Last minute revision of Infectious Disease

Staph. Aureus Inflammatory dis. :

skin infections

organ abscesses

Pneumonia ( often after influenza virus infection )


Septic arthritis



Toxin-mediated dis. :

Toxic shock syndrome (TSST-1 ) : fever , vomiting , rash , desquamation , shock , end-organ failure


Scalded skin syndrome (exfoliative toxin ): widespread formation of fluid-filled blisters that are thin walled and easily ruptured and the patient can be positive for Nikolsky’s sign , a widespread painful

erythroderma, often involving the face, diaper, and other intertriginous areas.

Extensive areas of desquamation might be present. Perioral crusting and fissuring are seen early in the course.


Rapid-onset food poisoning ( enterotoxin ):short incubation period ( 2-6 hr ) followed by nonbloody diarrhea and emesis .

MRSA serious nosocomial and community-acquiered infections
Staph. Epidermidis Infects prosthetic devices ( e.g. hip implant , heart valve ) and intravenous catheters
Staph. saprophyticus Second most common cause of Uncomplicated UTI in young women
Strep. Pneumoniae Most common cause of :


Otitis media ( in children )



Viridians group strep. 1. Strep. Mutans: Dental caries

2. strep. Sanguinis: Subacute bact. Endocarditis at damaged heart valves

Streptoccus pyogenes Pyogenic :



Impetigo : more common precedes glemurulonephritis than pharyngitis



Toxigenic :

Scarlet fever : scarlet rash with sandpaper-like texture , strawberry tongue , circumoral pallor , subsequent desquamation


Toxic shock-like syndrome

Necrotizing fasciitis


Immunologic :

Rheumatic fever : migrating polyarthritis , pancrditis , subcutaneous nodules , erythema marginatum , Sydenham chorea .

Acute glomerulonephritis

Streptococcus agalactiae Mainly in babies



Sepsis : fever, low body temperature, rapid breathing, elevated heart rate, confusion, and edema. Early signs are a rapid heart rate, decreased urination, and high blood sugar. Signs of established sepsis include confusion, metabolic acidosis (which may be accompanied by faster breathing and lead to a respiratory alkalosis) , low blood pressure due to decreased systemic vascular resistance, higher cardiac output, and dysfunctions of blood coagulation (whereclotting may lead to organ failure). The drop in blood pressure seen in sepsis may lead to shock. This may result in light-headedness. Bruising or intense bleeding may occur

Enterococci ( E.faecalis and E. faecium ) UTI

Biliary tract infections

Subacute endocarditis ( following GI , GU procedures)

Streptococcus bovis Bacteremia

Subacute endocarditis

Associated with colon cancer

Corynebacterium diphteria Pseudomembranous pharyngitis ( grayish white membrane )




Clos. tetani Tetanus : spastic paralysis , trismus ( lockjaw ) , risus sardonicus ( raised

eyebrows and open grin ) opisthotonos (spasms of spinal extensors).

Clos. Botulinum In adults : Double vision, drooping of both eyelids, loss of facial expression and swallowing problems . a dry mouth and throat , difficulty postural hypotension , constipation , nausea, vomiting , with talking , weakness , and may lead to coma and death


In babies : floppy baby syn. : poor feeding , lethargy , constipation , weakness

Clos. perfringens Myonecrosis ( gas gangrene ), gas production, and sepsis . Progression to toxemia and shock is often very rapid. It can easily be noticed by the large, blackened sores that form, as well as a degree of loud and distinctive crepitus caused by gas escaping the necrotic tissue.


Pseudomembranous colitis diarrhea
Anthrax Cutaneous anthrax : painless papule surrounded by vesicles → ulcer with black eschar ( painless necrotic ) → uncommonly progresses to bacteremia and death .


Pulmonary anthrax : flu-like symptoms that rapidly progress to fever , pulmonary hemorrhage , mediastinitis , and shock .

Bacillus cereus Food poisoning :

Emetic type : nasea and vomiting within 1-5 hours .

Diarrheal type : watery , nonbloody diarrhea , and GI pain within 8-18 hr.

Listeria monocytogenes Amnionitis : One of the earliest signs can be regular contractions with cervical dilation; these symptoms together signify the start of preterm labor. A flu-like feeling may also be noted at this early stage. As the infection progresses, the abdomen (uterus) can become tender to touch and fever may develop .



