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What are the symptoms of HIV?

Human immunodeficiency virus (HIV) is a sexually transmitted disease, with three typical stages of infection – acute infection, chronic infection, and acquired immunodeficiency syndrome (AIDS). Symptoms differ depending on the stage of infection.

Acute HIV Infection
The initial phase of acute HIV infection is when HIV is most infectious (1), even though many individuals are unaware that they have contracted HIV, as they do not display any symptoms, or only experience mild symptoms. Other people experience more serious symptoms within 2-4 weeks after infection, which can last for just a few days or for several weeks (2, 3). Symptoms can include:

  • High fever
  • Sore throat
  • Swollen lymph nodes
  • Skin rashes
  • Diarrhea
  • Mouth ulcers
  • Muscle aches
  • Persistent coughing
  • Chills
  • Night sweats

Chronic HIV Infection
The second stage of HIV infection can also be known as clinical latency or asymptomatic HIV infection. The virus is still multiplying during this stage, but only at very low levels, and many individuals do not show any symptoms. However, without HIV treatment, individuals in this stage can still transmit HIV (2).

AIDS
HIV targets cells of the immune system reducing the ability to fight other infections and eventually progressing to AIDS (stage 3 of HIV infection) in untreated individuals (2). The symptoms of AIDS include:

  • Rapid weight loss
  • Extreme fatigue
  • Pneumonia
  • Skin discoloration
  • Memory loss
  • Depression
  • Increased susceptibility to other infections such as tuberculosis, severe bacterial infections, and certain cancers

How quickly does an HIV infection progress?
HIV progression can vary widely. Typically untreated HIV infections progress to AIDS in 8-10 years, but it can be shorter or longer for some people. Most of those with untreated AIDS only survive about three years, or less depending on opportunistic infections and cancers.

Nowadays, effective HIV medications, called antiretroviral therapy (ART), are available treat HIV. Although these medications do not cure the disease, they reduce the replication of HIV in the blood to an undetectable level. This enables infected individuals to live relatively normal lives and prevents the transmission of HIV (1).

References
1. HIV/AIDS. World Health Organization.
2. Symptoms of HIV. Clinical Info HIV.gov. July 2020.
3. HIV Basics: About HIV. CDC. November 2020. 

Posted in HIV

A brief history of HIV

Chimpanzees as the source of HIV-1
Human immunodeficiency virus (HIV) shares many similarities with Simian immunodeficiency virus (SIV), which is a virus that attacks the immune systems of monkeys and apes. Researchers discovered a strain of SIV, called SIVcpz, in a chimpanzee that is almost identical to HIV-1 in humans (1). It is believed that this virus was spread to humans through hunting of the chimpanzees, where the virus was transmitted during consumption of the chimpanzee or the chimpanzee blood getting into wounds on the hunter (2). The much less common HIV-2 was transmitted from sooty mangabey monkeys in likely the same hunter scenario (3).

African origins of HIV
Although the earliest verified HIV case is from a blood sample collected in 1959, there were numerous earlier clusters of deaths from opportunistic infections, which are a now known to be ‘AIDS-defining’ patterns (2). Retrospective analyses of the 1959 blood sample have allowed scientists to create a ‘family-tree’ ancestry of HIV, from which it has been concluded that the first transmission of SIV to humans (and the subsequent small changes to become HIV) occurred around 1920 in what is now Kinshasa in the Democratic Republic of Congo (4).

Around the time that HIV began to spread, Kinshasa had a growing sex trade and was also a transport hub, enabling to virus to spread around the country and further into Africa (5).

Spread around the world
In the 1960s, many Haitian professionals who had been working in DR Congo returned to Haiti, unwittingly bringing HIV with them (5). Around this time, HIV is believed to have also spread to other regions of the world. People often think of the HIV epidemic starting in the 1980s, but by this point, HIV had likely already spread to five continents (North America, South America, Europe, Africa, and Australia), infecting between 100,000 and 300,000 people (6, 7).

HIV in the US in the early 1980s
In June 1981, there was a report of Pneumocystis carinii pneumonia (PCP) in previously healthy, homosexual men in LA (8). This was the first official report of what became known as the AIDS epidemic. At the same time, an unusually aggressive cancer named Kaposi’s Sarcoma was reported in groups of men in New York and California (9).

