RICKETTSIACEAE Dr.T.V.Rao MD T Dr.T.V.Rao MD.

RICKETTSIACEAE Dr.T.V.Rao MD T Dr.T.V.Rao MD

Zinsser, Lice And History
In 1935, Harvard Medical School physician and researcher Hans Zinsser wrote the brilliant and original Rats, Lice and History in which he traced the effects of vermin-borne disease on armies, cities and populations. From his extensive research on head and body lice, Zinsser stated unequivocally that "the body and head louse carry the infection [typhus] from one human to another. Dr.T.V.Rao MD

Zinsser, Lice And History
Dr.T.V.Rao MD

General Characteristics
Small obligate intracellular coccobacilli Gram negative (poorly), better stained with Giemsa (Blue) Have cell wall, bigger than virus but smaller than bacteria Have DNA and RNA Have an ATP transport system that allows them to use host ATP Arthropod reservoirs and vectors ( e.g., ticks, mites, lice or fleas). Sensitive to antibiotics Dr.T.V.Rao MD

Category of rickettsia
Genus Rickettsia, Coxiella ,Orientia,Ehrlichia Bartonella Species Rickettsia prowazekii (epidemic typhus), Rickettsia typhi (endemic typhus), Rickettsia rickettsii (spotted fever), Rochalimaea quintana (trench fever), Coxiella burnetii (Q fever) Dr.T.V.Rao MD

History 17th-19th century 1909: Transmission by lice 1917-1925: Russia
Epidemics in Europe as a result of war, disaster, or in prisoners 1909: Transmission by lice : Russia Estimated 25 million cases End of WWII DDT used for control Vaccine developed Epidemics of typhus occurred throughout Europe from the 17th to the 19th centuries. Widespread epidemics occurred during the Napoleonic Wars and the Irish Potato famine of 1846 to Charles Jules Henri Nicolle a Frenchman received the Nobel Prize for his work on typhus in He demonstrated that the transmission of typhus was by the human body louse. During World War I the disease caused three million deaths in Russia and more in Poland and Romania. Later epidemics were avoided due to the discovery of DDT. A vaccine was also developed in World War II, and today epidemics mainly occur in Eastern Europe, the Middle East and parts of Africa where living conditions and hygiene are poor. Image: A U.S. soldier is demonstrating DDT-hand spraying equipment while applying the insecticide. The use of DDT increased enormously on a worldwide basis after WWII, because of its effectiveness against the mosquito that spreads malaria and lice that carry typhus. The World Health Organization claims that the use of DDT saved 25 million lives. Decline in the use of DDT began the 1970’s and was attributed to a number of factors including increased insect resistance, development of more effective alternative pesticides, growing public and use concern over adverse environmental side effects and increased government restriction. The lower photo shows a typhus ward after the liberation of the prison camps in WWII. fcit.coedu.usf.edu/holocaust/ PICS31/16951.jpg Dr.T.V.Rao MD

Historical Photograph on Typhus
Dr.T.V.Rao MD

Structure: of Bacteria
Similar with Gram negative bacteria Cell wall: outer membrane peptidoglycan lipopolysaccharide (LPS) Microcapsule and polysaccharide Two antigenically distinct groups: LPS: heat-stable, cross-reactive with somatic antigens of non-motile Proteus species (Weil-Felix test) Outer membrane protein: heat-unstable, species-specific Dr.T.V.Rao MD

Rickettsia Small gram negative Bacilli
Obligate intracellular pathogens. Parasites on - Lice, Fleas, Ticks Mites colonizes the Gut. In vertebrates colonizes Vascular endothelium and Reticuloendothelial system. T.V.Rao MD Dr.T.V.Rao MD

Five genera in this class cause human diseases:
Rickettsia Bartonella Coxiella (does NOT cause skin rash) Ehrlichia Orientia Dr.T.V.Rao MD

