Jean Jacques Muyembe-Tamfum

Clinical, Virologic, and Immunologic Follow-Up of Convalescent Ebola Hemorrhagic Fever Patients and Their Household Contacts, Kikwit, Democratic Republic of the Congo

A cohort of convalescent Ebola hemorrhagic fever (EHF) patients and their household contacts (HHCs) were studied prospectively to determine if convalescent body fluids contain Ebola virus and if secondary transmission occurs during convalescence. Twenty-nine EHF convalescents and 152 HHCs were monitored for up to 21 months. Blood specimens were obtained and symptom information was collected from convalescents and their HHCs; other body fluid specimens were also obtained from convalescents. Arthralgias and myalgia were reported significantly more often by convalescents than HHCs. Evidence of Ebola virus was detected by reverse transcription-polymerase chain reaction in semen specimens up to 91 days after disease onset; however, these and all other non-blood body fluids tested negative by virus isolation. Among 81 initially antibody negative HHCs, none became antibody positive. Blood specimens of 5 HHCs not identified as EHF patients were initially antibody positive. No direct evidence of convalescent-to-HHC transmission of EHF was found, although the semen of convalescents may be infectious. The existence of initially antibody-positive HHCs suggests that mild cases of Ebola virus infection occurred and that the full extent of the EHF epidemic was probably underestimated.

Risk Factors for Marburg Hemorrhagic Fever, Democratic Republic of the Congo

We conducted two antibody surveys to assess risk factors for Marburg hemorrhagic fever in an area of confirmed Marburg virus transmission in the Democratic Republic of the Congo. Questionnaires were administered and serum samples tested for Marburg-specific antibodies by enzyme-linked immunosorbent assay. Fifteen (2%) of 912 participants in a general village cross-sectional antibody survey were positive for Marburg immunoglobulin G antibody. Thirteen (87%) of these 15 were men who worked in the local gold mines. Working as a miner (odds ratio [OR] 13.9, 95% confidence interval [CI] 3.1 to 62.1) and receiving injections (OR 7.4, 95% CI 1.6 to 33.2) were associated with a positive antibody result. All 103 participants in a targeted antibody survey of healthcare workers were antibody negative. Primary transmission of Marburg virus to humans likely occurred via exposure to a still unidentified reservoir in the local mines. Secondary transmission appears to be less common with Marburg virus than with Ebola virus, the other known filovirus.

Ebola between outbreaks: intensified Ebola hemorrhagic fever surveillance in the Democratic Republic of the Congo, 1981-1985.

Surveillance for Ebola hemorrhagic fever was conducted in the Democratic Republic of the Congo from 1981 to 1985 to estimate the incidence of human infection. Persons who met the criteria of one of three different case definitions were clinically evaluated, and blood was obtained for antibody confirmation by IFA. Contacts of each case and 4 age- and sex-matched controls were also clinically examined and tested for immunofluorescent antibody. Twenty-one cases of Ebola infection (persons with an antibody titer of > or = 1:64, or lower if they fit the clinical case definition) were identified, with a maximum 1-year incidence of 9 and a case fatality rate of 43%. Cases occurred throughout the year, but most (48%) occurred early in the rainy season. Fifteen percent of contacts had antibody titers > or =1:64 to Ebola virus, compared with 1% of controls (P < .0001). Results suggest that Ebola virus periodically emerges from nature to infect humans, that person-to-person transmission is relatively limited, and that amplification to large epidemics is unusual.

Short communication: A cluster of Marburg virus disease involving an infant*

A noteworthy cluster of six cases of Marburg haemorrhagic fever (MHF) was identified in the Democratic Republic of Congo. One of the cases is the first infant Marburg fever patient ever documented. Three of six cases presented surprisingly mild symptoms. The results of epidemiological and virological investigations are compatible with person‐to‐person transmission through body fluids and with mother‐to‐child transmission while nurturing. The findings show that mild cases of MHF have to be expected during an outbreak and point out the difficulty to base patient management decisions on clinical case definitions alone.

Emergence of vaccine-derived polioviruses, Democratic Republic of Congo, 2004-2011.

TOC summary: These viruses can emerge independently where immunity to poliovirus is inadequate.

Genomic Variability of Monkeypox Virus among Humans, Democratic Republic of the Congo

Health authorities should be vigilant for this rapidly evolving virus.