The original names given to this infectious disease were related to the word ‘gay’ due to the cases occurring in homosexual males. However, soon cases were reported in other populations, including heroin users and hemophiliacs. By September 1982, the spreading epidemic was officially called acquired immunodeficiency syndrome (AIDS) (10).

Discovery of the cause of AIDS
In May 1983, researchers at the Pasteur Institute in France reported the discovery of a new retrovirus called Lymphadenopathy-Associated Virus (or LAV) that could be the cause of AIDS (11). Scientists working at the USA National Cancer Institute isolated the same virus and called it HTLV-III. LAV and HTLV-III were later acknowledged to be the same, and renamed HIV (12).

First testing for HIV
The first commercial blood test to detect HIV was an ELISA licensed by the FDA in March 1985. This enabled HIV screening of blood donations at the blood banks. In 1987, a more specific western blot test kit was approved for detecting HIV antibodies. A testing kit became available to healthcare providers in 1992, and the first rapid HIV test in 2002 (7).

How quickly was the epidemic growing?
By the end of 1985, AIDS had been reported in every region of the world, with 20,303 reported cases in total. This nearly doubled to 38,401 reported cases by the end of 1986, and 71,751 reported cases by the end of 1987. By December 1990, there were already over 100,000 AIDS cases in the US and over 307,000 AIDS cases reported worldwide. However, actual numbers were predicted to be closer to a million, and an estimated 8-10 million people were living with HIV worldwide.

Despite the approval of effective HIV treatments, the numbers kept escalating. By December 1996, an estimated 23 million people around the world were living with HIV, 30 million by 1997, and 33 million by 1999. In 1999, the WHO announced that AIDS was the most common cause of death in Africa, and the fourth biggest cause of death worldwide, with an estimated 14 million AIDS deaths having occurred by this point. AIDS-related deaths reached a peak in 2005, and by 2013, the death rate had fallen by 30% (7).

HIV drugs
In March 1987, the FDA approved the first antiretroviral drug, zidovudine (AZT), as treatment for HIV. However, it wasn’t until the approval of highly reactive antiretroviral treatment (HAART) in 1995 that there was such a noticeable decrease (60-80% decline) in AIDS-related deaths, and this was only in those countries that could afford it (13). In the early 2000s, antiretroviral drug prices were reduced for developing countries and a global fund was created to reduce the spread of HIV (7). By 2017, more than half the global population affected by HIV was receiving effective HIV treatment, which prevents the development of AIDS and the transmission of HIV if viral load is undetectable (14).

References
1. Gao F, et al. (1999). Origin of HIV-1 in the chimpanzee Pan troglodytes troglodytes. Nature, 397 (6718), 436-441.
2. Sharp PM & Hahn BH (2011). Origins of HIV and the AIDS pandemic. Cold Spring Harb Perspect Med. 1 (1), a006841.
3. Chen Z, et al. (1997). Human Immunodeficiency Virus Type 2 (HIV-2) Seroprelavence and Characterization of a Distinct HIV-2 Genetic Subtype from the Natural Range of Simian Immunodeficiency Virus-Infected Sooty Mangebeys. J Virol. 71 (5), 3953-3960.
4. Faria NR, et al. (2014). The early spread and epidemic ignition of HIV-1 in human populations. Science, 346 (6205), 56-61.
5. Origin of HIV & AIDS. Avert. 30 Oct, 2019.
6. Mann JM (1989). AIDS: A worldwide pandemic. Current Topics in AIDS Volume 2, edited by Gottlieb MS, et al. John Wiley & Sons.
7. History of HIV & AIDS Overview. Avert. 10 Oct, 2019.
8. Epidemiologic Notes and Reports (June 1981). Pneumocystis Pneumonia – Los Angeles. MMWR. 30 (21). 1-3. 
9. CDC (1981). Kaposi’s Sarcoma and Pneumocystis Pneumonia among Homosexual Men- New York City and California. MMWR, 30 (25), 305-308.
10. HIV and AIDS Timeline. CDC. 21 Oct 2020. 
11. Barré-Sinoussi F, et al. (1983). Isolation of a T-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS). Science, 220 (4599), 868-871.
12. Marx JL (1984). Strong new candidate for AIDS agent. Science, 224 (4648), 475-477.
13. James JS (1995). Saquinavir (Invirase): first protease inhibitor approved – reimbursement, information hotline numbers. AIDS Treatment News, 22 (237), 1-2.
14. UNAIDS (2017). Ending AIDS: Progress towards 90-90-90. [pdf]

Posted in HIV

Who is the most at risk for hepatitis C?

