Retrospective Evaluation of Control Measures for Contacts of Patient with Marburg Hemorrhagic Fever

Aura Timen

, Leslie D. Isken, Patricia Willemse, Franchette van den Berkmortel, Marion P.G. Koopmans, Danielle E.C. van Oudheusden, Chantal P. Bleeker-Rovers, Annemarie E. Brouwer, Richard P.T.M. Grol, Marlies E.J.L. Hulscher, and Jaap T. van Dissel

Author affiliations: Author affiliations: National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands (A. Timen, L.D. Isken, M.P.G. Koopmans); Elkerliek Hospital, Helmond, the Netherlands (P. Willemse); Atrium Medical Centre, Heerlen, the Netherlands (F. van den Berkmortel); Public Health Service Brabant-Zuidoost, Helmond (D.E.C. van Oudheusden); Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands (C.P. Bleeker-Rovers, R.P.T.M. Grol, M.E.J.L. Hulscher); Elisabeth Hospital, Tilburg, the Netherlands (A.E. Brouwer); Leiden University Medical Centre, Leiden, the Netherlands (J.T. van Dissel)

Abstract

After an imported case of Marburg hemorrhagic fever was reported in 2008 in the Netherlands, control measures to prevent transmission were implemented. To evaluate consequences of these measures, we administered a structured questionnaire to 130 contacts classified as either having high-risk or low-risk exposure to body fluids of the case-patient; 77 (59.2%) of 130 contacts responded. A total of 67 (87.0%) of 77 respondents agreed that temperature monitoring and reporting was necessary, significantly more often among high-risk than low-risk contacts (p<0.001). Strict compliance with daily temperature monitoring decreased from 80.5% (62/77) during week 1 to 66.2% (51/77) during week 3. Contacts expressed concern about development of Marburg hemorrhagic fever (58.4%, 45/77) and infecting a family member (40.2%, 31/77). High-risk contacts had significantly higher scores on psychological impact scales (p<0.001) during and after the monitoring period. Public health authorities should specifically address consequences of control measures on the daily life of contacts.

In July 2008 in the Netherlands, an imported case of Marburg hemorrhagic fever (MHF) (1) was diagnosed in a person after possible exposure in a bat cave in Uganda. MHF is caused by Marburg virus, which belongs to the family Filoviridae (2,3). The main route of transmission is by direct contact with blood or body fluids (4). The virus was discovered in 1967 during a laboratory outbreak in Marburg, Germany (5,6). Apart from this person, since the outbreak in Marburg, MHF has been diagnosed only once outside Africa (7).

Because of the high case-fatality rate and propensity for further transmission, a case of MHF is considered to be a public health emergency of international concern and requires prompt intervention to isolate the case-patient and trace and monitor all contacts for early signs of disease. Persons at risk for contracting MHF caused by prior or ongoing contact with an infected person were identified by means of a public health investigation conducted by public health services. The national outbreak response team issued guidelines for classification of these contacts and control measures, including restrictions on leaving the country.

Imported cases of hemorrhagic fever and other severe diseases with the potential to spread among health care workers and the general population have a small, yet realistic chance of occurring in the Western world, as was the situation with Ebola fever and Lassa fever (8–12). Outbreaks can also originate from other sources, as was the case with Ebola-Reston virus (13). Because there are no alternative interventions, such as vaccination or prophylactic treatment, to protect contacts from acquiring MHF, control measures are aimed at early identification of possible case-patients and isolating them from the rest of the population. However, we do not know how persons exposed to MHF respond when confronted with control measures. To date, the consequences of measures to control outbreaks (e.g., monitoring, quarantine) have only been partially investigated for diseases that are not comparable to MHF from the point of view of routes and risk of transmission, e.g., severe acute respiratory syndrome or influenza (14–17). Evidence is needed to determine the effectiveness of follow-up procedures for MHF contacts.

To evaluate the consequences and the psychological effect of control measures on contacts’ daily life, a retrospective cohort study (including serologic testing) was undertaken among 130 contacts of the person in the Netherlands in 2008 who acquired MHF. Contacts were categorized as high-risk or low-risk on the basis of their exposure history. We describe criteria to optimize the effect of control measures and provide proper care to contacts exposed to a person-to-person transmissible virus with the potential to cause severe disease.