Replication Dr.T.V.Rao MD

Five genera in this class cause human diseases:
Rickettsia Bartonella Coxiella (does NOT cause skin rash) Ehrlichia Orientia Dr.T.V.Rao MD

Dr.T.V.Rao MD

Genera 1.Rikettsia, 2.Orientia 3.Ehrcichia Dr.T.V.Rao MD

Typhus Group Murine typhus (also known as endemic
typhus and flea borne typhus) – Rickettsia mooseri (typhi) • Epidemic typhus (also known as Brill- Zinsser disease and louse borne typhus) – Rickettsia prowazekii • Scrub typhus (or Chigger fever) – Rickettsia tsutsugamushi Dr.T.V.Rao MD

The Others Q Fever – Coxiella burnetii • Ehrlichiosis
– Ehrlichia canis – Ehrlichia equi – Ehrlichia chafeensis – Several others now identified Dr.T.V.Rao MD

RICKETTSIAL INFECTIONS
Fever, headache, malaise, prostration, skin rash & Hepatosplenomegaly Classified into groups: 1. Typhus Group – Epidemic typhus, Murine typhus, Scrub typhus 2. Spotted Fever Group – RMSF, Rickettsia pox 3. Q Fever 4. Trench fever 5. Ehrlichiosis Dr.T.V.Rao MD

Diseases Caused by the Rickettsia
Organism Vector Reservoir Rocky Mountain spotted fever R. Rickettsii Tick Tick, wild rodents Scrub typhus R. Tsutsugamushi Laval Mite (chiggers) Mites, wild rodents Epidemic typhus R. Prowazekii Louse Humans, squirrel fleas, flying squirrels Murine typhus R. Thphi Flea Wild rodents Q fever Coxiella Burnetii None Cattle, sheep, goats, cats Dr.T.V.Rao MD

TYPHUS GROUP DISEASES a) Epidemic typhus R. prowazekii Louse Human
RICKETTSIAL AGENT INSECT VECTOR MAMMALIAN RESERVOIR TYPHUS GROUP a) Epidemic typhus R. prowazekii Louse Human b) Murine typhus (Endemic typhus) R. typhi Flea Rodents c) Scrub typhus) R. tsutsugamushi Mite Dr.T.V.Rao MD

Rickettsia Prowazekii ( Von Prowazekii )
Humans natural vertebrate hosts Vector - Human body louse,( Pediculus humans corporis ) Lice get infected from patients. Life cycle – get multiplied in gut 1 week Person – person contact. Lice bite causes itching and scratching Enters through respiratory tract / Conjunctivae Incubation days Dr.T.V.Rao MD

Genus -Rickettsia Two groups Typhus fevers, Spotted fever.
Morphology Rickettsia pleomorphic Coco bacillary, Size 0.3 to 0.6 micron x microns. Gram negative, non motile Non capsulate not stained easily Giemsa and Gimenez staining methods. Dr.T.V.Rao MD

Typhus Fever Dr.T.V.Rao MD

2. Recrudescent typhus ( Brill Zinsser’ disease ) 3. Endemic typhus
Typhus Fever group 1. Epidemic Typhus 2. Recrudescent typhus ( Brill Zinsser’ disease ) 3. Endemic typhus Dr.T.V.Rao MD

EPIDEMIC TYPHUS (LOUSEBORNE TYPHUS)
Etiology: R. prowazekii severe systemic infection & prostration more fatal Brill-Zinsser Disease  recrudescent disease Dr.T.V.Rao MD

Epidemic Typhus - 1 Also known as louse borne typhus because it
is spread human-to-human via the body louse (which dies of its infection with Rickettsia prowazekii after about three weeks) • This is a serious disease consisting of fever, severe headache, myalgia, and central rash • Untreated, the mortality ranges from 20-40% • Major killer in concentration camps of WW II Dr.T.V.Rao MD

Cultivation Needs cell culture lines Grows in the Cytoplasm
Grows at 32 to 350 c Grows in yolk sac of developing chick embryo Grows in mouse fibroblasts, Hela,Hep2 Dr.T.V.Rao MD