The most common way that hepatitis C is transmitted is through sharing needles. Other potential sources of infection include at birth (~6% of infants of infected mothers), sexual intercourse (rare but more common in men who have sex with men), healthcare exposures, blood transfusions and organ transplants (now very uncommon), unregulated tattoos or body piercings, and sharing personal items that have been contact with infected blood (e.g. glucose monitors, razors) (1).

Those who have an increased risk of hepatitis C include:

  • HIV-positive individuals
  • Current or former injectable drug users
  • Individuals on hemodialysis or who have other selected medical conditions
  • Recipients of blood or organ donations prior to July 1992
  • Recipients of clotting factors before 1987
  • Individuals who received blood from a donor who later tested positive for hepatitis C
  • Health care personnel who may be exposed to blood from infected individuals
  • Children born to hepatitis C-positive mothers

Testing recommendations
The CDC recommends universal hepatitis C screening at least once in a lifetime for all adults and for all pregnant women during each pregnancy, except in populations where the prevalence of hepatitis C is less than 0.1%. Testing should occur in HIV-positive individuals, anyone who has ever injected drugs, individuals with abnormal liver tests and/or liver disease, and in anyone who received donated blood or organs before July 1992 or clotting factor concentrates before 1987. Anyone who has been potentially exposed to the blood of an infected individual should get tested. Regular testing is recommended for individuals who currently use injectable drugs or are on hemodialysis (2).

Cirrhosis associated with hepatitis C
When an individual is infected with hepatitis C their immune system produces specific antibodies against the hepatitis C virus. The presence of these hepatitis C antibodies is consistent with both current and past infections. Up to 50% of individuals who test positive for antibodies to hepatitis C no longer have an active infection (3), which indicates that they have spontaneously cleared the virus after an acute (short-term) infection.

However, more than half of infected individuals develop a chronic (long-term) infection, which can be due to viral changes that evade the immune response (4). Furthermore, 5-25% of all individuals infected with hepatitis C will develop cirrhosis within 10-20 years post-exposure. This is associated with an increased risk of hepatocellular carcinoma and hepatic decompensation.

These factors increase the risk of cirrhosis associated with hepatitis C:

  • Male gender
  • Over 50 years of age
  • Increased alcohol consumption
  • Fatty liver disease
  • Hepatitis B or HIV coinfection
  • Receiving immunosuppressive therapy

References
1. Viral Hepatitis – Q&As from the Public. (2020, July). CDC.
2. Testing Recommendations for Hepatitis C Virus Infection. (2020, July). CDC.
3. Seo S, et al. (2020). Prevalence of Spontaneous Clearance of Hepatitis C Virus Infection Doubled From 1998 to 2017. Clin Gastroenterol Hepatol, 18 (2), 511-513.
4. Thomas DL, & Seeff LB. (2005). Natural history of hepatitis C. Clin Liver Dis, 9 (3), 383-398.

What health complications can occur due to an untreated syphilis infection?

Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases. If syphilis is untreated it can cause serious health complications. There are distinct stages of a syphilis infection, known as primary, secondary, latent, and tertiary.

Primary stage
A skin lesion, called a chancre, is the first sign of a syphilis infection. Chancres appear at the location where syphilis entered the body anytime from 10-90 days after infection, with an average onset of 21 days post-infection (1). Chancres last for three to six weeks and heal whether or not treatment is received. Individuals in this stage are very infectious. If untreated, the infection progresses to the secondary stage (2).

Secondary stage
Skin rashes and/or lesions in the mouth, vagina, or anus occur during the secondary stage of infection. These may appear when the primary chancre is healing or several weeks after it has healed. Additional symptoms in the secondary stage can include fever, sore throat, hair loss, weight loss, swollen lymph glands, headaches, muscle aches, and fatigue. Individuals in this stage are infectious. Like the primary symptoms, secondary symptoms will also disappear whether or not treatment is received. However, the syphilis infection will progress to the latent stage if adequate treatment does not occur (2).

Latent stage
There are no visible signs or symptoms of syphilis during the latent (hidden) stage. However, syphilis-causing bacteria (T. pallidum) are still present. The latent stage can last for many years, with 15-40% of untreated individuals developing tertiary syphilis (3). Individuals in the early latent stage (less than 1-2 years after the original infection) may be infectious, but individuals in the late latent stage are generally not infectious.