Spontaneous abortion in pregnant women


Granulomatosis infantiseptica : pyogenic granulomas distributed over the whole body .


Neonatal meningitis


Meningitis in immunocompromised pat.


Mild gastroenteritis in healthy indiv. : incubation period is 21 days, with diarrhea lasting anywhere from 1–3 days. Patients present with fever, muscle aches, gastrointestinal nausea or diarrhea , headache , stiff neck, confusion, loss of balance, or convulsions.

Actinomyces Oral/fascial abcessess that drain through sinus tracts , forms yellow ” sulfar granules ”
Nocardia Pulmonary infections in immunocompromised : cough, dyspnea (shortness of breath), and fever.

encephalitis and/or brain abscess formation

Cutaneous infections in immunocompetent : actinomycetoma (especially N. brasiliensis), lymphocutaneous disease, cellulitis, and subcutaneous abscesses.

Myobac. Tuberculosis Primary TB : fever , night sweat , weight loss , cough , ( nonproductive or productive ) , hemoptysis .


Progressive lung disease ( HIV , malnutrition ) → death .


Severe bacteremia → military tuberculosis → death


Extrapulmonary TB : CNS : parynchymal tuberculoma or meningitis ) , vertebral body : pott disease , lymphadenitis , renal , adrenals .

M.avium-intracellulare Dessiminated none-TB disease in AIDS
M.scrofulaceum Cervical lymphadenitis in children
M.marinum Hand infections in aquarium handlers
Myobac. Leprae Lepromatous leprosy : presents diffusely over the skin, with leonine (lion-like) facies , testicular destruction , blindness , regional anesthesia , skin thickening plaque hypopigmentation .


Tuberculoid leprosy : limited to a hypoesthetic hairless skin plaques and hypopigmentation .

Neisseria gonorrhoeae Gonorrhea : urethritis , prostatitis , epididymitis , cervicitis , PID , creamy purulent discharge .

Septic arthritis

Neonatal conjunctivitis

Pelvic inflammatory disease

Fitz-hugh-curtis syn. Fitz-hugh-curtis syn. : rare complication of pelvic inflammatory disease (PID) involving liver capsule inflammation leading to the creation of adhesions , acute onset of right upper quadrant (RUQ) abdominal pain aggravated by breathing, coughing or laughing, which may be referred to the right shoulder
Nesisseria meningitidis Meningococcemia


Waterhose-friedrichsen syndrome : (adrenal insufficiency, fever, DIC, shock)

Haemophilus influenza Epiglottitis : sore throat , dysphagia , respiratory distress


Otitis media


Haemophilus ducreyi (chancroid) painful genital ulcer with exudates , inguinal adenopathy
Legionella pneumophila Legionnaires dis. : severe pneumonia , ( often unilateral and lobar ) , fever , GI and CNS symptoms .

Pontiac fever : mild flu-like syndrome .

Pseudomonas auroginosa Pneumonia


Otitis externa ( swimmers ear )



Ecthyma gangrenosum : rapidly progressive , necrotic cutaneous lesion

Wound infections in burn victims

Hot tub folliculitis

E.coli EIEC : invasive dysentry

ETEC : travelers dirrhea

EPEC : diarrhea in children

EHEC : Bloody Diarrhoea


Hemolytic uremic syn. : triad of anemia , thrombocytobenia , and acute renal failure .

klebsiella lobar pneumonia in alcoholics and diabetics nosocomial UTIs
campylobacter jejuni major cause of bloody diarrhea , specially in children common antecedent to Guillain-barre syn.
salmonella typhi typhoid fever : ( red spots on abdomen , constipation , abdominal pain , fever )


constipation followed by diarrhea

salmonella spp. Bloody diarrhea
Shigella Bloody diarrhea ( bacillary dysentery )
Vibrio cholera Traveler’s diarrhea
Yersinia enterocolitica Acute diarrhea

Pseudoappendicitis : right lower abdominal pain due to mesenteric adenitis and/or terminal ileitis

Helicobacter pylori Gastritis

Peptic ulcer

Leptospira interrogans Leptospirosis : flu-like symptoms, myalgias (classically of calves), jaundice, photophobia with conjunctival suffusion (erythema without exudate).


