Infectious Diseases Practice Questions

Q: Which one of the following is NOT a contagious disease?

Malaria. ***Malaria*** - Malaria is caused by **Plasmodium parasites** transmitted through the bite of infected Anopheles mosquitoes. It is not spread directly from person to person. - Transmission requires a **vector** (mosquito), making it a non-contagious infectious disease. *Trachoma* - Trachoma is a contagious bacterial infection caused by **Chlamydia trachomatis**, spread through direct contact with eye and nose discharge of an infected person. - It can also be transmitted via **fomites** like contaminated towels or clothing, or through eye-seeking flies. *Leprosy* - Leprosy, caused by **Mycobacterium leprae**, is a chronic infectious disease that is considered contagious, although with low infectivity. - It is primarily transmitted through **nasal droplets** during close and prolonged contact with an untreated infected person. *Scabies* - Scabies is a contagious skin infestation caused by the **mite Sarcoptes scabiei**, which burrows into the outer layer of the skin. - It is easily spread through **direct, prolonged skin-to-skin contact** with an infected person.

Q: How does the presence of STIs increase the risk of HIV transmission?

By disrupting mucosal barriers and causing inflammation. ***By disrupting mucosal barriers and causing inflammation*** - Many STIs, particularly those causing **genital ulcers** (e.g., herpes, syphilis) or inflammation (e.g., gonorrhea, chlamydia), disrupt the integrity of the **mucosal barriers** in the genital tract. This provides easier entry points for HIV, as the epithelial cells act as a physical barrier. - The inflammatory response triggered by STIs leads to the recruitment of **HIV target cells** (CD4+ T-cells and macrophages) to the site of infection, increasing their concentration in genital secretions and making them more accessible to HIV during exposure. *By direct enhancement of HIV replication* - While some inflammatory cytokines can enhance HIV replication in vitro, this is not the primary or most significant mechanism by which STIs increase transmission risk in vivo. - The main mechanism involves increased exposure to target cells and disrupted barriers rather than direct viral replication enhancement. *By increasing CD4 receptor density on target cells* - STIs do not demonstrably increase the density of **CD4 receptors** on the surface of individual target cells. - Instead, they increase the *number* of available CD4+ target cells at the site of exposure due to inflammation and immune cell infiltration. *By inhibiting cytotoxic T-cell responses* - Some STIs might have localized immunosuppressive effects, but their primary contribution to increased HIV transmission risk is not through a generalized inhibition of **cytotoxic T-lymphocyte (CTL) responses**. - The key mechanisms are related to physical barriers and increased target cell availability, not suppression of the systemic antiviral immune response.

Q: A 22-year-old woman presents for STI screening. She reports multiple sexual partners and inconsistent condom use. What screening tests would be most appropriate?

HIV, syphilis, gonorrhea, and chlamydia testing. ***HIV, syphilis, gonorrhea, and chlamydia testing*** - This comprehensive panel screens for the most common bacterial and viral STIs in sexually active individuals with **multiple partners** and **inconsistent condom use**, as recommended by **NACO and WHO guidelines**. - **Gonorrhea and chlamydia** often present asymptomatically but can lead to serious reproductive health complications including pelvic inflammatory disease (PID) and infertility if untreated. - In high-risk populations, comprehensive screening is essential for early detection and prevention of transmission. *HPV DNA testing only* - **HPV DNA testing** is primarily for cervical cancer screening in women over 30 years or as a co-test with cytology; it doesn't cover other STIs. - While HPV is common, testing for other prevalent STIs like chlamydia, gonorrhea, syphilis, and HIV is crucial given her risk factors. *Complete blood count and urinalysis* - A **complete blood count (CBC)** assesses overall health and detects conditions like anemia or infection but is not a specific STI screening test. - **Urinalysis** checks for urinary tract infections or kidney issues and does not directly screen for STIs. - These are general screening tests and miss the targeted STI screening needed. *HIV and syphilis testing only* - Although **HIV and syphilis testing** are essential components of STI screening, this option misses other common and treatable bacterial STIs like gonorrhea and chlamydia. - Given the patient's risk factors (multiple partners, inconsistent condom use), a more comprehensive screening panel is warranted to prevent long-term reproductive complications.