Tertiary stage
In rare cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection. Multiple different organ systems can be affected including the brain, nerves, eyes, heart, liver, bones, and joints. The associated symptoms vary depending on the affected body parts. Individuals with tertiary syphilis are not infectious (1).

Gummatous syphilis or later benign syphilis can occur in the tertiary stage. It is characterized by soft, tumor-like balls of inflammation, which typically affect the skin, bone, and liver. Cardiovascular syphilis is a relatively common complication of tertiary syphilis, where the heart tissue is affected (1).

Neurosyphilis and ocular syphilis
At any stage of infection, T. pallidum can invade the nervous system causing neurosyphilis, or the eyes causing ocular syphilis. Neurosyphilis symptoms can include headaches, paralysis, dementia, sensory deficits, and altered behavior. Ocular syphilis can cause vision changes, decreased visual acuity, and blindness (2). 

Congenital syphilis
Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases. Congenital syphilis occurs when an infected pregnant woman passes syphilis to her baby during pregnancy. If an infected infant is not treated immediately, serious health complications can occur, including enlargement of the liver and spleen, rashes, fever, neurosyphilis, lung inflammation (4), developmental delays, seizures, and other fatal complications (5).

References
1. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharmacother, 42 (2), 226-236.
2. Syphilis – CDC Fact Sheet (Detailed). (2017, January).
3. Peeling RW, et al. (2017). Syphilis. Nat Rev Dis Primers, 3 (17073).
4. Woods CR. (2009). Congenital syphilis-persisting pestilence. Pediatr Infect Dis J , 28 (6), 536-537.
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).

Chlamydia Quick Facts

What is chlamydia?
Chlamydia is a common sexually transmitted disease (STD) that is spread through sexual contact with the penis, vagina, mouth, or anus of an infected individual. Chlamydia can also be transmitted from a mother with an untreated cervical infection to her newborn during childbirth (1).

What causes chlamydia?
Chlamydia is caused by infection with the obligate intracellular bacterium Chlamydia trachomatis.

What are the symptoms of chlamydia?
Most individuals infected with chlamydia remain asymptomatic. If symptoms occur, it’s usually 1-3 weeks after exposure. Symptoms can include:

  • Abnormal vaginal discharge
  • Bleeding between periods and/or after sexual intercourse
  • Increased urinary frequency
  • Dysuria – painful urination
  • Pain during sexual intercourse
  • Abdominal and/or pelvic pain
  • Urethral discharge
  • Testicular pain
  • Burning or itching in the urethra

Chlamydia can also affect the rectum, resulting in rectal pain, discharge, and bleeding (2), and the eyes, resulting in chlamydial conjunctivitis (red, watery, painful eyes) (3). 

Who is at risk of chlamydia?
Any sexually active individual is at risk of chlamydial infection, with an increased risk among younger individuals. Chlamydia is one of the most prevalent STDs in the United States, with annual chlamydia cases estimated to be around 2.86 million (4). 

How is chlamydia diagnosed?
Modern nucleic acid amplification testing (NAAT) provides the most sensitivity and specificity for a chlamydia diagnosis. These can be performed on vaginal swabs (either clinician- or patient-collected) or urine.

How is chlamydia treated?
Chlamydia is easily cured with antibiotics. However, repeat chlamydial infections from sexual contact with an infected partner are common, increasing the risk of serious reproductive health complications. Antibiotics do not repair any permanent damage done by the disease (5).

References
1. Sexually Transmitted Disease Surveillance, 2018. CDC. [Online]. October 2019. 
2. Quinn TC, et al. (1981). Chlamydia trachomatis Proctitis. N Engl J Med, 305 (4), 195-200.
3. Kalayoglu MV (2002). Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.
4. Satterwhite CL et al. (2013). Sexually transmitted infections among US women and men: prevalence and incidence estimates. Sex Trans Dis, 40 (3), 187-193.
5. Workowski KA & Bolan GA (2015) Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep, 64 (RR-03), 1-137.

Is there a cure for syphilis?

Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It is primarily transmitted during sexual contact or during pregnancy from an infected mother to her infant. It has been called “The Great Pretender”, as symptoms can resemble other diseases. If syphilis is untreated it can cause serious health complications.

Penicillin G is the preferred drug for treating individuals in all stages of syphilis. Although treatment cures the disease and prevents disease progression, it does not repair any tissue damage that has already occurred, and does not prevent reinfection at a later date (1). There is currently no effective vaccine available for syphilis (2).

