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  1. 1. 1
  2. 2. Vector borne diseases DR RAHIM IQBAL MBBS(Pb).MPH(H.S.A) Senior Demonstrator Rawalpindi Medical college Rawalpindi 2
  3. 3. Vector borne diseases VectorIt is defined as an arthropod or any living carrier (e.g. snail) that transport an infectious agent to a susceptible individuals. The transmission by a vector may mechanical or biological 3
  4. 4. Arthropods-borne diseasesArthropods Diseases transmittedMosquito Malaria, Filariasis, Dengue, Yellow FeverHousefly Typhoid, Diarrhea, Gastro-enteritis Amoebiasis, Poliomyelitis, TrachomaSand fly Kalaazar, Sand fly fever, Oraya FeverTsetse fly Sleeping SicknessLouse Epidemic Typhus, Relapsing feverRat Flea Plague, endemic typhusBlack Fly Onchocerciasis 4
  5. 5. Arthropods-borne diseasesHard tick Viral Hemorrhagic fever, Tick Paralysis , Viral EncephalitisSoft Tick Q fever, Relapsing FeverItch Mite ScabiesCyclops Guinea-worm disease, Fish tape wormCockroach Enteric pathogens 5
  6. 6. Vector born diseases Methods in which vectors are involved in the transmission and propagation of parasites. Mechanical transmission Propagative Cyclo-Propagative Cyclo-developmental Biological transmission 6
  7. 7. Malaria 7
  8. 8. MALARIAMalaria is a protozoal disease caused byinfection with parasites of the genusPLASMODIUM and transmitted to manby certain species of infected femaleAnopheline mosquito. 8
  9. 9. HISTORY Malaria is one of the oldest recorded disease in the world. 1880; Laveran a French Army Surgeon discovered the malaria parasite in Algiers, North Africa. 1897; Ronald Ross, who discovered the transmission of malaria by Anopheline mosquitoes. 9
  10. 10. TYPES OF MALARIA1. Tribal Malaria:2. Rural Malaria:3. Urban Malaria:4. Malaria in Project Areas:5. Border Malaria: 10
  11. 11. AGENT FACTORSa). AGENT: “Malaria in man is caused by four distinct species of the malaria Parasite:” * P. Vivax, * P. Falciparum * P. Malariae * P. Ovale. 11
  12. 12. LIFE HISTORY: i). Asexual Cycle: * Hepatic Phase * Erythrocytic Phase ii). Sexual Cycle: 12
  14. 14. HOST FACTORS Age • Housing Sex • Population Mobility Race • Occupation Pregnancy • Human Habit Socioeconomic • Immunity Development 14
  15. 15. MODE OF TRANSMISSIONa) Vector Transmissionb) Direct Transmissionc) Congenital Malaria 15
  16. 16. INCUBATION PERIOD This is the length of time between the infective mosquito bite and the first appearance of clinical signs of which fever is most common. This period is usually not less than 10 days.Extrinsic incubation period=organism is present in the vector+excrete to infect ie eligible to infect16
  17. 17. CLINICAL FEATURESa) Cold Stageb) Hot Stagec) Sweating Stage 17
  18. 18. DIAGNOSIS (malaria) 18
  19. 19. MEASUREMENT OF MALARIAPRE-ERADICATION ERA: In the pre-eradication era, the magnitude of the malaria problem in a country used to be determined mostly from the reports of the clinically diagnosed malaria cases. The classical malariometric measures are spleen rate, average enlarged spleen, parasite rate etc. in a control programe, the case detection machinery is weak. Therefore, the classical malariometric measure may provide the needed information, i.e. the trend of the disease. 19 Continued:
  20. 20. a). SPLEEN RATE: It is defined as the percentage of children between 2 & 10 yrs of age showing enlargements of spleen. Adults are excluded from spleen surveys because causes other than malaria frequently operate in causing splenic enlargement in them. The spleen rate is widely used for measuring the endemicity of malaria in a community. 20 Continued:
  21. 21. b). AVERAGE ENLARGED SPLEEN: This is a further refinement of spleen rate, denoting the average size of the enlarged spleen. It is useful malariometric index.c). PARASITE RATE: It is defined as the percentage of children between the ages 2 & 10yrs showing malaria parasites in their blood films. 21 Continued:
  22. 22. d). PARASITE DENSITY INDEX: It indicates the average degree of parsitaemia in a sample of well defined group of the population. Only the positive slides are included in the denominator. 22 Continued:
  23. 23. e). INFANT PARASITES: It is defined as the percentage of infants below the age of one year showing malaria parasites in their blood film. It is regarded as the most sensitive index of recent transmission of malaria in a locality. If the infant parasite rate is zero for 3 consecutive years in a locality, it is regarded as absence of malaria transmission even though, the Anopheline vectors responsible for previous transmission may remain. 23
  24. 24. f). PROPORTIONAL CASE RATE: Since the morbidity rate is difficult to determine, except in conditions when the diagnosis and reporting to each case is carried to perfection, proportional case rate is used. It is defined as the number of cases diagnosed as clinical malaria for every 100 patients attending the hospitals and dispensaries. This is a crude index because the cases are not related to their time/space distribution. 24
  25. 25. Important parameters Annual parasites incidence(API) API=confirm cases during year/population under surveillance*1000 Annual blood examination rate(ABER)/population Number of slides examined*100 Annual falciparum incidence(API) Slide positivity rate(SPR) Slide falciparum rate(SFR) 25
  26. 26. MODIFIED PLAN OF OPERATION1. Objectives2. Reclassification of endemic areas3. Areas with API > 2: a). Spraying b). Entomological Assessment c). Surveillance d). Treatment of cases 26 Continued:
  27. 27. 4. Areas with API < 2: a). Spraying b). Surveillance c). Treatment d). Follow Up e). Epidemiological investigation5. Drug distribution centers & fever treatment depots6. Urban malaria scheme7. P. Falciparum containment8. Research9. Health education 27
  28. 28. SURVEILLANCEa) Active Surveillanceb) Passive Surveillancec) Parameters of malaria surveillance 28
  29. 29. APPROACHES & STRATEGIES OF MALARIA CONTROLa. Management of malaria casesb. Disease control strategies i). Case Detection ii). Treatment * Presumptive treatment *Radical Treatment 29
  30. 30. per tablet orGeneric Name Common For prophylaxis For treatment capsule trade namesChloroquineb Aralen 100 / 150mg 300mg (base) = tablets 600 mg (base) on Avlochlor (base) of 100mg or 2 tablets of the 1st & 2nd days, 150mg once a week 300mg (base) on Nivaquine OR the third day Resochin (total 10 tablets of 100mg (base) = 1 tablet 150mg or 15 of of 100mg daily for six days per week 100mg.Proguanil Paludrine 100 mg 200mg = 2 tablets once Not applicable a daySulfadoxine- Fansidar 500mg + 25mg Not applicable 1500mg + 75mgpyrimethamine = 3tablets in one doseSulfalene- Metakelfin 500mg + 25mg Not applicable 1500mg + 75mgpyrimethamine = 3tablets in one dose 30
  31. 31. Mefloquine Lariam 250 mg 250mg = 1 1000mg (4tablets) or Mephaquin tablet one a 15mg/kg of body week, on the weight, whichever is same day each lower in one dose week OR 100mg (4tablets) initially, followed by 500mg (2tablets) 6- 8hrs later.Quinine 300mg Not applicable 600mg (2tablet) 3 times a day for 7 days (total 42 tablets)Doxycycline Vibramycin 100mg 100mg = 1 Not applicable capsule once a dayHalofantrineb.f Halfan 250mg Not applicable 500mg (2tablets) in one dose + 500mg after 6hrs, + 500mg after 6 more hrs, (total 31 6 tablets in 12hrs)
  32. 32. Drugs resistance malaria WHO recommendation. 32
  33. 33. Situation of Clinical Malaria (Fever) inINTRODUCTION Pakistan Malaria is one of the most devastating tropical disease in the world, with nearly 2.1 billion people at risk of infection. It is particularly dangerous for young children and for pregnant women and their unborn children, although others may be seriously affected in some circumstances. About 250 to 300 million cases of malaria occur annually many among young children. New anti- malarial drugs and more efficient diagnostic techniques are being tested to cope with the problem. Malaria is a curable and preventable disease, but it still kills many people. The main reasons for this unsatisfactory situation are: Some people do not come for treatment until they are very ill because: • they do not realize they might have malaria (people often think they have a cold, influenza or other common infection); • they do not realize that malaria is very dangerous; or • they live far away from health care facilities. People living far from health services will often go to local medicine vendors (sellers) for advice, which is not always appropriate, or to buy medicines, which are not always effective. 33 Many people do not know what causes malaria or how it is spread, so they are not able to protect themselves from the disease.
  34. 34.  Pakistan launched Malaria eradication campaign with the help of WHO in 1960. But eradication of malaria could not be achieved because of socio- economic and epidemiological factors and so it poses a potential threat to the health of millions of people. On the advice of WHO, Malaria Eradication Programme was converted into Malaria Control Programme. The current project is an extension of on- going Malaria Control Programme. A patient of any age having axillary or oral temperature of 38?C or more, rectal temperature of 38.5?C or more, continues or irregular at the start of the illness, but soon it may become irregular with attacks every 2-3 days. The attack begins with sever shivering, followed by fever and finally by profuse sweating. Malaria is a disease that is caused by the presence of very small organisms (malaria parasites) in the blood. Malaria parasites are so small that they can only be seen under a 34 microscope. They feed on the blood cells, multiply inside
  35. 35.  NHMIS is actively functioning in almost all the districts of the country. Presently National HMIS is collecting valuable information, which flows directly from the peripheral health facilities to the District Computer Centers, then to the Divisional and the Provincial Computer Centers. Ultimately, the information reaches the National HMIS Cell on computer diskettes where it is analyzed through HMIS software and also through Statistical Package of Social Sciences (SPSS). This monograph has been compiled from the data received by the National HMIS Cell of the Ministry of Health from the HMIS Cells located within the provincial health departments. The National HMIS Cell has made all efforts in compiling this bulletin to reflect the true picture of malaria burden in Pakistan to its readers. The prime purpose of this monograph is to present the analysis of malaria data received from the provinces during Jan 1998 - July 2000. This report is hoped to generate interest and debate at various levels of health care delivery system as to pinpoint areas with high endemicity of 35 malaria, particularly the falciprum malaria prevalence in
  36. 36. Malaria Vaccineburning issue of today1)sexual blood stage vaccine2)second vaccine is designed to arrest the development of the parasite in the mosquito3)SP166(cocktail) vaccine for p.falciparum(dr.m.Pattaryo)4)Transmission blocking vaccine.Pfs 25(USA 1995) 36
  37. 37. Thank youVery much 37