Table 4 Comparison between previous and present surveys
Dozie et al. 2004 [19] | Siewe et al. 2018 | Remarks | |
|---|---|---|---|
Study sites | 13 villages in the Imo river basin, Nigeria | Two villages in the Imo river basin, Nigeria | The two villages in 2018 were those closest to the Imo river |
Number of years of CDTI before the study | 10 years | 24 years | The 24 years of CDTI in 2018 included four years of biannual distribution |
Methods | - Door-to-door epilepsy surveys - Epilepsy screening by asking about previous epilepsy experience in the households, and confirmation by a doctor trained in paediatric neurology - Skin snip microscopy, no Ov16 testing | - Door-to-door epilepsy surveys - Epilepsy screening using a 5-item questionnaire, and confirmation by a neurologist or a doctor trained in epilepsy - Skin snip microscopy and Ov16 testing | Possible underestimation of epilepsy in 2004 because only one screening question was asked, and it is likely that only generalized convulsive seizures were detected |
Onchocerciasis prevalence | 26.8% | 4.6% | P < 0.0001 |
Microfilaria density | 22.1 per mg of skin snip | 2 per skin snip | Average density from all infected participants |
Ov16 RDT positive results | Not done | 0% | Children and adults were tested in 2018 |
Onchocerciasis endemicity | Meso-endemic | Hypo-endemic | Reduced endemicity after 14 years of CDTI |
Epilepsy prevalence | 1.2% | 0.5% | P = 0.07 |