Detection of rabies virus RNA in dog-bite wounds in a rabies-endemic area: evidence from an observational cohort study

BACKGROUND: Rabies causes over 59,000 human deaths each year, primarily in endemic regions where surveillance is challenging. We report a prospective observational cohort study evaluating rabies virus (RABV) RNA detection from wound swabs of individuals bitten by dogs as a tool to strengthen surveillance and assess human exposure. METHODS: We enrolled 100 individuals with unwashed, less than 24 hours-old, WHO-defined category III bite wounds at the Rabies Prevention Center, Indus Hospital, Karachi, Pakistan. Swabs were collected from wounds before and after washing. Serum samples were obtained before and 14 days after initiation of the three-visit intradermal IPC post-exposure prophylaxis (PEP) regimen. Demographic and clinical data were recorded. RABV RNA was detected using genotype-1 and pan-lyssavirus PCR assays; detection of RABV neutralising antibodies was evaluated by rabies fluorescent antibody virus neutralisation test (rFAVN). Primary outcome was RABV RNA detection; secondary outcomes included bite characteristics and virus-neutralising antibody (VNA) titres. FINDINGS: Among 100 participants (mean age 18.9 years; 82% male), bites occurred mainly on the lower limb (34%), head (21%) and arm (15%). RABV RNA was detected in 64% of swabs by genotype-1 and 44% by pan-lyssavirus PCR; from 40/64 positive samples the RABV-N gene was sequenced and used for downstream phylogenetic analysis. Wound washing slightly decreased RNA levels. At day 14, RABV neutralising antibodies were detected in 93.8% (75/80) of the individuals (mean titre 5.8 IU/mL). INTERPRETATION: Wound swab-based RABV RNA detection is a feasible, scalable method for rabies surveillance and exposure assessment in endemic settings. Combined with serology, it informs both viral exposure and PEP efficacy, supporting broader application in high-volume clinical care. FUNDING: Supported by a VENI Grant (NWO-VENI 09150162010181, to CWEE) and Off Road grant (ZonMw 04510252520092, to CWEE).