The American Journal of Tropical Medicine and Hygiene

MORBID: Morbidity Operational Research for Bilharziasis Implementation Decisions (Pilot)

A pilot study to identify meaningful and measurable targets for detecting the control of schistosomiasis-related morbidity in Africa. The overall study is designed to answer the following primary evaluation questions:

  • What are the infection levels of Schistosoma mansoni and S. haematobium below which there is little, or no, detectable schistosomiasis-associated morbidity?
  • What are the optimal morbidity markers for S. mansoni and S. haematobium?
  • What are the optimal species-specific morbidity goals for which schistosomiasis control programs should be aiming?
Countries: Kenya | Malawi
Diseases: Schistosomiasis

Triple Drug Therapy (India)

To determine the frequency, type and severity of adverse events following triple-drug therapy (IVM+DEC+ALB, IDA) compared to the standard two-drug treatment (DEC+ALB, DA) in infected and uninfected individuals in a community.

To compare the efficacy of IDA vs. DA administered in communities for clearance of Mf and filarial antigenemia (Ag) in cohort and effectiveness (prevalence) in community settings. To assess the presence and intensity of filarial infection on the frequency and severity of adverse events. To compare community acceptance of MDA with IDA vs. DA.

Countries: India

Analysis of LF-Antibody Responses Following MDA in Kenya

To determine the current status of LF using a combination of seroepidemiological tools to determine prevalence of circulating filarial antigen (CFA) and antifilarial antibodies.

Preliminary study findings:

  • 2,976 individuals (age: 2 to 100 years) were tested for circulating filariail antigen using the immunochromatographic (ICT) test during daytime visits. Night-time blood samples to detect microfilariae (MF) were requested from those who tested positive via the ICT test.
  • Out of the 38 persons found to be positive for LF infection by ICT test, 33 provided a night-time blood sample for examination of MF. Overall, nine individuals were found to be MF positive, with the highest prevalence in Ndau Island.
  • The current study suggests that LF transmission may be absent in Taita-Taveta and Tana River counties in coastal Kenya and therefore transmission assessment surveys (TAS) should be considered with a view to stopping MDA. By contrast, evidence for ongoing transmission in Kwale, Kilifi and Lamu counties indicates the need for further MDA rounds in these counties.
  • Additionally, the study demonstrated the feasibility of conducting integrated serosurveillance of several infectious diseases of public health interest, as well as levels of seroprotection against vaccine preventable diseases. The findings of the current study underscore the added value of using multiplex antibody measurements to guide and monitor LF elimination efforts.
Countries: Kenya

Alternative approaches to coverage surveys (Uganda)

To compare coverage evaluation methods to identify a method that is statistically rigorous and feasible for programs. This study will focus on assessing MDA coverage for lymphatic filariasis by comparing the cost, time and feasibility of 3 different methods: the EPI approach (n=1768), LQAS design (n=95) and probability sampling alternatives (n=1768).

Primary Findings and Lessons Learned

Coverage surveys are an important tool for programs to evaluate their reporting systems and to determine whether effective MDA coverage has been achieved. However, for various reasons coverage surveys are seldom implemented.  Some key challenges are: perceived technical difficulty, lack of resources, and lack of standardized guidance on how to conduct coverage surveys.  This protocol seeks to address the 1st and 3rd points by comparing the feasibility of three different coverage survey methods (EPI approach, LQAS, and segmentation).     This study was completed in 3 districts in Burkina Faso.  All 3 districts found that their survey coverage was above the WHO target threshold (65% for LF).  Furthermore, in all 3 cases the survey coverage validated (or nearly validated) the reported coverage. Taken together this suggests that the Burkina Faso program is working well.   The feasibility results found all 3 methods to be very similar with regards to time, cost and perceived difficulty.  Because only the segmentation approach results in a probability sample, this method was recommended by the M&E Working Group and ultimately approved by the STAG.  Since the approval, significant work has been underway to create guidelines for conducting coverage surveys for preventive chemotherapy.  An excel tool was created to improve the usability of the tool and online learning modules are currently in the works.

Countries: Uganda

Alternative approaches to coverage surveys (Malawi)

Compare coverage evaluation methods to identify a method that is statistically rigorous and feasible for programs. This study will focus on assessing MDA coverage for lymphatic filariasis by comparing the cost, time and feasibility of the EPI approach (n=1768), LQAS design (n=95) and probability sampling alternatives (n=1768).

Primary Findings and Lessons Learned

Coverage surveys are an important tool for programs to evaluate their reporting systems and to determine whether effective MDA coverage has been achieved. However, for various reasons coverage surveys are seldom implemented.  Some key challenges are: perceived technical difficulty, lack of resources, and lack of standardized guidance on how to conduct coverage surveys.  This protocol seeks to address the 1st and 3rd points by comparing the feasibility of three different coverage survey methods (EPI approach, LQAS, and segmentation).     This study was completed in 3 districts in Burkina Faso.  All 3 districts found that their survey coverage was above the WHO target threshold (65% for LF).  Furthermore, in all 3 cases the survey coverage validated (or nearly validated) the reported coverage. Taken together this suggests that the Burkina Faso program is working well.   The feasibility results found all 3 methods to be very similar with regards to time, cost and perceived difficulty.  Because only the segmentation approach results in a probability sample, this method was recommended by the M&E Working Group and ultimately approved by the STAG.  Since the approval, significant work has been underway to create guidelines for conducting coverage surveys for preventive chemotherapy.  An excel tool was created to improve the usability of the tool and online learning modules are currently in the works.

Countries: Malawi

Understanding Lymphatic Filariasis Antigenemia and Antibody responses in Sentinel sites post LF transmission interruption (The Gambia)

Assess Wb123 antibody responses in communities where LF transmission was interrupted without MDA.

Countries: Gambia