Treatments in the primary and secondary stages
The primary stage of syphilis is generally characterized by the appearance of one or more skin lesions (chancres) at the location where syphilis entered the body. This can appear anytime from 10-90 days after infection, with an average onset of 21 days post-infection. Skin rashes mark the secondary stage of syphilis, which may appear as the primary chancre is healing or several weeks later (3).

Individuals with either primary or secondary stage syphilis are treated with a single intramuscular dose of Benzathine penicillin G. Adults receive 2.4 million units, while infants and children receive 50,000 units/kg (up to 2.4 million units). These individuals should also be tested for HIV, and retested in three months in areas with a high prevalence of HIV. Clinical and serologic evaluations should be conducted at six and twelve months after treatment (1).

Treatments during the latent and tertiary stages
There are no visible signs or symptoms of syphilis during the latent (hidden) stage. However, syphilis-causing bacteria (Treponema pallidum subspecies pallidum) are still present. In the early latent phase (less than one to two years after original infection), transmission can still occur as up to 25% of individuals can develop a recurrent secondary infection (4). In rare cases, the latent stage progresses to a potentially fatal tertiary stage. This can occur 10-30 years or more after acquiring a syphilis infection.

The recommended treatment in the early latent stage is the same as for the primary and secondary stages – a single intramuscular dose of Benzathine penicillin G. Individuals with late latent syphilis, or latent syphilis of unknown duration, or tertiary stage syphilis should be treated with three intramuscular doses of Benzathine penicillin G at one-week intervals. Adults receive 2.4 million units per dose, while infants and children receive 50,000 units/kg per dose (up to 2.4 million units per dose) (1).

Treatments during pregnancy
Penicillin G is the only known effective treatment for preventing the transmission of syphilis from an infected pregnant mother to her baby. The penicillin dosage depends on the stage of syphilis and pregnancy. Any infected woman with a penicillin allergy should be desensitized and treated as normal with penicillin, as there are no proven alternative treatments for syphilis during pregnancy (1).

Treatments for neurosyphilis and ocular syphilis
At any stage of infection, Treponema pallidum subspecies pallidum can invade the nervous system causing neurosyphilis, or the eyes causing ocular syphilis. The recommended regimen for individuals with these complications is with Acqueous crystalline penicillin G for 10-14 days. This can be administered as 3-4 million IV units every four hours, or by continuous infusion (1).

Treatment complications
The Jarisch-Herxheimer reaction is a complication that can occur within the first 24 hours of any syphilis treatment. When penicillin kills the harmful syphilis-causing bacteria, toxic bacterial products are released. Some individuals develop a systemic inflammatory reaction to these toxins in the bloodstream, resulting in symptoms including fever, chills, rigor, hypotension, headaches, muscle pain, hyperventilation, and anxiety (5). This reaction is more common in individuals with early syphilis. It may also induce early labor or cause fetal distress in pregnant women (1).

References
1. 2015 STD Treatment Guidelines Syphilis. CDC. (2015, June 4). 
2. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).
3. Kent ME & Romanelli F (2008). Reexamining syphilis: an update on epidemiology, clinical manifestations, and management. Ann Pharmacother, 42 (2), 226-236.
4. O’Byrne P & MacPherson P (2019). Syphilis. BMJ, 365 (4159).
5. Belum GR, et al. (2013). The Jarisch-Herxheimer reaction: revisited. Travel Med Infect Dis, 11 (4), 231-237.

Facts about congenital syphilis

Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases.

Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases (1). Congenital syphilis occurs when an infected pregnant woman passes syphilis to her fetus during pregnancy. The transmission of syphilis to the infant is more likely to occur in situations where the mother has been infected during the pregnancy, but many cases still occur where the mother was infected prior to the pregnancy (2). There is about a 70% chance of an untreated woman passing syphilis to her fetus (3).

