Lack of vehicles, poorly maintained low-quality vehicles, and lack of fuel posed challenges for case investigators to cover daily alerts of sickness and death in the 2 districts.

Poor-quality unpaved roads, riverine areas, and the rainy season from May to September further complicated response efforts.

GOAL collaborated with DFID, NERC, WHO, and other NGOs to provide high-quality off-road vehicles, along with fuel, drivers, and other logistical support.

GOAL rented 12 vehicles in Port Loko and Kambia, and advocated with WHO and NERC to provide additional vehicles.

GOAL requested authorization and funding from DFID for Catholic Relief Services in Port Loko and GOAL in Kambia to fuel the additional vehicles.

GOAL advocated and helped facilitate the acquisition of boats from the Republic of Sierra Leone Armed Forces to facilitate access to riverine areas in Kambia.

Deficiencies in telecommunications infrastructure made it difficult for communities to raise sickness and death alerts, particularly in rural areas.

Case investigators could not reliably locate alerts and often failed to communicate important information due to unspecific reported locations, lack of phone credit, or unreliable network coverage.

GOAL distributed cellular phones, phone credit, and satellite phones to case investigators and their coordinators in the DHMT and DERC.

GOAL provided closed user groups to all case investigation teams and selected individuals in the DERC, enabling free unlimited calling between case investigators, their supervisors, and epidemiology teams in WHO and CDC.

Mismanagement of investigation materials posed a challenge to locating specific information, tracking efforts, and building case histories.

Discrepancies occurred at the field and district levels, and no formal filing mechanism existed for completed case investigation forms.

Inconsistency in naming conventions, spelling, and characterization of residence made matching documents difficult.

GOAL developed standard operating procedures in collaboration with all surveillance stakeholders.

Standard operating procedures ensured that case investigation forms were collected, stored, and organized in a retrievable manner.

GOAL hired data managers in both the Port Loko and Kambia DERC to file and immediately digitize this information in real time.

WHO established an after-action review in Port Loko in collaboration with GOAL, CDC, and the DHMT to review case investigation information and data at the end of each day.

Case investigators were unable to eat during their long work day due to dangers of purchasing food from high-risk communities, stigma from communities who feared them, a lack of personal funds, and insufficient time.

GOAL immediately provided daily take-away breakfast and lunch to all case investigators.

Case investigators received hand sanitizer and personal protective equipment to help prevent EVD infection, and rain gear allowed for easier movement of personnel during the rainy season.

A lack of community trust in response staff and enormous stigma resulted in difficulties conducting case investigations, lack of truthful information, and sometimes violence.

Case investigators rarely returned to the same communities each day and generally did not work in their own communities.

GOAL assigned a dedicated team for each of Port Loko's and Kambia's chiefdoms to ensure familiarity and consistency.

To the extent possible, case investigators were assigned to work in their chiefdom of origin.

A lack of trust in facility-based health care and fear of nosocomial infections drove many to seek health care from traditional healers.

Despite the fact that traditional healers were legally banned from practicing and required to report cases of illness, many people disregarded the bylaws despite fears of punitive measures.

Cases of sickness and death went unreported, and traditional healers fueled new EVD clusters when they contracted the disease from their patients.

DERC stakeholders, including GOAL, attempted to formally involve traditional healers as public health agents in the EVD response. However, due to the illegality of their work under the national bylaws, there was strong political hesitation to permit activity that appeared to legitimize the trade. As such, further efforts to include traditional healers were not pursued.

In Port Loko, GOAL became the lead operational agency and coordinator of the surveillance pillar. However, in Kambia, WHO continued leading surveillance, directing operational activities, and overseeing logistical needs despite not controlling operational resources. Crucial operational adjustments in Port Loko were therefore not easily implemented in Kambia.

No single organization was identified as the lead agency for case investigators, and therefore no single point of advocacy existed to resolve their needs, complicating the resolution of problems.

Leadership challenges in Kambia were addressed to some degree through relationship building and regular coordination with technical leads and DERC management.

GOAL, WHO, and CDC developed an active surveillance strategy in Port Loko to address the high proportion of EVD cases identified post-mortem or with no known source case.

The lack of sufficient case investigators and the work fatigue that resulted were among the biggest challenges facing case investigators.

Funding constraints and a perceived lack of need at the NERC resulted in a national directive that prevented hiring new surveillance staff.

GOAL advocated with DFID and NERC to bring in additional human resources.

The DHMT, GOAL, WHO, and CDC trained the new case investigators.

Mentorship in the field reinforced the training.

A rotation system was implemented to provide time off to address surveillance efficiency, quality, and case investigator work fatigue.

Case investigators averaged more than a month of missed pay per person and could sometimes not afford to buy food or pay rent.

At the national level, case investigators were sometimes incorrectly relegated to lower pay categories and clerical errors resulted in their removal from payroll.

Threats of strikes were frequent and morale was extremely low.

Resolving case investigator salary issues was a protracted and complicated process.

Initially, NERC paid all case investigators, with funding from the World Bank.

Ultimately, GOAL secured DFID funding and NERC permission to pay all case investigators directly in both districts beginning in July 2015.

Many of the 11 vertical pillars of operation at DERCs performed complementary work.

Horizontal integration and cooperation between pillars was profoundly challenging, which often resulted in a lack of effective cooperation between them.

Meetings were established to create horizontal linkages between the pillars in Port Loko in January 2015 and in Kambia in April 2015.

GOAL attempted to reinforce horizontal communication by developing an EVD response framework, which was not fully realized because it was developed late in the response.