To assess symptoms of CHIKV infections, researchers questioned the participants regarding current symptoms, symptoms that occurred since the time of their last menorrhea, or symptoms they recalled from a recent confirmed or suspected CHIKV infection.
A total of 154 of the 1,244 pregnant women (12.4%) were positive for IgG against CHIKV, and 116 of them (75.3%) had reported a history of symptoms of CHIKV infection since their last menorrhea. The highest rates of IgG against CHIKV (Mananjary 44.6%, Manakara 22.7%) and IgM against DENV (Mananjary 17.4%, Manakara 10.8%) were found in the 2 coastal cities (Figure 1; Table 1).
Delayed menarche may be caused by chronic illness; cryptomenorrhea (symptoms of menorrhea
occur without any external bleeding, as in cases of imperforate hymen); and polycystic ovary syndrome, among other endocrine problems.