Early congenital syphilis
The signs of early congenital syphilis are usually apparent at 3-14 weeks of age, but in rare cases, there may be no obvious symptoms until 2-5 years of age. A wide range of symptoms are associated with early congenital syphilis including:

  • Inflammation of the umbilical cord, iris of the eye, and bone joints
  • Fever
  • Skin rash and shedding of the skin on the palms and soles
  • Low birth weight
  • Anemia
  • High cholesterol levels at birth
  • Meningitis
  • Jaundice
  • Mental retardation
  • Hair loss
  • Pneumonia
  • Enlarged liver and spleen

Late congenital syphilis
The signs of late congenital syphilis appear after five years of age, but may not be diagnosed until adulthood. A wide range of symptoms are associated with late congenital syphilis including:

  • Bone pain
  • Retinitis pigmentosa (serious eye disease)
  • Peg-shaped upper central incisors
  • Interstitial keratitis (blurred vision, eye pain, light sensitivity)
  • Bone abnormalities (prominent forehead, saddle nose, short upper jaw)
  • Fissuring around the mouth and anus

Diagnosis
Congenital syphilis should be suspected in any child of a mother with syphilis, as there is a 70% chance of transmission in untreated pregnant women (3). However, the wide range of symptoms associated with congenital syphilis often leads to a delayed diagnosis. Furthermore, maternal antibodies to syphilis transferred through the placenta to the fetus can complicate the interpretation of diagnostic tests (4).

Factors that influence newborn treatment decisions include:

  • Diagnosis of syphilis in the mother
  • Syphilis treatment of the mother
  • Presence of clinical, laboratory, or radiographic evidence of syphilis in the newborn
  • Comparisons of maternal and newborn antibody titres

Prevention and treatment
The prevention of congenital syphilis is by far the best option. This is by routine syphilis testing in pregnant women and prompt treatment to prevent the transmission to the fetus. If an infected pregnant woman is untreated there is a 70% risk of passing syphilis to her fetus.

For infected infants, treatment must begin immediately to prevent developmental delays, seizures, and other fatal complications (5). Penicillin is the most effective treatment for infants with congenital syphilis. Additional treatments may include corticosteroids and atropine drops (2).

References
1. Syphilis – CDC Fact Sheet (Detailed). (2017, January). 
2. Congenital Syphilis. (2009). Rare Disease Database. 
3. Sheffield JS, et al. (2002). Congenital syphilis after maternal treatment for syphilis during pregnancy. Am J Obstet Gynecol, 186 (3), 569-573.
4. 2015 STD Treatment Guidelines – Congenital Syphilis. (2015, June 4). CDC. 
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).

Causes and symptoms of chlamydial conjunctivitis

Chlamydia is a common sexually transmitted disease (STD) caused by infection with the obligate intracellular bacterium Chlamydia trachomatis. Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected individual. It can also be transmitted from a mother with an untreated chlamydial cervical infection to her newborn during childbirth (1). 

Chlamydial infections most commonly occur in the genital area. However, chlamydia can also affect the eyes, resulting in chlamydial conjunctivitis (2). Chlamydial conjunctivitis is also known as adult inclusion conjunctivitis or swimming pool conjunctivitis (3).

How do people get chlamydial conjunctivitis?
Chlamydial conjunctivitis usually occurs through sexual contact with a person that has a genital chlamydia infection. In rare cases, an infection may be acquired from contaminated and incompletely chlorinated swimming pool water (3). Often the infection arises due to the spread of semen or vaginal fluids from an infected person to the eye (1).

Conjunctivitis can also occur due to other bacterial infections, as well as viral infections that tend to be more common than bacterial causes (4).

What are the symptoms of chlamydial conjunctivitis?
The incubation period (time from exposure to symptom appearance) is between two and 19 days. The severity of symptoms varies, but generally people present with mild symptoms that have lasted for several weeks or months. Often only one eye is affected, but symptoms can occur in both eyes for some people. The symptoms of conjunctivitis are due to inflammation of the conjunctiva (mucous membrane of the eye). Symptoms can include:

  • Bloodshot eyes
  • Watery eyes, due to overactive tear glands
  • Mucus production that sticks to and coats the eyelashes
  • Eye pain and grittiness feeling
  • Swelling and redness of the eyes
  • Eye irritation and itchiness

Severe infections may scar the conjunctiva, causing abnormalities in the tear film, or spread to the cornea of the eye (4).

Many people affected by chlamydial conjunctivitis also have symptoms of a genital infection, such as painful urination and abnormal discharge from the penis/vagina (4).

How is chlamydial conjunctivitis diagnosed?
Chlamydial conjunctivitis symptoms tend to last for several weeks and fail to clear up from topical antibiotics that are effective against other bacterial conjunctivitides (3). A clinical evaluation of symptoms, as well as laboratory testing (e.g. bacterial cultures, immunofluorescent staining, and nucleic acid detection), is generally undertaken for an accurate diagnosis (3).

