120 The Philippine Journal of Science i9is 



the same house, some distance away from either focus. In- 

 vestigation showed that they had been living in house "C," 

 having left there within the week and being sick at the time of 

 leaving. They were unquestionably infected in house "C." 

 Following this, there developed a case at house "D," another 

 at house "C," and another (the last) at house "D." Eight 

 cases in all occurred within a period of less than two months. 



The occurrence of a fourth case in each focus would indicate 

 that previous disinfections had not proved efficacious. There- 

 fore, the entire work of disinfection was repeated with petro- 

 leum and kreso. Walls, floors, beds, and chairs were thoroughly 

 sprayed with a view toward exterminating bedbugs. In nipa 

 houses it is difficult to reach bedbugs lurking between the layers 

 of nipa, and, therefore, after disinfection, house "C" was vacated 

 and closed for a period of two months. Houses in the immediate 

 vicinity were also treated to kill bedbugs. 



Double walls and ceilings in house "D" were torn out, and 

 special effort made to exterminate the bugs. 



The writer is of the opinion that this outbreak of plague was 

 an instance of bedbug transmission, starting with a case of 

 human plague, introduced into Iloilo from Manila, where plague 

 had previously appeared, or possibly from a plague-infected 

 foreign port, the reasons being as follows : 



1. The absence of rat infection, 



2. The decidedly circumscribed foci. 



3. The sudden cessation of the outbreak after the houses 

 believed to be infected had been thoroughly treated to kill 

 vermin. 



4. House "C" was owned by a Chinaman, who was as well 

 one of its inmates, and who undoubtedly had at least business 

 intercourse with the Chinamen living in the focus Y, and who 

 could have readily carried infected bedbugs from one focus to 

 another. 



It is regretted that an effort to secure bedbugs was not made 

 earlier in the campaign so that inoculation experiments could 

 have been carried on to prove or disprove the validity of the 

 theory in this case. However, that bedbugs may and often do 

 carry plague infection has been proved beyond a doubt by 

 various observers. 



