Malaria prevention

prevention and control of malaria

1. MALARIA CONTROL AND PREVENTION

2. DIAGNOSIS- Microscopic Serological test Rapid diagnostic test

3. microscopy Two types of blood films are useful in searching for and identification of malaria parasite. The "thin film" and the "thick film". It is recommended that both types of film be prepared on a single microscope glass slide. The thick film is more reliable in searching for parasite, as large volume of blood is examined under each microscope field. The thin slide is more valuable for identifying the species of the parasite present.

4. Serological test The malarial fluorescent antibody test usually becomes positive two weeks or more after primary infection . The test is of the greatest value in epidemiological studies and in determining whether a person has had malaria in the past .

5. Rapid diagnostic test (RDT) Rapid Diagnostic Tests are based on the detection of circulating parasite antigens with a simple dipstick format.

6. Measurement of malaria- It is u sed to know the malaria load in the community. API- Annual Parasite Incidence ABER-Annual Blood Examination Rate AFI- Annual Falciparum Incidence SPR- Slide Positivity Rate SFR-Slide Falciparum Rate among these API AND ABER and SPR Important.

7. Annual blood examination rate (ABER): It is the percentage of the population examined for peripheral blood smear during a given year. Government of India, under MPO, fixed a minimum of ABER of 10 percent per year. This is an index of operational efficiency (i.e. quality of case detection).

8. Annual parasite incidence (API): It is the number of new confirmed cases of malaria occurring in an area during a given year and confirmed by blood smear examination and is expressed per 1000 population. This is a sophisticated indicator to measure malaria. Based on this, India was redefined, under the Modified Plan of Operation of Malaria Control, into two areas, for spray operations.

9. Slide positivity rate (SPR): It is the percentage of slides (smears) found positive for malarial parasites, irrespective of type of species. This gives information about the parasite load in the community.

10. Approaches to malaria control Management of malaria cases in the community. Active intervention to control or interrupt malaria transmission with community participation.

11. Management of malaria cases in community- Health guides and multipurpose workers are fully trained to detect and treat cases of malaria at the community level with support from referral system(PHC,CHC and higher levels).

12. Prevention and control- Elimination of reservoirs Breaking the channel of transmission Protection of susceptible

13. Elimination of reservoirs- This consists of making the infectious cases non-infectious by giving treatment. The treatment consists of presumptive treatment, radical treatment and mass treatment. Early diagnosis and treatment of the infectious malaria cases. Mass treatment in cases of highly endemic areas . Chemoprophylaxis with chloroquine for travelers to malarious areas, pregnant women living in endemic and hyperendemic areas.

14. Presumptive treatment: All fever cases attending hospitals for the treatment, are assumed to be the cases of malaria and treated accordingly, depending upon whether that area is a low-risk area or high-risk area . Radical treatment: This is given for those, whose blood smear report comes as positive for malarial parasites Mass treatment: This is recommended in highly endemic areas, where API is more than 5 per 1000 population. This will be more effective, when supplemented by anti-mosquito measures.

15. Breaking the Channel of Transmission This measure consists of control of vectors. The different methods of control of vectors are - a. Antiadult measures b . Antilarval measures.

16. Anti-adult measures: This consists of spraying the insecticides - Residual spraying: This consists of spraying of indoor surfaces of houses, cattle sheds with residual insecticides like DDT, malathion , fenitrothion. Space spraying: This consists of out-door spraying of the insecticides. The technology is that the insecticide ( malathion ) is sprayed in the form of fog or mist by ultra low volume thermal fogging method by using agricultural aircraft or by using ground equipment, fitted over a vehicle. This method controls the vectors quickly.

17. Anti-larval measures: This consists of bioenvironmental control strategy components are - Source reduction. Environmental modification and manipulation. Biological control . Source reduction : This consists of elimination of nonessential water bodies, which includes periodical emptying of domestic water container, sealing of water tanks, filling pot holes, puddles, burrow–pits and canalizing drains so that water does not stagnate.

18. Environmental modification and manipulation : This consists of leveling of land or filling of depressions and making of soakage pits help in prevention of mosquito breeding . Biological control : Mosquitoes (Larvae) can also be controlled by employing their natural enemies such as fish, bacteriae and fungi.

19. Biological control Larvivorous fish : Use of larvivorous fish are the most promising ones. Gambusia affinis and Lebister reticulates (often known as Barbados millions). Other fish which can also be employed is Poecilia reticulata. Use of bacteriae (i.e. Biocides): The best known biocides are Bacillus sphaericus and Bacillus thuringiensis. They kill the mosquito larvae . should not be used for larval control in potable water, i.e. drinking water collections.

20. Integrated control: It includes bioenvironmental and personal protection measures, so that the vectors can be controlled effectively. Thus, integrated control is an approach , considering more than one method , whether directed only against larvae or adults or both.