How is chlamydial conjunctivitis treated?
Chlamydial conjunctivitis usually resolves spontaneously, but symptoms can last for 6-18 months before recovery (5). Oral antibiotics are required to treat chlamydial conjunctivitis, as topical antibiotics are often ineffective. Options include azithromycin, doxycycline, or erythromycin. These antibiotics also cure any concomitant genital infections (3). Sexual partners should be evaluated and treated at the same time as an infected individual.

References
1. Sexually Transmitted Disease Surveillance, 2018. CDC. October 2019. 
2. Kalayoglu MV. (2002) Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.
3. Adult Inclusion Conjunctivitis. MERCK MANUAL Professional Version. October 2019. 
4. Infectious Conjunctivitis. MERCK MANUAL Consumer Version. December 2019. 
5. Yang EB, Oetting TA. (2007). Adult Chlamydial Conjunctivitis: 23-year-old male with 6-week duration of red eyes. EyeRounds.org

Important things to note if you test positive for hepatitis C

What does a positive hepatitis C antibody test mean?
A positive result on a hepatitis C antibody test indicates that hepatitis C antibodies were detected in the specimen tested. This result is consistent with a current infection, or a past infection that has resolved, or a biologic false positivity for hepatitis C antibody (1).

What are the next steps?
Consult with a health care professional for follow up testing for hepatitis C nucleic acid (RNA). The detection of hepatitis C RNA utilizes a different lab technique compared to the detection of hepatitis C antibodies.

If hepatitis C RNA is not detected, it indicates a past hepatitis C infection that has resolved, and generally no further action or treatment is required. It is estimated that up to half of all infected individuals are able to spontaneously clear hepatitis C after an acute infection (2).

If hepatitis C RNA is detected, it indicates a current hepatitis C infection. Generally an additional test for hepatitis C RNA is recommended to confirm a current infection before any treatment protocols begin (3).

Management and treatment of an active hepatitis C infection
Appropriate counseling, care and treatment will be organized by the health professional who requested the hepatitis C RNA test (4). Management and treatment options may include:

  • Medical evaluation for chronic liver disease
  • Vaccinations for hepatitis A and hepatitis B (no vaccines are available for hepatitis C)
  • Screening for and control of alcohol consumption
  • HIV testing
  • Direct acting antivirals to limit the replication of the hepatitis C virus and slow the progression of the disease
  • Following a healthy diet and staying physically active
  • Consultations before taking any new prescriptions, medications or supplements (to prevent further potential liver damage)
  • Avoid donating blood, tissue, or semen
  • Covering of cuts and sores to prevent transmission of hepatitis C

References
1. Ghany MG, Strader DB, Thomas DL, & Seeff LB. (2009). Diagnosis, management, and treatment of hepatitis C: An update. Hepatology, 49 (4),1335-1374.
2. Seo S, et al. (2020). Prevalence of Spontaneous Clearance of Hepatitis C Virus Infection Doubled From 1998 to 2017. Clin Gastroenterol Hepatol, 18 (2), 511-513.
3. Hepatitis C. (2020, July). World Health Organization. 
4. Viral Hepatitis – Hepatitis C Questions and Answers for Health Professionals. (2020, August). CDC

What are the differences between hepatitis A, B, and C?

What is hepatitis?
Hepatitis refers to inflammation and damage to the liver. The most common cause of hepatitis is a viral infection, particularly from the hepatitis A, B, and C viruses, but also including the less common hepatitis D and E viruses (1). Autoimmune hepatitis and excessive alcohol and drug intake are also causes of hepatitis. This article focuses on the similarities and differences between hepatitis A, B, and C, which account for the majority of hepatitis cases.

Functions of the liver
The liver damage associated with hepatitis results in multiple different symptoms, because the liver performs many critical functions, including:

  • Bile production for digestion
  • Filtering of toxins
  • Metabolism of carbohydrates, fats, and proteins
  • Activation of enzymes
  • Storage of various mineral and vitamins
  • Synthesis of blood proteins and clotting factors. 

Hepatitis transmission
Hepatitis A is generally transmitted by the consumption of food or water contaminated with faeces from an infected individual, or through close direct contact with an infectious individual (e.g. oral-anal sex) (2).

Hepatitis B is transmitted through contact with infectious body fluids, including blood, vaginal secretions, and semen. The most common source of transmission is from an infected mother to her child during childbirth. Risk factors for hepatitis B include using injectable drugs, sexual intercourse with an infected partner, and sharing razors (or other products that may have come into contact with blood) from an infected individual (3).

