Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Mar 13;17(3):e0011179.
doi: 10.1371/journal.pntd.0011179. eCollection 2023 Mar.

Seasonal variation of diarrhoeal pathogens among Guinea-Bissauan children under five years of age

Sointu Mero  1   2 , Tinja Lääveri  2   3 , Johan Ursing  4   5   6 , Lars Rombo  7   8 , Poul-Erik Kofoed  6   9 , Anu Kantele  1   2
Affiliations

Seasonal variation of diarrhoeal pathogens among Guinea-Bissauan children under five years of age

Sointu Mero et al. PLoS Negl Trop Dis. .

Abstract

Background: Diarrhoea remains a major cause of childhood morbidity and mortality in low-income countries (LICs). The frequency of diarrhoeal episodes may vary by season, yet few prospective cohort studies have examined seasonal variation among various diarrhoeal pathogens using multiplex qPCR to analyse bacterial, viral and parasitic pathogens.

Methods: We combined our recent qPCR data of diarrhoeal pathogens (nine bacterial, five viral and four parasitic) among Guinea-Bissauan children under five years old with individual background data, dividing by season. The associations of season (dry winter and rainy summer) and the various pathogens were explored among infants (0-11 months) and young children (12-59 months) and those with and without diarrhoea.

Results: Many bacterial pathogens, especially EAEC, ETEC and Campylobacter, and parasitic Cryptosporidium, prevailed in the rainy season, whereas many viruses, particularly the adenovirus, astrovirus and rotavirus proved common in the dry season. Noroviruses were found constantly throughout the year. Seasonal variation was observed in both age groups.

Conclusion: In childhood diarrhoea in a West African LIC, seasonal variation appears to favour EAEC, ETEC, and Cryptosporidium in the rainy and viral pathogens in the dry season.

PubMed Disclaimer

Conflict of interest statement

I have read the journal’s policy and the authors of this manuscript have the following competing interests: TL received honoraria from Pfizer unrelated to this article. AK received research grants from Valneva and Pfizer unrelated to this article. Other authors have declared that no competing interests.

Figures

Fig 1
Fig 1. Flow chart of the study.
The final study population comprised 429 children; 424 of these were tested for bacterial, 397 for viral, and 426 for parasitic pathogens.
Fig 2
Fig 2. Seasonal variation of diarrhoeal pathogens identified over the 24-month study period with respect to rainfall [4] (A) and temperature (B).
Monthly proportions given for those with samples positive for bacterial, parasitic, or viral diarrhoeal pathogens.
Fig 3
Fig 3. Seasonal variation of diarrhoeal pathogens with respect to rainfall [4].
For the six pathogens showing seasonal variation in incidence, data are shown as monthly proportions of samples positive for A) bacterial (EAEC, ETEC), B) parasitic (Cryptosporidium), and C) viral pathogens (adeno-, astro-, and rotavirus). Details of all pathogen findings are shown in S1 Fig. Numbers of children are indicated in parentheses for each month.
See this image and copyright information in PMC

References

    1. Levy K, Woster AP, Goldstein RS, Carlton EJ. Untangling the impacts of climate change on waterborne diseases: a systematic review of relationships between diarrheal diseases and temperature, rainfall, flooding, and drought. Environ Sci Technol. 2016. May 17;50(10):4905–22. doi: 10.1021/acs.est.5b06186 - DOI - PMC - PubMed
    1. Lal A, Hales S, French N, Baker MG. Seasonality in human zoonotic enteric diseases: a systematic review. PloS One. 2012;7(4):e31883. doi: 10.1371/journal.pone.0031883 - DOI - PMC - PubMed
    1. Lo Iacono G, Armstrong B, Fleming LE, Elson R, Kovats S, Vardoulakis S, et al. Challenges in developing methods for quantifying the effects of weather and climate on water-associated diseases: A systematic review. PLoS Negl Trop Dis. 2017. Jun;11(6):e0005659. doi: 10.1371/journal.pntd.0005659 - DOI - PMC - PubMed
    1. Bissau Climate Weather Averages [Internet]. WorldWeatherOnline.com. [cited 2022 Aug 11]. https://www.worldweatheronline.com/bissau-weather/bissau/gw.aspx
    1. Kotloff KL, Blackwelder WC, Nasrin D, Nataro JP, Farag TH, van Eijk A, et al. The Global Enteric Multicenter Study (GEMS) of diarrheal disease in infants and young children in developing countries: epidemiologic and clinical methods of the case/control study. Clin Infect Dis Off Publ Infect Dis Soc Am. 2012. Dec;55 Suppl 4(Suppl 4):S232–245. doi: 10.1093/cid/cis753 - DOI - PMC - PubMed

Publication types