Trypanosoma cruzi: New foci of enzootic Chagas' disease in California

Trypanosoma cruzi was discovered in 2–3rd instar nymphs of Triatoma protracta protracta from Paicines, 57 of 257 adults from Mulholland Overcrossing, and 2 males of 27 bugs from Juniper Hills, California. Thirty experimentally infected albino Mus musculus revealed low grade parasitaemias. Of 785 laboratory-raised Triatoma fed on 11 mice with Paicines isolate, 675 T. p. navajoensis and 1 T. p. protracta became infected; of 856 T. p. navajoensis fed on 13 mice with Mulholland isolate, 792 were positive; and of 137 T. p. navajoensis fed on 6 mice with the Juniper Hills isolate, 32 were infected with Trypanosoma cruzi. Examination of 7599 mm² area of tissue films for Paicines isolate revealed 31 type b and 15 type c sphaeromastigotes; 5650 mm² for the Mulholland isolate revealed 9 a-, 149 sphaero-, 8 epi-, and 7 trypo-mastigotes; and 15,209 mm² for the Juniper Hills isolate revealed 245 a-, 2865 sphaero-, 42 epi-, and 21 trypo-mastigotes. Field xenodiagnosis of 228 rodents in Juniper Hills revealed 11 Peromyscus truei montipinoris and 1 Neotoma fuscipes macrotis with Chagas' trypanosome.