Ebola Virus Neutralizing Antibodies Detectable in Survivors of theYambuku, Zaire Outbreak 40 Years after Infection

Duration of immunity against Ebola virus among survivors remains unclear. We assessed serological immune profiles and retention of Ebola virus neutralizing antibodies in 14 survivors of the 1976 Yambuku outbreak 40 years postinfection, providing the longest documentation of such measures reported.

Phylogeny of Imported and Reestablished Wild Polioviruses in the Democratic Republic of the Congo From 2006 to 2011

BACKGROUNDnThe last case of polio associated with wild poliovirus (WPV) indigenous to the Democratic Republic of the Congo (DRC) was reported in 2001, marking a major milestone toward polio eradication in Africa. However, during 2006-2011, outbreaks associated with WPV type 1 (WPV1) were widespread in the DRC, with >250 reported cases.nnnMETHODSnWPV1 isolates obtained from patients with acute flaccid paralysis (AFP) were compared by nucleotide sequencing of the VP1 capsid region (906 nucleotides). VP1 sequence relationships among isolates from the DRC and other countries were visualized in phylogenetic trees, and isolates representing distinct lineage groups were mapped.nnnRESULTSnPhylogenetic analysis indicated that WPV1 was imported twice in 2004-2005 and once in approximately 2006 from Uttar Pradesh, India (a major reservoir of endemicity for WPV1 and WPV3 until 2010-2011), into Angola. WPV1 from the first importation spread to the DRC in 2006, sparking a series of outbreaks that continued into 2011. WPV1 from the second importation was widely disseminated in the DRC and spread to the Congo in 2010-2011. VP1 sequence relationships revealed frequent transmission of WPV1 across the borders of Angola, the DRC, and the Congo. Long branches on the phylogenetic tree signaled prolonged gaps in AFP surveillance and a likely underreporting of polio cases.nnnCONCLUSIONSnThe reestablishment of widespread and protracted WPV1 transmission in the DRC and Angola following long-range importations highlights the continuing risks of WPV spread until global eradication is achieved, and it further underscores the need for all countries to maintain high levels of poliovirus vaccine coverage and sensitive surveillance to protect their polio-free status.

Predictors of measles vaccination coverage among children 6–59 months of age in the Democratic Republic of the Congo

Highlights • DRC’s overall measles vaccination coverage level of 70% is too low to halt the spread of measles.• Socioeconomic variables and residence are associated with vaccination coverage disparities.• Vaccination coverage and data quality are linked, and as such, dated records must be increased.

Multifunctional Pan-ebolavirus Antibody Recognizes a Site of Broad Vulnerability on the Ebolavirus Glycoprotein

SUMMARY Ebolaviruses cause severe disease in humans, and identification of monoclonal antibodies (mAbs) that are effective against multiple ebolaviruses are important for therapeutics development. Here we describe a distinct class of broadly neutralizing human mAbs with protective capacity against three ebolaviruses infectious for humans: Ebola (EBOV), Sudan (SUDV), and Bundibugyo (BDBV) viruses. We isolated mAbs from human survivors of ebolavirus disease and identified a potent mAb, EBOV‐520, which bound to an epitope in the glycoprotein (GP) base region. EBOV‐520 efficiently neutralized EBOV, BDBV, and SUDV and also showed protective capacity in relevant animal models of these infections. EBOV‐520 mediated protection principally by direct virus neutralization and exhibited multifunctional properties. This study identified a potent naturally occurring mAb and defined key features of the human antibody response that may contribute to broad protection. This multifunctional mAb and related clones are promising candidates for development as broadly protective pan‐ebolavirus therapeutic molecules. Graphical Abstract Figure. No caption available. HighlightsBroad human antibody recognizes a quaternary site of vulnerability on ebolavirus GPThe antibody possesses pan‐ebolavirus neutralizing and protective capacityThe antibody mediates protection principally by direct virus neutralizationThe antibody uses several mechanisms for contributing to broad immunity &NA; Gilchuk et al. isolated and characterized new broadly neutralizing human monoclonal antibodies active against all three clinically relevant ebolaviruses. Some potent antibodies bind to the glycoprotein base region, act principally by direct virus neutralization, and exploit several mechanisms for contributing to pan‐ebolavirus protective immunity.