Other Infections


A tick bite can deliver Borrelia plus a plethora of other pathogens (hyperlink to definition) referred to as co-infections.  This further complicates the clinical picture as they often have similar symptomatology and it is hard to differentiate between them. See Co-Infections table. 

Globally common co-infections include Babesia, Bartonella, Ricketsia, Ehrlichia/Anaplasma, Q-fever, tick borne encephalitis virus, West Nile virus, Francisella  tularensis and others.  Babesia is the most commonly found co-infection in USA and the incidence with Borrelia varies with the endemic area and the reservoir animals. (Diuk-Wasser et al 2014; Pujalte &  Chua 2013).   B.microti, B.duncani, B.divergens, B.venatorum are infectious to humans to date. See Co-Infections table and Ticks in Australia table. Tick borne encephalitis virus has become a growing health concern in Europe and Asia and a vaccine has been developed.
Rickettsia is the most common tick-borne infection found in Australia.  It can be transmitted by a a tick, flea or mite bite and infects the microvascular endothelium bordering blood vessels, leading to disseminated inflammation, loss of barrier function and altered vascular permeability (vasculitis) (Manseuto et al 2012, Sahni et al., 2013) and spreads from cell to cell.  Prominent effects include increased vascular permeability, water retention in tissues, reduced blood volume, low blood pressure and low albumin with low blood osmolality (Mansueto et al 2012). See Co-Infections table and Ticks in Australia table.
Ehrlichia and Anaplasma are very similar microorganisms that infect host neutrophils and/or monocytes. Ehrlichia is a tick-borne bacterial infection of the family Anaplasmataceae genera Ehrlichia. Anaplasma is of the same family but part of genera Anaplasma. The most common in humans is Anaplasma phagocytophilum – human granulocytic anaplasmosis (HGA), previously known as Human granulocytic ehrlichiosis (HGE), and the other common one is E. chaffeensis – human monocytic ehrlichiosis (Breitschwerdt et al 2014). 

Bartonella is an emerging pathogen. Nine genospecies have been shown to be pathogenic in humans to date (Woolley et al, 2007). It is transmitted by lice, fleas, ticks infected rats, and cats. See Co-Infections table and Ticks in Australia table.


Opportunistic infections may be activated due to immune dysfunction caused by multiple infections.  They further complicate the clinical picture and treatment.

The opportunistic infections that predominate depend on the patient’s previous pathogen exposure and load.  For example Chlamydophyla pneumoniae is believed to be very common. due to air borne transmission.   Some go on to develop persistent chronic - pneumonia symptoms  which can be controlled after two weeks of treatment but it is not eradicated, and can disseminate within the host (Puolakkainen, 2013).

Chlamydophyla  pneumoniae

C. pneumoniae exists in two phases - the elementary body (extracellular) is transported via moist airborne droplets between hosts and into the lungs. Once inside the cell it becomes the reticulate body (intracellular) which is very difficult to eradicate (Sessa et al 2014). C. pneumoniae is implicated in sarcoidosis, lung cancer, chronic obstructive pulmonary disease (COPD), asthma, atherosclerosis and Alzheimer’s disease (De Chiara et al 2012).  

The main symptoms are pharyngitis, bronchitis, atypical pneumonia, cough, fever, difficulty breathing, whitening of the back of the tongue and nasal congestion (Wang B et al 2013). When C. pneumoniae symptoms surface in the presence of Borrelia and co-infections, it is very hard to differentiate between specific symptoms of each pathogen due to overlap. Fortunately the antibiotics that kill Borrelia are also effective against C. pneumoniae.

For an excellent site about information and help with Chlamydophyla infections and complications visit http://www.cpnhelp.org


Mycoplasma is the smallest of the cell-wall-free bacteria. It has sterols in its cell membrane requiring cholesterol for growth and stability. Mycoplasma can be parasitic or saprotrophic (utilise dead host cells). It can cause pneumonia, neurological symptoms such as encephalitis, meningitis, brain-stem dysfunction, cerebellar dysfunction (Simpkins et al 2012).
Mycoplasma infections is thought to be important in Lyme co-infections especially with neuroborreliosis (Greenblatt et al 2013).  A useful website for information on Mycoplasma is the Institute for Molecular Medicine.

Some co-infections and opportunistic infections are known, but there are probably many that have not been characterised.

Prevention of infections is better than trying to find a cure. See how to prevent tick bites.
For available testing in Australia see Diagnostics.
For treatment of co-infections see Treatments
Co-Infections table 
Ticks in Australia table
Opportunistic infection table
Coming soon
Copyright: sarahdesign / 123RF Stock Photo

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Growing evidence of an emerging tick-borne disease that causes a Lyme like illness for many Australian patients

On 12 November 2015, the Senate referred the following matter to the Senate Community Affairs References Committee for inquiry and report:

The growing evidence of an emerging tick-borne disease that causes a Lyme‑like illness for many Australian patients.

Submissions should be received by 31 March 2016. The reporting date is 20 June 2016.
Nov 17, 2015

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