MALARIA

CONTENTS

1) Introduction 2) Vector 3) Causes 4) Epidemiology 5) Transmission6) Life cycle of plasmodium vivax7) Signs and symptoms8) Prevention9) Treatment

INTRODUCTION

Malaria is a protozoal disease caused by the bite of infected female anopheles mosquito.

Malaria is both preventable and curable.Malaria is an important cause of death and

illness in tropical countries.

Malaria kills more than 3000 children under the age of five each year and more than 1.5 million each year.

According to WHO it has an infection rate of approximately 400 to 500 million a year of which majority of cases occur in sub-Saharan Africa where poverty is the biggest problem facing this epidemic.

HISTORY

Laveran(1880) a french physician working in Alergia identified the causative agent for human malaria while viewing blood slides under microscope.

P.vivax and P.malariae were identifed in 1885 byGolgi while sakharov(1897) and Marchifava and celli(1890)identified P.falciparam. .

Sir Ronald Ross(1897) demonstrated the malarial oocysts in the gut tissue of female anopheles mosquito

VECTOR

Malaria is a protozoan disease caused by the bite of infected female anopheles mosquito.

A single infected vector ,during her life time,may infect several persons.

The mosquito is not infected unless sporozoites are present in salivary glands.

CAUSES:

Malaria is caused by the bite of four species of parasite:

Plasmodium vivaxPlasmodium ovalePlasmodium malariaePlasmodium ovale

A bitting mosquito:

INCUBATION PERIOD

The duration of infection varies with the species of parasite:

Plasmodium falciparam-12 daysPlasmodium ovale-17 daysPlasmodium vivax/Plasmodium malariae-28

days

EPIDEMIOLOGY:

HOST

AGENT ENVIRONMENT

Host factor:

AgeSex RacePregnancyHousingOccupation Immunity Socio economic developmentPopulation mobility

Environmental factors:

Season TemperatureHumidityRainfallAltitude

Agent factor:

The severity of malaria is related to the species of malaria.

Malaria due to Plasmodium falciparam is the dangerous one.

Malaria in world:

According to world malaria report 2008:Annual worldwide cases of acute illness due

to malaria:300-500 millionAnnual worldwide deaths due to

malaria:881,000.Number of malaria endemic countries:109Number of people risk for malaria:3.3 millionMalaria is endemic to majority of sub-

Saharan African countries.

Malarial drug resistant map:

Global distribution:90% almost all cases occur in topical countries, in sub Saharan in Africa.

Percent of malaria deaths in children under 5:85%During the 1950s and 1960s a vigorous campaign to

eradicate malaria was waged through out the world with great success. The disease was in the process of being eliminated in some regions. But over the past few decades, resurgence is being witnessed. The dream of the global eradication of malaria is beginning to fade with the growing number of cases, rapid spread of drug resistance in people and increasing insecticide resistance in mosquitoes.

Epidemiology in Nepal:

About 10,000 cases of malaria was reported each year in Nepal, with 90% being of the species Plasmodium vivax, which causes a relatively benign form of malaria. The remainder of cases Plasmodium falciparam malaria,a potentially dangerous infection. In addition ,the transmission of malaria is very seasonal, with most transmission occuring between June and August, and very little occuring in winter months between November and March.

It is mostly seen in 12 districts Jhapa ,Morang, and Illam in Eastern Region;Dhanusa, Mahottari, Sindhuli and Kabre in Central Region;Nawalparasi in Western Region;Bardia in Mid-Western Region;Kailali, Kanchanpur and Dadeldhura in Far-Western Region.

Transmission

Vector transmission

Direct transmission

Congenital transmission

Vector transmission

Malaria is transmitted by the bite of certain species of infected female anopheles mosquito.

A single infected vector during her life time ,may infect several persons.

The mosquito is not infected unless the sporozoites are present in the blood.

Direct transmission:

Malaria may be induced accidentally by hypodermic intramuscular and intravenous injection of blood.

eg: blood transfusion, malaria in drug addicts.

Congenital transmission:

Transmission of malaria from infected mother to a newborn but it is comparatively rare.

Life cycle:

Clinical features:

The typical attack comprises three stages:a) Cold stage:

In early part of this stage, skin feels cold and later it becomes hot. The temperature rises rapidly to 39-41 degree Celsius. parasites are usually demonstrable in the blood. The pulse is rapid and may be weak. This stage last for 2-6 hrs.

b)Hot stage: The skin is hot and dry to touch. Headache

is intense but nausea commonly diminishes.The pulse is full and respiration is weak. This stage last for 2-6 hrs.

c)Sweating stage: fever comes down with profused sweating.

The temperature drops down to normal and skin is cool and moist. The pulse rate becomes slower. Patient feels relieved and often falls sleep. This stage last for 2-4 hrs.

Signs and Symptoms:

HeadacheFeverChillsSweatingDry coughSplenomegalyNauseaVomitingBack pain

Prevention:

1) Avoiding mosquito bites like by wearing full sleeve clothes to limit exposed skin.

2) Using mosquito repellent cream or mustard oil in exposed parts.

3) Insecticide-treated mosquito nets.

4)Filling the ditches with mud or sand so that there maynt be the collection of water which is a reservoir of mosquito in rainy season.

5)Maintaining sanitation around the housing areas by removing large bushes,properly disposing garbage

Treatment:

We can treat malaria by the use of following antimalarial drugs.

a) Chloroquineb) Mefloquinec) Primaquined) Quinidinee) Tetracyclinef) Artesunate

Control stragies made by Nepal govt. for its control:

• Malaria control has been integrated at all levels. • At central level MCP is a unit under Section of

Disease Control of the Directorate of Epidemiology and Disease Control.

• SEAR working group recommendation on revised control strategy has been adopted.

•  India and Nepal has prepared a joint plan of action for cross-border interventions and selected three districts namely Kailali, Bara and Rautahat. For these districts, a plan of action that includes kala-azar, TB and HIV/AIDS has been developed and will become operational in 2002.