Andrew Balkin takes a look at some of the more common opportunistic infections: their symptoms, diagnosis, prophylaxis and treatment.
An opportunistic infection is, as the name suggests, an infections that takes the opportunity to run riot in a host. A person with a healthy immune system can often easily fight off infections, but for someone with HIV, they can be incredibly damaging and in some instances fatal. HIV works by weakening the body's immune system and it is this that can leave people susceptible to opportunistic infections (Ols).
Some opportunistic infections can be treated: others can be prevented.
However, treatment may depend on how healthy your immune system is and how early (or late) the opportunistic infection is diagnosed.
This article touches on some of the more common opportunistic infections and contains information on how they may be treated or prevented.
However, as with many illnesses, opportunistic infections can be difficult to diagnose and the best advice is, if in any doubt or if you suspect anything may be wrong, seek professional medical advice as soon as possible. The earlier an OI is diagnosed, the better your chances of it being treated or controlled.
CaNdidiasis (Thrush)
A fungal infection that can infect the whole body: usually the mouth, vagina and/or penis.
Symptoms
White patches on the gums, tongue or mouth lining, painful or difficult to swallow and loss of appetite. Can also cause itching and redness around the genital area, burning sensation when urinating and white discharge (resembling cottage cheese and smelling like yeast).
Diagnosis
A visual examination, smear or culture.
Prevention
Using condoms during sex (anal, vaginal or oral) with an infected person.
Men with a foreskin should ensure it is washed daily (including underneath and inside by pulling it back fully).
Avoid using highly scented toiletries.
Avoid wearing tights, nylon or lycra.
Prophylaxis (preventative therapy)
It is not usually recommended because there are effective treatments, plus you could get resistant Candida developing, which would then be even more difficult to treat.
Studies have shown that continuous use of fluconazole can reduce the likelihood of thrush occurring.
Pregnant women should avoid preventive treatments because they may cause birth defects.
Treatment
A variety of anti-fungal treatments can be used to effectively treat thrush. These are often available as creams, pessaries or tablets. Some anti-fungal treatments are only available on prescription, but others are available over the counter.
Cryptococcosis
A fungal infection that primarily affects the brain.
Symptoms
Headaches, nausea, vomiting, fatigue, irritability, loss of concentration and mood swings. It may also cause seizures, coughing fits, sweats, sleep disturbance and breathing difficulties.
Diagnosis
Usually a lumbar puncture (or spinal tap) to test cerebrospinal fluid.
Prevention
It is not an infection that is easy to prevent, although you should avoid high prevalence areas or regions where there may be an outbreak.
Prophylaxis (preventative therapy)
Not recommended because the efficacy of such treatments are not proven and cryptococcal infections are rare. It is also inadvisable because of possible drug interactions and the development of resistance to other anti-fungals.
Treatment
Amphotericin is the commonly used treatment initially, often followed by a course of fluconazole. Once you have cleared the infection, you will most likely be on maintenance therapy (probably fluconazole daily) for life.
Cryptosporidiosis
A parasite that can cause chronic diarrhoea: it is potentially fatal.
Symptoms
Chronic diarrhoea (often very runny), stomach cramps, nausea, fatigue, loss of appetite, weight loss, vomiting, dehydration, electrolyte imbalances and sleep disturbance.
Diagnosis
A stool sample to look for eggs (called oocysts). Alternative, a biopsy of the small intestines may be necessary.
Prevention
Cryptosporidiosis is often found in tap water. It can spread through the water supply and often outbreaks occur in areas that are supplied by the same water system. Drinking bottled or filtered water may reduce the risk of infection.
Prophylaxis (preventative therapy)
There are no proven effective preventive treatments.
Treatment
There are no known treatments: most people clear the infection naturally, although it can be life threatening for those with an impaired immune system.
Treatment should revolve around re-hydration, replacing electrolytes and stopping the diarrhoea.
Cytomeglavirus (CMV)
A virus that can affect the whole body and cause a multitude of painful symptoms.
Symptoms
CMV can affect the eyes causing blurred vision, loss of central vision and blindness - known as CMV retinitis.
It can cause a fever, diarrhoea and stomach craps - CMV colitis.
The virus can cause mouth ulcers, pain in the mouth and throat and difficulty swallowing - CMV oesophagitis.
CMV can affect the lungs and cause pneumonia-like symptoms - known as CMV pneumonitis.
It can also cause confusion, memory loss, fever and lethargy - CMV encephalitis.
Diagnosis
CMV retinitis can be tested for by an eye examination.
CMV oesophagitis and colitis can be detected by endoscopy or biopsy.
CMV pneumonitis is usually diagnosed through bronchoscopy or biopsy. It is often only diagnosed after certain bacteria and PCP have been ruled out.
CMV encaphilitis diagnosis often involves a lumbar puncture or spinal tap (for cerebrospinal fluid) and/or a brain MRI (magnetic resonance imaging) scan.
Prevention
This is one of the many opportunistic infections that are difficult to prevent.
Those with a low CD4 count (below 50) are deemed to be most at risk. Sometimes your specialist may consider administering ganciclovir to reduce the likelihood of CMV occurring. Pregnant women should not use ganciclovir because of the effects it may have on their unborn child.
Treatment
Ganciclovir can be used to treat any of the forms of CMV and is successful in a large number of patients. Other treatment options may include foscarnet for any form of CMV. There are other treatments that may be used for some forms of CMV, although they could be administered in combination with other drugs, these include cidofovir and probenecid.
Histoplasmosis
A fungal infection that can affect your breathing.
Symptoms
Fever, tiredness, general fatigue, weight loss, breathing difficulties, pneumonia-like symptoms and swollen lymph glands.
