Seasonality and outbreak of a predominant Streptococcus pneumoniae serotype 1 clone from The Gambia: Expansion of ST217 hypervirulent clonal complex in West Africa

2008

Study of Streptococcus pneumoniae Serotype 1 in The Gambia

Sample size: 163 publication Evidence: moderate

Author Information

Author(s): Antonio Martin, Hakeem Ishrat, Awine Timothy, Secka Ousman, Sankareh Kawsu, Nsekpong David, Lahai George, Akisanya Abiodun, Egere Uzochukwu, Enwere Godwin, Zaman Syed MA, Hill Philip C, Corrah Tumani, Cutts Felicity, Greenwood Brian M, Adegbola Richard A

Primary Institution: Medical Research Council Laboratories, Banjul, The Gambia

Hypothesis

What is the molecular epidemiology and invasive capacity of Streptococcus pneumoniae serotype 1 isolates in The Gambia?

Conclusion

Isolates of ST618 have been the dominant lineage among serotype 1 carriage and disease isolates circulating in The Gambia for over a decade.

Supporting Evidence

ST618 was the most prevalent clone among the 163 isolates, accounting for 70.5%.
The study revealed 23 different sequence types, 18 of which were novel.
The odds ratio of ST618 causing invasive disease relative to non-ST618 clones was 1.74.

Takeaway

This study found that a specific type of bacteria, ST618, is very common in sick people in The Gambia and can cause outbreaks, especially during the dry season.

Methodology

The study analyzed 127 invasive and 36 nasopharyngeal carriage serotype 1 isolates using serotyping, antibiotic susceptibility testing, and multi-locus sequence typing (MLST).