Polioviruses
Dr Riadh Al ObaidiEtiology
RNA viruses belonging to the Picornaviridae family ,transferred by feco-oral route to infect children. Polioviruses spread from the intestinal tract to the central nervous system (CNS), where they cause aseptic meningitis and poliomyelitis. Incubation period ; range 7-20 daysEpidemiology
94% of infections are asymptomatic or not apparent but induce protective immunity. Most of the cases now a day is not due to Wild- virus, but due to the live attenuated vaccine virus .TRANSMISSION
Humans are the only known reservoir for the polioviruses. Poliovirus has been isolated from faeces more than 2 wk before paralysis to several weeks after the onset of symptoms.Clinical presentations
1.ABORTIVE POLIOMYELITIS In about 4% of infected person, a nonspecific influenza-like syndrome ,fever, malaise, running nose ,headache, occurs 1–2 wk after infection and lasts 2-3 days 2. NONPARALYTIC POLIOMYELITIS.In about 1% of all infected patients meningial irritation features; Nuchal and spinal rigidity are the basis for the diagnosis of nonparalytic poliomyelitis (aseptic meningitis)3. PARALYTIC POLIOMYELITIS. Paralytic poliomyelitis develops in about 0.1-0.5% of persons infected with poliovirus These are 3 forms (1) spinal paralytic poliomyelitis, (2) bulbar poliomyelitis, and (3) polioencephalitis . the paralysis progresses up to 1 week. Complete evaluation of the extent of the paralysis can be done after one month of onset.
Diagnosis
Poliomyelitis should be considered in any unimmunized or incompletely immunized child with acute asymmetric flaccid paralysis, acute weakness or limping in the leg, aseptic meningitis. Polio also can be considered in any child with paralytic disease occurring 7–14 days after receiving oral poliovirus vaccine
The World Health Organization (WHO) currently recommends that the laboratory diagnosis of poliomyelitis can be confirmed by isolation and identification of poliovirus in the stool, with specific identification of wild-type and vaccine type strains. In suspected cases of acute flaccid paralysis, 2 stool specimens should be collected 24–48hr apart, and send for culture of the virus as soon as possible when diagnosis of poliomyelitis is suspected
DIFFERENTIAL DIAGNOSIS acute flaccid paralysis
treatmentSupportive All intramuscular injections and surgical procedures are contraindicated during the acute phase of the paralytic illness, especially in the first week. Vaccination: OPV drops and IPV inj.
Infectious mononucleosis caused by Epstein-Barr virus (EBV)
Clinical ManifestationsThe majority of cases of primary EBV infection in infants clinically silent. In older children, the onset of illness is usually insidious and vague. Patients may complain of malaise, fatigue, fever, headache, sore throat, nausea, abdominal pain, and myalgia.
The physical examination is characterized by anterior and posterior cervical and submandibuler lymphadenopathy (90% of cases), splenomegaly (50% of cases), and hepatomegaly (10% of cases). Up to 80% of patients with infectious mononucleosis experience “ampicillin rash” if treated with ampicillin or amoxicillin.
Complications includes; splenic rupture if exposed to trauma , upper respiratory air way obstruction due to tonsiller and oropharyngeal edema, may need steroids and even intubation and even urgent tonsilloadenoidectomy. Thrombocytopenia; mild is common ,but severe is rare. Rare complication includes Coomb +ve hemolytic anemia, aplastic anemia, jaundice, meningitis, facial nerve palsy, encephalitis, Guillain-Barre syndrome.
Diagnosis
A presumptive diagnosis may be made by the presence of typical clinical symptoms with atypical lymphocytosis (reactive cell to the B-lymphocyte infected with EB. V) in the peripheral blood. HETEROPHILE ANTIBODY TEST) The heterophile antibodies of infectious mononucleosis, by Monospot test is more specific but if negative and still suggestion is high, send for confirming test: EB virus serology for IgM specific antibody
treatment
Rest and symptomatic therapy are the mainstays of management Short courses of corticosteroids (less than 2 wk) may be helpful for complications of infectious mononucleosis( acute airway obstruction, thrombocytopenia with hemorrhage, autoimmune hemolytic anemia, and in seizures and meningitis)VISCERAL LEISHMANIASIS
kala-azarTypically affects children younger than 5 yr by parasite : (L. chagasi) ,(L. infantum) and (L.donovani).
After inoculation of the organism into the skin by the sand fly, the child may have a completely asymptomatic infection that resolves spontaneously or it gradually and progressively evolves into active kala-Azar.(fever , big hepatomegaly and big splenomegaly ,anemia and wasting).
The classic clinical features of high fever, marked splenomegaly, hepatomegaly, and severe cachexia typically develop approximately 6 mo after the sand-fly bite.
At the terminal stages of kala-azar the hepato-splenomegaly is massive, there is gross wasting, the pancytopenia ; anemia, leucopenia, thrombocytopenia and jaundice. Edema, and ascites may be present. Anemia may be severe enough to precipitate heart failure