Anopheles gambiae sensu lato is the most important malaria vector in Nigeria. Referral hospitals have a mandate to provide patients with the best health care. The persistent complaints of the nuisance caused to patients, professionals, and visitors by mosquitoes at the University of Port Harcourt Teaching Hospital (UPTH), a referral Hospital, prompted the design of this study to assess the species composition, density, and man-biting rates of endophilic mosquitoes at the UPTH. A longitudinal entomological survey covered dry and wet seasons, February–July 2017, with sampling done thrice weekly, using the aspiration method. Caught mosquitoes were identified by standard keys using a dissecting microscope and classified according to their gonotrophic status. A total of 1,307 mosquitoes in two genera (Culex, Anopheles) and three species (Culex quinguefasciatus, Anopheles gambiae s.l. and Anopheles mouchetti) were caught, comprising 150 (11.5%) males and 1,157 females. The most abundant species was Culex quinguefasciatus (98.01%), An. gambiae s.l. (1.64%), and the least abundant, An. mouchetti (0.35%). Gonotrophic examinations of caught females revealed 52.8% blood-fed and 40.1% unfed. Culex quinquefasciatus had higher man-biting rates (1.26 bites/patient/night) than Anopheles (0.2 bites/patient/night). The Accident and Emergency ward, 595 (45.5%), and the Obstetrics and Gynecology ward, 328 (25.1%), had the highest records of caught mosquitoes among the four wards visited for collections. No significant difference (Fcal 5 1.0722, Ftab 5 13, p > 0.05, df 5 2) existed between wet and dry seasons’ collections. Because of the high numbers of blood-fed Anopheles, an urgent need for intervention is required to reduce the case of vector/human contacts; notably, larval source management will be a principal approach toward control.
