Ectoparasite Endoparasite 1/26/2007
http://tolweb.org/tree/ToLimages/Xenopsylla_cheopis.200a.jpg Xenopsylla cheopis http://www.megades.nl/upload/1071039250.jpg Rattus rattus http://www.cdc.gov/ncidod/dvbid/images/wayson.jpg Yersinia pestis
http://www.insektenmodelle.de/modelle/bilder/muecke01.jpg Anopheles gambieae http://bepast.org/docs/photos/malaria/P.%20falciparum%20macrogametocyte.jpg Plasmodium falciparum
http://www.nhc.ed.ac.uk/images/collections/ticks/hard/image033.jpghttp://www.nhc.ed.ac.uk/images/collections/ticks/hard/image033.jpg Female Hyalomma tick http://dtirp.dtra.mil/cbw/graphics/crime.gif Crimean-Congo Hemorrhagic Fever
http://www.sciencenews.org/articles/20030823/a3929_2615.jpg Pediculus humanus corporis http://encyclopedia.quickseek.com/images/Napoleons_retreat_from_moscow.jpg Napoleon retreating from Russia http://parasite.natur.cuni.cz/jirovec/images//bi101.jpg
Burundi Mwaramutse http://images.google.com/images?q=tbn:15i-OvAwJsW8VM:http://www.christiantoday.com/files/afr/afr_20040818_wed4cart.jpg http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t058/T058961A.jpg
CDC Traveler’s health warning • Malaria, yellow fever, traveler’s diarrhea, cholera, typhoid fever, dengue, filariasis, leishmaniasis, onchocerciasis, rift valley fever, African trypansomiasis, rickettsial infections, schostosomiasis, tuberculosis, polio, HIV, HBV
WHO Burundi profile • Since the beginning of 2004, up to 140,000 internally displaced persons and some 80,400 refugees have returned spontaneously or with assistance. However, an overall estimate of 69% of the population lives below the absolute poverty line. several parts of the country still face armed unrest and a large group of Burundian displaced and refugees are unable to return home. • Crisis involving: the whole population
Quick Stats • Under five crude mortality far exceeds Emergency criteria • Malaria is responsible for >50% of deaths under five • Less than 50% have access to potable water • Food insecurity widespread • HIV/AIDS 6% • 80% of the population lives close to medical facilities which are inadequate, of poor quality and expensive.
A little poetic license… • Chaos still reigns in the wake of ongoing conflict between Hutu and Tutsi. 760,000 people inhabit refugee camps in squalor. There is not enough water, the population is malnourished. Epidemics have broken out already in the early 90’s. The year is 1995.
In the seclusion of Switzerland • A middle aged nurse recently back from Burundi walks into your clinic. He complains of fever, rash, myalgias and fatigue. He tells you that he was working in poor conditions in the N’Gozi prison in Northern Burundi which houses about 1200 people. It was overcrowded and full of lice and they had no medicine.
Common causes of fevers in returned travellers • Malaria 27-42% • Dengue, viral hepatitis, typhoid fever, enteric pathogens. • 25% no diagnosis made • Mandell’s
Hospital course • He was admitted on the sixth day of disease with headache as his chief complaint. T 40.7° C. P 108. RR 36. Blood pressure 126/66 mm. NAD. No rash. Otherwise unremarkable. WBC 7.5. http://history.amedd.army.mil/booksdocs/wwii/infectiousdisvolii/default.htm
Continued • Hospital course.—Throughout the first week of hospitalization the patient's fever remained high and a rash appeared, with intense conjunctival injection and the development of petechiae in the left conjunctival sac. The patient, actively delirious, became very talkative and attempted to get out of bed. He eventually needed IV fluids.
The rash Raoult et al.
Continued • On the 13th day he became more stuporous and then semicomatose. He lay with half-opened eyes, breathing quietly. Facial grimaces and grinding of the teeth were noted. Around day 17, the rash gradually faded out during this period and the conjunctival suffusion disappeared.
Continued • In the next 2 days he was able to obey simple commands. It was evident that he was almost totally deaf. On the 20th day his temperature reached normal levels.
Improving • From this time onward improvement in his general condition was steady but slow. The ability to stand and walk unassisted returned before the ability to form words. At the time of discharge 68 days after the onset of the disease, speech was slow, expressionless, and labored. Hyperactive reflexes were still present in the lower extremities, but the positive Babinski phenomenon had disappeared.
In retrospect, you wish you had done something… So, you were lucky that the patient lived. Now from the natural history, what do you think it could have been?
