Unspecified malaria

Unspecified malaria refers to malaria for which the Plasmodium species was not specified in the available report or surveillance record, with the cited sources using the term to classify a substantial fraction of cases ^[1][2]. The disease is catalogued here as parasitic malaria under ICD-10 B54 and ICD-11 1F40 [disease]. In the evidence set, unspecified malaria appears as a surveillance label applied when species-level identification is absent, while other entries in the same datasets identify P. falciparum, P. vivax, and P. malariae separately ^[1][2][3].

The sources do not provide a species-independent symptom profile for unspecified malaria, and detailed clinical features attributable specifically to this category are not yet available from the supplied material ^[1][2][3]. One hospital-based study of malaria cases reports that clinical “unspecified” malaria was diagnosed according to WHO criteria, but the abstract does not describe a unique symptom constellation for that label ^[3]. In the same study, complicated falciparum malaria was associated with cerebral malaria, malarial hepatitis, acute pneumonia and/or pulmonary edema, acute renal failure, algid malaria, and black water fever, but these complications are described for falciparum malaria rather than for unspecified malaria specifically ^[3]. The surveillance reports also do not provide severity, course, or complication data for the unspecified category as such ^[1][2].

In the available surveillance material, unspecified malaria is reported in military populations and in a hospital series from Bangladesh, indicating that the term is used across both travel/exposure-associated and clinical care settings ^[1][2][3]. Among U.S. service members, malaria cases were linked to endemic-area exposure during long-term duty assignments, shorter-term contingency operations, and personal travel, and unspecified cases comprised 12 of 44 cases in 2014 and 17 of 32 cases in 2017 ^[1][2]. The same military reports note cases associated with Africa, Korea, Afghanistan, and several treatment/reporting sites across multiple countries, but they do not assign those geographies specifically to the unspecified subset ^[1][2]. In the Bangladesh hospital study, malaria accounted for 136.17 per thousand admissions over 1998–2001, with the series dominated by falciparum, vivax, and mixed infections; clinical unspecified malaria is mentioned, but its separate burden is not quantified in the abstract ^[3].

The supplied sources do not describe a distinct transmission mechanism for unspecified malaria, and source-backed detail on route, persistence, or vector ecology specific to this category is not yet available ^[1][2][3]. The surveillance reports do, however, identify acquisition in endemic areas during duty assignments, contingency operations, and personal travel, indicating that exposure is tied to time spent in malaria-endemic settings rather than to person-to-person spread in the cited materials ^[1][2]. Because the species is unspecified, no additional transmission inference can be made from the evidence provided ^[1][2][3].

The evidence provided identifies U.S. service members in endemic areas as a key monitored population, especially those on long-term duty assignments, shorter-term contingency operations, or personal travel ^[1][2]. More broadly, the sources support heightened attention for people exposed in malaria-endemic settings and for clinicians evaluating illness outside endemic areas, but they do not supply additional source-backed risk groups for unspecified malaria specifically ^[1][2].

The cited sources emphasize exposure avoidance and vigilance in endemic-area travelers and deployed personnel, rather than a disease-specific preventive regimen for unspecified malaria ^[1][2]. Providers are advised to remain knowledgeable about and vigilant for malaria presentations outside endemic areas, reflecting the need for surveillance and case recognition in returning travelers or deployed populations ^[1][2]. Beyond these general exposure-control implications, source-backed prevention detail for the unspecified category is not yet available ^[1][2][3].

In surveillance practice, unspecified malaria should be interpreted as a malaria case that lacks species-level identification in the report, and therefore it can materially affect the apparent distribution of Plasmodium species in a dataset ^[1][2]. The military surveillance reports show that unspecified cases constituted a large share of reported malaria in 2017 and a notable minority in 2014, underscoring the importance of laboratory characterization where possible ^[1][2]. The hospital study likewise demonstrates that clinical records may include an unspecified category diagnosed by WHO criteria, but the abstract does not provide enough detail to distinguish that label analytically from confirmed-species malaria ^[3].

1. 1 Update: malaria, U.S. Armed Forces, 2014. MSMR. 2015 Jan. PMID: 25643089. PubMed: https://pubmed.ncbi.nlm.nih.gov/25643089/
2. 2 Armed Forces Health Surveillance Branch et al. Update: Malaria, U.S. Armed Forces, 2017. MSMR. 2018 Feb. PMID: 29485890. PubMed: https://pubmed.ncbi.nlm.nih.gov/29485890/
3. 3 Hussain SM et al. The recent malaria situation in Chittagong, Bangladesh. Southeast Asian J Trop Med Public Health. 2003. PMID: 19238662. PubMed: https://pubmed.ncbi.nlm.nih.gov/19238662/
4. 4 UNSPECIFIED (UNSPECIFIED). Bulletin of the Institute of Classical Studies. 1986. doi: 10.1111/j.2041-5370.1994.tb01908.x. DOI: https://doi.org/10.1111/j.2041-5370.1994.tb01908.x
5. 5 Prednisone/unspecified antibiotics/unspecified NSAIDs. Reactions Weekly. 2021. doi: 10.1007/s40278-021-91411-0. DOI: https://doi.org/10.1007/s40278-021-91411-0
6. 6 Montelukast/unspecified Antihistamines/unspecified Steroids. Reactions Weekly. 2025. doi: 10.1007/s40278-025-82140-x. DOI: https://doi.org/10.1007/s40278-025-82140-x

ICD-10

B54

ICD-11

1F40

Total cases

0

Peak month

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Coverage

0 reporting countries · —