Q: How does trichomoniasis affect HIV transmission?

By increasing HIV viral shedding from genital tract. ***By increasing HIV viral shedding from genital tract*** - **Trichomoniasis** causes inflammation and disruption of the **genital mucosal barrier**, leading to an increased concentration of HIV in genital secretions. - This elevated **viral load** in the genital tract directly increases the likelihood of HIV transmission during sexual contact. *By selection for drug-resistant HIV strains* - This mechanism is not directly associated with **trichomoniasis**; drug resistance typically develops due to suboptimal adherence to antiretroviral therapy (ART) or drug mutations. - **Trichomoniasis** does not exert selective pressure on HIV to develop drug resistance. *By direct activation of HIV transcription* - While other co-infections can activate immune cells and enhance HIV replication, the primary mechanism of **trichomoniasis** enhancing HIV transmission is through increased shedding, rather than direct transcriptional activation. - **Trichomoniasis**-induced inflammation creates a fertile environment for immune cells, which in turn can become targets for HIV, but direct transcription activation is not its main role. *By inhibiting host macrophage function* - **Trichomoniasis** is primarily associated with immune system activation and inflammation, rather than significant inhibition of **macrophage function**. - Impaired macrophage function would more likely decrease, rather than increase, viral dissemination or immune response.

Q: Which of the following factors does NOT increase the risk of acquiring gonorrhea?

Use of barrier contraceptives. ***Use of barrier contraceptives*** - **Barrier contraceptives**, such as **condoms**, work by physically preventing the exchange of bodily fluids and microorganisms during sexual activity. - Consistent and correct use of barrier contraceptives significantly **reduces the risk** of acquiring sexually transmitted infections (STIs), including gonorrhea. *Multiple sexual partners* - Engaging in sexual activity with **multiple partners** increases the likelihood of encountering an infected individual, thereby elevating the risk of gonorrhea transmission. - A higher number of partners inherently increases exposure to the **prevalence of STIs** within a population. *Previous history of gonorrhea* - A **previous infection** with gonorrhea does **not confer immunity**; individuals can be reinfected multiple times. - A history of gonorrhea may indicate a higher-risk sexual health profile or practices, making future infections more likely if behaviors do not change. *Young age (15-24 years)* - Individuals in this age group are at a **higher risk** for gonorrhea due to a combination of factors, including biological susceptibility, common sexual behaviors, and a lower likelihood of consistent condom use. - **Immature cervical biology** in younger women makes them more susceptible to infection, and this group often engages in more frequent partner changes.

Q: Identify the character shown in the image:

Sapna from Leprosy campaign. ***Sapna from Leprosy campaign*** - The image depicts Sapna, a character created for the **National Leprosy Eradication Programme (NLEP)** in India. - This character was developed as part of public health campaigns to spread awareness about leprosy and reduce stigma associated with the disease. - Sapna has been widely used in educational materials and community outreach programs for leprosy awareness. *Arohi from HIV* - Arohi is a different character associated with awareness campaigns for **HIV/AIDS**, not leprosy. - She is part of distinct public health initiatives focusing on HIV prevention, treatment, and stigma reduction under the National AIDS Control Programme. *Meena from UNICEF* - Meena is a prominent animated character created by **UNICEF** to advocate for children's rights, particularly girls' education, gender equality, health, and child protection. - While UNICEF works on a wide range of health issues including communicable diseases, Meena is not specifically associated with the leprosy awareness campaign. *None of the options* - The image clearly depicts the character **Sapna**, who is specifically associated with leprosy awareness campaigns in India. - Therefore, the first option accurately identifies the character and her associated health program.

Q: Identify the logo?

Leprosy. ***Leprosy*** - This logo, often featuring a stylized flower or protective shape, is widely recognized as a symbol associated with **leprosy awareness** and efforts to eradicate the disease. - Organizations dedicated to **leprosy elimination** and care frequently use similar designs to represent compassion, hope, and the journey towards healing for individuals affected by this condition. *TB* - The emblem for **tuberculosis (TB)** awareness predominantly features a **red ribbon**, which symbolizes solidarity in the fight against the disease. - While TB is a global health concern, its associated imagery differs significantly from the flower-like logo presented. *Malaria* - The international symbol for **malaria** often incorporates a stylized **mosquito** or images representing its lifecycle and geographic prevalence. - The logo displayed does not resemble any common imagery used in malaria prevention or awareness campaigns. *HIV* - The **red ribbon** is the most universally recognized symbol for **HIV/AIDS** awareness, representing solidarity with people living with HIV and those who have died from AIDS. - This specific logo does not align with the established iconography for HIV/AIDS.

