Table 2.
Model-estimated incidence rate ratio (IRR) of 26 selected infectious diseases.
| Disease† | South | North | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Phase II‡ | Phase III‡ | Phase IV‡ | Phase II‡ | Phase III‡ | Phase IV‡ | |||||||
| IRR (95%CI) | p value | IRR (95%CI) | p value | IRR (95%CI) | p value | IRR (95%CI) | p value | IRR (95%CI) | p value | IRR (95%CI) | p value | |
| Respiratory diseases | ||||||||||||
| Measles | 0.55 (0.28−1.06) | 0.080 | 0.78 (0.51−1.18) | 0.238 | 0.72 (0.43−1.20) | 0.213 | 0.02 (0.001−0.44) | 0.017 | 1.85 (0.37−9.30) | 0.460 | 4.47 (1.2−16.58) | 0.028 |
| Mumps | 0.53 (0.39−0.71) | <0.001 | 0.38 (0.32−0.44) | <0.001 | 0.33 (0.28−0.39) | <0.001 | 0.48 (0.35−0.65) | <0.001 | 0.34 (0.28−0.41) | <0.001 | 0.40 (0.33−0.48) | <0.001 |
| Pertussis | 0.45 (0.23−0.88) | 0.022 | 0.06 (0.03−0.10) | <0.001 | 0.12 (0.08−0.18) | <0.001 | 0.23 (0.13−0.40) | <0.001 | 0.05 (0.03−0.08) | <0.001 | 0.11 (0.07−0.17) | <0.001 |
| Rubella | 0.10 (0.02−0.47) | 0.005 | 0.02 (0.004−0.08) | <0.001 | 0.01 (0.004−0.06) | <0.001 | 0.18 (0.06−0.59) | 0.006 | 0.06 (0.02−0.15) | <0.001 | 0.11 (0.06−0.23) | <0.001 |
| Scarlet fever | 0.22 (0.15−0.32) | <0.001 | 0.26 (0.21−0.32) | <0.001 | 0.26 (0.21−0.31) | <0.001 | 0.11 (0.07−0.18) | <0.001 | 0.10 (0.07−0.14) | <0.001 | 0.13 (0.10−0.17) | <0.001 |
| Seasonal influenza | 0.16 (0.03−0.76) | 0.024 | 0.06 (0.02−0.15) | <0.001 | 0.05 (0.02−0.12) | <0.001 | 0.21 (0.10−0.44) | <0.001 | 0.15 (0.10−0.23) | <0.001 | 0.11 (0.07−0.17) | <0.001 |
| Tuberculosis | 0.87 (0.78−0.97) | 0.014 | 0.97 (0.92−1.03) | 0.389 | 0.96 (0.91−1.02) | 0.221 | 0.85 (0.73−1.00) | 0.057 | 0.86 (0.79−0.94) | <0.001 | 0.83 (0.76−0.90) | <0.001 |
| Gastrointestinal or enteroviral disease | ||||||||||||
| AHC | 0.67 (0.38−1.18) | 0.172 | 0.49 (0.36−0.68) | <0.001 | 0.46 (0.33−0.65) | <0.001 | 0.96 (0.83−1.11) | 0.577 | 1.01 (0.93−1.09) | 0.844 | 1.18 (1.10−1.27) | <0.001 |
| Bacterial dysentery | 0.71 (0.58−0.85) | <0.001 | 0.85 (0.77−0.95) | 0.004 | 0.84 (0.75−0.93) | 0.002 | 0.62 (0.50−0.75) | <0.001 | 0.76 (0.68−0.84) | <0.001 | 0.84 (0.75−0.93) | 0.001 |
| Hepatitis A | 0.66 (0.54−0.81) | <0.001 | 0.83 (0.75−0.92) | <0.001 | 0.91 (0.82−1.00) | 0.060 | 0.87 (0.70−1.08) | 0.219 | 0.69 (0.61−0.79) | <0.001 | 0.61 (0.54−0.70) | <0.001 |
| Hepatitis E | 0.70 (0.58−0.84) | <0.001 | 0.78 (0.71−0.86) | <0.001 | 0.80 (0.73−0.88) | <0.001 | 0.70 (0.57−0.86) | 0.001 | 0.78 (0.70−0.87) | <0.001 | 0.80 (0.72−0.89) | <0.001 |
| HFMD | 0.10 (0.02−0.49) | 0.006 | 0.20 (0.10−0.42) | <0.001 | 0.77 (0.54−1.10) | 0.160 | 0.10 (0.03−0.33) | <0.001 | 0.13 (0.07−0.25) | <0.001 | 0.31 (0.21−0.47) | <0.001 |
| Infectious diarrhea | 0.49 (0.31−0.77) | 0.003 | 0.86 (0.69−1.07) | 0.172 | 0.83 (0.67−1.02) | 0.084 | 0.52 (0.37−0.72) | <0.001 | 0.72 (0.62−0.83) | <0.001 | 0.77 (0.68−0.88) | <0.001 |
| Typhoid and paratyphoid | 0.71 (0.54−0.94) | 0.019 | 0.73 (0.64−0.84) | <0.001 | 0.70 (0.60−0.80) | <0.001 | 0.61 (0.37−1.00) | 0.054 | 0.68 (0.52−0.89) | 0.007 | 0.68 (0.52−0.88) | 0.005 |
