Investigation of Crimean-Congo hemorrhagic fever virus transmission from patients to relatives: a prospective contact tracing study.

We investigated the possibility of transmission of Crimean-Congo hemorrhagic fever (CCHF) virus through respiratory and physical contact. In this prospective study, we traced 116 close relatives of confirmed CCHF cases who were in close contact with the patients during the acute phase of the infection and evaluated the type of contact between patients and their relatives. These relatives were followed for clinical signs or symptoms indicative of CCHF disease, blood samples of those with and without clinical signs were analyzed for CCHF virus immunoglobulin M and G (IgM and IgG, respectively) by enzyme-linked immunosorbent assay. No close relatives developed any signs or symptoms of CCHF and were negative for CCHF virus IgM and IgG. The results suggest that CCHF virus is not easily transmitted from person to person through respiratory or physical contact.

Recommended precaution procedures protect healthcare workers from Crimean-Congo hemorrhagic fever virus.

OBJECTIVES: The Crimean-Congo hemorrhagic fever (CCHF) virus can spread from person to person and may cause nosocomial outbreaks among healthcare workers (HCWs). The US Centers for Disease Control and Prevention have recommended the use of personal protective equipment (PPE). We investigated the compliance of HCWs with PPE usage during the follow-up of patients, and also the number of risky contacts that occurred between patients and HCWs. We also aimed to determine the seroprevalence of CCHF virus in HCWs. METHODS: This study was conducted at Cumhuriyet University Education and Research Hospital, a medical center located in a highly endemic area for CCHF where a total of 1284 confirmed CCHF patients were followed-up between 2002 and 2012. All HCWs who were at risk of CCHF virus contact and infection were included in the study. The compliance of the HCWs with PPE usage and the number of contacts that had occurred were recorded. HCW serum samples were analyzed for CCHF virus IgM and IgG by ELISA. RESULTS: The total rates of PPE usage were 93.7% for gowns, 77.4% for gloves, and 38.9% for masks; the highest compliance was detected in the infectious diseases ward: 100%, 88.6%, and 82.9%, respectively. A total of four HCWs had a history of high-risk contact with contaminated material (two percutaneous exposure and two mucosal contacts), but the number of low-risk contacts was quite high. The total seroprevalence rate was only 0.53%. CONCLUSIONS: Although the HCWs at our medical center have dealt with an extremely high number of CCHF patients during the last decade, the total seropositivity for CCHFV IgG was only 0.53%. This low rate may be a result of high compliance with PPE usage and also regular education programs.

Serum levels of Mannan-binding lectin in patients with Crimean-Congo hemorrhagic fever.

OBJECTIVE: Mannan-binding lectin (MBL) is a central component of the innate immune response. Genetic variations in the MBL gene that reduce circulating levels and alter functional properties of the MBL are associated with susceptibility for many infectious diseases. Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease caused by an arbovirus in the family Bunyaviridae. We have investigated serum MBL levels in CCHF patients and a possible association between circulating MBL concentrations and the severity of CCHF. MATERIALS AND METHODS: Forty-seven patients found to have CCHF in Cumhuriyet University Hospital and 29 healthy controls were recruited for this study. There were no differences in terms of age and sex between the patients and the healthy controls (p = 0.64 and p = 0.484, respectively). This study was conducted between July 1 and August 31, 2007, in Cumhuriyet University Hospital in Sivas, a city located in the central Anatolian region of Turkey. Patients with CCHF were matched with healthy controls, and serum MBL levels were measured. RESULTS: The median serum MBL level was significantly lower in the patient group than in the healthy control group (48.0 ng/mL [inter-quartile range (QR) 30.4-128.0] and 212.0 ng/mL [IQR: 115.8-524.0], respectively; p < 0.001). No significant difference was found between serum MBL levels in CCHF patients with severe and nonsevere form of the disease (p = 0.167). CONCLUSION: MBL levels were significantly lower in patients with CCHF than in healthy controls. There was no meaningful correlation between the serum MBL level and severity of CCHF disease. Low serum MBL level may be associated with the high consumption of MBL in CCHF infection and/or MBL gene polymorphism.