Rickettsia prowazekii Scrub typhus Borrellia recurrentis Bartonella quintana Leptospirosis Rift Valley fever Typhoid fever N. meningiditis Malaria Yellow fever Dengue African trypanosomiasis West Nile Rickettsia africae Plague Katayama fever The Unknown… Diagnosis DDx
Katayama fever- Schistosomiasis • Fresh water exposure in rural areas with snails • Fevers, chills, myalgias, arthralgias, cough, headache, diarrhea, lymphadenopathy, hepatosplenomegaly Return to DDx
Rickettsia africae • Throughout subsaharan Africa • Vector Amblyomma variegatum • Eschars prominent in this rickettsiosis • HA, fever, myalgia, rash lymphadenitis Return to DDx
Vector – glossina morsitans Fever, malaise, headache. Untreated, death ensues in weeks to months. Return to DDx African Trypanosomiasis
Aedes aegypti Self limited to hemorrhagic fever Fever, headache, myalgias, followed by remission of symptoms and then renewal with back pain, n/v, abdominal pain, somnolence and prostration. GIB, purpura, jaundice and sometimes death can ensue. Return to DDx Yellow Fever:
A flavivirus Aedes aegypti Dengue –HA, myalgia, rash, URI sxs. Fever may have saddleback pattern. Dengue hemorrhagic fever – hemorrhage and hypovolemic shock. Indistinguishable early, but then progresses Return to DDx Break bone fever: Dengue
Culex pipiens Acute high fever, rigors, headache, myalgia, arthralgia May develop assymetric acute flaccid paralysis Return to DDx West Nile Virus
Malaria – esp Plasmodium falciparum • Malaria transmission can occur all year in the African Great Lakes region • Mosquitoes do not like altitude • Can have a classic paroxysmal fever in tertian or quartan cycles
Plague : Yersinia pestis Global distribution Madagascar, Tanzania and DR of Congo leading the pack Vector Xenopsylla cheopis Bubonic plague- Fever, chills, weakness and headache, then the buboe Sepicemic plague- the above without necessarily the lymphadenitis Pneumonic plague- the above with a severe contagious pneumonia Return to DDx
Neisseria meningiditis • Epidemics occur in crowded conditions throughout the world- especially during the dry season in the Meningitis belt • Vector – humans by respiratory droplets • Bacteremia without sepsis – URI w or w/o exanthem • Meningiococcemia sans meningitis • Meningitis w or w/o meningococcemia Return to DDx From the CDC
Typhoid fever: Salmonella typhii • Enlargement of Peyer’s patches is the historical way it was differentiated from typhus • Vector: children and Typhoid Mary • Endemic in South Asia, SE Asia, S&C America, Africa • Fevers, chills, headache, myalgia, abdominal pain, diarrhea Return to DDx
Rift Valley Fever • Transmittted by Aedes mcintoshi • Epidemics after flooding • It also can be transmitted by direct contact with animal blood. • Fever, hemorrhage, jaundice, hepatitis, encephalitis. Return to DDx
Leptospirosis: Leptospira interrogans • Extreme variation in presentation • Confused with yellow fever in the 19th century • Endemic globally • Epidemics occur around times of heavy rainfall • Infection from urine from small animals • High fever, septicemic picture with headache, myalgias, abdominal pain, n/v/ diarrhea. Progressing to jaundice, renal failure, arrhythmias, respiratory failure, aseptic meningitis Return to DDx
Trench FeverBartonella quintana • Lower mortality especially compared to Oroya fever • Vector Pediculus humanus • Around 5 episodes of 5 days of fever • Sudden onset fever, rigor with headache, myalgia, arthralgia, rash • Global distribution Return to DDx
Epidemic relapsing fever:Borrellia Recurrentis • Vector Pediculus humanus • Infection comes from smashing the bugs into the wound • Acute onset of high fever, rigors, headache, myalgia, arthralgia, lethargy • Global distribution Return to DDx
Epidemic typhus: Rickettsia prowazekii • Transmitted through the vector of body lice • Recrudescence may occur years later (Brill Zinsser) • Endemic in Andes, Burundi, Rwanda, Russia, Senagal, Algeria, France, major epidemics in North Africa and Italy in the last century. • Reservoir Glaucomys volans. • Rash, fever, HA, stupor, cough, myalgias. Return to DDx
Scrub typhus:Orientia tsutsugamushi • Triangle delineated by Hokkaido, Eastern Australia, and the Indian subcontinent. • Vector: chiggers (thrombiculid mite larvae) • Fever, mental changes, inoculation eschar, lymphadenopathy. Return to DDx
Ebola and Marburg are filoviruses in a group that is considered “hot” It is generally believed that diseases with a predilection for humans need to be somewhat attenuated with respects to virulence or an epidemic cannot be sustained. Return to DDx Five health workers, in head-to-toe "Ebola suits," on their way to pick up a man stricken ill in the Marburg virus outbreakin Uige, Angola.(Photo: Florence Panoussian / AFP /Getty Images) The Unknown
Diagnosis • Lumbar puncture - pleocytosis • LFT’s – elevated with increased bilirubin • CBC – leukopenic, thrombocytopenic • Serum protein - low • Blood culture - negative • Weil Felix reaction - negative • PCR and indirect IFA positive for…
Typhus • Typhos in the Greek which means smoky or hazy • Describes a handful of syndromes caused by Rickettsial species. • Rickettisals are intracellular bacteria
The only epidemic rickettsial disease Spread by lice and shortens their life span too Responsible for many epidemics in history Brill Zinsser recrudescence may occur years later Southern flying squirrels are an extrahuman reservoir Rickettsia prowazekii
Pathogenesis • Like other Rickettsiae, it enters through endothelial cells, but unlike many of the others, it does not polymerize actin in invading adjacent cells. Organisms multiply until cells burst which sets up for an intravascular inflammatory reaction, further spread and petechial hemorrhage. Little is known about potential toxins or other virulence mechanisms.
Clinical Symptoms • HA • Chills • Myalgias • Rash- erythematous macules ~ day 5 • Conjunctival injection • Rales • Delirium • Cough • Gangrene • Coma • death
Diagnosis and Treatment • Historically, the Weil-Felix reaction was important, but it is not sensitive nor specific. • Serology and PCR are used • Treatment – Doxycycline and chloramphenicol. Also, kill the lice. • No vaccine is available
Pediculus humanus corporis Louse Times - Wanted ads Looking for a warm body in a cold place. I like inseams and layered clothes. I am not into rich people but like to meet a lot of people. Poor grooming is not a turnoff. Must like nits!!! The Vector
Breaking news • In Burundi, thousands are coming down with fevers of unknown origin. Many of them are dying. Especially affected are the jails Ngozi, Bururi and Gitega. The locals call it “sutama.”