Cultivation Rickettsia can not be grown in bacteriological media, Obligate intracellular pathogens. In continuous cell lines, Guinea pig, Mice Infect the endothelial cells of vascular system. Can synthesize ATP Dr.T.V.Rao MD

Life Cycle of Rickettsia
Dr.T.V.Rao MD

Replication Dr.T.V.Rao MD

Transmission Human body louse Pediculus humanus corporis
Infective for 2-3 days Infection acquired by feeding on infected person Excrete R. prowazekii in feces at time of feeding Lice die within 2 weeks There are several species of human louse, it is only the body louse that is responsible for transmitting typhus. The louse may take a new blood meal as often as every 5 hours. After ingestion, rickettsiae multiply in the gut epithelial cells of the louse. During the multiplication process the gut cells rupture. The organisms are excreted in the feces of the louse within 2-6 days or earlier if crushed. The louse generally spends its entire life cycle on the same host. If overcrowding occurs the louse may relocate to a new host. Lice remain infective for 2-3 days and acquire the organism from taking a meal from an infective person. People remain infective during the febrile phase of illness and possibly for 2 to 3 days after the temperature returns to normal. The louse dies within 2 weeks after infection, the ricketsiae may remain viable in the dead louse for weeks and may remain infective in the feces for 2-3 days longer. Photo of human body louse, Dr.T.V.Rao MD

Transmission Sylvatic typhus
Louse feces rubbed into bite or superficial abrasions Inhalation of feces Sylvatic typhus Flying squirrel 30 human cases in eastern and central U.S. Human infection occurs when R. prowazekii are rubbed into the bite wound or a superficial abrasion. Inhalation of R. Prowazekii from the infective lice feces may also occur. In 1975, in the United States, a new sylvatic (wild animal) host was found for typhus. The flying squirrel, Glaucomys volans, in the eastern United States have been found to act as a host to R. prowazekii, in addition to humans. Approximately 30 documented cases of typhus have been reported in the central and eastern United states and these infections are thought to have occurred from transmission of the flying squirrel. Most human infection occurs in people over the age of 20. Photo of human body louse, Dr.T.V.Rao MD

PATHOLOGY Multiply in endothelial cells of small blood vessels
Vasculitis (skin – rashes;other organs – DIC & vascular occlusion) Swollen & necrotic Thrombosis of the vessels Dr.T.V.Rao MD

Antigenic structure Species differ with Group specific antigens.
Sharing of antigens between Rickettsia and Proteus basis of Weil – Felix Heterophile agglutination Test. Used Proteus strains 0X 19, OX2 OXK T.V.Rao.MD Dr.T.V.Rao MD

Epidemic Typhus Also called as Louse borne Typhus Classical Typhus Russia Eastern Europe Devastating Epidemics in wars Napoleons retreat Russia 3 million deaths 1917 – 1921 India - Kashmir Dr.T.V.Rao MD

R. Prowazekii Louse Human Human Epidemic typhus Dr.T.V.Rao MD

(much milder than epidemic typhus)
R. Typhi Rodent Flea Rat Tick Flea Human Murine typhus (much milder than epidemic typhus) Dr.T.V.Rao MD

Lesions in Epidemic Typhus
Dr.T.V.Rao MD

Rickettsia Prowazekii ( Von Prowazekii )
Humans - natural vertebrate hosts Vector - Human body louse,( Pediculus humans corporis ) Lice get infected from patients. Life cycle – get multiplied in gut 1 week Person – person contact. Lice bite causes itching and scratching Enters through respiratory tract / Conjunctivae Incubation days Dr.T.V.Rao MD

