Monkeypox (Mpox)NCT07067723
Epidemiological and Clinical Characteristics of Human Mpox Outbreak in Equateur Province in the Democratic Republic of Congo (Part2)
An observational study of Monkeypox (Mpox), run by Osaka Metropolitan University at 1 site in Democratic Republic of the Congo.
Trial 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. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Monkeypox (Mpox)
- How many people
- 122 participants
- Where
- 1 siteDemocratic Republic of the Congo
- Study dates
- 1 Aug 2024to 31 Dec 2025
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
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.
Who may be able to join
- 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.
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Democratic Republic of the Congo1 site
Equateur Provincial Public Health Laboratory
Mbandaka, Équateur Province
About this study
Official title: Epidemiological and Clinical Characteristics of Human Mpox Outbreak in Equateur Province in the Democratic Republic of Congo (Part3)
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.
Read the detailed description
Mpox is caused by the monkeypox virus (MPXV), a member of the genus Orthopoxvirus (family Poxviridae). This virus is closely related to the variola virus, which causes smallpox. MPXV was first identified in 1958, and the first human case was reported in the Democratic Republic of the Congo (DRC) in 1970. It was presumed that the smallpox (vaccinia) vaccine would confer cross-protection against mpox. Following the global eradication of smallpox in 1980, mpox remained largely confined to limited regions in Central Africa-where zoonotic spillover from wild animal reservoirs constituted the primary route of transmission. Equateur Province is among the areas in the DRC with a notably high burden of reported mpox cases.
Over the past five decades, routine smallpox vaccination ceased worldwide, resulting in waning herd immunity against orthopoxviruses. During this period, mpox incidence rose markedly, with an estimated tenfold increase in global cases. Two principal genetic clades of MPXV have been identified: clade I (historically referred to as the Congo Basin clade) and clade II (the West African clade). In 2018, Nigeria experienced a resurgence of mpox, highlighting the virus's potential to emerge in previously controlled areas. Starting in 2022, clade II mpox circulated globally, especially among men who have sex with men (MSM), peaking in mid-2022 before declining to persistently lower levels by early 2023. Although clade II mpox typically exhibits a low case-fatality ratio (<1%), clade I has historically been associated with more severe disease and higher mortality. In 2023, the number of reported mpox cases continued to climb in the DRC, prompting the World Health Organization (WHO) to declare a Public Health Emergency of International Concern (PHEIC) in August 2024.
Recent surveillance indicates that sub-clade Ia MPXV is spreading in western DRC through multiple transmission modes, including contact with infected wild animals, household exposure, or sexual contact. By contrast, sub-clade Ib mpox in the eastern part of the country appears initially to spread via intimate or sexual contact between adults, followed by household transmission. Numerous environmental and social risk factors-including the consumption of rodent species, deforestation, climate change, civil unrest, population displacement, emerging MPXV variants, and weakened immunity-may be driving mpox incidence. Clade Ia mpox is currently affecting western parts of the DRC, yet the epidemiology remains poorly understood due to the limited number of laboratory-confirmed cases.
This study aims to better understand the dominant modes of transmission of Mpox in Equateur Province in DRC and to estimate the extent of transmission among contacts by determining the secondary infection rate for human-to-human transmission at an indicidual level and identifying factors associated with secondary infections. The findings will advance understanding of mpox transmission dynamics, ultimately informing more effective prevention and control strategies in endemic settings.
