Travel Medicine & Insect-borne Illness for Emergency Physicians Aedes aegypti Triatoma spp. Joe Alcock MD MS, NM VAMC, UNM Dept EM A bit about travel medicine Of 100,000 travelers to the developing world in 1 month: Of 100,000 travelers to the developing world in 1 month: 300 will require hospitalization 300 will require hospitalization 50 will need air evacuation 50 will need air evacuation 1 will die 1 will die Travelers Mortality Cardiovascular 49% Cardiovascular 49% Accidental Injury 22% Accidental Injury 22% Infectious Disease 1% Infectious Disease 1% So dont smoke & do wear your seat belts! So dont smoke & do wear your seat belts! Spring break in Mexico Surfer returns from trip to Mexico, 3 days later - fever 104, retro-orbital headache Doesnt want to move Doesnt want to move Persistent nausea & vomiting Persistent nausea & vomiting Exam shows erythematous macular rash that soon becomes confluent. Exam shows erythematous macular rash that soon becomes confluent. Dengue (Breakbone) fever Flavivirus Single-stranded RNA Widespread in tropics mil cases/yr K hemorrhagic 24K deaths Aedes aegypti Patas blancas Day biter Restless feeder Multiple hosts Anthrophilic 2/3 world population Between 30N & 20S Mosquito Vector Eradication: discontinued or ineffective Eradication: discontinued or ineffective Transovarial spread in mosquitos Transovarial spread in mosquitos Periodically amplified in humans Periodically amplified in humans Flying squirrel reservoir. Flying squirrel reservoir. Common febrile disease in travelers Dengue increasing Vector likes small collections H2O Habitat for larvae Insecticide Resistance Increasing population Urbanization Fl. Dept Health Variable clinical picture Incubation is 4-7 d Incubation is 4-7 d Viremia 2-12 d Viremia 2-12 d Petechial hemorrhage Petechial hemorrhage Effusions Effusions Vasculitis sm.Vessels Vasculitis sm.Vessels Midzonal hepatic necrosis Midzonal hepatic necrosis Photo:Doug Valentine Classic Dengue Older kids and adults Older kids and adults Sudden onset fever Sudden onset fever Headache, myalgias, arthralgias of shoulders and knees Headache, myalgias, arthralgias of shoulders and knees Prostrating weakness Prostrating weakness By 3rd day: rash over thorax, flexure joints By 3rd day: rash over thorax, flexure joints Hyperethesia, taste aberration Hyperethesia, taste aberration Defervescence Defervescence Dengue may mimic URI 8 yo boy in Bankok develops mild fever, cough, ST, rash. Misses 1 day of school, returns the next day with no further symptoms and lifelong immunity. 8 yo boy in Bankok develops mild fever, cough, ST, rash. Misses 1 day of school, returns the next day with no further symptoms and lifelong immunity. In Thailand only 13% miss school in 15 yrs - classic dengue San Salvador, El Salvador Female, 11, falls ill with fever, rash, myalgias, vomiting. 4 days into illness fever begins to decrease. Female, 11, falls ill with fever, rash, myalgias, vomiting. 4 days into illness fever begins to decrease. Confusion/somnolence. Confusion/somnolence. Hct 38, then 45, then 50. Hct 38, then 45, then 50. Edema, ascites, RUQ pain Edema, ascites, RUQ pain B/P 70/34, requires IVF B/P 70/34, requires IVF CXR: large effusions, breathing is labored, post-intubation coma briefly precedes death. CXR: large effusions, breathing is labored, post-intubation coma briefly precedes death. Dengue Hemorrhagic Fever Rare Rare Typically afflicts patients < 15 years. Typically afflicts patients < 15 years. Often no hemorrhage Often no hemorrhage Diagnostic criteria include: Diagnostic criteria include: Platelets 3/sq cm Treatment Supportive Supportive No ASA/NSAIDs No ASA/NSAIDs Treat vascular leak with IVF Treat vascular leak with IVF Massive plasma leak may last 48h Massive plasma leak may last 48h Correct coagulopathy Correct coagulopathy Death or complete recovery Death or complete recovery Lab diagnosis has limited clinical utility Elisa tests now available Dengue Prevention No record of epidemic dengue 1946 and 1963 No record of epidemic dengue 1946 and 1963 DDT DDT Yellow fever Yellow fever Successful in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, C.R., Equador, Guatemala, Mex, Panama, Uruguay Successful in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, C.R., Equador, Guatemala, Mex, Panama, Uruguay Discontinued in 1970s Discontinued in 1970s Aedes aegypti Persisted in Caribbean Islands, Venezuela, and USA. (!) Persisted in Caribbean Islands, Venezuela, and USA. (!) Reinfested countries where once eradicated Reinfested countries where once eradicated Dengue outbreak in Jamaica 1977, followed by epidemics until 1981 in every Caribbean