Pediculus humanus corporis is the Vector
Dr.T.V.Rao MD

Clinical Symptoms Incubation: 7-14 days
High fever, chills, headache, cough, severe myalgia May lead to coma Macular eruption 5-6 days after onset Initially on upper trunk, spreads to entire body Except face, palms and soles of feet The incubation period for typhus is generally 12 days. It is often characterized by the sudden appearance of headaches, chills, prostration, high fever, coughing and severe muscular pain. On the fifth to sixth day, a macular eruption (dark spot on the skin) appears initially on the upper trunk, it spreads to the entire body except, the face, palms and soles of the feet. The disease progresses with a high fever that continues for approximately two weeks. Additional symptoms may include severe headaches, bronchial disturbances, and mental confusion. Typhus is from the Greek word “typhos” meaning stupor which may explain the connection with mental confusion . Dr.T.V.Rao MD

Clinical Features Fever, chills Rash on 4 th day
Spread from Trunk to Limbs Not face palms, sole. In 2 nd week may into stuporous,delirious state May reach 40 % fatality Bacteria remain latent in Lymphoid tissue, cloudy state. Because of called as Typhus May cause Recrudescent Typhus ( Called as Brill Zinser Disease.) Dr.T.V.Rao MD

Brill-Zinsser Disease
Occurs years after primary attack Person previously affected or lived in endemic area Viable retained organisms reactivated Milder symptoms Febrile phase 7-10 days Rash often absent Low mortality rate Brill-Zinsser disease is a recurrent form of epidemic typhus, occurring years after an initial attack. Affected patients either had acquired epidemic typhus earlier or lived in an endemic area. When a persons immune systems is weak, viable organisms retained in the body are activated, causing recurrent typhus. The mechanism by which the organism remains viable in the host is not understood. Lice that feed on patients with Brill-Zinsser disease may acquire infection and transmit the agent. The disease is sporadic, occurring at any season and in the absence of infected lice. Symptoms of the illness are almost always mild and resemble epidemic typhus with similar circulatory disturbances and include hepatic, renal, and CNS changes. The febrile period lasts about 7 to 10 days. The rash is often absent and mortality is very rare. Dr.T.V.Rao MD

Brill- Zinser Disease Recrudescent typhus fever
Earlier recovery from typhus fever Latency of the organism in lymphoid tissue Reactivation leads to recrudescence. Even louse get infected from patients. Clinically similar but mild. Dr.T.V.Rao MD

Pattern of Temperature chart in Typhus Fever
Dr.T.V.Rao MD

Endemic Typhus R.mooseri
Also called as Murine or Flea borne typhus From Rats -Transmitted by Rat flea Rickettsia multiplies in Gut and shed in feces Humans bitten by infected Rat flees. Saliva or feces rubbed on bitten area, may lead to infection. R.typhi R. Prowazekii similar, Biological and Immunological tests. Dr.T.V.Rao MD

Clinical features Mild disease Rat act as reservoir.
Vector – Rat flea -Xenopsylla – cheopsis Rat flea bites rat Multiplies in the gut of the rat Fleas un affted. Man gets infected accidentally Mexico Kashmir - china T.V.Rao MD Dr.T.V.Rao MD

Experiments on Animals Neill-Mooser Reaction
Male guinea pig inoculated intra peritioneally with blood of patients, or isolates of S.typhi produce – Fever, and scrotal swelling, enlarged tests, and cannot be pushed back.-due inflammation and adhesions between layers of Tunica vagina Test positive in R.typhi Dr.T.V.Rao MD

Treatment Chloramphenicol Tetracycline Response within 48 hrs. usually
Doxycycline 200mg Response within 48 hrs. usually Vaccine Developed after World War II Not commercially available Chloramphenicol is empirically used for infections due to its broad spectrum effects. Many physicians prefer to use tetracyclines for treatment of typhus because it is inexpensive and has fewer side effects than chloramphenical. Patients generally respond within 48 hours of treatment. Though both an inactive and live vaccine for typhus have been developed they are not commercially available. Dr.T.V.Rao MD

Spotted Fever Group Rickets 1906
Rickettsia of this group, multiplies in Nucleus and Cytoplasm Ticks transmit Dr.T.V.Rao MD