Weil dis. : (icterohemorrhagic leptospirosis)—severe form with jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, and anemia.

Borrelia burgdorferi (Lyme dis.) Stage 1—early localized: erythema migrans (typical “bulls-eye” is pathognomonic but not always present) , flu-like symptoms. Stage 2—early disseminated: secondary lesions, carditis, AV block, facial nerve (Bell) palsy, migratory myalgias /transient arthritis. Stage 3—late disseminated: encephalopathies, Chronic arthritis.
Spirochete treponema pallidum : syphilis Primary syphilis : Localized disease presenting with painless chancre .

Secondary syphilis : Disseminated disease with constitutional symptoms, maculopapular rash (including palms and soles), condylomata lata (smooth, moist, painless, wart-like white lesions on genitals), lymphadenopathy, patchy hair loss .

Tertiary syphilis : Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, “general paresis”), Argyll Robertson pupil (constricts with accommodation but is not reactive to light; also called “prostitute’s pupil” since it accommodates but does not react).

Signs: broad-based ataxia, Romberg, Charcot joint, stroke without hypertension


Congenital syphilis : facial abnormalities such as rhagades (linear scars at angle of mouth, black arrowin ), snuffles (nasal discharge, red arrow in), saddle nose, notched (Hutchinson) teeth , mulberry molars, and short maxilla; saber shins; CN VIII deafness.

Jarish-hexheimer reaction  Flu-like syndrome (fever, chills, headache, myalgia) after antibiotics are started ; due to killed bacteria (usually spirochetes) releasing toxins.
Bartonella spp. Cat scratch dis. : tender, swollen lymph nodes near the site of the inoculating bite or scratch or on the neck, and is usually limited to one side. A vesicle or an erythematous papule may form at the site of initial infection .


systemic symptoms : malaise , decreased appetite, and aches.


Other complaints : headache, chills, muscular pains, joint pains , arthritis , backache , and abdominal pain .

bacillary angiomatosis : may take several forms :


papules or nodules which are red, globular and non-blanching, with a vascular appearance .


purplish nodules sufficiently similar to Kaposi’s sarcoma .


a purplish lichenoid plaque .


a subcutaneous nodule which may have ulceration, similar to a bacterial abscess

Borrelia recurrentis Relapsing fever : sickness between five and 15 days after they are bitten . a sudden fever, chills, headaches, muscle or joint aches, and nausea, rash .


These symptoms usually continue for two to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated .

Brucella spp. Brucellosis/ undulant fever :


First stage : septicaemia occurs and leads to the classic triad of undulant fevers, sweating (often with characteristic smell, likened to wet hay), and migratory arthralgia and myalgia (joint and muscle pain) . The focalizations of brucellosis occur usually in bones and joints and spondylodiscitis of the lumbar spine accompanied by sacroiliitis is very characteristic of this disease. Orchitis is also common in men. The disease’s sequelae are highly variable and may include granulomatous hepatitis arthritis , spondylitis , anaemia, leukopenia ,thrombocytopenia, meningitis, uveitis, optic neuritis, endocarditis, and various neurological disorders collectively known as neurobrucellosis.

Clamydophila psittaci Psittacosis : incubation period of 5–19 days , disease range from inapparent illness to systemic illness with severe pneumonia. It presents chiefly as an atypical pneumonia . In the first week of psittacosis the symptoms mimic typhoid fever: prostrating high fevers, joint pains, diarrhea, conjunctivitis, nose bleeds and low level of white blood cells in the blood. Rose spots can appear and these are called Horder’s spots. Spleen enlargement is common towards the end of the first week.
Coxiella burnetti (Q fever) flu-like symptoms with abrupt onset of fever , malaise , profuse perspiration, severe headache, muscle pain, joint pain, loss of appetite, upper respiratory problems , dry cough, pleuritic pain, chills, confusion, and gastrointestinal symptoms, such as nausea, vomiting, and diarrhea. About half of infected individuals exhibit no symptoms. During its course, the disease can progress to an atypical pneumonia, which can result in a life-threatening acute respiratory distress syndrome
Ehrlichia chaffeensis Ehrlishiosis : headache, muscle aches, and fatigue. A rash may occur, but is uncommon. Ehrlichiosis can also blunt the immune system by suppressing production of TNF-alpha, which may lead to opportunistic infections such as candidiasis . “toxic shock-like” syndrome is seen in some severe cases of ehrlichiosis. Some cases can present with purpura.
francisella tularentis tularemia : fever, lethargy, loss of appetite, signs of sepsis, and possibly death . Inflammation spreads to the lymph nodes, which enlarge and may suppurate
Pasteurella multocida Cellulitis , osteomyelitis.
Rickettsia prowazekii Epidemic typhus : severe headache, a sustained high fever,cough , rash, severe muscle pain, chills, falling blood pressure , stupor , sensitivity to light, delirium and death. A rash begins on the chest about five days after the fever appears , and spreads to the trunk and extremities .
Rickettsia rickettsii Rocky mountain spotted fever : Initial symptoms: Fever Nausea , Emesis (vomiting ) , Severe headache , Muscle pain , Lack of appetite , Parotitis in some cases (somewhat rare) .


