Resurgence of Schistosoma Haematobium Infection after Mass Chemotherapy in Rural Cross River State

Abstract

Background: Selective mass chemotherapy is known to be very effective in reducing and controlling the prevalence of urinary schistosomiasis. However, re-infection and resurgence of Schistosoma (S) haematobium infection after effective mass chemotherapy is also common in the absence of other control programmes. Objective: To determine the prevalence of S. haematobium infection among primary school children in a rural community, ten years after effective mass chemotherapy in the same school. Subjects and Methods: The prevalence and intensity of S. haematobium infection were determined in a rural primary school by the nytel milipore filter method in 2003. The results were compared with those of a similar study carried out in the same primary school ten years earlier, before and after effective mass chemotherapy. Results: In the current study, two hundred and twenty six of the 443 children studied had urinary schistosomiasis giving a prevalence of 51.0 percent. One hundred and seventy five (77.4 percent) of those infected had infection of mild intensity (<49 ova/10ml). A previous study, carried out 10 year's earlier in the same school had shown a drop in prevalence of infection from 69.0 percent to 21.7 percent following treatment and re-treatment with praziquantel within a two-year period. Compared to the 21.7 percent prevalence obtained after two years of retreatment ten years previously, there was a rise of prevalence to 51.0 percent in this study (p<0.001). Conclusion: This study shows that the prevalence of S. haematobium among the school children was high, 10 years after effective mass chemotherapy in the same school. However, the intensity of infection was milder. We conclude that there is a need to control infection through a multifaceted approach.

Keywords

• urinary schistosomiasis
• mass chemotherapy
• resurgence