CASE SCENARIO

A 33 years old Malay man was admitted to a hospital with a history of fever for 5 days and maculopapular rash for 2 days. Physical examination showed a positive tourniquet test with petechial haemorrhages over his arms and legs. There were no investigations showing leukopenia and thrombocytopenia with increase in haematocrit concentration.

1. What is the most likely diagnosis? Explain your answer.Dengue feverReason : Topical country

Fever for 5 daysMaculopapular rash for 2 daysPositive tourniquet testPetechial haemorrhagesLeukopenia and thrombocytopeniaHigh haematocrit concentration

2. What is the causative organism?Dengue virus (causes dengue and dengue haemorrhagic fever)Have 4 serotypes (DEN-1, DEN-2, DEN-3, DEN-4)Small enveloped virus (40-50nm)

3. What is the mode of transmission?Transmitted by mosquitos: Aedes aegypti

Aedes albopictusDistinct physical feature (black & white stripes on its body and legs)Bites during the dayLays its eggs in clean, stagnant waterOnly the female feeds on blood

i. Mosquito bites and sucks blood containing the virus from an infected personii. Virus is carried in its bodyiii. And passes the virus to healthy people when it bites them

4. Discuss the clinical symptoms of this disease.Plasma leakageHepatomegalyLow blood pressureHypovolemic shockDeath

5. Mention the types of dengue infection.i. Dengue without warning signsii. Dengue with warning signsiii. Severe dengue

6. What are the principles of treatment?There is no specific treatment for dengue infectionOnly supportive (treatment of symptoms)Assess for dehydration and ability to drink fluidsTherapy for pain (avoid aspirin because of exacerbating haemorrhagic tendencies)Fluid replacement through IVMedication to reduce fever

7. What are the measurements of prevention?Vector control: Improved water storage practice

Eliminate any sources that may collect water, such as tins, bottles & old tiresInsecticides such as larvicide’sIntroduction of mosquito eating fishAlways clean and check drains to ensure they are not blocked especiallyduring rainy season

Vaccination: No licensed commercialized vaccine Needs to prevent all 4 serotypes (tetravalent)

MCQ (1)

Regarding Viral Haemorrhagic Fevers:

a) Caused by several distinct families of RNA viruses Tb) Only effect humans Fc) Bleeding often occurs depending on the virus Td) Natural reservoir host plays important role in the survival of haemorrhagic viruses Te) Mainly transmitted by person to person contact F

MCQ (2)

Regarding Yellow Fever:

a) Transmitted by female Anopheles mosquito Fb) Caused by Rift Valley Fever virus Fc) Virus can be cultured in early blood samples Td) Preventable by immunization Te) Treated by specific anti-viral drug F

MCQ (3)

Regarding Dengue Fever:

a) Endemic in more than 100 countries Tb) Caused by dengue viruses that belong to family Flaviviridae Tc) Growth of global travel plays an important role in increasing the incidence of

the infection Td) Preventable by immunization Fe) Mainly treated by specific anti-viral drug F

MCQ (4)

Regarding Dengue Fever

a) Secondary infections tend to produce DHFb) DSS results due to severe plasma leakagec) Presence of IgM is an indication of secondary infectiond) Virus isolation only useful during the convalescence stage of infectione) Tetravalent vaccine is necessary for effective immunization

MCQ (5)

In viral myocarditis:

a) Coxsackievirus B is one of the most implicated viruses Tb) Incidence can be effected by the level of provided health services as immunization Tc) Immunocompromised patients are more susceptible to the infection Td) Easy to diagnose because majority of the cases are symptomatic Fe) One causes of sudden death T

MCQ (6)

Regarding Viral Myocarditis:

a) Histopathology is a useful identification of causative agent Fb) Necrosis can be due to both inflammatory response and viral damage of myocytes Tc) Highly associated with pericarditis Td) Patient mainly suffering from excessive fatigue Te) ECG shows right and left S3 & S4 gallops T

MCQ (7)

Regarding Epstein-Barr Virus:

a) Associated with several human tumours such as Burkitts lymphoma Tb) Spread in the body by infected circulating T cells Fc) Member of the family Herpesviridae Td) Spread by contact with oral secretions Te) Endemic in topical and sub-topical countries only F

MCQ (8)

Regarding Epstein-Barr virus:

a) Phagocytosis control proliferating infected B lymphocytes Fb) Lymphocytosis results due to uncontrolled proliferation of infected B cells Tc) Infection complication include Guillain-Barre syndrome Td) Preventable by immunization Fe) Pharyngitis is less frequently seen in infectious mononucleosis F

MCQ (9)

Regarding IM:

a) Presence of Downey cells is helpful in diagnosis Tb) Is a self-limiting disease and require supportive & symptomatic treatments Tc) Excessive aerobics activity is highly recommended during the course of infection Fd) Antibodies against early antigens is useful in serological diagnosis Te) Is a disease of young adults T

MCQ (10)

Regarding malignant diseases associated with EBV infection:

a) Includes nasopharyngeal carcinoma Tb) African lymphoma characterized by malignant B-cell neoplasm Tc) Nasopharyngeal carcinomas highly associated with reactivation of latent EBV infection Td) Burkitt’s lymphoma is a slow growing tumor and seldom respond to treatment Fe) B cell lymphomas are more prevalent in immunocompromised patients T

MCQ (11)

Regarding viral infections of upper respiratory tract:

a) Alveolar macrophages are the main defence mechanism Fb) Interferon and antibodies play the major role in recovery Tc) Viruses are the most common invader of the nasopharynx Td) Spread by aerosol and contaminated hands Te) Pharyngoconjunctival fever caused by Coxsackie A16 F

MCQ (12)

Regarding common cold:

a) Transmitted by blood transfusion Fb) Treatment basically is symptomatic with rest Tc) Diagnosis is clinically based on characteristics typical symptoms of Rhinorrhoea Td) Preventable by immunization Fe) Pharyngitis is less frequently seen in infectious mononucleosis F

MCQ (13)

Regarding pharyngitis:

a) 70% of acute sore throats are caused by viruses Tb) Occur due to inflammatory and immune responses in the lymphoid tissues Tc) More severe than common cold in case of Rhinoviruses Fd) Due to multiplication of EBV and CMV in the pharynx Te) Occurs in 70-90% of glandular fever patients T

MCQ (14)

Regarding croup:

a) The most common pathogen is parainfluenza viruses Tb) It is common in both adult and children Fc) Steeple sign is the main diagnostic criteria Td) Spread by aerosol and contaminated hands Te) Mainly treated with anti-viral drugs such as ribavirin F

MCQ (15)

Regarding respiratory syncytial virus (RSV):

a) Belongs to orthomyxovirus family Fb) Pathogenesis mainly based on the attachment to the host cells using F

haemagglutinin and neuraminidasec) Important causes of both upper and lower respiratory infection Td) Preventable by immunization Fe) Transmitted by droplets contaminated hands T

MCQ (16)

Regarding SARS:

a) Caused by influenza viruses Fb) Transmitted through droplet transmission Tc) Inflammatory and immune responses play an important role in infection T

pathogenesisd) Mechanical ventilation is required in patient’s management especially in T

respiratory failuree) It is a serious and life-threatening infection T