Disease Surveillance for Malaria ELIMINATION

1. Disease Surveillance for MalariaELIMINATION Dr. Charles KM PALUKU WHO IST-ESA TEAM First Rwanda Malaria Forum 26-28 September 2012 | Serena Hotel | Kigali | Rwanda

2. Elimination? Prove it.

3. Outline • Key concept in Malaria Surveillance System • Key features of Surveillance System • Data Recording and Analysis • Core Surveillance Indicators in the Elimination Phase

4. Disease Surveillance for Malaria Control & EliminationWHO and RBM Operational Manuals http://www.who.int/malaria/surveillance_monitoring/operationalmanuals/en/

5. Surveillance definition Control programmes Elimination programmes That part of the programme designed for: identification, investigation and elimination of continuing transmission, prevention and cure of infections, and final substantiation of claimed elimination • Ongoing, systematic collection, analysis and interpretation of disease-specific data for use in planning, implementing and evaluating public health practice

6. Elimination PhaseKey concept in Malaria Surveillance System (1) • The aim of the elimination phase is to stop local transmission of malaria, in contrast to the control phase, in which the objective is to reduce the number of cases to low levels but not necessarily interrupt local transmission • The objective of a malaria surveillance system in the elimination phase is to detect all malaria infections, whether symptomatic or not, and ensure that they are radically cured so early that they do not generate secondary cases

7. Elimination PhaseKey concept in Malaria Surveillance System (2) • Although malaria may be focal in the elimination phase, surveillance systems must cover the entire country • Surveillance systems have to be of high standard - all suspected cases should be parasitologically tested and subjected to quality control. • All cases and foci should be fully investigated, records should be kept of all tests and investigations. • Certification of malaria elimination by WHO depends almost entirely on the quality of surveillance and its documentation.

8. Case Definition • Aperson in whom, regardless of the presence or absence of clinical symptoms, malaria parasites (including gametocytaemia only) have been confirmed by quality controlled laboratory diagnosis. • Light microscopy is the usual means and gold standard of identifying malaria infection during the elimination phase. • The species of Plasmodium should be identified on thin films and the parasite stages detected and described. • Even when rapid diagnostic tests are used for initial patient management, clinics should make a microscopy slide at the same time for subsequent confirmation of the diagnosis at a nearby reference laboratory.

9. Elimination PhaseKey features of Surveillance System (I) • Each confirmed case is immediately notified to district and central levels. • A full investigation of each case is undertaken, including additional blood sampling from the locality of origin of detected case • For each determine whether case is imported, locally acquired (introduced, indigenous, relapsed) or induced. • Each new focus of transmission is investigated, including an entomological investigation. • The focus is classified and its status is updated continuously. • Health facilities and districts monitor the extent of surveillance by village in high risk foci comparing the number of diagnostic tests done with the number expected.

10. Elimination PhaseKey features of Surveillance System (II) • Program managers at district level keep • Databases of malaria case investigation forms, foci investigation forms and a foci register with changes in status • Maps showing the distribution of cases by household, vector breeding places, possible sites of transmission and a range of geographical features. • The national reference laboratory reconfirms all positive test results and a sample of negative test results and organizes testing panels for laboratories participating in the quality assurance network. • A full set of documentation is kept at national level in preparation for certification of elimination.

11. Case Detection • Potential foci are initially identified using data reported by public and private sector health facilities (Passive Case Detection). • In areas where populations have limited access to facilities, or in particularly high risk areas, malaria control programs may search for cases in the community (Active Case Detection). • Passive case detection is generally the preferred method for detecting malaria cases while active case detection should only be used to fill gaps in the passive case detection system.

12. Passive Case Detection Common criteria include: • Patients with fever and no other obvious cause of fever (in areas of risk) • Patients with fever and history of travel to endemic areas (in all areas) Wider categories could include: • Patients with fever, malaise and chills; • Recipients of blood with increasing temperature, which was developed during the 3 months following a blood transfusion; • All febrile patients from active foci of malaria during the malaria season; • …...

13. Active Case Detection When is it done? • where passive surveillance in the public and private sector is considered inadequate • Particularly useful for population groups that are not likely to be covered by existing health services such as migrant workers or tribal populations. (Ex. monthly visits to miner's camps by a health team) • May involve taking a blood sample from those with a history of fever or may involved testing all persons in a targeted population (mass blood screening).

