Epidemiological and Clinical Characteristics of Human Mpox Outbreak in Equateur Province in the Democratic Republic of Congo (Part2)

NCT07067723 | Enrolling By Invitation

• 1 other identifier: N553/BN/PMMF/2024-2
• Study Type: observational
• Target: 122
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this observational study is

• to better understand the dominant modes of transmission
• to estimate the extent of transmission among contacts by determining the secondary infection rate for human-to-human transmission at an individual level and identifying factors associated with secondary infections.
• to determine the proportion of asymptomatic or pauci-symptomatic infections.
• to characterize the incubation period of mpox and the duration of infectiousness, including reproduction numbers.
• to assess serological responses following confirmed infection.

Conditions

Monkeypox (Mpox)

Keywords

contact tracing; transmission; outbreak investigation

Outcome Measures

Primary Outcomes (5)

• Transmission chain

  Definition: The sequence and structure of mpox transmission events within households and beyond, including identification of primary and secondary cases. To map transmission dynamics and determine how mpox spreads within close-contact settings. Detailed epidemiological tracing and genetic sequencing to confirm transmission links.

  through study completion, average 4 weeks

• Incubation Period

  Definition: The time between exposure to the mpox virus and the onset of symptoms. To estimate the range and median incubation period of mpox based on detailed exposure history and symptom onset data. Exposure dates and symptom onset dates from confirmed cases and their contacts.

  through study completion, an average 4 weeks

• Serial Interval

  Definition: The time between the onset of symptoms in a primary case and the onset of symptoms in a secondary case they infect. To estimate the serial interval of mpox, which is critical for understanding transmission timelines and epidemic control. Symptom onset dates for linked cases within households and other close-contact settings.

  through study completion, an average 4 weeks

• Secondary Attack Rate (SAR)

  Definition: The proportion of susceptible household contacts who develop mpox after exposure to a confirmed case. To quantify transmission efficiency within households and identify risk factors influencing SAR.

  through study completion, an average 4 weeks

• Effective Reproduction Number (Re)

  Definition: The average number of secondary cases generated by a single infectious individual in the current population. To estimate Re during the study period, which reflects real-time transmission potential under existing control measures. Based on observed transmission chains and SAR data.

  through study completion, an average of 2 years

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

This study targets laboratory-confirmed cases of mpox and their contacts, defined based on exposure to the primary case within the household or in external settings (e.g., workplaces, social interactions). This study targets patients reported as suspected mpox cases (all ages, both sexes) to the Health District Central Office in the selected sites. The study population is designed to minimize selection bias related to health-seeking behavior. Cases are defined as Individuals who reported to local health agents with symptoms consistent with mpox and subsequently tested positive for mpox through a molecular-based diagnostic test. Contacts are defined as individuals identified as having close contact with a laboratory-confirmed mpox case. Close contact includes but is not limited to the following type of contact.

You may qualify if:

• Provision of informed consent:
• Proxy-assisted informed consent is allowed under safety considerations. Following oral consent, the investigator will document this on the informed consent form as a witness.
• Fulfillment of the current mpox clinical case definition in the DRC, which includes:
• Presence of a vesicular or pustular eruption with deep-seated, firm pustules.
• At least one of the following symptoms:
• Fever preceding the eruption. Lymphadenopathy (inguinal, axillary, or cervical). Presence of pustules or crusts on the palms of the hands or soles of the feet.
• Laboratory confirmation:
• At least one molecular-based mpox diagnostic test confirming the diagnosis.

You may not qualify if:

• Participants will be excluded from the study under the following conditions:
• Refusal to participate in the study:
• Individuals who decline to provide consent for study participation will be excluded

Sponsors & Collaborators

• Osaka Metropolitan University: lead

Study Sites (1)

Equateur Provincial Public Health Laboratory

Mbandaka, Équateur Province, Democratic Republic of the Congo

Location

Biospecimen

Retention: SAMPLES WITH DNA

Skin lesion and oral mucosa swab sample

MeSH Terms

Conditions

Mpox, Monkeypox

Condition Hierarchy (Ancestors)

Poxviridae Infections; DNA Virus Infections; Virus Diseases; Infections; Primate Diseases; Animal Diseases; Rodent Diseases

Study Officials

• Yasutoshi Kido, Professor

  Osaka Metropolitan University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: May 14, 2025
• First Posted: July 16, 2025
• Study Start: August 1, 2024
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: July 16, 2025

Record last verified: 2025-07

Locations

DE (1)