient with fever in endemic area during transmission season, or who has recently visited an endemic area, without any other obvious cause of fever will be considered as a case of clinical malaria if the diagnosis cannot be established within 24 hours and treated accordingly. For ruling out other causes of fever, the following should be looked for.

1. Cough and other signs of respiratory infection

2. Running nose and other signs of cold

3. Diarrhea

4. Pelvic inflammation indicated by severe low back ache, with or   without vaginal discharge and urinary symptoms

5. Skin rash suggestive of eruptive illness

7. Skin infections e.g. boils, abscess, infected wounds

8. Painful swelling of joints

9. Ear discharge

Uncomplicated malaria

—A patient with fever without any other obvious cause and diagnosis confirmed by microscopy showing asexual malaria parasites in the blood and/or positive rapid diagnostic test (RDT) and not having complications. These cases are recorded as either Pf or Pv; a case of mixed infection is recorded as Pf in the programme.

Severe malaria

—A patient, who presents with symptoms and/or signs of severe malaria with laboratory confirmation of diagnosis.

—Severe malaria is clinically characterized by confusion or drowsiness with extreme weakness (prostration).

—In addition, the following may develop: cerebral malaria;generalized convulsions; pulmonary oedema; severe anaemia; renal failure;hypoglycaemia; metabolic acidosis; circulatory collapse/shock; spontaneousbleeding; laboratory evidence of DIC; macroscopic haemoglobinuria; hyperthermia and hyperparasitaemia.

Malaria death

—Death of a patient with severe malaria, defined according to the above criteria. A death can be medically certified as due to malaria only if blood smear and/or RDT have been positive for P.falciparum.

MALARIA SURVEILLANCE

—Programme monitoring enables continuous follow up of processes and outputs to identify problems at local level and help decision making where it is most needed.

—The importance of surveillance is that it provides actionable information related to disease trends. 

—It is also important locally for the PHC team to assess the impact of malaria control activities and find prevailing gaps as well as for early detection of outbreaks.

—Correspondingly, at the district and higher levels, surveillance is useful in tracking disease burden over time and space and also to fine tune the planning.

—MPWs are involved in active case detection by house to house visit.

—Over the years shortage of these MPWs has lead to poor surveillance activity in the programme.

—The integration with NRHM and induction of Accredited Social Health Activist (ASHA), as the first point of contact with the health care delivery, has called for further modification of reporting requirements.

Active Case Detection (ACD)

—Detection of cases through house to house search of fever cases by MPW (M) is active case detection (ACD).

—In villages where no ASHA or other volunteer has been trained and deployed for providing early diagnosis and effective treatment, ACD is done with regular, preferably weekly visits, by a health worker, who provides case management also.

—The health worker during these house to house visits inquires whether there is a fever case in the residents of the household or in visitors on the day of the visit or was there any fever case between the current and previous visit, if the answer is ‘yes’, a blood slide is taken.

—The MPW (F) may also encounter fever cases during antenatal clinics or village visits.

Passive Case Detection (PCD):

—Detection of cases through the agency of health care staff like ASHAs/ CHVs/ AWWs and MO-PHC who do not search for cases through active efforts in the field is termed as Passive Case Detection (PCD).

—These cases of fever have sought health care on their own.

—These cases are important to the programme as their health care seeking behavior is based upon their felt need and recognition of illness.

—With the deployment of ASHAs in malaria endemic areas it is expected that a major proportion of malaria cases will be detected through this method.

—Some of such cases going to the MPW (M) or MPW (F) and would also be included under PCD.

Diagnosis of malaria

—Any volunteer, health worker or health professional observing a case of suspected malaria must immediately initiate a diagnostic test by

  ● Microscopy of blood for malarial parasites and/or

  ● RDT

—Wherever a microscopy result can be made available within 24 hours, microscopy will be maintained as the only routine method.

— All efforts will be made to make microscopy services available to the health care providers managing the patient within 24 hours (in practice on the day, when the patient presents or the day after). 

Malaria Drug Policy

Dosage Chart for Treatment of Vivax Malaria

Age Group  (Years)	Day 1		Day 2		Day 3		Day 4 to 14
	CQ ( 150 mg base)	PQ (2.5 mg)	CQ (150 mg base)	PQ (2.5 mg)	CQ (150 mg base)	PQ (2.5 mg)	PQ (2.5 mg)
Less tha 1 years	½	0	½	0	¼	0	0
1-4 years	1	1	1	1	½	1	1
5-8 years	2	2	2	2	1	2	2
9-14 years	3	4	3	4	1½	4	4
15 yrs or more	4	6	4	6	2	6	6
Pregnancy	4	0	4	0	2	0	0

Dosage Chart for Treatment of falciparum Malaria with ACT-SP
Age Group (Years)	1st day		2nd day		3rd day
	AS	SP	AS	PQ	AS
0-1 years (Pink Blister)	1 (25 mg)	1 (250 +12.5 mg)	1 (25 mg)	Nil	1 (25 mg)
1-4 years (Yellow Blister)	1 (50 mg)	1 (500+25 mg each)	1 (50 mg)	1 (7.5 mg base)	1 (50 mg)
5- 8 years  (Green Blister)	1 (100 mg)	1 (750+37.5 mg each)	1 (100 mg)	2 (7.5 mg base each)	1 (100 mg)
9-14 years (Red Blister)	1 (150 mg)	2 (500+25 mg each)	1 (150 mg)	4 (7.5 mg base each)	1 (150 mg)
15 & Above years  (White Blister)	1(200 mg)	2 (750+37.5 mg each)	1(200 mg)	6 (7.5 mg base each)	1(200 mg)

Dosage Chart for Treatment of mixed (vivax and falciparum) Malaria with ACT-SP
Age Group  (Years)	1st day			2nd day			3rd day		Days 4-14
	AS tablet (50 mg)	SP	PQ (2.5 mg)	AS	PQ	PQ (2.5 mg)	AS	PQ (2.5 mg)	PQ (2.5 mg)
0-1   years  (Pink Blister)	½	½	0	½	0	0	½	0	0
1-4 years (Yellow Blister)	1	1	1	1	1	1	1	1	1
5- 8 years (Green Blister)	2	1 ½	2	2	2	2	2	2	2
9-14 years   (Red Blister)	3	2	4	3	4	4	3	4	4
15 & Above years (White Blister)	4	3	6	4	6	6	4	6	6

    In cases where parasitological diagnosis is not possible due to non-availability of either 

timely microscopy or RDT, suspected malaria cases will be treated with full course of 

chloroquine, till the results of microscopy are received. Once the parasitological 

diagnosis is available, appropriate treatment as per the species, is to be administered. 

Presumptive treatment with chloroquine is no more recommended.

 

Treatment of malaria in pregnancy :

        The ACT should be given for treatment of P.falciparum malaria in second and third 

trimesters of pregnancy, while quinine is recommended in the first trimester. Plasmodium 

vivex malaria can be treated with chloroquine.