Varicella in Tshuapa Province, Democratic Republic of Congo, 2009–2014

Abstract

Objective To describe varicella cases in Tshuapa Province of the Democratic Republic of the Congo identified during monkeypox surveillance. Methods Demographic, clinical and epidemiological data were collected from each suspected monkeypox case 2009–2014. Samples were tested by PCR for both Orthopoxviruses and varicella‐zoster virus (VZV); a subset of VZV‐positive samples was genotyped. We defined a varicella case as a rash illness with laboratory‐confirmed VZV. Results There were 366 varicella cases were identified; 66% were ≤19 years old. Most patients had non‐typical varicella rash with lesions reported as the same size and stage of evolution (86%), deep and profound (91%), on palms of hands and/or soles of feet (86%) and not itchy (49%). Many had non‐typical signs and symptoms, such as lymphadenopathy (70%) and sensitivity to light (23%). A higher proportion of persons aged ≥20 years than persons aged ≤19 years had ≥50 lesions (79% vs. 65%, P = 0.007) and were bedridden (15% vs. 9%, P = 0.056). All VZV isolates genotyped from 79 varicella cases were clade 5. During the surveillance period, one possible VZV‐related death occurred in a 7‐year‐old child. Conclusions A large proportion of patients presented with non‐typical varicella rash and clinical signs and symptoms, highlighting challenges identifying varicella in an area with endemic monkeypox. Continued surveillance and laboratory diagnosis will help in rapid identification and control of both monkeypox and varicella and improve our understanding of varicella epidemiology in Africa.

Enhanced surveillance of monkeypox in Bas-Uélé, Democratic Republic of Congo: the limitations of symptom-based case definitions

“…The low specificity of the case definition for community surveillance of monkeypox implies the inclusion of many false positives in both the epidemiological and clinical records scattered in peripheral health structures, with some under-and over-estimation of the actual caseload. Most captured cases were in fact chickenpox patients, confirming that the epidemiological characterization and clinical identification of monkeypox in Bas-Uélé are also seriously blurred by the co-endemicity of both conditions that share many similar and overlapping features (Jezek et al, 1988, Leung et al, 2019, MacNeil et al, 2009. It is expected that cases first captured by the very sensitive "community" case definition are assessed through the more restrictive "health facility" case definition, but this two-step clinical strategy may be not very well apprehended by less trained health workers.…”

Development and Characterization of Recombinase-Based Isothermal Amplification Assays (RPA/RAA) for the Rapid Detection of Monkeypox Virus

“…Mortality is higher among children and adults with comorbidities, and the disease course is more severe in immunocompromised individuals [ 14 ]. The epidemiologic characterization and clinical identification of monkeypox in the DRC is also complicated by the coendemicity of both viruses, which make differential diagnosis between monkeypox and chickenpox particularly challenging in the field [ 42 , 43 , 46 ]. Therefore, the development of a rapid test that can be used for clinical and field evaluation is key for helping community health workers to distinguish between these two conditions, and to perform surveillance studies in humans, as well as any potential reservoir animal species.…”

Enhanced surveillance of monkeypox in Bas-Uélé, Democratic Republic of Congo: the limitations of symptom-based case definitions

“…The low specificity of the case definition for community surveillance of monkeypox implies the inclusion of many false-positives in both the epidemiologic and clinical records scattered in peripheral health structures, with some under- and overestimation of the actual caseload. Most captured cases were in fact chickenpox, confirming that the epidemiologic characterization and clinical identification of monkeypox in Bas-Uélé are also seriously blurred by the coendemicity of both conditions that share many similar and overlapping features ( Jezek et al ., 1988 ; Leung et al ., 2019 ; MacNeil et al ., 2009 ). It is expected that cases first captured by the very sensitive “community” case definition are assessed through the more restrictive “health facility” case definition, but this two-step clinical strategy may be not very well apprehended by less trained health workers.…”

“…Several diseases with generalized skin eruption may mimic monkeypox, such as chickenpox, measles, molluscum contagiosum, or rickettsioses. The field differential diagnosis between monkeypox and chickenpox is particularly challenging ( Jezek et al ., 1988 ; Leung et al ., 2019 ; MacNeil et al ., 2009 ) and coinfections are frequent ( Hughes et al ., 2020 ). Recent attempts to design clinical case definitions with a higher specificity for surveillance or care purposes have not yet undergone external validation ( Osadebe et al ., 2017 ).…”