Abstract: Synanthropic urban insects in high-density dwellings act as persistent reservoirs of enteric bacterial pathogens. This study assessed infestation dynamics, bacterial dissemination, and quantitative vectorial capacity (VC) of the German cockroach (Blattella germanica) in student hostels at Abubakar Tafawa Balewa University, Bauchi, Nigeria. Seventy-two cockroaches were collected from Yelwa and Gubi campus hostels (May–July 2024) and identified taxonomically; 35 were subjected to bacteriological analysis of external and internal homogenates. Temperature, humidity, and sanitation were recorded. Bacterial isolates were identified by culture, Gram staining, and biochemical tests. Quantitative microbial risk assessment estimated transmission efficiency (TE). Gubi, a peri-urban site, showed higher infestation (54.17%) than urban Yelwa (45.83%), with kitchens as primary foci. Escherichia coli was predominant (45%), followed by Proteus (20%), Enterobacter (15%), Klebsiella (10%), and Shigella (10%). Internal and external carriage rates were 52% and 40%, respectively. Pathogen load was 8.7 × 10⁵ CFU/cockroach, TE was 0.0003%, and integrated VC was 120.06. Despite low direct surface-contact transfer, high vector density, elevated microbial loads, and humidity up to 72% sustain substantial bacterial transmission potential in communal living quarters. High temperatures (28–32°C) and increasing humidity (44–72%) favoured proliferation, while poor kitchen and lavatory sanitation amplified pathogen carriage. These findings quantify B. germanica as a public health risk in communal residences, underscoring the need for integrated pest management and environmental sanitation interventions.
Keywords: Blattella germanica; Student Hostels; Vectorial Capacity; Environmental Sanitation; Microbial Load; Transmission Efficiency
jaerem Wali, M. M
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