SPOTTED FEVER GROUP DISEASES a) Indian tick typhus R. conorii Tick
RICKETTSIAL AGENT INSECT VECTOR MAMMALIAN RESERVOIR SPOTTED FEVER GROUP a) Indian tick typhus R. conorii Tick Rodent, Dog b) Rocky mountain spotted fever R. rickettsii Rodents, Dogs c) Rickettsial pox R. akari Mite Mice Dr.T.V.Rao MD

Tick Typhus R.rickettsii Rock mountain spotted fever R.siberica
R.conori R.australis. Ticks transmits bite- Trans ovarian spread T.V.Rao MD Dr.T.V.Rao MD

Rocky Mountain spotted fever
Ticks in North / South America Tick type R.conori. Rickettsial Pox Resembles like chicken pox R. akari by mite Mouse reservoir host. Dr.T.V.Rao MD

Ticks acts as vectors and reservoirs of Infection
Dr.T.V.Rao MD

Dr.T.V.Rao MD

Rocky mountain spotted fever
Dr.T.V.Rao MD

Dr.T.V.Rao MD

Genus - Ehrlichia Small – Gram negative , obligate intracellular pathogens, Can infected Phagocytic cells. Called as Glandular fever Ehrlichia sennetsu causative agent. Cause atypical lymphocytosis No arthropod vector, Eating fish infected with flukes infected by these bacteria. Dr.T.V.Rao MD

Monocytic Ehrlichiosis
Caused by Ixodid ticks, E.chaffensis. Deer, cattle, Sheep reservoirs Leucopenia Thrombocytopenia Liver is involved. Doxycycline effective in Ehrlichosis Human granulocytic Ehrlichosis E.equi. Dr.T.V.Rao MD

Laboratory Diagnosis of Rickettsial diseases
Isolation Serology Isolations can be dangerous if not well protected. R.typhi R.conori, R.akari causes tunica reaction R.prowazeki only fever Dr.T.V.Rao MD

Diagnosis and Prevention
Microscopy Serological Test (Weil-Felix reaction, ELISA, IF, PCR) Breaking the infection chain ( controlling and killing the intermediate hosts and reservoir hosts) Inactivated vaccine has protective effect Chloromycetin, tetracycline are helpful for therapy, Sulphonamides are not administered (increasing the penetrating of the vessel). Dr.T.V.Rao MD

Laboratory Diagnosis Tissue cultures In Vero cells, MRC – 5 cells.
Dr.T.V.Rao MD

Serology Weil – Felix Test OX19,OX2,OXK
Test based on principle of Hetrophile agglutination tests Non motile strains of Proteus are selected. OX19,OX2,OXK Sharing alkali stable carbohydrate antigen by some Rickettsia X certain strains of Proteus vulgaris OX19,OX2, and Proteus mirabilis OXK. Dr.T.V.Rao MD

Laboratory Diagnosis Weil – Felix is simple to perform but of Historical importance Other tests Complement fixation tests, Agglutination, Passive hem agglutination. PCR Dr.T.V.Rao MD

DISEASE WEIL-FELIX OX19 OX2 OXK Epidemic typhus ++ +/- -
Endemic typhus Scrub typhus RMSF + Rickettsial pox Q fever Trench fever ? Dr.T.V.Rao MD

Different Methods of Diagnosis
Dr.T.V.Rao MD

Older Techniques Giemsa Staining Technique
:to detect O. tsutsugamushi Giemsa Staining Technique :- utilizes peritoneal scrapings of infected mice. 2. Weil-Felix Proteus Agglutination Test :-is a test which relies on the fact that Rickettsia and Proteus OX strains have common antigens. :-is a test for the presence & type of rickettsial disease based on the agglutination of X-strain Proteus vulgaris with suspected Rickettsia in a patient’s blood serum sample. :-is commonly used in hospitals & clinics :-This test is now being replaced by a complement-fixation test. Weil-Felix Proteus Agglutination Test Dr.T.V.Rao MD

