**5. Conclusions**

This particular case has been the first diagnosed in the city of Querétaro and reported in the Mexican Republic and illustrates casual infection of *L. blattarum*, a rare opportunistic pathogen, probably acquired by air, developing the patient's lung infection, due to his immunocompromised state. It is essential that doctors consider *Lophomonas blattarum* in their differential clinical diagnosis. Since some dust mites are vectors of similar flagellates, whose respiratory manifestations are due to allergy, are similarly presented and are due to lack of an accurate diagnosis, they are transformed

**Figure 9.**

*Expectoration samples stained with Papanicolaou, Hematoxylin and Eosin (H/E) and with Giemsa, respectively. Observed at 400 X. with immersion oil. Note the difference in the observation of the parasites with each of the staining procedures. Photo Villagrán-Herrera.*

into chronic allergies without response to the administered treatment. Regarding the staining procedures applied to the biological sample of our patient, a great difference was observed between the multifilated structures worked in fresh and with saline solution, finding more clearly in the fresh and staining of Hematoxylin and Eosin, than with preparations with Pap smears and Giemsa (**Figure 9**).