Later signs and symptoms: Maculopapular rash , Petechial rash , Abdominal pain Joint pain , Conjunctivitis , Forgetfulness .

Rickettsia typhi Endemic typhus : headache, fever, muscle pain, joint pain, nausea and vomiting. 40–50% of patients will develop a discrete rash six days after the onset of signs. Up to 45% will develop neurological signs such as confusion, stupor, seizures or imbalance.


Yersinia pestis Plague :


Pubonic plague : Y. pestis spreads through the lymphatic vessels of the infected human until it reaches a lymph node, where it stimulates severe haemorrhagic inflammation that causes the lymph nodes to expand. The expansion of lymph nodes is the cause of the characteristic “bubo” associated with the disease .


Septicemic plague : In septicemic plague, bacterial endotoxins cause disseminated intravascular coagulation (DIC), causing tiny clots throughout the body and possibly ischaemic necrosis . there is bleeding into the skin and other organs, which can cause red and/or black patchy rash and hemoptysis/hematemesis (coughing up/ vomiting of blood) .


Pneumonic plague : coughin , sneezing , headache, weakness, and hemoptysis or hematemesis (spitting or vomiting of blood) .


Pharyngeal plague : resembles tonsillitis .


Meningeal plague : meningitis .

Gardnerella vaginalis Bacterial vaginosis : gray vaginal discharge with a fishy smell; nonpainful (vs vaginitis). Associated with sexual activity .
Chlamydia trachomatis Types A , B and C : follicular conjunctivitis → blindness


Types D-K :

Urethritis , cervicitis , conjunctivitis , reactive arthritis


Ectopic pregnancy

Neonatal pneumonia ( staccato cough ) with eosinophilia

Neonatal conjunctivitis


Types L1 , L2 , L3 :

Lymphogranuloma venereum : small, painless ulcers on genitals → swollen, painful inguinal lymph nodes that ulcerate (buboes).

Mycoplasma pneumonia Atypical pneumonia : (insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate).


Hemolytic anemia

Blastomycosis Inflammatory lung disease , can dissiminate to skin and bone
Coccidiodomycosis Pneumonia and meningitis , can dissiminate to bone and skin , profound feeling of tiredness, fever, cough, headaches, rash, muscle pain, and joint pain .

The classic triad of coccidioidomycosis known as “desert rheumatism” includes the combination of fever, joint pains, and erythema nodosum. Osteomyelitis, including involvement of the spine, and meningitis which may occur months to years after initial infection

Paracoccidiodomycosis high prostrating fever, generalized lymphadenopathy , and pulmonary involvement with milliary lesions. Painful lesions with a violaceous hue in lips and oral mucosa are common as is cervical lymphadenitis . Pulmonary involvement is also common; it starts as lobar pneumonia or pleurisy , Other organs can be involved, such as bones, meninges, arteries, and spleen, but this is very rare.
Tinea ( dermatophytes ) T. capitis : occurs on head , scalp , associated with lymphadenopathy .

T. corporis : Occurs on torso. Characterized by erythematous scaling rings (“ringworm”) and central clearing .

Tt. cruris : Occurs in inguinal area . Often does not show the central clearing seen in tinea corporis.