island, Central and South America. Dengue outbreak in Jamaica 1977, followed by epidemics until 1981 in every Caribbean island, Central and South America. Experimental Vaccine Development started in 1970s and 1980s at Walter Reed lab Development started in 1970s and 1980s at Walter Reed lab All 4 dengue serotypes All 4 dengue serotypes Live attenuated virus Live attenuated virus Incomplete immunity may allow DHF if reexposed Incomplete immunity may allow DHF if reexposed Meanwhile: Yellow fever Flavivirus carried by Aedes aegypti Flavivirus carried by Aedes aegypti 200,000 cases/ yr 200,000 cases/ yr 30,000 of these die 30,000 of these die YF in 33 countries 468 million people at risk YF in 33 countries 468 million people at risk Yellow Fever Virus - influenza-like illness to severe hepatitis Virus - influenza-like illness to severe hepatitis Case fatality rate > 20%. Children, infants at risk Case fatality rate > 20%. Children, infants at risk Risk illness & death 10 x lower in SA vs Africa Risk illness & death 10 x lower in SA vs Africa FULMINANT LIVER FAILURE Cytoplamic coagulation in hepatocytes Councilman bodies. Yellow fever endemic areas Yellow Fever History New World via Africa in 1600s. New World via Africa in 1600s. Wiped out Carib tribes Wiped out Carib tribes 1647 Outbreaks in Mexico, Havana, Barbados, Guadeloupe 1647 Outbreaks in Mexico, Havana, Barbados, Guadeloupe 1649 Spanish Florida 1649 Spanish Florida New Orleans became YF capital of Americas (with Havana) New Orleans became YF capital of Americas (with Havana) Yellow Fever Maritime trade brings YF to NYC, Boston, Halifax Maritime trade brings YF to NYC, Boston, Halifax Summer 1793 Philadelphia, city of 50K. YF kills 10% of population. Summer 1793 Philadelphia, city of 50K. YF kills 10% of population. City paralyzed, survivors abandon sick and dying. City paralyzed, survivors abandon sick and dying. Yellow Fever in Travelers Epidemic disease Epidemic disease 10 cases since cases since of 5 First world cases visited South America, All fatal 4 of 5 First world cases visited South America, All fatal Risk to unvaccinated person in endemic area is 1:1000 per month Risk to unvaccinated person in endemic area is 1:1000 per month Risk to US travellers = in million Risk to US travellers = in million Yellow Fever Vaccine Live attenuated virus. Live attenuated virus. Contraindicated in immunosuppressed and children less than 4 years Contraindicated in immunosuppressed and children less than 4 years Recommended for travel to Amazonian region and parts of Panama. Also equatorial Africa Recommended for travel to Amazonian region and parts of Panama. Also equatorial Africa Highly immunogenic/effective. Highly immunogenic/effective. O.5 ml primary and 0.5ml 10 year boosters O.5 ml primary and 0.5ml 10 year boosters YF Vaccine Risks Yellow Fever Vaccine- associated viscerotropic disease Yellow Fever Vaccine- associated viscerotropic disease Clinically & Pathologically = Yellow Fever Clinically & Pathologically = Yellow Fever 23 cases of vaccine disease, 14 fatal, 17% had had thymectomy for thymoma 23 cases of vaccine disease, 14 fatal, 17% had had thymectomy for thymoma Elderly at risk Elderly at risk Malaria, by contrast Briefly: No Vaccine No Vaccine Malaria kills 1,500,000 yearly Malaria kills 1,500,000 yearly Young children and pregnant women Young children and pregnant women Immunity partial and not durable Immunity partial and not durable 30,000 travelers: preventable with chemoprophylaxis and behavior 30,000 travelers: preventable with chemoprophylaxis and behavior Expedition to Amazonia While napping in a remote outpost, this pair wakes up to find pale fleshy bugs on their faces Kissing Bug Barbeiro Barbeiro Vinchuca Vinchuca Reduviidae Triatoma spp. Reduviidae Triatoma spp. Chagas disease Chagas Disease Carlos Chagas, Brazilian, described the disease in 1909 He discovered the vector: Triatoma bug He named the pathogen, Trypanosoma cruzi, after his mentor, Oswaldo Cruz. Carlos Chagas Oswaldo CruzTriatoma Chagas is endemic from Mexico to Argentina Chagas is endemic from Mexico to Argentina Transmitted by Triatoma bug - 30 species are vectors. Transmitted by Triatoma bug - 30 species are vectors. 