- Conditions
- Monkeypox (Mpox)
- Keywords
- contact tracing, transmission, outbreak investigation
- Medical subject headings
- Mpox, Monkeypox
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: through study completion, an average of 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2025
- Study start1 Aug 2024
- Primary completion31 Dec 2025 (estimated)
- Study completion31 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Monkeypox (Mpox)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 122 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Osaka Metropolitan University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yasutoshi KIDO, Osaka Metropolitan University
- Investigators
- Yasutoshi Kido, Professor, Principal investigator, Osaka Metropolitan University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07067723
- Sponsor's protocol ID
- N553/BN/PMMF/2024-2
- Status last verified
- Jul 2025
- First submitted
- 14 May 2025
- Last updated
- 16 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Epidemiological and Clinical Characteristics of Human Mpox Outbreak in Equateur Province in the Democratic Republic of Congo (Part3)
- ClinicalTrials.gov ID
- NCT07067723
- Acronym / sponsor ID
- N553/BN/PMMF/2024-2
- Conditions
- Monkeypox (Mpox)
- Keywords
- contact tracing, transmission, outbreak investigation
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 122 participants (estimated)
- Lead sponsor
- Osaka Metropolitan UniversityUniversity, hospital or other
- Study start
- 1 Aug 2024 (actual)
- Primary completion
- 31 Dec 2025 (estimated)
- Study completion
- 31 Dec 2025 (estimated)
- First posted
- 16 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Mpox is caused by the monkeypox virus (MPXV), a member of the genus Orthopoxvirus (family Poxviridae). This virus is closely related to the variola virus, which causes smallpox. MPXV was first identified in 1958, and the first human case was reported in the Democratic Republic of the Congo (DRC) in 1970. It was presumed that the smallpox (vaccinia) vaccine would confer cross-protection against mpox. Following the global eradication of smallpox in 1980, mpox remained largely confined to limited regions in Central Africa-where zoonotic spillover from wild animal reservoirs constituted the primary route of transmission. Equateur Province is among the areas in the DRC with a notably high burden of reported mpox cases.
Over the past five decades, routine smallpox vaccination ceased worldwide, resulting in waning herd immunity against orthopoxviruses. During this period, mpox incidence rose markedly, with an estimated tenfold increase in global cases. Two principal genetic clades of MPXV have been identified: clade I (historically referred to as the Congo Basin clade) and clade II (the West African clade). In 2018, Nigeria experienced a resurgence of mpox, highlighting the virus's potential to emerge in previously controlled areas. Starting in 2022, clade II mpox circulated globally, especially among men who have sex with men (MSM), peaking in mid-2022 before declining to persistently lower levels by early 2023. Although clade II mpox typically exhibits a low case-fatality ratio (<1%), clade I has historically been associated with more severe disease and higher mortality. In 2023, the number of reported mpox cases continued to climb in the DRC, prompting the World Health Organization (WHO) to declare a Public Health Emergency of International Concern (PHEIC) in August 2024.
Recent surveillance indicates that sub-clade Ia MPXV is spreading in western DRC through multiple transmission modes, including contact with infected wild animals, household exposure, or sexual contact. By contrast, sub-clade Ib mpox in the eastern part of the country appears initially to spread via intimate or sexual contact between adults, followed by household transmission. Numerous environmental and social risk factors-including the consumption of rodent species, deforestation, climate change, civil unrest, population displacement, emerging MPXV variants, and weakened immunity-may be driving mpox incidence. Clade Ia mpox is currently affecting western parts of the DRC, yet the epidemiology remains poorly understood due to the limited number of laboratory-confirmed cases.
This study aims to better understand the dominant modes of transmission of Mpox in Equateur Province in DRC and to estimate the extent of transmission among contacts by determining the secondary infection rate for human-to-human transmission at an indicidual level and identifying factors associated with secondary infections. The findings will advance understanding of mpox transmission dynamics, ultimately informing more effective prevention and control strategies in endemic settings.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- 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.
Key inclusion criteria (8 listed)
- 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.
- Presence of a vesicular or pustular eruption with deep-seated, firm pustules.
- 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.
- At least one molecular-based mpox diagnostic test confirming the diagnosis.
Key exclusion criteria (3 listed)
- Participants will be excluded from the study under the following conditions:
- Individuals who decline to provide consent for study participation will be excluded
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Transmission chain
Time frame: through study completion, average 4 weeks
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.
Incubation Period
Time frame: through study completion, an average 4 weeks
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.
Serial Interval
Time frame: through study completion, an average 4 weeks
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.
Secondary Attack Rate (SAR)
Time frame: through study completion, an average 4 weeks
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.
Effective Reproduction Number (Re)
Time frame: through study completion, an average of 2 years
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jul 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Yasutoshi Kido, Professor principal investigator
Osaka Metropolitan University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Monkeypox (Mpox), run by Osaka Metropolitan University at 1 site in Democratic Republic of the Congo.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 16 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Democratic Republic of the Congo. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Transmission chain (time frame: through study completion, average 4 weeks). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jul 2025.