Presentation on theme: "Malaria in trauma. Studies of post-traumatic malaria falciparum in Cambodia."— Presentation transcript:
Malaria in trauma. Studies of post-traumatic malaria falciparum in Cambodia
Contents Background Landmines Malaria: The public health problem in the world and in Cambodia, livecycle, immunology, clinical features, postoperative and postinjury malaria Aims Material and methods Discussion Conclusions Recommendations for further studies
Land mines Injuries by blast and penetration of fragments Many dies out in the field if pre-hospital life support is not provided
Malaria Malaria caused by Plasmodium falciparum is a major public health threat, over 500 million cases of malaria annually among the world’s poorest populations P. falciparum has proven adept at acquiring and rapidly spreading resistance to antimalarial drugs Vector control is threatened by the inevitability of the emergence of insecticide- resistant mosquitoes boardingpasses.orgboardingpasses.org.
Malaria and land mines: the poor man’s burden
“… Living here you starve to death or you have to take risks.”
Anti-malarial drug resistance in cambodia Verdens mest drug resistene parasitt 60-70:Chloroquin -80: Fansidar, quinine -90: Mefloquine 2003: Artemisin
Counterfeit drugs Associated with up to 20 % of all malaria deaths Typically sold in small village drugstores, where owners may lack the expertise to identify fakes. An estimated 70 percent of malaria patients in Cambodia seek treatment at local village vendors Containes a variety of drugs and chemicals Some containe small amounts of genuine artesunate, which can cause spread of drug- resistant paracites
Malaria livssyklus og kroppens immunrespons
RBC rupture When the RBC rupture the malariatoxin is released in to the bloodstream where it stimulates inflammatory cells to release pro- inflammatory cytokines giving rise to the malariasymptoms.
Pathophysiology and clinical features Sequestration: PfEMP1 (variant Ag) on RBC’s infected with paracites binds to host receptors. Avoids destruction in the spleen.
Cytoadhesion and parasite var- antigens (PfEMP1) Battambang 20/21 November 2012 Dias 12 Centre for Medical Parasitology + Ab Variant multigene encoded proteins expressed on the surface of infected red blood cells – PfEMP1 blockage of microvasculature and detrimental inflammation
The wave Parasite attacs come in waves, corresponding to a new family of PfEMP1. 60 different types The human host developes antibodies to each new type
Centre for Medical Parasitology Battambang 20/21 November 2012 Dias 14 Surface antigens and the development of immunity in malaria endemic areas 23 October 2012 Dias 14 Each parasite (clone) has the capacity to express many antigenically distinct surface antigens and a broad repertoire of Ab and immunity is developed after repeated infections …………… + Ab However, immunity to severe malaria develops after a few infections Effective binding/growth advantage >< Limited variation Vaccination: Induce an immune response resembling the naturally acquired immunity
Natural aquired immunity and malaria tolerance High endemic areas Low-grade parasitemia without symptoms Control disease and parasite denisty Antidisease:Repetive stimulation of TLR by the toxine leads to downregulation of the receptor→reduced production av cytokines→Reduced symptoms (Rapidly acquired) Antiparasite: Antibodies (slowly acquired)
Postoperative malaria Malaria may follow surgery Relapse rates 6-15% Routine anti-malarial chemophylaxis
Study aims 1.Post-injury incidence and risk fators for developing malariasympthoms after trauma (Paper I). 2.Effects on post-traumatic mortality and morbidity (Papers II and III). 3.The sources of knowledge (Paper III). 4.To examine if post-injury malaria can be prevented by early anti-malarial treatment of trauma patients (Paper IV).
Study populations Study population 1: All land mine and war casualties consecutively admitted for in-hospital trauma care at Emergency (1998 to 2000.)Study sample 1: 342 patients. Study sample 2: Subsample of study population 1, 227 patients Study population 2: 18 experienced trauma care providers working in rural hospitals in Battambang province in North-western Cambodia Study population 3: All patients in the provinces Battambang and Pailin managed and referred for primary trauma surgery to rural district hospitals by Trauma Care Foundation medics during the period May 2002 to October trauma patients were examined. A subset of 108 patients from Pailin Hospital was used for the main analysis.
Study design Study I and II were performed as retrospective cohort trials The Information of study number III was gathered by semi-structured interviews and focus groups.
Study design Study IV was an interventional study. Dipstick test after medical stabilization All patients testing positive received antimalarial treatment Additional treatment, bloodsmears and mapping out malaria symtoms at hospital
Definition of variables Post-injury malaria: Positive blood smear and fever after trauma, within 10 days after the injury. Bacterial WI: Within 30 days, purulent disharge + one of the three following signs - pain/tenderness, localized swelling, or tenderness/heat. Malaria endemicity: High and low endemic areas were defined based on public reports. Anatomical injury severity: Injury Severity Score (ISS). Severe injuries: ISS above or equal to nine.