Diagnosis
A urine or blood sample to detect histoplasma, possibly also in bone marrow.
A biopsy of a lesion (possibly in the mouth, on the skin or a swollen lymph gland) may be necessary.
Prevention
It is difficult to know how to prevent histoplasmosis except to avoid areas where there are known infections or an outbreak has occurred.
Prophylaxis (preventative therapy)
HIV-positive people in high-risk areas or who are exposed to the infection in the workplace may be offered prophylaxis such as itraconazole or fluconazole. Pregnant women should avoid these treatments because of the possible birth defects they may cause.
Treatment
For people with severe disease, amphotericin may be administered. Mild disease is often treated with itraconazole or fluconazole.
Everyone who has had histoplasmosis is recommended to stay on maintenance therapy for life; stopping maintenance therapy is not recommended.
MYCOBACTERIUM AVIUM COMPLEX (MAC)
An increasingly common OI originating in water, dust, soil and bird droppings.
Symptoms
Fever (usually persistent), night sweats, high temperature, fatigue, weight loss, abdominal pain, anaemia, diarrhoea, dizziness and weakness.
Diagnosis
A blood sample, bone marrow, lumbar puncture or spinal tap: a culture is then grown.
Prevention
Avoiding tap water and maintaining a high standard of personal hygiene may help, but is not foolproof.
Prophylaxis (preventative therapy)
People with low CD4 counts (usually below 50) may be offered preventive therapy that may consist of clarithromycin or azithromycin (or possibly rifabutin).
Treatment
There are many treatments including: azithromycin; clarithromycin plus ethambutol and rifabutin; or possibly either azithromycin or clarithromycin used alongside ethambutol, rifabutin, ciprofloxacin and amikacin.
Higher doses of clarithromycin may be linked to an increased risk of death.
Everyone who has had MAC should be on maintenance therapy. Your specialist may recommend you consider stopping maintenance therapy after 6-12 months, although this will be dependant on your CD4 count, viral load and other circumstances.
Pneumocystis Carini Pneumonia (PCP)
A parasite infecting the lungs and causing breathing disorders that can be fatal.
Symptoms
Breathing difficulties, fever, hot and cold sweats, cough, weight loss and fatigue.
Diagnosis
An X-ray, induced sputum sample or bronchoscopy.
Prevention
Avoid contact with people known to have PCP and dress sensibly during the cold weather, taking care to protect your mouth and neck.
Prophylaxis (preventative therapy)
People with a low CD4 count (usually below 200) may well be offered prophylaxis. This may consist of a number of drugs, possibly TMP/SMX, dapsone, pyrimethamine and/or leucovorin.
In some cases pentamidine or atovaquone may be used.
Treatment
TMP/SMX is often used. Other treatments include trimethoprim and dapsone, atovaquone, clindamycin and primaquine, or intravenous pentamidine. Sometimes trimetrexate and leucovorin may be administered.
Everyone who has had PCP should be on maintenance therapy; this consists of the same drugs used for prophylaxis. Some doctors may suggest you come off maintenance therapy if your CD4 count rises and stays at a healthy level.
Toxoplasmosis
A parasitic infection that affects the brain and can be fatal.
Symptoms
Confusion, brain fog, memory loss, mood swings, headaches, fever, seizures and in rare instances coma.
Can also affect the eyes (and behind the eyes) - causing severe pain and impaired vision.
Diagnosis
MRI scan to check for brain lesions. Blood tests for antibodies. Possibly also tissue cultures and lumbar puncture or spinal tap for cerebrospinal fluid. A brain biopsy may also be considered to rule out lymphoma or PML (progressive multifocal leukoencephalopathy).
Prevention
It is advisable to avoid eating raw or undercooked meat, as this is the primary source of toxoplasmosis infection.
Prophylaxis (preventative therapy)
Often prophylaxis is only offered to those with a low CD4 count (below 150 or sometimes 100) and may include TMP/SMX, or possibly pyrimethanine, sulfadoxine, and/or dapsone.
Pregnant women are recommended to delay taking prophylaxis until after the first three months of pregnancy.
Treatment
Treatment options vary, but could include a combination of pyrimethanine, leucovorin, sulfadiazine and/or clindamycin. There are other treatment combinations and these may also include dapsone, atovaquone or trimetrexate.
Everyone who has experienced toxoplasmosis should remain on maintenance therapy for life: insufficient data exists to support stopping therapy.
Tuberculosis (TB)
A bacterial infection primarily affecting the lungs and can be fatal.
Symptoms
Cough, fever, breathing difficulties, night sweats and weight loss.
Avoid areas of high prevalence: often resource poor settings and regions with poor sanitation. Always cover your mouth when coughing or sneezing.
Prophylaxis (preventative therapy)
All HIV-positive people are considered to be at possible risk and should be offered a test (tuberculin skin test). Preventive therapy can only be started if TB is present, but there is no active disease.
Preventive treament may consisit of a variety of different drugs in combination: these may include any of the following: isoniazid, pyridoxine, rifampicin, pyrazinamide and/or rifabutin.
Treatment
There are several treatment options available and people co-infected with HIV and TB are usually treated with a combination of drugs. These may include any of the following: isoniazid, rifampicin, pyridoxine, pyrazinamide and/or ethambutol.
Maintenance therapy is not required for people who successfully clear tuberculosis.
takes the opportunity to run riot in a host. A person with a healthy immune system can often easily fight off infections, but for someone with HIV, they can be incredibly damaging and in some instances fatal. HIV works by weakening the body's immune system and it is this that can leave people susceptible to opportunistic infections (Ols). 