2. Indirect Immuno-Peroxidase (IIP)
Newer Techniques :to detect O. tsutsugamushi Immunological Assays Control Infected 2. Indirect Immuno-Peroxidase (IIP) IIP= is a modification of IFA technique that replaces the fluorochrome with peroxidase. Slide is observed using a bright-field microscope. Staining reaction is positive when O. tsutsugamushi particles stain light brown. Dr.T.V.Rao MD

Newer Techniques Immunological Assays
:to detect O. tsutsugamushi Immunological Assays 4. Enzyme-linked Immuno-Sorbant Assay (ELISA) ELISA test is a technique for detecting & measuring antigen or antibody. :-It is one of the most reliable techniques to detect antibody against scrub typhus infection. :-Its procedure is the principal for development of recent rapid diagnostic kits. :-This technique is widely used in laboratories & hospitals. 1. Add antigens Ag-coated well 3. Add anti-Ab 2. Add mouse serum Ag-Ab complex Optical Density (OD) Reading 4. Add enzyme-substrate mix 5.Let colorize Dr.T.V.Rao MD

Destruction animal reservoirs,
Prophylaxis Control of vectors. Destruction animal reservoirs, Dr.T.V.Rao MD

Scrub Typhus Scrub typhus caused by Mild to fatal
6-18 days after bite of Mite An Escher is formed at the site of bite With enlargement of Lymph nodes, Interstitial pneumonitis ,lymphadenopathy,spleenomegaly Encephalitis, Respiratory failure, circulatory failure Dr.T.V.Rao MD

SCRUB TYPHUS Etiology: Orientia tsutsugamushi
resembles Epidemic typhus except for the ESCHAR generalized lymphadenopathy & lymphocytosis cardiac & cerebral involvement may be severe Dr.T.V.Rao MD

Epidemiology Source of infection--------Rat
Route of transmission-----Trombiculid mites Susceptible population----All susceptible Epidemic features Tsutsugamushi triangle Dr.T.V.Rao MD

Epidemiology Human Infected animal Larva Egg Adult
Nymph Adult Human Natural cycle-natural focalization Natural focus disease-zoonosis-borne diseases Dr.T.V.Rao MD

Scrub Typhus An important vector-borne disease, first described in 1899 in Japan. During World War II, this disease killed thousands of soldiers who were stationed in rural or jungle areas of the Pacific theatre. The disease occurred and threatened people throughout Asia & Australia. The range stretches from the Far-east to the Middle-east (from Japan and Korea, Southeast Asia, Pakistan, India, to Arab countries and Turkey). There are approx. 1 million cases each year world-wide, & over 1 billion people at risk. Dr.T.V.Rao MD

Eggs Adult stage Nymphal stage
R. Tsutsugamushi Eggs Adult stage Nymphal stage Chigger Rats Nymphal stage Nymphal stage Human Nymphal stage Adult stage Eggs Scrub typhus Dr.T.V.Rao MD

Scrub typhus Dr.T.V.Rao MD

Vector: Leptotrombidium
Scrub Typhus: A Rickettsial Disease Pathogen: Orientia tsutsugamushi Rickettsial bacteria An acute febrile, rickettsial disease caused by a gram-negative, rod-shaped (cocco-bacillus) bacterium, known as Orientia (Rickettsia) tsutsugamushi. Vector: Leptotrombidium Chigger-Mite O. tsutsugamushi is transmitted to vertebrate hosts (rodents-primary host & humans-secondary or accidental host) by the bite of larval mites (chiggers) of the genus Leptotrombidium, e. g. L. deliense, L. dimphalum, etc. Dr.T.V.Rao MD

Pathogenesis and pathology
Inoculation Invade Local lymph node Spread by Blood stream Invade Vascular endothelium Papule maculoppular eschar ulcer Enlargement of local lymph node General symptoms of intoxication General organ hyperaemia. Systemic lyphadenopath Dr.T.V.Rao MD

