Other common opportunistic infections--bacillary angiomatosis (cat-scratch disease) and bacterial pneumonia

I gave PCP it’s own section, owing to how common it is. PCP is often the first infection to show up in patients with AIDS and usually occurs as the CD4 moves under 200.  The infections I cover in this section usually start to appear as the CD4 count moves under 100.  I have placed the infections in alphabetical order.

Once you have one of these opportunistic infections, the treatment usually requires many months of taking two or three drugs, two or three times a day, just to treat the opportunistic infection.  That doesn’t count the HIV medicines that just work against the virus.  This isn’t fun, so if your CD4 is moving near 200 or so, it’s time to get on HIV medicines.  You can read about that in another section.

Bacillary Angiomatosis, or Cat-Scratch Disease

Bacillary angiomatosis is caused by two types of bacteria: Bartonella hensalae (most common) and Bartonella quintana.  Bartonella hensalae is transmitted from a cat scratch or bite, ticks, and fleas.  Researchers believe that flea feces under the cat’s nails or in the cat’s saliva carry the bacteria.  Bartonella quintana is carried by the body louse (lice).  People that get bacillary angiomatosis are those with HIV (especially those with a CD4 less than 200), those who have contact with cats, and those who are  homeless or live in bad housing.  

Bartonella henselae is more likely to infect kittens and young cats; the cat will not have symptoms of the infection and will carry the infection for weeks to years.

Signs and Symptoms of Bacillary Angiomatosis

Bacillary angiomatosis usually involves only the skin, but the infection can be on the surface (superficial), or go deep into the skin.  Superficial sores will look like red to violet colored, fragile (easy to bleed), bumps that are usually no bigger than a finger tip.  The sores may be open or closed.  The sores have this appearance because the infection causes tiny blood vessels to grow rapidly beneath the skin.  

Deep infection will look like large (several finger tips in diameter) skin-colored nodules or tumors beneath the skin.  These sores may also be open or closed.  

Bacillary Angiomatosis Picture

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The bacteria can spread from the skin and into the bones and other organs, like the liver and spleen.  The infection can be cured; however, without treatment, the infection can kill.

Diagnosis and Treatment of Bacillary Angiomatosis

Diagnosis of bacillary angiomatosis is made by taking a biopsy or culture of the skin or other organ involved.  The drug of choice to treat bacillary angiomatosis is erythromycin taken 4 times a day for eight weeks.  Erythromycin can be upsetting to the stomach, so other drugs--tetracycline, clarithromycin, azithromycin, rifampin, ciprofloxacin, or doxycyline may be used.  

Bacterial Pneumonia

Bacterial pneumonia is more common, more severe, and is likely to lead to more complications in those with HIV than those without HIV.   Bacterial pneumonia can occur at any CD4 count  but it is more common in those with a low CD4 count, intravenous drug users, and cigarette smokers.  

Bacterial pneumonia is caused by several types of bacteria, the most common of which is streptococcus pneumoniae.  Haemophilus influenzae, pseudomonas aeruginosa, and staphylococcus aureus make up the top four types of bacterial pneumonia in those with HIV.  Three other bacteria--legionella, mycoplasma, and chlamydia all cause bacterial pneumonia, but these types are rare.  Bacterial pneumonia can also be due to two different bacteria at the same time.  

Bacterial pneumonia caused by pseudomonas aeruginosa is more likely to occur in those who have a CD4 count less than 50; who have lung disease (like asthma, chronic bronchitis, or emphysema), live in or have stayed in a health care settings like hospitals, nursing homes, and assisted living facilities in the past 90 days; those on kidney dialysis; or who take steroids, and/or are malnourished.  Staphylococcus aureus bacterial pneumonia is more common in intravenous drug users and those with recent viral infections, including influenza (the flu).

Signs and Symptoms of Bacterial Pneumonia

Bacterial pneumonia comes on fast over 3 to 5 days.  Fever, chills, a dry or “wet” cough, chest pain with deep breaths, difficulty breathing, and shortness of breath are common.  

Those people with these symptoms will get a chest x-ray and a pulse oximeter to measure how well the person is getting oxygen to his/her tissues will be placed on one of their fingers.  If the sick person’s pulse oximeter reading is less that 95%, or if their pulse is very fast (for instance, over 120 beats per minute), or if the person appears to be having difficulty breathing, that person may need to have their “blood gases” measured; this involves putting a small needle into the artery that runs through the wrist area.  The nurse withdraws blood from the artery, which shows exactly how much oxygen is in the blood.  A decision on whether or not to hospitalize the patient will be based on the results of the blood gases as well as how bad the sick person looks.

Diagnosis of Bacterial Pneumonia

The diagnosis is made by seeing one or more “infiltrates” or white cloudy areas on the chest x-ray.  The lungs on a normal chest x-ray show up black or dark grey and the heart and ribs show up as white.  If the areas that are supposed to be black look white, this is called an infiltrate.  More evidence of bacterial pneumonia is an increased white blood count.  Samples of the sputum, or phlegm, coughed up from the lungs may or may not be helpful to figure out what type of bacteria is causing the pneumonia.

Treatment for Bacterial Pneumonia

Antibiotics to treat bacterial pneumonia will be given for 7 to 14 days.  The first choice antibiotic for hospitalized pneumonia patients is ceftriaxone, given directly into the vein (intravenously).  The oral antibiotic azithromycin or clarithromycin or erythromycin will also be given.  

Other drugs that may be used are: *ampicillin/sulbactam, *aztreonam, *ceftazidime, *cefepime, *cefotaxime, ciprofloxacin, clindamycin, doxycycline, *imipenem, **levofloxacin, linezolid, *meropenem, moxifloxacin, *piperacillin/tazobactam or *vancomycin.  The person will most likely recover fully from their illness.  

Preventing Bacterial Pneumonia

Bacterial pneumonia caused by streptococcus pneumoniae can be prevented with one shot of polysaccharide pneumococcal vaccine (PPV), also called the pneumovax.  One additional shot will be given five years after the first shot.  If the shot is given with the CD4 count less than 200, another shot will be needed after the CD4 count moves above 200 due to HIV medicines.  The annual flu (influenza) shot will also prevent pneumonia, since many cases of pneumonia occur as a complication of the flu.

The good news is that those people who take Bactrim (TMP/SMX) because their CD4 is less than 200 or azithromycin or clarithromycin because their CD4 is less than 100 are somewhat protected against getting bacterial pneumonia. 

Smokers run the risk of even slight colds later becoming a full-blown pneumonia, due to the damage that the smoking causes to their respiratory tract.  Quitting smoking is a good idea for everyone, especially those with HIV.