 T. pedis : Three varieties: Interdigital ; most common Moccasin distribution Vesicular type

T. unguium : Onychomycosis; occurs on nails.

candida albicans systemic or superficial fungal infections

oral and esophageal thrush in immune compromised


diaper rash

endocarditis in IV drug users

dissiminated candidiasis

chronic mucocutaneous candidiasis

aspergillus fumigates invasive aspergillosis

allergic bronchopulmonary aspergillosis : associated with asthma and cystic fibrosis ; may cause bronchiectasis and eosinophilia .

aspergillomas in lung cavities especially after TB infection

Sporothrix schenckii Sporotricosis

Local pustule or ulcer

Nodules along draining lymphatics ( ascending lymphangitis )

Giardia lamblia bloating , flatulence , foul-smelling , fatty diarrhea
Entamoeba histolytica Amebiasis – bloody diarrhea ( dysentery) , liver abscess , RUQ pain
Cryptosporidium Severe diarrhea in AIDS

Mild disease ( watery diarrhea ) in immunocompetent host .

Toxoplasmosis gondii Congenital toxoplasmosis = classic triad of chorioretinitis , hydrocephalus and intracranial calcification .

Reactivation in AIDS : brain abscess

Naegleria fowleri Rapidly fatal meningoencephalitis
Trypanosoma bruci African sleeping sickness – enlarged lymph nodes , recurring fever , somnolence , coma .
Plasmodium Malaria – fever , headache , anemia , splenomegaly


p.vivax/ovale : 48-hr cycle ( tertian ; include fever on first day and third day , thus fevers are actually 48 hr apart )


p.falciparum : severe irregular fever .


p.malariae : 72-hr cycle

babesia babesiosis – fever and hemolytic anemia
Trypanosome cruzi chagas disease – dilated cardiomyopathy with apical atrophy , megacolon , megaesophagus , unilateral periorbital swelling .
Leishmania donovani visceral leishmaniasis ( kala- azar ) – spiking fever , hepatosplenomegaly , pancytopenia
Trichomonas vaginitis vaginitis – foul-smelling greenish discharge , itching and burning
Onchoceca volvulus hyperpigmented skin and river blindness allergic reaction
loa loa swelling in skin , worm in conjunctiva
wuschereria bancrofti elephantiasis – worms block lymphatic vessels
toxocara canis visceral larva migrans
taenia solium intestinal infection



diphyllobothrium latum vit B12 defic. : megaloblastic anemia
echinococcus granulosus hydatid cyst in liver
schistosoma mansoni liver and spleen enlargement , fibrosis and inflammation
schistosoma haematobium squamous cell carcinoma of the bladder ( painless hematuria ) and pulmonary hypertension .
clonorchis sinensis biliary tract inflammation , pigmented gallstones , cholangiocarcinoma .
Herpes virus (HSV-1) Oral ( and some genital ) lesions



herpes labialis

spontaneous temporal lobe encephalitis .

HSV-2 genital ( and some oral ) lesions . herpes genitalis , neonatal herpes
VZV ( HHV-3 ) Varicella-zoster ( chickenpox-shingles )



Post-herpetic neuralgia

EBV ( HHV-4 ) Mononucleosis : fever , hepatosplenomegaly , pharyngitis and lymphadenopathy
CMV ( HHV-5 ) Congenital infection : ( chorioretinitis ) , hydrocephalus and intracranial calcification , +/- ” blueberry muffin “rash.


Pneumonia , typically after organ transplantation




HHV-6 / HHV-7 Roseola : high fever for several days that can cause seizures , followed by a diffuse macular rash
HHV-8 Kaposi sarcoma
HBV Acute or chronic hepatitis
Adenovirus Febrile pharyngitis – sore throat

Acute hemorrhagic cystitis



B19 virus aplastic crisis in sickle cell disease , “Slapped cheeks” rash in children

In fetus : Hydrops fetalis and death

In adults : pure RBC aplasia and rheumatoid arthritis-like symptoms .