| Amebic dysentery | 0.78 (0.56−1.09) | 0.156 | 1.17 (0.99−1.39) | 0.073 | 1.13 (0.96−1.34) | 0.153 | − | − | − | − | − | − |
| Sexually transmitted or bloodborne diseases | ||||||||||||
| Gonorrhea | 0.80 (0.61−1.03) | 0.088 | 1.25 (1.11−1.42) | <0.001 | 1.30 (1.15−1.46) | <0.001 | 0.45 (0.37−0.54) | <0.001 | 0.82 (0.75−0.89) | <0.001 | 0.96 (0.88−1.04) | 0.320 |
| Syphilis | 0.72 (0.62−0.82) | <0.001 | 0.85 (0.79−0.91) | <0.001 | 0.84 (0.79−0.90) | <0.001 | 0.69 (0.58−0.81) | <0.001 | 0.88 (0.81−0.95) | 0.002 | 0.86 (0.80−0.92) | <0.001 |
| HIV/AIDS | 0.93 (0.78−1.11) | 0.438 | 0.92 (0.84−1.00) | 0.063 | 0.87 (0.80−0.95) | 0.003 | 0.89 (0.75−1.05) | 0.172 | 0.92 (0.84−1.01) | 0.072 | 0.93 (0.85−1.02) | 0.111 |
| Hepatitis B | 0.77 (0.68−0.86) | <0.001 | 0.97 (0.91−1.03) | 0.324 | 0.96 (0.91−1.02) | 0.172 | 0.69 (0.58−0.81) | <0.001 | 0.90 (0.84−0.98) | 0.013 | 0.88 (0.81−0.95) | 0.001 |
| Hepatitis C | 0.69 (0.62−0.77) | <0.001 | 0.95 (0.91−1.00) | 0.075 | 0.95 (0.91−1.00) | 0.065 | 0.62 (0.52−0.74) | <0.001 | 0.88 (0.80−0.95) | 0.003 | 0.87 (0.80−0.94) | 0.001 |
| Vector borne or zoonotic disease | ||||||||||||
| Brucellosis | 0.92 (0.70−1.22) | 0.587 | 1.21 (1.05−1.40) | 0.011 | 1.49 (1.30−1.70) | <0.001 | 1.03 (0.83−1.29) | 0.762 | 1.12 (1.00−1.25) | 0.054 | 1.34 (1.21−1.48) | <0.001 |
| HFRS | 0.71 (0.53−0.97) | 0.032 | 0.83 (0.70−0.97) | 0.022 | 0.78 (0.66−0.92) | 0.003 | 0.51 (0.37−0.70) | <0.001 | 0.61 (0.52−0.72) | <0.001 | 0.77 (0.66−0.90) | 0.002 |
| Malaria | 0.51 (0.42−0.64) | <0.001 | 0.35 (0.30−0.40) | <0.001 | 0.42 (0.37−0.49) | <0.001 | 0.62 (0.45−0.85) | 0.004 | 0.12 (0.08−0.17) | <0.001 | 0.22 (0.16−0.30) | <0.001 |
| Hydatid disease | 0.76 (0.36−1.58) | 0.461 | 1.99 (1.38−2.89) | <0.001 | 1.90 (1.31−2.77) | 0.001 | 0.68 (0.44−1.05) | 0.084 | 0.98 (0.79−1.20) | 0.814 | 1.20 (0.99−1.45) | 0.073 |
| Dengue | 0.41 (0.05−3.32) | 0.404 | 0.01 (0.001−0.22) | 0.004 | 0.01 (0.0004−0.16) | 0.002 | − | − | − | − | − | − |
| Typhus | 0.62 (0.38−1.01) | 0.056 | 0.90 (0.70−1.16) | 0.408 | 0.93 (0.73−1.19) | 0.563 | − | − | − | − | − | − |
Generalized linear models (GLM) were used for estimating the IRRs measuring the association of NPIs with disease trends. The models were adjusted for monthly healthcare visits and yearly long-term trend after seasonality was removed by a time series method. IRR < 1 with P < 0.05 indicates significant decline in incidence rate in year 2020 compared to year 2014–2019. All p-values are two-sided and not adjusted for multiple comparisons.
Statistically significant reductions (IRR < 1) are displayed in bolded font.
*Data of Hubei and Tibet (both in South China) were not included in modeling due to unavailable healthcare visits data during the COVID-19 pandemic.
† HFMD, hand, foot and mouth disease; AHC, acute hemorrhagic conjunctivitis; HFRS, hemorrhagic fever with renal syndrome.
‡Phase II: Feb 2020 and Mar 2020; Phase III: Apr 2020 to Aug 2020; Phase IV: Sep 2020 to Dec 2020. The reference period is Jan 2014 to Jan 2020.
–: GLM was not fitted for disease with median monthly case number is less than 50.