Trypanosoma brucei complex - Host Immunity, Clinical Manifestation, Complication, Prognosis

Last Modified: December 22, 2022

Contents

Host Immunity of Trypanosoma brucei complex

Trypanosoma brucei induces host immunity - a strong humoral immune response.
IgM macroglobulinaemia and massive B cell proliferation are involved in the host immunity
the Trypanosoma brucei parasites evade the host immune system by producing a series of variant antigenic types (VAT) over a period of time
the host VAT-specific antibodies kill the parasites by lysis and opsonization which results in remissions
however, at the time during which the host immune system is able to kill off the parasites, trypanosomes evade the complete elimination by expressing a new VAT and then multiplying rapidly
the trypanosomes continue to multiply until new antibodies against the new VAT are formed
through this process, Trypanosoma brucei is able to cause infection over a period of time
other serological features of this infection include
high level of IgM antibodies in CSF
elevated levels of anti-DNA antibodies, heterophile antibodies, and rheumatoid factors
high level of antigen-antibody complex

Clinical manifestations of Trypanosoma brucei complex

The clinical manifestations of Trypanosoma brucei complex include such as:

the incubation period of East African trypanosomiasis is four weeks and symptoms are more acute
the incubation period of West African trypanosomiasis may vary from months to years and are more slow and insidious
both types of trypanosomiasis start with a development of chancre at the site of inoculation which progresses from stage I disease (hemolymphatic stage) to stage II disease (meningoencephalitic stage)

Chancre

Chancre within a few days of a bite from an infected tsetse fly, a painless trypanosomal chancre appears
characterized by swelling, local tenderness, erythema
chancre resolves spontaneously within several weeks

Stage I disease (hemolymphatic stage)

Stage I disease (hemolymphatic stage) may appear within weeks to months after inoculation
the first symptom to appear is fever, which is most common in East African trypanosomiasis than the West African trypanosomiasis
other symptoms at this stage include headaches, general malaise, intermittent fever, myalgia
as Trypanosoma brucei the parasitic infection progresses, other serious conditions occur such as irregular rash, anemia, weight loss, tachycardia, hepatosplenomegaly, etc
lymphadenopathy, mostly in the cervical areas, shows enlarged, non-tender at the mobile posterior cervical lymph node (Winterbottoms’ sign) in the West African trypanosomiasis while axillary and inguinal lymphadenopathy is observed in East African trypanosomiasis

Stage II disease (meningoencephalitic stage)

Stage II disease (meningoencephalitic stage) is slower in West African trypanosomiasis and faster in East African trypanosomiasis
involves the involvement of the host Central Nervous System (CNS)
symptoms include behavioral or personality changes (seizures, mania or psychosis, speech disorders), mood swings, depression, irritability, increased muscle rigidity and tonicity
other clinical features are persistent headaches resistant to analgesics, a profound disorder of sleep patterns including daytime somnolence followed by nighttime insomnia
Finally, the disease manifests into cachexia, stupor, and coma

Complications

Complications of Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense infection include wasting syndrome, meningoencephalitis, stupor, coma, and death.