HPV Condyloma acuminate : genital Warts ( serotypes 1 , 2 , 6 , 11 )


Cervical cancer ( most commonly 16 , 18 )



JC virus : Progressive multifocal leukoencephalopathy

BK virus : Transplant patient , commonly targets kidney

Smallpox The initial or prodromal symptoms are similar to other viral diseases such as influenza and the common cold: fever of at least 38.3 °C (101 °F) , muscle pain, malaise, headache and prostration. As the digestive tract is commonly involved, nausea and vomiting and backache often occur. The prodrome, or preeruptive stage, usually lasts 2–4 days. By days 12–15 the first visible lesions—small reddish spots called enanthem— appear on mucous membranes of the mouth, tongue, palate, and throat, and temperature falls to near normal. These lesions rapidly enlarge and rupture, releasing large amounts of virus into the saliva. Smallpox virus preferentially attacks skin cells, causing the characteristic pimples (called macules) associated with the disease. A rash develops on the skin 24 to 48 hours after lesions on the mucous membranes appear. Typically the macules first appear on the forehead, then rapidly spread to the whole face, proximal portions of extremities, the trunk, and lastly to distal portions of extremities .
Cowpox ( milkmaid blisters ) localized, pustular lesions generally found on the hands and limited to the site of introduction.


Molluscum contagiosum flesh-colored papule with centaral umbilication


Colitivirus – Colorado tick fever Initial symptoms include fever, chills, headaches, pain behind the eyes, light sensitivity, muscle pain, generalized malaise, abdominal pain, hepatosplenomegaly, nausea and vomiting, and a flat or pimply rash . Complications with this disease have included aseptic meningitis, encephalitis,and hemorrhagic fever, but these are rare.
Rotavirus #1 cause of fatal diarrhea in children
Poliovirus In 95% of cases only a primary, transient presence of viremia (virus in the bloodstream) occurs, and the poliovirus infection is asymptomatic. In about 5% of cases, the virus spreads and replicates in other sites such as brown fat, reticuloendothelial tissue, and muscle. The sustained viral replication causes secondary viremia and leads to the development of minor symptoms such as fever, headache, and sore throat. Paralytic poliomyelitis occurs in less than 1% of poliovirus infections. Paralytic disease occurs when the virus enters the central nervous system (CNS) and replicates in motor neurons within the spinal cord, brain stem, or motor cortex, resulting in the selective destruction of motor neurons leading to temporary or permanent paralysis. In rare cases, paralytic poliomyelitis leads to respiratory arrest and death
Echovirus aseptic meningitis .
Rhinovirus common cold , nasopharyngitis : nasal congestion , discharge , sneezing , cough , sore throat
Coxsackivirus aseptic meningitis , herpangina ( mouth blisters , fever ) , hand ( oval-shaped vesicles on palms and soles ) , foot and mouth disease (vesicles and ulcers in oral mucosa ) , myocarditis , pericarditis
HAV acute viral hepatitis : episodes of fever , fatigue , nausea , appetite loss , abdominal discomfort , jaundice , dark urine , ↑AST , ALT
HEV jaundice, fatigue and nausea. The symptomatic phase coincides with elevated hepatic aminotransferase levels .


HCV acute infection : mild and vague, including a decreased appetite, fatigue, nausea, muscle or joint pains, and weight loss and rarely does acute liver failure result. Most cases of acute infection are not associated with jaundice. The infection resolves spontaneously in 10– 50% of cases .


Chronic infection : fatigue and mild cognitive problems. Chronic infection after several years may cause cirrhosis or liver cancer , Fatty changes to the liver occur in about half of those infected and are usually present before cirrhosis develops. Liver cirrhosis may lead to portal hypertension, ascites (accumulation of fluid in the abdomen) , easy bruising or bleeding, varices (enlarged veins, especially in the stomach and esophagus), jaundice, and a syndrome of cognitive impairment known as hepatic encephalopathy .

Yellow fever high fever , black vomitus and jaundice .


Dengue sudden-onset fever, headache (typically located behind the eyes), muscle and joint pains “breakbone fever ” , and a rash: flushed skin, or as a measles-like rash. A rash described as “islands of white in a sea of red” has also been observed. Some petechiae (small red spots that do not disappear when the skin is pressed, which are caused by broken capillaries) as may some mild bleeding from the mucous membranes of the mouth and nose. The fever itself is classically biphasic or saddleback in nature, breaking and then returning for one or two days . fluid accumulation in the chest and abdominal cavity as well as depletion of fluid from the circulation and decreased blood supply to vital organs. There may also be organ dysfunction and severe bleeding , typically from the gastrointestinal tract. Shock (dengue shock syndrome) and hemorrhage (dengue hemorrhagic fever) occur in less than 5% of all cases of dengue . Other neurological disorders have been reported in the context of dengue, such as transverse myelitis and Guillain–Barré syndrome. Infection of the heart and acute liver failure are among the rarer complications.