Antimalaria treatment The anti-malarial treatment was given according to national standards, one initial dose of artesunate 3.2 mg/kg was to be given as a single injection intravenously, further in-hospital treatment of P. falciparum carriers consisted of two doses of artesunate 1.6 mg/kg followed by one single per oral dose of mefloquine 20 mg/kg.
Rapid Diagnostic Test Detect presence of parasite spesific antigens Para check dipstic detect P.falciparum Highly sensitive at high parasitaemia density
Aim 1: Post-injury malaria incidence and risk factors 33.3 % (114/342) developed post-injury malaria. More than 40 times increased incidence rate
Riscfactors Malaria endemicity ISS (22% vs 40%) Duration of surgery (20.4% vs 51.2%) Pre-hospital evacuation time (barely statistically significant)
Recurrence or re-infection? 54% occured wthin two days after injury, only 12 % occured after 10 days The incidence of malaria outbreaks did not follow the seasons
Aim 2: Post-injury malaria morbidity and mortality (Papers II and III) Quantitative data Rate of WI: 36.1 % vs 10.0% Duration of hospital stay: 31 days vs 19 days Qualitative data A well known complication Develops within 1-5 days Increased risk of wound infection Protracted recovery has a severe impact also on families‘ income. (”The single most important cause of losing land is indebtedness caused by illness and medical treatment costs” (Williams,1999) Early treatment important Some recommended blood screening and start of anti-malarial treatment in all parasite carriers immediately after the injury.
Aim 3: The source of knowledge of post-injury malaria (Paper III) “This knowledge doesn‘t come from the books, but from experience. In the university they teach about trauma and malaria separately.”
Aim 4: Early anti-malarial treatment of parasite carriers (Paper IV) 222 patients, 30 dipstick-positive (parasite carriers). Subsample (Pailin): 108 patients, 28 dipstick- positive. Microscopi positive in 23 dipstick-positive and 0 dipstic negative patients. 21 developed post-injury malaria. Prevalence of fever was higher: 21% vs 89% Mean duration of fever: 3 d Higher morbidity
Comparing Microscopy with RDT The agreement of rapid test results (RDT) to blood smear examination was very good, kappa of 0.93 (95% CI 0.85 to 1.00).
Summary of findings 1/3 of trauma patients developed post-injury malaria. Risck factors: ISS, duration of surgery and malaria endemicity in the patients‘ area of origin Increasing the risk of bacterial wound infections and delaying recovery Prophylactic treatment did not prevent development of post injury malaria
Why does symptomatic falciparum infection develop after trauma? Because of Immunosuppression?
Why did Mefloquine artesunate and early diagnosis not work? ”Failure of artesunate-mefloquine combination therapy for uncomplicated Plasmodium falciparum malaria in southern Cambodia?” Rogers WO et al,Malar J Jan 12;8:10 BMJ 2011; 342:d211 WHO unveils plan to stop artemisinin resistance
Conclusions 1.A considerable number of trauma victims from P. falciparum endemic areas may develop post-injury malaria. The risk of the complication increases with the severity of the injury and the duration of trauma surgery. 2.Post-injury malaria does not seem to not affect mortality, but adds to the burden of trauma by increasing the risk of bacterial wound infections and delaying recovery. 3.Early antimalarial treatment of injured P. falciparum carriers did not seem to prevent post-injury malaria.
Recommendation for further studies: Identify levels of resistance to antimalarials in South East Asia among trauma-patients. Is PfEMP1 variants expressed in an increased level in trauma patients? (Study of variant antigens in post-injury malaria versus non-trauma malaria and their potential similarity or difference from those in pregnancy related malaria.)
Dag 0: Traume- RDT+ blodutstryk+ bloddråpe på filterpapir: reistensmarkører (Umiddelbar oppstart behandling (1.linje) på alle med pos RDT, kontinuere behandling på alle med positivt blodutstryk) Dag 1. Blodutstryk, klinisk respons, bloddråpe på filter papir: PCR (mRNA) VAR gener og ELISA antigen og Ab-nivå mot VAR2CSA (o.a PfEMP1 VAR-Ag) Dag 2-6: Blodutstryk, klinisk respons (inntil symptomfri og parasittere er cleared fra blod) Dag 7: resistensmarkører, mengde medikament i blod Dag 28: resistensmarkører, mengde medikament i blod, PCR (mRNA) VAR gener og ELISA antigen og Ab-nivå mot VAR2CSA (o.a PfEMP1 VAR-Ag) Endre behandling dersom manglende respons (2.linje)
To identify the PfEMP1 variants expressed in trauma patients Indirect identification of PfEMP1 protein expressed in trauma patients: Serum/Plasma samples collected at admission and 3 weeks after malaria disease (2ml full blood in CPDA- tubes -20˚C, or filter paper) ELISA or Luminex to determine if these individuals have acquired Abs to VAR2CSA or other PfEMP1 types (20-30 individuals) - trauma patients will develop Abs (IgG) to the PfEMP1 variants expressed by the parasites during malaria disease Large panel of recombinant PfEMP1 proteins from 3 P.f. genomes Battambang 20/21 November 2012 Dias 38 Centre for Medical Parasitology