Eggs Adult stage Nymphal stage
R. Tsutsugamushi Eggs Adult stage Nymphal stage Chigger Rats Nymphal stage Nymphal stage Human Nymphal stage Adult stage Eggs Scrub typhus Dr.T.V.Rao MD

Scrub typhus Dr.T.V.Rao MD

Clinical Manifestation
Incubation period is 4~21 Sudden onset with a fever 1st week, systemic toxic symptoms 2nd week, get worse, complication 3th week, convalesce Dr.T.V.Rao MD

Specific features Eschar Probability: Higher than 60%.
Location: Axillary fossa, inguinal region, perianal region, scrotum, buttocks and the thigh. Appearance: an ulcer surrounded by a red areola, is often covered by a dark scab. The most specific manifestation of scrub typhus. Dr.T.V.Rao MD

Ricketisial pox Transmitted by mites, Similar other spotted fever
Head ache ,fever Escher at the site of bite by mite. Maculopapular rash, can be vesicular, Fever lasts for 1 week Dr.T.V.Rao MD

Skin Lesion Mite Dr.T.V.Rao MD

Q Fever Occurs in veterinarians, ranchers, and animal researchers who are in contact with infected placenta from sheep, cattle, or goats (no arthropod vector for C. burnetii) • Incubation period is days • Fever and headache are common; 50% will develop pneumonia after inhaling the organism; hepatitis & endocarditis are rare • Specific serology establishes the diagnosis • Bioterrorist threat? Dr.T.V.Rao MD

Coxiella Burnetii Q fever（query fever ）
Self-limiting flu-like syndrome with high fever (40℃) Primary reservoirs are wild (cattle, sheep, goat etc.) Non-cross reactive antigen with non-motile Proteus (Weil-Felix reaction negative) Live in macrophages of vertebrate host Dr.T.V.Rao MD

Genus – Coxiella Q Fever
Etiological agent ? Small in size called Coxiella burnetti Ixodid tick spread the disease Domestic live stock get infected. Coxiella abundant in Tick feces, Survive in dried feces, Milk too infective Cause Human infection. Dr.T.V.Rao MD

Coxiella burnetti Q fever Cow and sheep tick High resistance
abrupt onset ,fever,headache,chills,myalgia,granulomatous hepatitis chronic diaease with subacute onset ,endocarditis,hepatic dysfunction Q fever Cow and sheep tick High resistance Dr.T.V.Rao MD

Q - Fever Dr.T.V.Rao MD

Q Fever Wool hides, Meat, Milk Enters through abrasions
System infection through Intestine, pulmonary, All organs are involved Can cause serious infection, Hepatitis and meningitis, May last for 2 – 3 years as chronic condition Infects Monocytes and Macrophages, Dr.T.V.Rao MD

Q Fever Dr.T.V.Rao MD

Pasteurization of Milk Which method is better ?
Pasteurization by holders method not effective Flash method effective. Phase variation applicable Phase I and Phase II Dr.T.V.Rao MD

Present with head ache, chills, Pneumonia
Clinical features Present with head ache, chills, Pneumonia Endocarditis, Meningitis, Encephalitis Can cause latent infections. Dr.T.V.Rao MD

Q Fever Dr.T.V.Rao MD

Laboratory Diagnosis Indirect Immunofluorescence methods
Polymerase chain reaction, Genus specific applications in progress. Isolation of the organism is dangerous. Dr.T.V.Rao MD

Treatment Doxycycline is effective. Tetracycline are highly effective
Nursing care May need blood transfusion. Dr.T.V.Rao MD

Ehrlichiosis Ehrlichia chaffeensis most common
Human monocytotropic ehrlichiosis (HME) E. ewingii has also been identified Transmitted by lone star tick (Amblyomma americanum) White-tailed deer major host for tick species and natural reservoir for bacteria Infections in coyotes, dogs, and goats have been documented Ehrlichia chaffeensis is the most common cause of Ehrlichiosis and leads to a disease known as human monocytotropic ehrlichiosis or HME. E. ewingii has also been identified as a cause of ehrlichiosis in humans. Both bacterial pathogens of ehrlichiosis are transmitted by the lone star tick. White-tailed deer are the major host for this tick species and serve as a natural reservoir for the bacteria. Infections of ehrlichiosis in coyotes, dogs, and goats have also been documented.