Hepatitis C is usually transmitted through exposure to blood from an infected individual, most commonly through sharing needles. Other potential sources of infection include at birth, sexual intercourse, healthcare exposures, blood transfusions and organ transplants, unregulated tattoos or body piercings, and sharing personal items that have been contact with infected blood (4). 

What are the symptoms of hepatitis?
Many individuals with hepatitis do not show any symptoms or only mild symptoms. Symptoms can include:

  • Fever
  • Loss of appetite
  • Diarrhea
  • Nausea
  • Abdominal pain
  • Dark urine
  • Jaundice

Hepatitis A is an acute (short-term) illness, which does not cause chronic liver disease, and is rarely fatal. However, it can still cause debilitating symptoms resulting in significant economic and social consequences, as it is one of the most frequent causes of foodborne infection. Infected children under six years of age often don’t experience any noticeable symptoms, while older children and adults are more likely to suffer from severe symptoms. The incubation period (time from exposure to onset of symptoms) is usually 14-28 days (2).

Hepatitis B can result in a chronic infection that can develop into cirrhosis or liver cancer. The most at-risk individuals for a chronic infection are infants and young children, with 80-90% of infected infants and 30-50% of infected children under 6 years of age developing a chronic infection. Less than 5% of infected adults will develop a chronic infection, assuming they have no other health complications. The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days (3).  

Hepatitis C can develop into a chronic infection (>50% of infected individuals) (5). Most individuals with chronic hepatitis C also remain asymptomatic or only show general symptoms such as fatigue or depression. Over several decades mild to severe liver disease develops in most affected individuals, including cirrhosis (5-25% of cases) and liver cancer (6). Several factors increase the risk of the development of cirrhosis in infected individuals, including being male, >50 years, increased alcohol consumption, hepatitis B or HIV coinfection, and immunosuppressive therapy (6). Chronic hepatitis C is a common reason for a liver transplant in the United States (7).

Treatment and prevention options for hepatitis
Hepatitis A treatment options aim to maintain comfort and adequate nutrition, particularly the replacement of fluids. Although most infections are mild, the recovery can take several weeks to months in some individuals. The majority of infected people develop immunity to further hepatitis A infection. The transmission of hepatitis A can be reduced by provisions of safe drinking water, proper sewage disposal, and following proper hygiene practices. There are also several effective hepatitis A vaccines available (2).

Hepatitis B treatment focuses on maintaining comfort and adequate nutrition for acute infections. Chronic hepatitis B infections can be treated with various medications, including antivirals, to reduce progression of cirrhosis and incidence of liver cancer. However, these treatments do not generally eliminate the hepatitis C virus, so treatment is life-long. Vaccination is the most effective prevention tool for hepatitis B and is included in routine childhood vaccination schedules worldwide (3).

Hepatitis C affected individuals should be provided with a medical evaluation for liver disease, vaccinations for hepatitis A and B, HIV testing, and advice regarding reduced alcohol consumption and weight management for overweight and obese individuals. Affected individuals should not donate blood, tissue, or semen, and refrain from sharing items that may come into contact with blood (e.g. razors, glucose meters, toothbrushes). Any cuts or sores on the skin should be covered to reduce the risk of transmission. There is currently no available vaccine for hepatitis C. It is treated with antiviral medications to eliminate the virus from the body. Newly developed “direct-acting” antivirals have improved treatment considerably with fewer side effects and shorter treatment periods. Nowadays, over 90% of individuals infected with hepatitis C can be cured with 8-12 weeks of oral therapy (8).

References
1. Hepatitis. from World Health Organization. 
2. Hepatitis A. (2020, July). World Health Organization. 
3. Hepatitis B. (2020, July). World Health Organization. 
4. Viral Hepatitis – Q&As from the Public. (2020, July). CDC. 
5. Liang TJ, Rehermann B, Seef LB, & Hoofnagle JH (2000). Pathogenesis, natural history, treatment, and prevention of hepatitis C. Ann Intern Med, 132 (4), 296-305.
6. Thomas DL, & Seef LB. (2005). Natural history of hepatitis C. Clin Liver Dis, 9 (3), 383-398.
7. Definition & Facts of Liver Transplant. (2017, March). National Institute of Diabetes and Digestive and Kidney Diseases. 
8. Initial Treatment of Adults with HCV Infection. (2020, August). AASLD.