9 of these vectors are in the US 9 of these vectors are in the US Amazingly the bite is painless! Chagas 16 million infected in Americas 16 million infected in Americas 50,000 deaths per year 50,000 deaths per year Indolent infections Indolent infections Manifestations after years Manifestations after years Cannot be treated once chronic Cannot be treated once chronic Chagas results when parasite-laden feces of bug are rubbed into eye/cut Chagas results when parasite-laden feces of bug are rubbed into eye/cut Food-borne Chagas? Sugar cane juice banned in Brazil Sugar cane juice banned in Brazil Guarapa Guarapa 25 confirmed cases in Santa Catarina BR 25 confirmed cases in Santa Catarina BR 3 deaths 3 deaths Symptoms arose within days - virulent Symptoms arose within days - virulent NY Times April 12, 2005 Romanas sign Hemilateral swelling of face, eyelid, and lymphadenopathy Acute Chagas disease in a Brazilian patient American Trypanosomiasis Parasitemia - C-shaped trypomastigotes of T. cruzi are seen in the peripheral blood Mal de Chagas African Trypanosomiasis Related trypanosome responsible for African Sleeping Sickness T. gambiense T. rhodesiense Tsetse fly vector Larger than T. cruzi Chagas Disease Amastigote T. cruzi Intracellular Non-flagellated form Indistinguishable from Leishmania Giemsa stain Chagas in Tennessee In 1998,mother of 18 month infant found triatoma bug in crib. Gut contents found to contain Trypanosoma cruzi In 1998,mother of 18 month infant found triatoma bug in crib. Gut contents found to contain Trypanosoma cruzi Infant blood was PCR positive for T. cruzi Infant blood was PCR positive for T. cruzi 2 of 3 raccoons trapped in area tested positive for T. cruzi 2 of 3 raccoons trapped in area tested positive for T. cruzi Herwaldt B.L., et al. (2000) The Journal of Infectious Diseases 181: Herwaldt B.L., et al. (2000) The Journal of Infectious Diseases 181: Chagas in America Animal reservior, T. cruzi, and Triatoma bugs are all abundant Animal reservior, T. cruzi, and Triatoma bugs are all abundant Local transmission epidemiology unknown Local transmission epidemiology unknown 3 cases of acute Chagas disease have been recorded in US 3 cases of acute Chagas disease have been recorded in US Exact number endemic cases unknown Exact number endemic cases unknown Many more cases are imported Many more cases are imported Chagas Heart Patients Chagas Heart Syndrome Ventricular Tachycardia, Syncope/Sudden Death, Anginal Chest Pain, Symptomatic AV block, Congestive Heart Failure. EKG suggestive of ischemia CAD mimic, underdiagnosed in US LV aneurysm, regional hypokinesis, many require pacers Hagar J.M. & Rahimtoola S.H. (1991) Chagas' heart disease in the United States. N. Engl. J. Med. 325: T. Cruzi myocarditis Amastigote in cardiomyocyte Chronic Chagas Cardiopathy Autopsy of Bolivian Chagas Case Infected cell in center Diffuse lymphocytic infiltration Cardiomyopathy Chagas in US Chronic Chagas Disease reported in Mississippi Seropositivity in US approximately 350,000 with 100,000 cases of chronic disease Megaesophagus, cardiomyopathy common Holbert R.D., et al. (1995) J. Miss. State Med. Assoc. 36: 1-5. Mega GI manifestations Megacolon in Chagas in Bolivia May also affect ureter, bronchus, esophagus, uterus Transfusion Risk In Latin America, blood transfusions are major risk for Chagas transmission In Latin America, blood transfusions are major risk for Chagas transmission ELISA assays are effective at detecting Chagas antibodies in human serum ELISA assays are effective at detecting Chagas antibodies in human serum Carvalho MR et al. (1993) Transfusion 33: Treatment Drug treatment for acute and congenital cases Drug treatment for acute and congenital cases Nifurtimox and Benznidazole can be used for early chronic phase. Nifurtimox and Benznidazole can be used for early chronic phase. T. cruzi antigens stimulate autoimmunity, so no vaccine T. cruzi antigens stimulate autoimmunity, so no vaccine Travelers can avoid the disease by not sleeping in infested housing. Travelers can avoid the disease by not sleeping in infested housing. Extra bonus arthropod! Yet another reason to use insect repellent Yet another reason to use insect repellent Bot Fly Credit: Marcelo de Campos Pereira Torsalo Life Cycle When female Dermatobia is ready to oviposit she captures another insect - fly or mosquito - and glues eggs to captured insect's abdomen. Eggs hatch with elevated temperature Dermatobia hominis eggs glued to abdomen of carrier fly. Third Instar Larva Prominent Mouth Hooks Larva in Holstein cow Myiasis caused by Cordylobia anthropophaga Myiasis Second instar larva of C. anthropophaga, an African and Asian fly Adapted to feed on humans In South America, Dermatobia hominis (Bot fly) is man-eating maggot. Bot fly Treatment/prevention Place Tiger Balm or Camphorated Oil over every bite in endemic area Larva needs to breathe Differential Diagnosis of Sebaceous cyst and Infraorbital mass Goodman et al. Arch Ophthalmol. 2000;118: Summary Classic Dengue: painful, afflicts teens/adults Classic Dengue: painful, afflicts teens/adults DHF: