Human exposure to Anaplasma phagocytophilum in two cities of Northwestern Morocco

Anaplasma phagocytophilum is an emerging tick-borne zoonosis with extensive increased interest. Epidemiological data are available in several regions of the USA, Europe and Asia in contrast to other parts of the world such as North Africa. Blood samples of 261 healthy individuals divided in two groups i.e., dog handlers and blood donors were analysed. Indirect immunofluorescent assay using a commercial kit was performed to detect specific A. phagocytophilum IgG. Two dilutions were used to assess the prevalence of seroreactive samples. Demographic variables were assessed as potential risk factors using exact logistic regression. Seropositivity rates reached 37% and 27% in dog handlers and 36% and 22% in blood donors. No statistically significant differences were found in the prevalence rates between the two groups. Analysis of risk factors such as gender, age groups, outdoor activities, self-reported previous exposure to ticks, or contact with domestic animals (dogs, cats, ruminants and horses) did not shown any significant difference. A. phagocytophilum exposure was common in both high-risk population and blood donors in Morocco

Distribution of age, sex, exposure to ticks, contact with dogs or other domestic animals and travel history outside Morocco in both dog handlers (n = 138) and blood donors (n = 115) groups.

<p>Distribution of age, sex, exposure to ticks, contact with dogs or other domestic animals and travel history outside Morocco in both dog handlers (n = 138) and blood donors (n = 115) groups.</p

Photographs of ultraviolet light microscopy (×400) of <i>A</i>. <i>phagocytophilum</i> IgG semi-quatitative IFA measurement using a commercial kit (Focus Diagnostics, Cypress, California, USA) showing a negative control (A), a positive control (B) and for positive dilutions i.e., 1:64 (C), 1:128 (D); 1:256 (E) and 1:516 (F) from the same patient.

<p>The positivity is set on the observation of green morulae surrounding the cell’s cytoplasmic membrane.</p

Distribution of positivity rates for the four <i>A</i>. <i>phagocytophilum</i> IgG dilutions (i.e, 1:64, 1:128, 1:256 and 1:516) in both dog handlers (A) and blood donors (B) groups.

<p>Distribution of positivity rates for the four <i>A</i>. <i>phagocytophilum</i> IgG dilutions (i.e, 1:64, 1:128, 1:256 and 1:516) in both dog handlers (A) and blood donors (B) groups.</p

Distribution of seropositive samples according to the gender, age group, presence of outdoor activities, contact with ticks, dogs or other animals and travel history in the blood donor group for both 1:64 (n = 41) and 1:128 (n = 25) dilutions.

<p>Distribution of seropositive samples according to the gender, age group, presence of outdoor activities, contact with ticks, dogs or other animals and travel history in the blood donor group for both 1:64 (n = 41) and 1:128 (n = 25) dilutions.</p

Distribution of <i>A</i>. <i>phagocytophilum</i> IgG positivity rates in blood donors according to the region of living the Rabat-Salé-Kénitra (RSK), Casablanca-Settat (CS), Tangier-Tétouane-Al Hoceima (TTAlH) and Souss-Massa-Drâa (SMD) regions and for both 1:64 (A) and 1:128 (B) dilutions.

<p>Distribution of <i>A</i>. <i>phagocytophilum</i> IgG positivity rates in blood donors according to the region of living the Rabat-Salé-Kénitra (RSK), Casablanca-Settat (CS), Tangier-Tétouane-Al Hoceima (TTAlH) and Souss-Massa-Drâa (SMD) regions and for both 1:64 (A) and 1:128 (B) dilutions.</p

Number of seropositive samples in both dog handlers (n = 138) and blood donors (n = 115) groups at the four different dilution.

<p>Number of seropositive samples in both dog handlers (n = 138) and blood donors (n = 115) groups at the four different dilution.</p

Distribution of the number of blood donors and of positive samples for both dilutions according to city.

<p>Distribution of the number of blood donors and of positive samples for both dilutions according to city.</p