Q: A patient from Bihar is admitted with splenomegaly and clinical features suggestive of leishmaniasis. What is the vector responsible for transmitting this disease?

Phlebotomus. ***Phlebotomus*** - **Phlebotomus** (sandfly), specifically ***Phlebotomus argentipes*** in India, is the principal vector for transmitting **Leishmania donovani** parasites causing **visceral leishmaniasis (kala-azar)**. - Bihar is a highly endemic region for kala-azar in India. - The sandfly transmits the parasite when it takes a blood meal from an infected host and then bites an uninfected individual. *Rat flea* - The **rat flea** (**Xenopsylla cheopis**) is the primary vector for diseases like **bubonic plague** and **murine typhus**, not leishmaniasis. - It transmits bacteria such as *Yersinia pestis* and *Rickettsia typhi*. *Black fly* - **Black flies** (**Simulium species**) are vectors for **onchocerciasis** (river blindness), caused by the parasitic worm *Onchocerca volvulus*. - They transmit the microfilariae when biting humans. *Chrysops fly* - The **Chrysops fly** (deer fly or mango fly) is the vector for **Loa loa filariasis** (African eye worm). - It transmits *Loa loa* eyeworm larvae when it bites humans.

Question 1

Which one of the following is NOT a contagious disease?

Accepted Answer

Malaria

Answer

Trachoma

Answer

Leprosy

Answer

Scabies

Question 2

Which of the following statements about screening for chlamydia and gonorrhea is MOST accurate?

Accepted Answer

Screening is recommended for sexually active women under 25, men who have sex with men, and pregnant women

Answer

Screening is not cost-effective and should be avoided in low-risk populations

Answer

Screening is only recommended for patients with symptoms

Answer

Annual screening is recommended for all sexually active adults regardless of age or risk factors

Question 3

How does the presence of STIs increase the risk of HIV transmission?

Accepted Answer

By disrupting mucosal barriers and causing inflammation

Answer

By direct enhancement of HIV replication

Answer

By increasing CD4 receptor density on target cells

Answer

By inhibiting cytotoxic T-cell responses

Question 4

A 22-year-old woman presents for STI screening. She reports multiple sexual partners and inconsistent condom use. What screening tests would be most appropriate?

Accepted Answer

HIV, syphilis, gonorrhea, and chlamydia testing

Answer

HPV DNA testing only

Answer

Complete blood count and urinalysis

Answer

HIV and syphilis testing only

Question 5

How does trichomoniasis affect HIV transmission?

Accepted Answer

By increasing HIV viral shedding from genital tract

Answer

By selection for drug-resistant HIV strains

Answer

By direct activation of HIV transcription

Answer

By inhibiting host macrophage function

Question 6

Why is syndromic management of STIs particularly important in resource-limited settings?

Accepted Answer

It allows treatment without waiting for laboratory confirmation

Answer

It's more cost-effective than targeted therapy

Answer

It prevents emergence of drug resistance

Answer

It's more effective than etiologic diagnosis

Question 7

Which of the following factors does NOT increase the risk of acquiring gonorrhea?

Accepted Answer

Use of barrier contraceptives

Answer

Multiple sexual partners

Answer

Previous history of gonorrhea

Answer

Young age (15-24 years)

Question 8

Identify the character shown in the image:

Accepted Answer

Sapna from Leprosy campaign

Answer

Arohi from HIV

Answer

Meena from UNICEF

Answer

None of the options

Question 9

Identify the logo?

Accepted Answer

Leprosy

Answer

TB

Answer

Malaria

Answer

HIV

Question 10

A patient from Bihar is admitted with splenomegaly and clinical features suggestive of leishmaniasis. What is the vector responsible for transmitting this disease?

Accepted Answer

Phlebotomus

Answer

Rat flea

Answer

Black fly

Answer

Chrysops fly

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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