21. Personal Protection These measures are directed against mosquito bites. a. Bednets: Nylon nets are preferred over cotton nets, because of their durability .They are impregnated with an insecticide either one g of deltamethrin or 0.5 g of cyfluthrin or 0.25 g of lambda cyhalothrin per square meter of mosquito-net. T he impregnated net will have efficacy for 6 months when not washed.

22. b. Use of mosquito repellents: They are applied on the skin . They repell the mosquitoes by their smell and protect the individual from the mosquito bites. Diethyl-toluamide (DEET) has been found to be very effective. Other repellents are Indalone, Dimethyl phthalate, Dimethyl carbate, Ethyl hexanediol, etc. However these repellents are effective for short period of 8 to 10 hours.

23. Malaria vaccines: They are under trial. Following are the types: i . Asexual blood stage vaccines(merozoite vaccine ) ii. Sporozoite vaccines iii. Gamete vaccines iv. A synthetic cocktail vaccine: This vaccine for P. falciparum is called ‘ PfS 66’. It is formulated as a peptide–alum combination. It has been found to be 30 percent effective. v. Transmission blocking vaccine: Like ‘ PfS 25’, it is also under trial

24. NATIONAL ANTIMALARIA PROGRAM History Control of malaria in the country was first recommended by Bhore Committee in 1946 . Government of India, in April 1953, launched National Malaria Control Program (NMCP), when malaria was the principal health problem. During 1953 malaria accounted for annual morbidity of 75 million cases.

25. The objective was to reduce the morbidity and mortality of malaria to such a low level that it should no more be a public health problem. The strategy to achieve the objective was to interrupt the transmission of malaria by controling the vectors (anopheline mosquitoes) by indoor residual spraying with DDT, twice a year in endemic areas, where spleen rates were above 10 percent.

26. NMEP Encouraged by the spectacular results of success of NMCP, it was decided by Government of India to eradicate the disease and therefore Government of India launched National Malaria Eradication Program (NMEP). Government of India decided in favor of eradication and launched NMEP during 1958.

27. The objectives were: Elimination of reservoir of infection (by case detection and prompt treatment ) Total ending of transmission of malaria, (by control of vectors) Prevention of re-establishment of malaria by 1968-69 . (That means there should not be occurrence of malaria even in the presence of carrier mosquitoes). The entire country was brought under NMEP including non-endemic areas, which were not covered under NMCP.

28. The NMEP was carried out in the same 4 phases: Preparatory Phase : This consisted of collection of data about the extent of the problem of malaria and to prepare for attacking the problem. Attack Phase - This was taken up directly and it was extended for 3 years from April 1958 to 61 April . The term ‘Attack’ implied on the attack of vector anopheline mosquitoes by the principal activity of spraying insecticides like DDT/BHC in all the human dwellings, twice a year.

29. Consolidation Phase : This phase was started when API was reduced to 0.1 per 1000 population , i.e. during 1961. The principal activity of this phase was stopping DDT spraying due to complete interruption of transmission and carrying out only active and passive surveillance and presumptive and radical treatment . Maintenance phase: The word ‘maintenance’ implied maintenance of vigilance to detect re-entry of infection in those areas declared ‘free’ of malaria.

30. The scenario of malaria eradication was as follows : - API came down to 0.1 per 1000 population Annual incidence was hardly 50,000 cases, by 1961. 25 percent of the population was under attack phase, 25 percent in the consolidation phase and 50 percent under maintenance phase.

31. From 1961, focal outbreaks of malaria began to occur and the annual incidence went on increasing year by year. By 1965, the cases reported were 1,00,000 (doubled). Malaria came back with greater force, i.e., vectors developed resistance against DDT and parasites started developing resistance against chloroquine. Hence the term ‘ Resurgence ’ .

32. Urban Malaria Scheme Urban Malaria Scheme (UMS) was launched during 1971, when it was realized that urban malaria was a significant problem and the vectors breed largely in man-made containers like over-headtanks , ornamental ponds, water coolers, flower vases , building constructions etc.

33. Plan of action Early diagnosis and treatment of malaria cases . Bioenvironmental management by source reduction measures such as emptying the water containers including overhead tanks, ponds, etc. once a week and observing weekly dry day. Controlling the larvae by weekly application of larvicidal oil, temphos , fenthion. Use of larvivorous fish as a good alternative method. Health education to the public was given to extend their co-operation in the control of malaria.

34. ROLL BACK MALARIA Roll black malaria (RBM) is a global partnership founded in 1998 by the WHO, UNDP, UNICEF and World Bank. The aim is to halve the world’s malaria burden by the year 2010. Political commitment is a key priority of RBM. RBM is giving priority to four technical strategies - Prompt access to effective treatment Promotion of insecticide treated bednets and improved vector control

35. Prevention and management of malaria in pregnancy and Improving response to malaria in epidemics and endemic areas . RBM also seeks to encourage the research in new and better drugs, insecticides and malaria vaccines. Goals T he goals for the malaria control set for the Tenth Five Year Plan are: - ABER over 10 percent API 1.3 or less 25 % reduction in malaria morbidity and mortality by 2007 and 50 % by 2010.

36. Thank you