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OTHER INFECTIONS

BARTONELLA (ROCHALIMAEA).-- Bacillary angiomatosis (epithelioid
angiomatosis), peliosis of liver and spleen, osteolytic bone lesions, and persistent fever with
bacteremia in HIV-infected persons are caused by fastidious gram negative organisms known as
Bartonella henselae (formerly Rochalimaea henselae) or as Bartonella quintana. This agent
appears to be Rickettsia-like, and it can be identified in tissue sections with Warthin-Starry
staining, by immunocytochemical methods, or by culture with confirmation via polymerase
chain reaction. This organism has appeared in many geographic areas. Epidemiologic evidence
suggests that bacillary angiomatosis is a zoonosis associated with traumatic exposure to cats,
poor living conditions, and infection with Bartonella.[508,509,510]

LYMPHOGRANULOMA VENEREUM (LGV).-- A sexually transmitted disease most
commonly seen in tropical and subtropical regions, LGV with HIV infection is caused by serovar
L2 of Chlamydia trachomatis. This infection develops in three stages. There is a primary stage
with a transient and often insignificant genital ulcer. The secondary stage is characterized by
inguinal adenitis, and bubo formation. Proctitis with purulent anorectal discharge, pain and
bleeding also occurs, with microscopic pathologic findings of mucosal ulceration, heavy
lymphocytic infiltrates in the lamina propria, cryptitis, crypt abscesses and granuloma formation.
The third stage produces chronic granulomatous inflammation, lymphedema, elephantiasis, and
often-irreversible rectal stricture. It is most likely to occur in the setting of HIV infection among
men having sex with men. Most cases respond to doxycycline therapy.[511]

LEISHMANIA INFECTIONS.-- Leishmaniasis is present in about 12 million persons
worldwide, with at least 1.5 million new cutaneous cases and 0.5 million visceral cases each
year. Most reported cases of leishmaniasis in persons with HIV infection are visceral
leishmaniasis, known also as kala azar, from endemic areas for Leishmania donovani, but these
infections may also be seen outside of endemic areas because of increased travel. Increasing
numbers of cases have been observed in Southwestern Europe. The CD4 count is <200/µL in
over 90% of cases. AIDS appears to increase the risk for leishmaniasis by 100 to 1000 fold. The
major risk factor for HIV infection in coinfected patients is injection drug use in more than 70%
of cases. The major surface molecule of L donovani is lipophosphoglycan which induces HIV
transcription in CD4 cells; thus, leishmaniasis may promote HIV infection.[512]
L donovani is a protozoan parasite transmitted via sand fly bite. The bite introduces
promastigotes into the skin, where they are then engulfed by macrophages. The organisms
become amastigotes and, after proliferating, peripheral blood mononuclear cells can become
infected and spread the infection through tissues of the mononuclear phagocyte system and
elsewhere. Clinical manifestations include fever, hepatosplenomegaly, and pancytopenia. In
some cases, leishmaniasis is the first severe infectious disease complicating HIV infection.
Serologic titers indicative of L donovani infection are present in only a third of cases.
Antimonial therapy may show an initial response followed by a chronic course with relapses, but
a complete response is observed in a minority of cases. The presence of additional opportunistic
infections during active leishmanial infections complicates diagnosis. In most cases, the stage of
AIDS is late and the prognosis poor.[513]
Diagnosis of L donovani infection has been made primarily through bone marrow biopsy
with culture or by identification of typical amastigotes in smears. The use of PCR to detect