The burden of asymptomatic dengue infections is understudied. Therefore, we systematically reviewed the literature to estimate the global prevalence of asymptomatic dengue infections. We searched cross-sectional studies reporting the prevalence of asymptomatic dengue infections from PubMed, Scopus, and Embase. Prevalence of asymptomatic dengue infections was pooled and reported as proportions with a 95% confidence interval (CI). This systematic review protocol was a priori registered in The International Prospective Register of Systematic Reviews (Reg: No. CRD42020218446). We included 41 studies with 131,953 cases in our analysis. The overall pooled prevalence of asymptomatic dengue infections was 59.26% (95% CI: 43.76-74.75, I² = 99.93%), with 65.52% (95% CI: 38.73-92.32, I² = 99.95%) during outbreaks and 30.78% (95% CI: 21.39-40.16, I² = 98.78%) during non-outbreak periods. The pooled prevalence among the acutely infected individuals was 54.52% (95% CI: 17.73-46.76, I² = 99.91%), whereas, among primary and secondary asymptomatic dengue infections, it was 65.36% (95% CI: 45.76-84.96, I² = 98.82) and 48.99% (95% CI: 27.85-70.13, I² = 99.08%) respectively. The majority of dengue cases are asymptomatic and may play a significant role in disease transmission. Public health strategies aimed at dengue outbreak response and mitigation of disease burden should include early detection of asymptomatic cases.

In 2016, the Government of India introduced the oral rotavirus vaccine (ROTAVAC, Bharat Biotech, India) in 4 states of India as part of the Universal Immunization Programme, and expanded to 5 more states in 2017. We report four years of data on rotavirus gastroenteritis in hospitalized children < 5 years of age prior to vaccine introduction. Children from 7 sites in southern and northern India hospitalized for diarrhoea were recruited between July 2012 and June 2016. Stool samples were screened for rotavirus using enzyme immunoassay (EIA). The EIA positive samples were genotyped by reverse-transcription polymerase chain reaction. Of the 5834 samples from the 7 sites, 2069 (35.5%) were positive for rotavirus by EIA. Genotyping was performed for 2010 (97.1%) samples. G1P[8](56.3%), G2P[4](9.1%), G9P[4](7.6%), G9P[8](4.2%), and G12P[6](3.7%) were the common genotypes in southern India and G1P[8](36%), G9P[4](11.4%), G2P[4](11.2%), G12P[6](8.4%), and G3P[8](5.9%) in northern India. The study highlights the high prevalence of rotavirus gastroenteritis in India and the diversity of rotavirus genotypes across different geographical regions. Pre- vaccine surveillance data is necessary to evaluate the potential change in admission rates for gastroenteritis and circulating rotavirus genotypes after vaccine introduction, thus assessing impact.

Scrub typhus, a neglected disease, is a significant health concern in the Tsutsugamushi triangle of the Asia–Pacific and has raised global concerns due to recent cases occurring outside this region. To estimate the global prevalence of scrub typhus, we conducted a systematic review and meta-analysis. We conducted a systematic search of PubMed, Scopus, and Embase databases for observational studies on scrub typhus. Using a random-effects model, we combined the prevalence estimates with inverse-variance weights while also evaluating heterogeneity and publication bias. Among 3551 reports screened, we identified 181 studies with 1,48,251 samples for inclusion in our synthesis. The overall pooled seroprevalence (95% confidence intervals) of scrub typhus infections was 24.93% (23.27–26.60). Gender-wise pooled prevalence was estimated to be 50.23% (47.05–53.40) for males and 48.84% (45.87–51.80) for females. Eschar prevalence was observed to be 30.34% (22.54–38.15) among the positive cases. One-fourth of all the samples tested positive for scrub typhus and eschar was present in one-third of these total positive cases, encompassing regions beyond the Tsutsugamushi triangle. This estimation underlines the importance of this neglected disease as a public health problem. Strengthening surveillance and implementing disease control measures are needed in the affected regions.

To characterize and describe patterns of HIV, sexually transmitted infections (STI) and sexual behaviour of male clients of female sex workers (FSW). A cross-sectional study was conducted among 4821 clients of FSW from 12 districts in three states in India: Andhra Pradesh, Maharashtra and Tamil Nadu. A structured questionnaire was administered to elicit demographic characteristics and sexual behavioural patterns. Blood and urine samples were tested for HIV, syphilis and herpes simplex type 2 serology, gonococal and chlamydial infection. The median age of clients surveyed was 30 years; 57% were married and 64% had a steady sexual partner; 61% had sex with more than one FSW and 39% had four or more sexual encounters in the past month. The prevalence of HIV ranged from 2.0% to 10.9%, syphilis ranged from 3.1% to 10.1%; gonorrhoea and chlamydia ranged between 0% and 4.5%. Clients older than 30 years [odds ratio (OR) 1.65; 95% confidence interval (CI) 1.33–2.05] and having a different mix of commercial and non-commercial partners (OR 1.56; 95% CI 1.25–1.96) had a higher volume of sex acts with FSW. Inconsistent condom use with FSW was significantly associated with older clients (OR 4.2; 95% CI 3.33–5.29), illiteracy (OR 1.39; 95% CI 1.14–1.69), age <18 years at first paid sex (OR 1.83; 95% CI 1.24–2.70) and having different FSW partners in the past month (OR 1.64; 95% CI 1.23–2.18). Clients of FSW studied here constitute a significant bridge group for HIV and other STI, because of their high volume of different sexual partners and very low consistent condom use. HIV prevention programmes need to address male clients.