A pregnant woman who develops dengue may be at a higher risk of miscarriage as well as low birth weight and premature birth.

St.louis eccephalitis illness, including fever and headache . severe : headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions and spastic paralysis , and may lead to death .
Zika virus conjunctivitis, low-grade pyrexia, and itchy rash in 20% cases. Can lead to congenital microcephaly or miscarriages if transmitted in utero
West nile virus Headache can be a prominent symptom of WNV fever, meningitis, encephalitis, meningoencephalitis, and it may or may not be present in poliomyelitis-like syndrome. Thus, headache is not a useful indicator of neuroinvasive disease
West Nile fever (WNF) In addition to a high fever, headache, chills, excessive sweating, weakness, fatigue, swollen lymph nodes, drowsiness, pain in the joints and flu-like symptoms . Gastrointestinal symptoms that may occur include nausea, vomiting, loss of appetite, and diarrhea. Fewer than one-third of patients develop a rash.
West Nile neuroinvasive disease (WNND) meningitis , encephalitis, meningoencephalitis or a poliomyelitis-like syndrome.
West Nile virus encephalitis (WNE) WNE presents with similar symptoms to other viral encephalitis with fever, headaches, and altered mental status
West Nile meningitis (WNM) usually involves fever, headache, and stiff neck
West Nile poliomyelitis (WNP) an acute flaccid paralysis syndrome associated with WNV infection, is less common than WNM or WNE. This syndrome is generally characterized by the acute onset of asymmetric limb weakness or paralysis in the absence of sensory loss
West-Nile reversible paralysis Like WNP, the weakness or paralysis is asymmetric
Rubella fever , postauricular and other lymphadenopathy , arthralgia and fine rash .
Congenital rubella “blueberry muffin ” appearance , microcephaly , mental retardation , cataract , deafness , PDA , PS .
Eastern equine encephalitis sudden onset of headache, high fever, chills, and vomiting. The illness may then progress into disorientation, seizures, or coma
HTLV ( human T lymphotropic virus ) T-cell leukemia
HIV recurrent opportunistic infections , chronic diarrhea , Kaposi sarcoma , lymphoma .
Coronavirus common cold
SARS ( severe acute respiratory syndrome Initial symptoms are flu-like and may include fever , myalgia , lethargy symptoms, cough, sore throat, and other nonspecific symptoms. The only symptom common to all patients appears to be a fever above 38 °C (100 °F). SARS may eventually lead to shortness of breath and/or pneumonia; either direct viral pneumonia or first bacterial pneumonia.
Orthomyxoviruses Influenza virus
Parainfluenza – croup seal-like barking cough and inspiratory stridor
RSV – bronchiolitis in babies URT symptoms followed by wheezing , cough , resp. distress
Laryngeotracheitis URT symptoms followed by hoarsness , barking cough , stridor .
Measles prodromal fever with cough , coryza and conjunctivitis , then eventually koplik spots , followed by a maculopaplar rash that starts at the head/neck and spread downward
Mumps parotitis , orchitis , and aseptic meningitis , can cause sterility
Rabies fever , malaise , then : agitation , photophobia , hydrophobia , hypersalivation , then : paralysis , coma , then : death
Ebola hemorrhagic fever abrupt onset of flu-like symptoms , diarrhea/vomiting , high fever , myalgia , can progress to DIC , diffuse hemorrhage , shock
Marburg hemorrhagic fever A maculopapular rash, petechiae, purpura, ecchymoses, and hematomas (especially around needle injection sites) are typical hemorrhagic manifestations.



1. Generalization Phase: Day 1 up to Day 5 from onset of clinical symptoms. : high fever (~40˚C) and a sudden, severe headache, with accompanying chills, fatigue, nausea, vomiting, diarrhea, pharyngitis, maculopapular rash, abdominal pain, conjunctivitis, & malaise.