14. Field Investigation (I) • A field investigation should be undertaken for each confirmed case of malaria detected. • Its aims is to determine whether or not an infection was acquired locally and therefore whether or not there is ongoing local malaria transmission. • Investigate details of each confirmed case • Review details of cases reported previously from the same locality NB: If a locally acquired case is likely to establish a new focus, a complete focus investigation should be done together with the case investigation

15. Field Investigation (II) The field investigation team (parasitologist, epidemiologist and entomologist) will need to assemble and review the following information: • Malaria case investigation form. A case investigation form should be completed for all confirmed malaria cases. • Epidemiological data from previous cases in the same village, locality, or focus. • Additional data from active case detection

16. Case classification • Imported. from outside the country. • Local or "autochthonous" transmission • Introduced case - a case contracted locally from an imported case • Indigenous - a case contracted locally from any other category of case, including introduced cases • Relapsing - a case contracted locally before cessation of local transmission : • from hypnozoites of P. vivax or P.ovale • “recrudescences” of P. falciparum or P. malariaeoriginating from previously-undetected latent blood forms in which the primary clinical attack was suppressed or unrecognized • P. vivax and ovale infections with prolonged incubation period or latent infections in which the primary clinical attack was suppressed or unrecognized. • Induced. A congenital infection or a case induced by contamination with infected blood.

17. Focus Investigation and Classification Each malaria focus needs to be investigated and a malaria focus investigation form should be completed The focus investigation identifies : • Features of the location • rivers, rice growing areas, dams, ponds, forests, roads, altitude • households, the location of test and treatment sites • Breeding places • Populations most at risk • Vectors responsible for transmission and receptivity

18. Data Recording and Analysis • Case Detection A register should be kept at health facility level for each suspected case attending • Field Investigation. For each confirmed case of malaria a case investigation form should be completed • Focus Investigation. For each new focus identified a focus investigation form should be completed

19. Data Recording and Analysis District Level • The district/intermediate level malaria team should maintain the following databases: • Monthly reports of the number of patients examined malaria tests and number of confirmed cases • A register of malaria programme health structures and staff • Malaria case investigation forms including results of active case detection …continued

20. Data Recording and Analysis continued… • Foci investigation forms • Foci register with changes in status • Entomological database containing an inventory of Anopheles breeding sites including Anopheles species, vector density and bionomics, seasonality and maps of the area. • Vector control activity database • Other: reports, maps, database

21. Data Recording and Analysis National level • Databases kept at central level serve two purposes (i) to aid program management (ii) as a repository of information for certification of malaria free status. They should include • National malaria case register. • Malaria foci investigation. • National malaria fociregister. • National malaria laboratory quality assurance databases • Entomological surveillance database • Vector control activities database. . • Reports of activities of specially assigned mobile teams. • National malaria programme health structures and staff • Malaria surveillance reports and analysis sent by districts • National annual malaria surveillance reports and analysis • Others….

22. Core Surveillance Indicators in the Elimination Phase Impact • Number and incidence rate of confirmed malaria cases by classification status, by sex, age group, risk group (school children, migrant workers etc). • Malaria case investigation database • Number of foci by classification status - Malaria foci database

23. Core indicators (2) Quantity and quality of surveillance • Annual blood examination rate (ABER) by district, foci status, PCD and ACD. • Percentage of expected monthly reports received from health facilities and laboratories by sector (with details of number of patients tested for malaria and number positive). Target: 100%. • Percentage of confirmed cases fully investigated (including case investigation form, focus investigation form, and active case detection data). Target 100%. • Percentage of foci fully investigated (malaria focus investigation form completed including data on an entomological investigation) and registered (on register with maps of each focus). Target: 100%. • Time from first symptoms (fever) to first contact with the health system. Target: within 48 hours. • Time from first contact to testing. Target: within 24 hours. • Time from positive test result to start of treatment. Target: same day. • Time from positive test result to notification of the NMP. Target: same day.

24. Core indicators (3) Quantity and quality of surveillance (continued) 9. Percentage of malaria testing laboratories participating in external quality assurance system (send all positive slides and 10% of negatives for re-testing and complete the blind proficiency panel each year). Target: 100%. 10. Percentage of last 5 years with national annual malaria programme report. Target: 100%.

25. Take home messages • All points of diagnosis : public and private • Count cases AND count foci – investigate , classify and map them • Agree on who needs to be tested • Test consistently all who fulfil criteria • For each RDT take also a slide • Keep good records.