Arthropod Born Infections PDF

Arthropod born Infections Community Medicine Department Malaria  Definition: Protozoal infection caused by plasmodium transmitted to man by female of anophalus. Typical attack cold stage, hot stage, and swetting stage.  Infective stage: 4 species Plasmodium Vivax, P.ova...

Arthropod born Infections Community Medicine Department Malaria  Definition: Protozoal infection caused by plasmodium transmitted to man by female of anophalus. Typical attack cold stage, hot stage, and swetting stage.  Infective stage: 4 species Plasmodium Vivax, P.ovale”in tropical Africa” P. Malariae, P. falciparam  Reservoir: Man harbors sexual form gametocyte “both sexes, mature from 2-4 days After appearance in blood  Period of communicability: Malaria communicable as long as mature, available gametocyte exist in circulating blood in sufficient density to infect female anopheles.  Mode of transmission: bite of female anophalus having the sporozites (the infective stage) in its salivary gland.  Female anophuls bites man between 5 PM and 7 AM (midnight)  Malaria  Other Modes of infection: -Blood transfusion: donor infected for years. -Mother to growing fetus (congenital malaria). Congenital malaria common in 1st pregnancy, non-immune population. -Needle stick injury: for ttt, or in drug addict.  Susceptibility & resistance: -All ages susceptible except newborn resistance to p. falciprum as high HB concentration suppresses its development -Sex: male at risk than females (outdoor) -Blood genetic trait “sickle cell” resistance to certain plasmodium -Pregnancy increase risk to malaria (intrauterine death, abortion, premature labor, 1st pregnancy at higher risk). -Socio-economic: poor housing, population mobility, sleeping outdoor, lowered immunity (collective immunity acquired after repeated exposure on several year) so young infant, children, travelers to endemic area at higher risk  Magnitude of MALARIA Problem Malaria Survey: field study of all factors which influence the existence of malaria disease in community. For purpose of planning & implementing malaria control program, follow up, monitoring & evaluation of different program activities.  Components of malaria survey: - Map showing water canals, population residence, data on rainfall, temp, humidity, demographic characteristics. - Malaria indicators: - Spleenic index: % of children 2-10 having enlarged spleen - Average enlarged spleen - Parasitic index: % of children 2-10 showing parasite in their blood film. - Infant Parasite index: % of infant < 1 yr showing parasite in their blood film. It’s the most sensitive index of recent transmission of malaria. - Vector index: - Human blood index: % of fresh fed female anophalus on human blood - Sporozite index: % of female anophalus with sporozites in salivary gland - Oocystic Index: % of female anophalus with oocyst in their stomach wall  Malaria Control  Case Management: Sick person should treated promptly, correct. To eliminate the parasite & interrupts transmission cycle.  WHO recommend ttt within 24 hrs after appearance of symptoms.  Prevention of infection - Vector control through destruction of larval breeding sites, insecticides, insecticides bed nets - Chemoprophylaxis: anti-malarial drugs not prevent infection but eliminate parasite from blood - Pregnant female: given intermittent Preventive ttt with anti-malarial drugs in 2nd-3rd  Barriers to Malaria Control: - Drug resistance - Insecticide resistance - Inadequate infrastructure