2. Early Organ Phase: Day 5 up to Day 13: prostration, dyspnea, edema, conjunctival injection, viral exanthema, and CNS symptoms, including encephalitis, confusion, delirium, apathy, and aggression. Hemorrhagic symptoms : bloody stools, ecchymoses, blood leakage from venipuncture sites, mucosal & visceral hemorrhaging, and possibly hematemesis.


Late Organ Phase: Day 13 up to Day 21+. Symptoms bifurcate into two constellations for survivors & fatal cases. Survivors will enter a convalescence phase, experiencing myalgia, fibromyalgia, hepatitis, asthenia , ocular symptoms, & psychosis. Fatal cases continue to deteriorate, experiencing continued fever, obtundation, coma, convulsions, diffuse coagulopathy, metabolic disturbances, shock and death, with death typically occurring between Days 8 and 16.

LCMV – lymphocytic choriomeningitis virus common symptoms include fever, lack of appetite, headache, muscle aches, malaise, nausea, and/or vomiting. Less frequent symptoms include a sore throat and cough, as well as joint, chest, and parotid pain . improves for a few days, then relapses with aseptic meningitis, or very rarely, meningoencephalitis. Patients with meningitis may have a stiff neck, fever, headache, myalgia, nausea and malaise. In some occasions, meningitis occurs without a prodromal syndrome. Meningoencephalitis is characterized by more profound neurological signs such as confusion, drowsiness, sensory abnormalities and motor signs . complications include myelitis, Guillain–Barré-type syndrome, cranial nerve palsies, transient or permanent hydrocephalus, sensorineural hearing loss, orchitis, arthritis and parotitis. LCMV infections have also been associated with pancreatitis, pneumonitis, myocarditis and pericarditis
Lassa fever encephalitis After an incubation period of six to 21 days, an acute illness with multiorgan involvement develops. Nonspecific symptoms include fever, facial swelling, and muscle fatigue, as well as conjunctivitis and mucosal bleeding.


The other symptoms arising from the affected organs are:

Gastrointestinal tract : Nausea , Vomiting (bloody) ,

Diarrhea (bloody) , Stomach ache , Constipation ,

Dysphagia (difficulty swallowing) , Hepatitis ,

Cardiovascular system : Pericarditis , Hypertension , Hypotension , Tachycardia (abnormally high heart rate) .

Respiratory tract : Cough , Chest pain , Dyspnoea , Pharyngitis , Pleuritis .

Nervous system : Encephalitis , Meningitis , Unilateral or bilateral hearing deficit Seizures

California encephalitis An early symptoms phase of 1–4 days commonly precedes the onset of encephalitis. This phase manifests as fever, chills, nausea, vomiting, headache, and abdominal pain .


The encephalitis is characterized by fever, drowsiness, and lack of mental alertness and orientation. Seizures occur in 50% of children.

Sandfly/rift valley fevers no symptoms or only a mild illness with fever , headache , muscle pains, and liver abnormalities. In a small percentage of cases (< 2%), the illness can progress to hemorrhagic fever syndrome , meningoencephalitis (inflammation of the brain and tissues lining the brain), or affect the eye. Patients who become ill usually experience fever, generalised weakness, back pain, dizziness, and weight loss at the onset of the illness. Typically, people recover within two to seven days after onset.
Crimean-congo hemorrhagic fever Typically, after a 1–3 day incubation period following a tick bite (5–6 days after exposure to infected blood or tissues), flu-like symptoms appear, which may resolve after one week. In up to 75% of cases, however, signs of hemorrhage appear within 3–5 days of the onset of illness in case of bad containment of the first symptoms: mood instability , agitation , mental confusion and throat petechiae; and soon after nosebleeds, vomiting, and black stools. The liver becomes swollen and painful. Disseminated intravascular coagulation may occur, as well as acute kidney failure, shock, and sometimes acute respiratory distress syndrome. Patients usually begin to show signs of recovery after 9–10 days from when symptoms presented. However 30% of the cases result in death by the end of the second week of illness.
Hantavirus hemorrhagic fever , Pneumonia
Prion diseases spongiform encephalopathy , dementia , ataxia and death
Creutzfeldt-jakob disease rapidly progressive dementia
Last minute revision of Infectious Disease
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