10.24265/horizmed.2024.v24n2.11
Brief Communication
Epidemiological
and clinical characteristics of mpox: a retrospective study in Lima, Peru
Fernando Manuel
Reaño Tovar 1, 0000-0001-9338-7408
Alejandra Bendezú
Chacaltana 2, 0000-0003-2967-4474
1Hospital Nacional
Guillermo Almenara Irigoyen.
Lima, Peru.
2Universidad Nacional
Mayor de San Marcos, School of Human Medicine, Departamento de Ciencia Dinámicas (Department of Evolving
Sciences). Lima, Peru.
a. Internist
b. Master’s degree in Medicine.
*Corresponding author.
ABSTRACT
The World Health Organization (WHO) began to receive
reports of mpox cases from non-endemic countries in 2022. In Peru, the number of cases increased
to the point where it ranked among the top 10 countries
in the world with the most
confirmed cases. The objective of this study was to determine the clinical and epidemiological characteristics of patients with a confirmed diagnosis of mpox treated
at a hospital in Lima from July to December
2022. A total of 124 cases were confirmed with molecular testing. The
mean age was 34 years. The vast majority of reported mpox cases were among
males, men who have sex with men, homosexuals and people with HIV. Moreover, the majority of people with HIV were receiving antiretroviral therapy at the time of diagnosis. Exanthem rash prevailed as a clinical
manifestation, followed by fever, headache and chills. The most common skin lesion was crust/scab (83.06 %) and most patients (98.39 %) did not require
hospitalization. No deaths were reported in this study. It is necessary
to educate the population in preventive actions, especially aimed at the most affected individuals. Additionally,
eliminating stigmas will contribute to its early detection and control
of the disease in future outbreaks.
Keywords: Mpox; Exanthema; Peru. (Source:
MeSH NLM)
INTRODUCTION
The first human case of mpox was detected in 1970 in the Democratic Republic of the Congo, with
subsequent cases reported across other African countries. The first case
outside of Africa was recorded in the United States in 2003 and was related to
contact with infected prairie dogs. While the exact reservoir of the virus
remains unidentified, it has been isolated in animals such as squirrels, rats,
dormice and primates, among others (1). Since 2017, there has been a
significant increase in cases in both endemic and non-endemic countries.
Mpox is a reemerging zoonotic disease that can be transmitted from animals to humans. It is caused
by a virus of the Orthopoxvirus genus in the Poxviridae family. Although
generally self-limiting, with most cases resolving in two to four
weeks, mpox can cause severe illness (2). Transmission occurs through close
or intimate contact
with an infected person or animal, or with virus-contaminated materials such as
blood, body fluids or respiratory droplets (2).
The incubation period ranges from 5 to 21 days. Common
signs and symptoms include fever, headache, myalgia, fatigue, painful
exanthem rash and lymphadenopathy, with potential
for various complications.
In May 2022, the WHO began to receive reports of cases
occurring in non-endemic countries across Europe (3).
In Peru, the first case of mpox was reported on June 26, 2022; by
July 15, the number of cases had risen to 64 (4), and by November 2, a total
of 3,110 confirmed cases had been recorded. Globally, Peru followed the United States,
Brazil and Colombia, which had 28,651, 9,260 and 3,523 cases,
respectively. As a result, Peru ranked among the top 10 countries in the world
with the most confirmed cases (5).
At the Hospital Nacional Guillermo Almenara Irigoyen,
patients suspected of having mpox were directed to a differentiated triage
area, specifically designated for diagnosis and medical treatment.
THE STUDY
A descriptive, observational and retrospective study was
conducted to determine the clinical and epidemiological characteristics of
patients with a confirmed diagnosis of mpox treated at the Hospital
Nacional Guillermo Almenara Irigoyen in Lima. A total of 210
patients with suspected mpox, all registered under the ICD-10 code B04, were
observed between July and December 2022; each patient was evaluated in the differentiated triage area. Molecular testing for mpox
deoxyribonucleic acid (DNA) was performed at the Instituto Nacional de Salud (INS - National
Institute of Health), resulting in 124 positive cases.
Data were sourced from digital medical records and
epidemiological data sheets, accessible only to the researcher. Patient
identification was maintained under strict confidentiality. The database was
compiled using the patient’s initials and national identity card (DNI) number.
The variables were extracted and analyzed in Excel to calculate the respective
frequencies, which were documented according to the Ficha de Investigación Clínica Epidemiológica de la Viruela del Mono (Viruela Símica) [Monkeypox Clinical
and Epidemiological Research Data Sheet], considering
its three versions (4-7), as well as additional information
from the digital medical records.
As for the findings, among the 124 positive cases, 122 were
Peruvian (98.39 %), while two were Venezuelan.
The youngest patient was 19 years old and the oldest 54;75.81 % of the
patients were between 21 and 40 years old,
with a mean age of 34 years. There
were two female patients (1.61 %) and 122 male patients (98.39 %). The most common
sexual orientation was homosexual, reported by 55 patients (44.35 %), followed
by heterosexual, with 40 patients (32.26 %). Regarding sexual risk behavior,
men who have sex with men (MSM) accounted for 61.29 %. No cases of transgender individuals or
sex workers were reported. Out of the 124 patients who tested positive, 71 had a history of human
immunodeficiency virus (HIV), accounting for 57.26 % of the total; among these, 58 were receiving antiretroviral therapy
(ART) (81.69 %). Syphilis was also noted as a medical history
in 12 patients (9.68 %). In terms of demographic distribution, 68 patients reported residing in the districts of San
Juan de Lurigancho, Lima Cercado and Ate (54.84 %) (Table
1).
Table 1. Demographic characteristics of patients with mpox
|
Characteristics |
Total (N=124) |
|
Mean age in years (range) |
34 (19-54) |
|
Age in years by decades |
|
|
≤ 20 |
2 (1.61) |
|
21-30 |
45 (36.29) |
|
31-40 |
49 (39.52) |
|
41-50 |
25 (20.16) |
|
≥ 51 |
3 (2.42) |
|
Nationality |
|
|
Peruvian |
122 (98.39) |
|
Foreign |
2 (1.61) |
|
Gender |
|
|
Male |
122 (98.39) |
|
Female |
2 (1.61) |
|
Sexual orientation |
|
|
Homosexual |
55 (44.35) |
|
Heterosexual |
40 (32.26) |
|
Bisexual |
21 (16.94) |
|
No information available |
8 (6.45) |
|
MSM |
|
|
Yes |
76 (61.29) |
|
No |
48 (38.71) |
|
HIV |
|
|
Positive |
71 (57.26) |
|
Negative |
43 (34.68) |
|
Unknown |
10 (8.06) |
|
ART for HIV-positive individuals |
|
|
Yes |
58 (81.69) |
|
No |
13 (18.31) |
|
History of syphilis |
|
|
Yes |
12 (9.68) |
|
No |
112 (90.32) |
|
District of residence |
|
|
San Juan de Lurigancho |
34 (27.42) |
|
Lima Cercado |
22 (17.74) |
|
Ate |
12 (9.68) |
|
San Martín de Porres |
8 (6.45) |
|
El Agustino |
7 (5.65) |
|
Independencia |
6 (4.84) |
|
Santa Anita |
6 (4.84) |
|
Rímac |
5 (4.03) |
|
San Luis |
4 (3.23) |
|
Breña |
3 (2.42) |
|
Surquillo |
3 (2.42) |
|
La Victoria |
3 (2.42) |
|
Surco |
2 (1.61) |
|
Lurigancho |
2 (1.61) |
|
San Miguel |
1 (0.81) |
|
Chorrillos |
1 (0.81) |
|
San Borja |
1 (0.81) |
|
San Juan de Miraflores |
1 (0.81) |
|
Callao |
1 (0.81) |
|
Carabayllo |
1 (0.81) |
|
Los Olivos |
1 (0.81) |
Risk behavior data was recorded
for 71 patients. Of these, 30 were categorized as having “no risk,” 18 had “engaged in sexual relations
with a stranger or multiple partners,” and five had “contact with individuals who developed
exanthem rash or skin lesions.”
Regarding the clinical characteristics, 43.55 % received a final diagnosis four to six days after symptom
onset. The most common symptoms were fever (66.13 %), headache (50.81 %) and chills (45.97 %). Less frequent
symptoms included myalgia
28.23 %), back pain and asthenia (both at
20.16 %). The most frequent clinical sign was generalized polymorphic exanthem
rash (87.10 %). Lymphadenopathy, proctitis, diarrhea and pruritus were less common (Table 2).
Samples were taken from active skin lesions (vesicles, pustules)
in 123 patients,
while one sample
was taken from a patient during crusting/scabbing. A total of 98.4 % of patients did not require
hospitalization; only two were admitted (Table 2).
Table 2. Clinical characteristics of patients with mpox
|
Characteristics |
Total (N =
124) |
|
Onset of symptoms to diagnosis (in days) |
|
|
≤ 3 |
10 (8.06) |
|
4-6 |
54 (43.55) |
|
7-9 |
35 (28.23) |
|
≥ 10 |
25 (20.16) |
|
Fever |
|
|
Yes |
82 (66.13) |
|
No |
42 (33.87) |
|
Headache |
|
|
Yes |
63 (50.81) |
|
No |
61 (49.19) |
|
Chills |
|
|
Yes |
57 (45.97) |
|
No |
67 (54.03) |
|
Myalgia |
|
|
Yes |
35 (28.23) |
|
No |
89 (71.77) |
|
Asthenia |
|
|
Yes |
25 (20.16) |
|
No |
99 (79.84) |
|
Back pain |
|
|
Yes |
25 (20.16) |
|
No |
99 (79.84) |
|
Lymphadenopathy |
|
|
Localized |
19 (15.32) |
|
Generalized |
9 (7.26) |
|
No |
96 (77.42) |
|
Proctitis |
|
|
Yes |
6 (4.84) |
|
No |
118 (95.16) |
|
Diarrhea |
|
|
Yes |
2 (1.61) |
|
No |
122 (98.39) |
|
Pruritus |
|
|
Yes |
1 (0.81) |
|
No |
123 (9.19) |
|
Distribution of exanthem rash |
|
|
Localized |
15 (12.10) |
|
Generalized |
108 (87.10) |
|
Not registered |
1 (0.81) |
|
Type of exanthem rash |
|
|
Polymorphic |
70 (56.45) |
|
Monomorphic |
52 (41.94) |
|
Not registered |
2 (1.61) |
|
Hospitalization |
|
|
Yes |
2 (1.61) |
|
No |
122 (98.39) |
|
Type of sample |
|
|
Skin lesion swab |
123 (99.19) |
|
Sphacelated skin or crust/scab |
1 (0.81) |
|
Oropharyngeal swab |
0 (0.00) |
The types of skin lesions identified at the time of sampling
are presented in Table 3.
Table 3. Types of skin lesions
|
Lesion |
n% |
|
Crust/scab |
103
(83.06) |
|
Pustule |
66 (53.22) |
|
Papule |
15 (12.09) |
|
Vesicle |
3 (2.41) |
|
Macule |
2 (1.61) |
|
Not recorded/not specified |
21 (16.93) |
DISCUSSION
In Peru, according to Epidemiological Alert 014-2022, a
confirmed case of mpox is defined as a person who meets the criteria for a
probable case, with the presence of the virus confirmed by laboratory results
through molecular testing (8). All cases considered in this study adhere to such
definition.
Our study included
patients from various
districts of Lima. Among them,
98.39 % were in good general condition and did not require hospitalization;
however, no data were available
regarding their complications or evolution. The studies conducted
by Benites-Zapata et al. (9) and León-Figueroa et al. (10) in 2022 indicated that male and younger patients were the
most affected, which aligns with our findings.
Notably, the present study did not include minors, in
contrast to the study by Benites-Zapata et al., which included patients as
young as two days old.
In our study, a high frequency of homosexuals, MSM and
patients with a history of HIV infection was observed, consistent with findings
from the systematic review by León-Figueroa
(10). These specific populations should be further studied to take preventive actions.
Both this study
and that of Benites-Zapata et al. identified exanthem rash as the
predominant clinical finding. However, while those authors reported pruritus as another prevalent manifestation, we found
it to occur at a low frequency (0.81
%). These discrepancies in clinical characteristics should be interpreted
considering the fact that the majority of the population in the Benites-Zapata
et al. study was of African descent. Additionally, our sources of information indicated
incomplete recording of the exanthem rash location.
In our research, most patients reported not having engaged in
risk behavior, contrasting with the first cases
reported globally by Thornhill et al. (11), where sexual activity was
considered as a risk behavior.
They noted that transmission
likely occurred through
sexual contact in 95 % of the cases.
The first global mpox study, published in August 2022,
included 528 patients from 16 countries, revealing high percentages of men and
homosexuals living with HIV. Anogenital exanthem rash was the predominant
clinical manifestation, noted in 73 % of the cases. Furthermore, 61 patients
experienced anorectal mucosal involvement, including pain, proctitis, tenesmus
or diarrhea, in contrast
to our findings, which reported proctitis in six cases and diarrhea in two. It
should be taken into account that the white population (75 %) prevailed in that
study (11).
In the studies
by León-Figueroa et al. and Thornhill et al.,
diagnoses were predominantly confirmed using swab samples
of skin lesions analyzed by polymerase chain reaction (PCR) tests. In contrast,
our research did not detail the anatomical
regions from which the samples were obtained.
In a Peruvian case report published in 2022, Pampa-Espinoza
et al. (12) highlighted the
characteristics of the first nine patients suspected of having mpox, out of
whom seven were male and two did not present fever. Unlike our study and the other aforementioned reports,
the majority (seven cases) did
not have HIV infection. Subsequently, two cases of mpox were confirmed in male patients
aged
33 and 58 years; the other seven were diagnosed with
various conditions, including
hand-foot-and-mouth disease
caused by coxsackievirus A6, chickenpox, acute leukemia, oral
herpes, secondary syphilis, contact dermatitis and nosological
entities that remind us of the importance of considering other differential diagnoses or the presence
of coinfections.
The findings from our research,
as well as the results
of the aforementioned studies,
differ from those reported in the
Democratic Republic of the Congo,
which is classified as an endemic country.
In a study conducted on 104 individuals during the 2013 outbreak (13),
children were the most affected group, including
those under five years of age. In addition, the actual number of affected
individuals could be higher, since several family members were infected, but only
one sought medical attention.
In terms of mortality, no deaths were reported in our study population. In endemic countries in Africa, 72 deaths had been reported up to
August 2022. Similarly, deaths were documented
in non-endemic countries
in Europe, Asia and
the Americas, according to Sah et al. (14). However, the accuracy of mortality data may be compromised due to the selection biases inherent in such studies, making it difficult
to draw definitive conclusions.
From an epidemiological perspective, there are demographic
characteristics that align with other studies and international reviews (9,10,15).
While the clinical manifestations vary, this variability is a common theme
across most studies, according to Bunge et al (16). However, the results presented here do not represent the broader
population and limit comparative analyses, which is a disadvantage of this type
of study.
Peru ranks among the 10 countries with the highest number of mpox cases globally;
therefore, continued research
on the subject is essential, particularly focusing on the most vulnerable
populations: people with HIV infection, homosexuals and MSM. This research will
help promote hygienic habits and preventive measures to protect other
population groups from the spread of the disease. In addition, health
professionals should receive training in the
diagnosis and management of mpox for early detection and possible complications,
especially given the lack of knowledge surrounding certain aspects of this
disease (17).
The population should be made aware of the importance of eliminating stigmas-as a strength-to encourage
openness about the disease
(18), which will impact early detection
of potential outbreaks, a challenge that persists even in more developed health systems (19,20).
BIBLIOGRAPHIC REFERENCES
1.Organización Mundial de la Salud. Viruela símica
[Internet]. Ginebra: OMS; 2023. Available from:
https://www.who.int/es/news-room/ fact-sheets/detail/monkeypox
2.Ministerio de Salud. Viruela
del mono (Monkeypox) [Internet]. Lima: MINSA; 2022. Available
from: https://bvcenadim.digemid.minsa. gob.pe/files/Ficha_Viruela_del_mono.pdf
3.Ministerio de Salud. Situación
de la enfermedad de la viruela
del mono [Internet]. Lima: MINSA; 2022. Available from:
http://dge. gob.pe/portal/docs/tools/teleconferencia/2022/SE212022/03.pdf
4.Ministerio de Salud. Incremento
de casos de viruela del
mono, en el Perú, 2022
[Internet]. Lima: MINSA; 2022. Available from: https://www.
dge.gob.pe/epipublic/uploads/alertas/alertas_202217_16_111037.pdf
5.Organización Panamericana de la Salud. Informe de situación sobre la respuesta al brote de viruela símica en varios países
[Internet]. Washington, D.C.: OPS; 2022.Available from:
https://www.paho. org/es/documentos/informe-situacion-sobre-respuesta-al-brote- viruela-simica-varios-paises-region-0
6.Ministerio de Salud. Casos de viruela
del mono en Lima y riesgo
de propagación a otras
regiones. [Internet]. Lima: MINSA; 2022. Available from:
https://www.dge.gob.pe/epipublic/uploads/ alertas/alertas_202216_01_191123.pdf
7.Ministerio de Salud. Riesgo de importación
de casos de viruela del
mono en el Perú
[Internet]. Lima: MINSA; 2022. Available from:https://www.dge.gob.pe/epipublic/uploads/alertas/
alertas_202212_26_143419.pdf
8.Ministerio de Salud. Incremento
de casos de viruela del
mono en el mundo y el riesgo
de introducción en el Perú [Internet]. Lima: MINSA; 2022.
Available from: https://www.dge.gob.pe/epipublic/ uploads/alertas/alertas_202214_19_094610.pdf
9.Benites-Zapata VA, Ulloque-Badaracco
JR, Alarcon-Braga EA, Hernandez-Bustamante EA, Mosquera-Rojas MD,
Bonilla-Aldana DK, et al. Clinical features, hospitalisation
and deaths associated with monkeypox: a systematic review and meta-analysis.
Ann Clin Microbiol Antimicrob. 2022;21(1):36.
10.León-Figueroa DA, Barboza JJ, Garcia-Vasquez EA,
Bonilla-Aldana DK, Diaz-Torres M, Saldaña-Cumpa HM,
et al. Epidemiological situation of monkeypox transmission by possible sexual
contact: a systematic review. Trop Med Infect Dis [Internet].
2022;7(10):267.
11.Thornhill JP, Barkati
S, Walmsley S, Rockstroh J, Antinori A, Harrison LB, et al. Monkeypox virus
infection in humans across 16 countries - April-June 2022. N Engl J Med
2022;387(8):679-91.
12.Pampa-Espinoza L, Meza K, Vargas-Huapaya M, Borgoño N, Martínez- Paredes C, Padilla-Rojas C, et al. Características de los primeros casos reportados como sospechosos de Monkeypox en el Perú. An Fac Med.
2022;83(3):228-34.
13.Nolen LD, Osadebe L,
Katomba J, Likofata J, Mukadi D, Monroe B, et al.
Extended human-to-human transmission during a monkeypox outbreak in the
Democratic Republic of the Congo. Emerg Infect Dis. 2016;22(6):1014-21.
14.Sah R, Mohanty A, Abdelaal A, Reda A,
Rodriguez-Morales AJ, Henao- Martinez AF. First Monkeypox deaths outside
Africa: no room for complacency. Ther Adv Infect Dis. 2022;9:20499361221124027.
15.Petersen E, Kantele A, Koopmans M, Asogun D, Yinka-Ogunleye A, Ihekweazu
C, et al. Human monkeypox: epidemiologic and clinical characteristics,
diagnosis, and prevention. Infect Dis Clin North Am. 2019;33(4):1027-43.
16.Bunge EM, Hoet B, Chen
L, Lienert F, Weidenthaler H, Baer LR, et al. The
changing epidemiology of human monkeypox-A potential threat? A systematic
review. PLoS Negl Trop Dis.
2022;16(2):e0010141.
17.Navarrete-Mejía PJ, Velasco-Guerrero JC, Sullcahuaman-Valdiglesias E. Conocimiento
sobre viruela del mono en profesionales de la salud, Lima-Perú. Rev Cuerpo Med HNAAA. 2022;15(2):252-5.
18.Solari L. Viruela del
mono y la eterna impredictibilidad
en el Perú. Rev Peru Med
Exp Salud Publica. 2022;39(3):264-6.
19.Adler H, Gould S, Hine P, Snell LB, Wong W,
Houlihan CF, et al. Clinical features and management of human monkeypox: a
retrospective observational study in the UK. Lancet Infect Dis.
2022;22(8):1153- 62.
20.Nakoune E, Olliaro P.
Waking up to monkeypox. BMJ. 2022;377:o1321.
Author contributions: FMRT
and ABC participated in the
conception and design
of the study. FMRT collaborated on data collection and methodology. ABC contributed to data
analysis and interpretation. Both authors performed the bibliographic search
and drafted the article.
Funding sources:
The article was funded by the authors.
Conflicts of interest: The authors declare no conflicts of interest.
*Corresponding author:
Alejandra Bendezú Chacaltana
Address: Pasaje Ideal 187, Jesús María. Lima, Perú. Telephone: +51 900 614 705
E-mail: alejandrabendezu128@gmail.com
Reception
date:
January 25, 2023
Evaluation
date:
February 8, 2023
Approval
date:
March 6, 2023