Proposed life cycle for the agent of Human Granulocytic Ehrlichiosis
Dr.T.V.Rao MD

Ehrlichiosis Clinical Information
Onset occurs 5–10 days after tick bite Infects leukocytes E. chaffeensis prefers monoctyes E. ewingii prefers granuloctyes Morulae can be identified Rash observed ~33% of patients with HME Vary from petechial or maculopapular to diffuse erythema Occurs later in disease Rash rarely seen with E. ewingii infections The onset of ehrlichiosis generally occurs about 5-10 days after a tick bite. The bacteria that causes Ehrlichiosis infects leukocytes, and more specifically, E. chaffeensis prefers to infect monocytes while E. ewingii prefers to infect granulocytes. The bacteria multiply in these cells in cytoplasmic membrane-bound vacuoles called morulae, which can sometimes be identified on blood smears. The picture to the right is an example of morulae in a monoctye caused by E. chaffeensis. A rash is observed in about 33% of patients with HME. The rash varies from a petechial or maculopapular rash to diffuse erythema and generally occurs later in the disease process. A rash is rarely seen in patients with E. ewingii infections.

E. Chaffeensis Laboratory Criteria
Confirmed Fourfold change in IgG by IFA in paired serum samples Detection of DNA by PCR Demonstration of antigen by IHC in biopsy or autopys sample Isolation of bacteria by cell culture Supportive Elevated IgG or IgM by IFA, ELISA, dot-ELISA or other formats Morulae identification by blood smear microscopic examination This is the lab criteria for E. chaffensis only.

Bartonella Gram – ve bacilli/Anthropoids
B.bacilliform, B.quintana,B henselae Bartonella bacilliform Also called as Oroya fever, A Medical student – Peruvian Daniel Carrion Credited for isolation. Called as Carrions Disease Dr.T.V.Rao MD

Bacterial Morphology B.bacilliform Pleomorphic gram negative bacteria
Carries a tuft of polar flagella. T.V.Rao MD Dr.T.V.Rao MD

Clinical features Progressive Anemia,
Bacterial invasion of Erythrocytes Carries high mortality Dr.T.V.Rao MD

Bartonella ( Rochalimia )
Bartonella Quintana Called as trench fever Called as five day fever. Grows in cell free culture media. Chronic/Latent infections Infection may lost > 20 years T.V.Rao MD Dr.T.V.Rao MD

Bartonella Henselae Cat scratch disease (CSD)
Weil-Felix reaction negative Infection by cats or dogs “Parinaud” Eye-Lymph node syndrome The eye looks red, irritated, and painful, similar to conjunctivitis. Dr.T.V.Rao MD

Bartonella henselae Also called s cat scratch disease
Caused by B.henselae Needs lymph node biopsy Staining sections with Warthim Starry sating Associated in AIDS patients. T.V.Rao MD Dr.T.V.Rao MD

Prevention Use of repellents in endemic areas
• Protective clothing in endemic areas • Careful inspection & quick removal of ticks • Useful vaccine for RMSF is available for high risk groups such as forest rangers that work in endemic areas • Weekly doxycycline may prevent scrub typhus infection in field workers Dr.T.V.Rao MD

Programme Created by Dr. T. V
Programme Created by Dr.T.V.Rao MD for Medical and Paramedical Students in the Developing World Dr.T.V.Rao MD

RICKETTSIACEAE Dr.T.V.Rao MD T Dr.T.V.Rao MD.

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