Malaria, pathogenicity, transmission, clinical features, indices, prevention, and treatment

Presentation covering endemic disease malaria, techniques of prevention and treatment

1. Malaria

2. Introduction Malaria is an acute febrile illness caused by Plasmodium parasites, which are spread to people through the bites of infected female Anopheles mosquitoes. According to the latest World malaria report, there were 241 million cases of malaria in 2020 compared to 227 million cases in 2019. The number of malaria deaths stood at 627 000 in 2020 – an increase of 69 000 deaths over the previous year.

3. Pathogenecity Infection causes intermittent fever With each species causing a characteristic fever: Species Duration of fever P .flaciparum 36-48h malignant tertian malaria P .malariae 72h quartan malaria P .ovale 48h benign tertian malaria P.vivax 48h benign tertian malaria P.knowlesi 24h quotidian malaria

4. Incubation period Species Incubation period P.falciparum 7-27 days (avg. 12 days) P.malariae 28-37 days (avg. 30 days) P.ovale 11-16 days P.vivax 8-31 days (avg. 14 days) P.knowlesi 9-12 days

5. Period of communicability As long as mature viable gametocytes exist in circulating blodd Of sufficient density to infect vector

6. Mode of transmission Vector transmission : Through bite of female Anopheles mosquito Direct transmission : By blood transfusion Congenital malaria : Congenital infection from infected mother

7. Clinical features Cold stage Sudden onset of fever with rigors and sensation of extreme cold May last from 15 minutes to one hour Hot stage Temperature may rise to 106 F Patient feels burning hot along with an intense headache Last from 2-6 hours Sweating stage Fever comes down with profuse sweating Lasts from 2-4 hours

8. Life cycle

9. Indices Pre-eradication era Spleen rate : percentage of children between 2 and 10 years of age showing enlargement of spleen. Average enlarged spleen : This is a further refinement of spleen rate denoting the average size of the enlarged spleen. Parasite rate : It is defined as the percentage of children between the ages 2 and 10 years showing malaria parasites in their blood films. Parasite density index : It indicates the average degree of parasitaemia in a sample of well-defined group of the population. Infant parasite rate : It is defined as the percentage of infants below the age of one year showing malaria parasites in their blood films. Proportional case rate : It is defined as the number of cases diagnosed as clinical malaria for every 100 patients attending the hospitals and dispensaries.

10. Indices Eradication era Annual parasite index : Areas having API are high risk areas Annual blood examination rate : Slide positivity rate : Percentage of slides found positive for malarial parasite Slide falciparum positivity rate : Percentage of slides found positive for P.falciparum  

11. Indices Vector Indices Human blood index : Proportion of freshly fed female anopheles mosquitoes, whose stomach contains human blood Sporozoite rate : Percentage of female anopheline mosquitos containing sporozoites in their salivary glands Mosquito density : Number of mosquitoes per man-hour-catch Man-biting rate : Average bites per day per hour Inoculation rate : The man-biting rate multiplied by the infective sporozoite rate.

12. Eradication Malaria eradication : Permanent reduction to zero of worldwide incidence of malaria Malaria elimination : Interruption of local mosquito-borne malaria and reduction of incidence to zero for at least 3 consecutive years. WHO embraced the goal of malaria eradication soon after it was founded in 1948. In 1955, a first Global Malaria Eradication Programme (GMEP) was launched. This commitment to eradication was reaffirmed in a World Health Assembly resolution of 1969, and later reinforced in 2015 through the Assembly’s endorsement of the Global technical strategy for malaria 2016-2030 (GTS).

13. Causes of failure of eradication programme in Pakistan Urban malaria not given consideration Spring transmission never taken into account Financial difficulties Development of resistance by A.culifacies against DDT Anti-mosquito measures other than house spraying never tried Passive case detection not properly organized Transport was withdrawn and used for flood duties and election campaign Provincial health services not prepared to take over maintenance phase

14. Roll-back malaria Due to setbacks in the malaria eradication programme , WHO, world bank and UN have launched a new campaign It seeks to: Strengthen health systems to ensure better delivery of health care, especially at district and community level Ensure the proper and expanded use of insecticide treated mosquito nets Ensure adequate access to basic health care and training of health care workers Encourage the development of more effective and new anti- malarial drugs and vaccines

15. In Pakistan In Pakistan the National Malaria Control Program was started in 1950. In 1961, Malaria control Programme was converted into Malaria Eradication Program under the auspices of WHO with the financial and technical support from WHO, UNICEF and USAID. In 1977 Malaria Control Program was integrated into health services as part of Communicable Disease Control in Punjab Province. Goal: By 2020, reduce the malaria burden by 75% in high and moderate endemic districts/agencies and eliminate malaria in low endemic districts of Pakistan Objective: To achieve <5 API in high endemic areas of province of Balochistan , Sindh, KPK and FATA region by 2020 To achieve <1% API within moderate endemic districts of Balochistan , Sindh, KPK and Punjab by 2020 To achieve Zero API within low endemic districts of Sindh, KPK and Punjab by 2020

16. Integrated vector management Integrated vector management (IVM) is defined as "a rational decision-making process for the optimal use of resources for vector control" and includes five key elements: Evidence-based decision-making Integrated approaches Collaboration within the health sector and with other sectors Advocacy, social mobilization, and legislation Capacity-building In 2004, the WHO adopted IVM globally for the control of all vector-borne diseases. All the tactics of standard vector control are included in the IVM approach

17. Integrated vector management for malaria

18. Prevention and control

19. Chemoprophylaxis

20. Intermittent preventive therapy Intermittent preventive therapy is an approach used in areas of seasonal malaria transmission. IPT is administered several times, typically monthly, during the seasonal occurrence of malaria. It includes intermittent preventive therapy during pregnancy (IPTp), Intermittent preventive therapy in children ( IPTc ), and intermittent preventive therapy in infants ( IPTi )

21. Treatment Vivax malaria or mixed infection (5 day regimen) Day1: 600mg Chloroquine + 15mg Primaquine Day2-5: 15mg Primaquine daily Falciparum malaria (3day regimen) Day1: 600mg Chloroquine followed by 300mg 6 hours later Day2: Chloroquine 300mg Day3: Chloroquine 300mg In case of chloroquine resistant malaria Sulphadoxine 1500mg + Pyremethamine 75mg combination plus 45mg Primaquine In case of resistance to both a 7 day regimen of quinine and tetracycline are used