Testing is one of the commendable measures for curbing the spread of coronavirus disease (COVID‐19). But, it should be done using the most appropriate specimen and an accurate diagnostic test such as real‐time reverse transcription‐polymerase chain reaction (qRT‐PCR). Therefore, a systematic review was conducted to determine the positive detection rate of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in different clinical specimens using qRT‐PCR. A total of 8136 pooled clinical specimens were analyzed to detect SARS‐CoV‐2, the majority were nasophar yngeal swabs (69.6%). A lower respiratory tract (LRT) specimens had a positive rate (PR) of 71.3% (95% confidence interval [CI]: 60.3%‐82.3%) while no virus was detected in the urinogenital specimens. Bronchoalveolar lavage fluid (BLF) specimen had the PR of 91.8% (95% CI: 79.9%‐103.7%), followed by rectal swabs; 87.8% (95% CI: 78.6%‐96.9%) then sputum; 68.1% (95% CI: 56.9%‐79.4%). A low PR was observed in oropharyngeal swabs; 7.6% (95% CI: 5.7%‐9.6%) and blood samples; 1.0% (95% CI: −0.1%‐2.1%) whereas no SARS‐CoV‐2 was detected in urine samples. Feces had a PR of 32.8% (95% CI:1 5.8%‐49.8%). Nasopharyngeal swab, a widely used specimen had a PR of 45.5% (95% CI: 31.2%‐59.7%). In this study, SARS‐CoV‐2 was highly detected in LRT specimens while no virus was detected in urinogenital specimens. BLF had the highest PR followed by rectal swab then sputum. Nasopharyngeal swab which is widely used had moderate PR. Low PR was recorded in oropharyngeal swab and blood samples while no virus was found in urine samples. Last, the virus was detected in feces, suggesting SARS‐CoV‐2 transmission by the fecal route

 Objective: We set an experiment to determine the diagnostic performance of the Widal test and stool culture in typhoid-suspected cases attending tertiary hospitals in Dar es Salaam, Tanzania using blood culture as a golden standard. We also evaluated the agreement between Widal, stool and blood culture. Results: This was a cross-sectional study conducted between June and September 2018, in three Regional Referral Hospitals in Dar es Salaam, Tanzania. A total of 158 typhoid-suspected cases were enrolled, after obtaining an informed consent. Of the 158 patients participated in the study, 128 (81%) tested positive for the Widal test and 17 (11%) patients were stool culture positive. Widal test recorded 81.5% sensitivity, 18.3% specifcity, 10.1% positive predictive value and 89.7% negative predictive value. Stool culture showed 31.3% sensitivity, 91.5% specifcity, 29% positive predictive value and 91.5% negative predictive value. In conclusion, Widal test is not reliable for diagnosis of typhoid fever since false positive and negative results are common. In addition, Widal test recorded poor agreement with the blood culture (kappa=0.014, p<0.05) while stool culture had strong agreement with the blood culture (kappa=0.22, p<0.05). 

Background: High Immunoglobulin G (IgG) response to Plasmodium falciparum antigens is associated with partial malaria protection in sickle hemoglobin (HbS) children. However, this response has been more studied in children with heterozygous sickle cell trait (HbAS) but little explored in those with homozygous sickle cell trait (HbSS). The current study was conducted to determine the IgG responses against specific Plasmodium falciparum antigens in children with homozygous sickle cell trait (HbSS) by comparing to those with normal hemoglobin (HbAA). Methods: A cross sectional study was conducted between April and July 2018 in Dar es Salaam tertiary hospitals. Parents were consented for their child to give about 5 ml of venous blood. IgG concentration from the blood plasma of 220 children (110 HbAA vs. 110 HbSS) were determined using indirect Enzyme Linked Immunosorbent Assay (ELISA). Then IgG medians were compared between the groups with prism 5 software (GraphPad) using Mann Whitney U test. Where the differences in age, hemoglobin levels and body weight between the groups was analyzed using independent sample t test. Multiple linear regressions were used to control cofounding variables such as body weight, age and hemoglobin level using statistical package for social sciences software (SPSS version 23). P value <0.05 was considered statistically significant. Results: The median IgG concentration to PfEBA-175, Pfg27, yPfs28C antigens were HbSS; 20.7 ng/ml (IQR; 18.1–25. 6) vs. HbAA; 2.3 ng/ml (IQR; 1.21–3.04), HbSS; 2.76 ng/ml (IQR: 2.08–5.69) vs. HbAA; 1.36 ng/ml (IQR: 1.28–1.76), and HbSS; 26,592 ng/ml (IQR: 10817–41,462) vs. HbAA; 14,164 ng/ml (IQR; 3069–24,302) respectively (p < 0.0001 for all IgG). In both groups; age, body weight and hemoglobin level had no impact on the levels of IgG responses to Plasmodium falciparum antigens except for HbAA group which showed a significant increase in IgG against Pfg27 by 0.004 ng/ml with 1 g/dl increase in Hb level (p = 0.028). Conclusions: This study found significant higher levels of specific Plasmodium falciparum IgG responses in children with homozygous sickle cell trait than those with normal hemoglobin